Which of the following statement(s) is/are true concerning oxygen consumption (O2)? a. O2 is normally 100–120 cc2/m2/min b. Resting O2 is controlled by the level of thyroid and catecholamine hormones c. Under steady state conditions the amount of oxygen consumed exceeds the amount of oxygen taken up by the pulmonary capillaries d. O2 is dependent on the status of pulmonary function

Which of the following statement(s) is/are true concerning oxygen consumption (O2)?  a. O2 is normally 100–120 cc2/m2/min b. Resting O2 is controlled by the level of thyroid and catecholamine hormones c. Under steady state conditions the amount of oxygen consumed exceeds the amount of oxygen taken up by the pulmonary capillaries d. O2 is dependent on the status of pulmonary function
by

1 Answer

Answer :

Answer: a, b  Oxygen consumed in the process of metabolism is expressed as the volume of oxygen per minute (O2). O2 is normally 100–120 cc2/m2/min, or 200 cc/min for a typical adult. Resting O2 is a function of metabolizing body cell mass, with fine tuning control provided by the level of thyroid and catecholamine hormones. O2 decreases under conditions of hypothermia, paralysis, and hypothyroidism. O2 increases during exercise or muscular activity, hyperthermia, profound hypothalamic injury, hyperthyroidism, catecholamines, and inflammatory mediators, particularly the interleukin cytokines. Under steady state conditions, the amount of oxygen consumed in systemic metabolism is exactly equal to the amount of oxygen taken up by the pulmonary capillaries via the airway. This is true regardless of the status of pulmonary function or dysfunction, so we measure O2 across the lung and assume that it is exactly the amount consumed in the systemic metabolism
by
selected

Related questions

Which of the following statement(s) is/are true concerning oxygen delivery? a. The amount of oxygen delivered to peripheral tissues is dependent upon the oxygen content in arterial blood and cardiac output b. Oxygen content is commonly measured in arterial blood c. The normal arterial-venous difference is 4 cc O2/dL d. Normal systemic oxygen delivery for a typical adult is approximately 1000 cc/min

Description : Which of the following statement(s) is/are true concerning oxygen delivery? a. The amount of oxygen delivered to peripheral tissues is dependent upon the oxygen content in arterial blood and cardiac ... O2/dL d. Normal systemic oxygen delivery for a typical adult is approximately 1000 cc/min

Last Answer : Answer: a, c, d The amount of oxygen that is delivered to peripheral tissues is the product of the oxygen content in arterial blood times the cardiac output. Normally, oxygen content of arterial blood is ... of venous blood is 16 cc/dL. Hence, the normal arterial-venous difference is 4 cc O2/dL

Which of the following statement(s) is/are true concerning carbon dioxide kinetics? a. The amount of carbon dioxide produced is equivalent to the amount of oxygen consumed b. Carbon dioxide levels in blood, present mostly as a bicarbonate ion, can quickly change c. Normally the amount of carbon dioxide excreted through the lung is exactly equal to the amount of carbon dioxide produced in peripheral tissues d. The amount of carbon dioxide excreted is a function of ventilation of perfused alveoli

Description : Which of the following statement(s) is/are true concerning carbon dioxide kinetics? a. The amount of carbon dioxide produced is equivalent to the amount of oxygen consumed b. Carbon dioxide levels ... tissues d. The amount of carbon dioxide excreted is a function of ventilation of perfused alveoli

Last Answer : Answer: a, c, d The total amount of carbon dioxide produced by systemic metabolism is roughly equivalent to the amount of oxygen consumed (100-120 cc/m2/min, 200 cc/min in a typical ... carbon dioxide excreted is a function of ventilation of perfused alveoli (i.e. the alveolar ventilation/min).

Which of the following statement(s) is/are true concerning the treatment of pulmonary interstitial edema? a. Diuresis and blood transfusion is a valuable step b. Salt-poor albumin leaks through the capillaries and worsens the condition c. Mannitol is contraindicated as a diuretic in this clinical situation d. Isoproterenol is a poor choice as an ionotropic agent

Description : Which of the following statement(s) is/are true concerning the treatment of pulmonary interstitial edema? a. Diuresis and blood transfusion is a valuable step b. Salt-poor albumin leaks through the ... a diuretic in this clinical situation d. Isoproterenol is a poor choice as an ionotropic agent

Last Answer : Answer: a Treatment of pulmonary edema has two important goals, the first is to improve oxygenation if it is impaired, and the second is to minimize fibrosis and bacterial infection, which often ... leaks out , the short term effects of expanding blood volume and decrease in edema will appear

Which of the following statement(s) is/are true concerning the multiorgan failure syndrome (MOFS)? a. Changes in the splanchnic and pulmonary microcirculation are critical to the development of MOFS b. Tissue fixed microphages, including the liver Kupffer cell, have little role in the development of MOFS c. MOFS represents systemic consequences of loss of homeostatic control of local inflammation and microcirculatory hypoperfusion d. The nature of MOFS is highly dependent upon the etiology of the underlying problem

Description : Which of the following statement(s) is/are true concerning the multiorgan failure syndrome (MOFS)? a. Changes in the splanchnic and pulmonary microcirculation are critical to the development of MOFS ... d. The nature of MOFS is highly dependent upon the etiology of the underlying problem

Last Answer : Answer: a, c The nature of multiorgan failure syndrome (MOFS) is that of a diffuse cellular injury, developing systemically as a consequence of losing homeostatic control of local ... of microorganism. In noninfectious cases, the response also appears independent of the specific underlying cause

Which of the following statements(s) is/are true concerning human energy requirement? a. In normal subjects, less than 5% of basal energy requirement is spent on cardiac output and the work of breathing b. Mechanical ventilation can decrease the energy expenditure for normal respiration c. For a 70 kg male, average resting energy consumption is almost 1500 kcal/day d. Similar increases in energy expenditures are associated with elective surgery and trauma or thermal injury

Description : Which of the following statements(s) is/are true concerning human energy requirement? a. In normal subjects, less than 5% of basal energy requirement is spent on cardiac output and the ... d. Similar increases in energy expenditures are associated with elective surgery and trauma or thermal injury

Last Answer : Answer: a, c Basal energy requirements are measured with the subject at rest when no external work is being done; the energy is used mainly for transport and synthetic work within cells. A ... average-sized adult who sustains a major burn rarely may require more than 3500 kcal/day for maintenance

Which of the following statement(s) is/are true concerning O2 venous saturation monitoring? a. The normal saturation of mixed venous blood is 50% b. Mixed venous blood obtained for saturation monitoring can be obtained from any peripheral vein c. If arterial blood is fully saturated, the saturation of mixed venous blood is 80% d. In less than fully saturated blood, the difference between arterial and venous saturation corresponds to oxygen extraction

Description : Which of the following statement(s) is/are true concerning O2 venous saturation monitoring? a. The normal saturation of mixed venous blood is 50% b. Mixed venous blood obtained ... than fully saturated blood, the difference between arterial and venous saturation corresponds to oxygen extraction

Last Answer : Answer: c, d The relationship between oxygen delivery and oxygen consumption is reflected in the amount of oxygen in venous blood. Under normal circumstances, oxygen delivery is 1000 ... and venous saturation corresponds to the oxygen extraction, hence the oxygen delivery/oxygen consumption ratio

Which of the following statement(s) is/are true concerning the relationship between cardiac function and effective blood volume? a. A pulmonary capillary wedge pressure of 5–10 rules out fluid overload as a cause of pulmonary edema b. A shift to the right in the Frank-Starling curve is associated with compromised cardiac function c. Dilutional anemia may contribute to tachycardia even though blood volume and filling pressures are normal d. The sole purpose of a pulmonary artery catheter is to measure pulmonary artery pressure and cardiac output

Description : Which of the following statement(s) is/are true concerning the relationship between cardiac function and effective blood volume? a. A pulmonary capillary wedge pressure of 5-10 rules out ... sole purpose of a pulmonary artery catheter is to measure pulmonary artery pressure and cardiac output

Last Answer : Answer: b, c Although physical findings are often adequate to establish a diagnosis and institute management of cardiac failure, direct measurement of filling pressures of the right heart ( ... blood volume is normal, filling pressures are normal, and total body extracellular fluid is excessive

Which of the following statement(s) is/are true concerning the effects of MOFS? a. Pulmonary dysfunction tends to arise early and may resolve within 7 to 10 days b. Unless the precipitating insult has prompted oliguric acute tubular necrosis, renal function tends to be maintained early in the course of MOFS c. Although hepatic dysfunction is common with MOFS, the GI tract plays little role in this process d. Intercurrent nosocomial infection, most commonly pulmonary, is a common complication providing a “second hit” to the patient

Description : Which of the following statement(s) is/are true concerning the effects of MOFS? a. Pulmonary dysfunction tends to arise early and may resolve within 7 to 10 days b. Unless the precipitating ... infection, most commonly pulmonary, is a common complication providing a second hit to the patient

Last Answer : Answer: a, b, d Pulmonary dysfunction typically arises early in the development of systemic inflammation and may represent mild relatively localized acute lung injury or it may be a prelude ... is marked by progressive rise in serum bilirubin levels after a latent period of several days

Which of the following statement(s) is/are true concerning CO2 transfer in the lung? a. Carbon dioxide excretion is a direct function of alveolar ventilation b. Normally end tidal CO2 should be identical to PaCO2 c. The gradient between end tidal and arterial CO2 can be an indirect measure of nonperfused alveoli d. Positive pressure ventilation under normal airway pressures creates a significant end tidal PaCO2 gradient

Description : Which of the following statement(s) is/are true concerning CO2 transfer in the lung? a. Carbon dioxide excretion is a direct function of alveolar ventilation b. Normally end tidal ... d. Positive pressure ventilation under normal airway pressures creates a significant end tidal PaCO2 gradient

Last Answer : Answer: a, b, c The amount of carbon dioxide excretion is directly related to alveolar ventilation. While oxygenation is a function of matching blood flow to alveoli, carbon dioxide excretion is ... high (over 30 cm H2O) and the compression volume is a significant component of each exhaled breath

Which of the following statement(s) is/are true concerning oxygen kinetics in a critically ill, febrile patient? a. Oxygen consumption will likely exceed three times normal b. The high cardiac output and pulse rate are designed to increase oxygen delivery c. The hyperdynamic response may actually increase oxygen delivery to exceed the increase in oxygen consumption d. The patient can maintain adequate compensation as long as the oxygen delivery/oxygen consumption rate is greater than 2:1

Description : Which of the following statement(s) is/are true concerning oxygen kinetics in a critically ill, febrile patient? a. Oxygen consumption will likely exceed three times normal b. The high cardiac ... adequate compensation as long as the oxygen delivery/oxygen consumption rate is greater than 2:1

Last Answer : Answer: b, d In critically ill patients oxygen consumption may be elevated or depressed, but slight to moderate elevations in oxygen consumption is the most common abnormality in critically ill patients. ... however, and the patient will remain stable as long as the ratio is greater than 2:1

Which of the following statement(s) is/are true concerning the autoregulation necessary to maintain oxygen consumption and oxygen delivery? a. A change in oxygen consumption is followed by a proportionate change in oxygen delivery b. A change in oxygen delivery is followed by a change in oxygen consumption c. Increases in oxygen delivery are due solely to an increase in cardiac output d. The normal ratio of oxygen delivery to consumption is 2:1

Description : Which of the following statement(s) is/are true concerning the autoregulation necessary to maintain oxygen consumption and oxygen delivery? a. A change in oxygen consumption is followed by a proportionate ... increase in cardiac output d. The normal ratio of oxygen delivery to consumption is 2:1

Last Answer : Answer: a The relationships between oxygen consumption and oxygen delivery represent one of the most interesting regulation systems in homeostasis. First of all, if one of the three components ... in oxygen consumption. The normal ratio of oxygen delivery to consumption is approximately 5:1

Sepsis causes a marked metabolic response. Which of the following statement(s) is/are true concerning the metabolic response to sepsis? a. Oxygen consumption is increased in the face of infection b. In a patient with a maximal metabolic rate secondary to trauma, the presence of infection will increase the rate further c. Metabolic rate increases at a rate of approximately 10% for each increase of 1°C in central temperature d. The extent of increase in oxygen consumption relates to the severity of the infection

Description : Sepsis causes a marked metabolic response. Which of the following statement(s) is/are true concerning the metabolic response to sepsis? a. Oxygen consumption is increased in the face of infection ... d. The extent of increase in oxygen consumption relates to the severity of the infection

Last Answer : Answer: a, c, d Oxygen consumption is usually elevated in the infected patient. The extent of this increase is related to the severity of the infection, with peak elevations reaching 50% ... suggest that the metabolic rate increases 10% to 13% for each elevation of 1°C in central temperature

Which of the following statements concerning monitoring techniques in the intensive care unit are true? A. Pulmonary artery and pulmonary capillary wedge pressure readings should be made at end inspiration, to minimize ventilatory artifacts. B. Continuous SvO 2 monitoring based on the technique of reflectance spectrophotometry has been shown to be accurate and reliable. C. Direct measurement of gastric intramucosal pH can be provided by gastrointestinal tonometry. D. Hyperlactatemia may be seen in a number of clinical conditions not associated with tissue hypoxia, including liver disease and hypermetabolic states.

Description : Which of the following statements concerning monitoring techniques in the intensive care unit are true? A. Pulmonary artery and pulmonary capillary wedge pressure readings should be made ... clinical conditions not associated with tissue hypoxia, including liver disease and hypermetabolic states.

Last Answer : Answer: BD DISCUSSION: Many different monitoring techniques may be used to assess the adequacy of therapy for shock. The pulmonary artery catheter can provide important hemodynamic and oxygen ... also be seen with liver disease, toxin ingestion, and hypermetabolic states not associated with shock

Which of the following statement(s) is/are true concerning the pulmonary response to shock? a. The acute pulmonary vascular response to shock differs markedly from that of systemic vasculature b. The pulmonary edema of ARDS occurs in the face of elevated left heart pressures c. The initial physiologic changes of ARDS involve the capillary endothelial cells and the type I pneumocyte d. Mechanisms proposed in the pathogenesis of ARDS include injury from mediators of inflammation elsewhere and from activated cellular elements e. A decrease in lung compliance may result from the loss of type I pneumocytes

Description : Which of the following statement(s) is/are true concerning the pulmonary response to shock? a. The acute pulmonary vascular response to shock differs markedly from that of systemic vasculature b. The ... elements e. A decrease in lung compliance may result from the loss of type I pneumocytes

Last Answer : Answer: c, d, e Contributing pathophysiologic processes to the pulmonary manifestations of shock include the pulmonary component of the cardiovascular response, disruption of the normal ... injury from mediators of inflammation elaborated elsewhere, and from activated cellular blood elements

The following statement(s) is/are true concerning viral infections. a. The most common post-transplantation viral infections are caused by herpes viruses and include CMV and herpes simplex virus b. Viral infections occur at equal frequency anytime during the post-transplantation period c. CMV infection in the post-transplant patient is most likely a pulmonary process d. Herpes simplex virus (HSV) infection primarily presents with a mononucleosis-type syndrome with fever, lethargy, and cough

Description : The following statement(s) is/are true concerning viral infections. a. The most common post-transplantation viral infections are caused by herpes viruses and include CMV and herpes simplex virus ... HSV) infection primarily presents with a mononucleosis-type syndrome with fever, lethargy, and cough

Last Answer : Answer: a, c, Solid organ transplant patients are prone to develop viral infection by virtue of exogenous immunosuppression. The most common post-transplantation viral infections are those ... transplant patient or as painful herpes zoster in patients who have previously developed chicken pox

Which of the following statement(s) is/are true concerning the results of a National Institute of Health Consensus Conference on venous thrombosis and low-dose heparin prophylaxis? a. The odds of developing deep venous thrombosis with low-dose heparin prophylaxis decreases by 67% b. The risk of pulmonary embolism is decreased by almost 50% c. There is no increase in mortality from other causes found in patients treated with low-dose heparin d. There was no difference in the incidence of bleeding complications

Description : Which of the following statement(s) is/are true concerning the results of a National Institute of Health Consensus Conference on venous thrombosis and low-dose heparin prophylaxis? a. The odds of ... treated with low-dose heparin d. There was no difference in the incidence of bleeding complications

Last Answer : Answer: a, b, c In a metaanalysis of 70 randomized trials in 16,000 patients comparing low-dose heparin prophylaxis with standard therapy, the odds of developing deep venous thrombosis ... Similarly, the effectiveness of prophylaxis was not influenced by either two or three times daily dosage

The following statement(s) is/are true concerning cellular defense mechanisms. a. Macrophages function solely as antigen processing cells in the initial reaction to exposure to an antigen b. Macrophages may become activated and secrete cytokines c. Macrophages serve as phagocytic cells in the tissues but not within the bloodstream d. Polymorphonucleocytes (PMNS) are normally present in only small numbers within the tissue and enter an area of infection through diapedesis

Description : The following statement(s) is/are true concerning cellular defense mechanisms. a. Macrophages function solely as antigen processing cells in the initial reaction to exposure to an antigen b. Macrophages ... in only small numbers within the tissue and enter an area of infection through diapedesis

Last Answer : Answer: b, d A wide variety of cell types serve to provide host defense at several levels. Macrophages act as the initial antigen processing cell that serves to ... through diapedesis after chemotactic stimuli are excluded by macrophages, bacterial breakdown products, and complement activation

Which of the following statement(s) is/are true concerning protein/amino acid metabolism in man? a. The major source of amino acids is breakdown of circulating proteins b. The recommended daily allowance for protein may triple in critically ill patients c. Urinary nitrogen losses will approach 0 in the face of protein starvation d. Negative nitrogen balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost

Description : Which of the following statement(s) is/are true concerning protein/amino acid metabolism in man? a. The major source of amino acids is breakdown of circulating proteins b. The recommended daily ... balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost

Last Answer : Answer: b, d About 15% of the total body weight is made up of proteins, about half of which are intracellular and half extracellular. In man and other animals, dietary protein is the source of ... is exceeded by the amount of nitrogen lost in the urine, stool, skin, wounds, and fistula drainage

Interleukin-6 is recognized as the cytokine primarily responsible for the alteration in hepatic protein synthesis recognized as the acute phase response. Which of the following statement(s) is/are true concerning acute phase protein response to surgical stress? a. Glucocorticoid hormones inhibit this response b. Proteins such as albumin and transferrin which serve in serum transport are generally increased in this response c. Examples of acute phase proteins include fibrinogen and C-reactive protein d. In general, the physiologic role of acute phase proteins are to reduce the systemic effects of tissue damage

Description : Interleukin-6 is recognized as the cytokine primarily responsible for the alteration in hepatic protein synthesis recognized as the acute phase response. Which of the following statement(s) is/are true ... physiologic role of acute phase proteins are to reduce the systemic effects of tissue damage

Last Answer : Answer: c, d IL-6 is now recognized at the cytokine primarily responsible for the alteration in hepatic synthesis recognized as the acute phase response. Glucocorticoid hormones augment ... that generally inhibit the tissue destruction that is associated with the local initiation of inflammation

Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of the following statement(s) is/are true concerning intracellular receptors? a. The messengers or hormones must by lipophilic b. These intracellular receptors generally regulate protein synthesis c. The intracellular receptors are located entirely in the nucleus of the cell d. A heat-shock protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein

Cell regulation can be thought of as the effector side of cell communication. Most commonly cell regulation occurs by means of extracellular chemical messengers. Which of the following statement(s) is/are true concerning these messengers? a. Paracrine regulation involves a messenger which is produced and acts systemically b. The extracellular signal or stimulus is received by a receptor on or in the target cell c. Neurocrine regulation depends on a physical connection between the neuron and the target cell d. Most hormones, local mediators, and neurotransmitters readily cross the cell plasma membrane

Description : Cell regulation can be thought of as the effector side of cell communication. Most commonly cell regulation occurs by means of extracellular chemical messengers. Which of the following statement(s ... d. Most hormones, local mediators, and neurotransmitters readily cross the cell plasma membrane

Last Answer : Answer: b, c Depending on how the extracellular messenger arrives, cell regulation can be classified as paracrine, endocrine, or neurocrine. In paracrine regulation, a chemical messenger ... , local mediators, and neurotransmitters are water-soluble and cannot readily cross the plasma membrane

The standard management oral anticoagulant therapy for chronic treatment of venous thromboembolism is with the drug warfarin. Which of the following statement(s) is/are true concerning the administration of warfarin? a. An important complication of warfarin therapy is skin necrosis in patients with protein C deficiency b. Warfarin interferes with vitamin K dependent clotting factors II, VII, IX, X c. For effective anticoagulation the prothrombin time (PT) should be kept at 2 control d. It is recommended that warfarin be continued for at least one year after initial episode of deep venous thrombosis

Description : The standard management oral anticoagulant therapy for chronic treatment of venous thromboembolism is with the drug warfarin. Which of the following statement(s) is/are true concerning the administration ... warfarin be continued for at least one year after initial episode of deep venous thrombosis

Last Answer : Answer: a, b Warfarin interferes with the vitamin K dependent clotting factors II, VII, IX and X, protein C, and protein S. An important complication of warfarin is skin ... the benefit from anticoagulant therapy and thus is the basis for discontinuing warfarin administration at this time

Which of the following statement(s) is/are true concerning translation of the mRNA message to protein synthesis? a. An adaptor molecule, tRNA, recognizes specific nucleic acid bases and unites them with specific amino acids b. Covalent attachment of tRNA to amino acids is energy dependent c. The formation of a peptide bond between the growing peptide chain and the free amino acid occurs in the free cytoplasm d. Complete protein synthesis takes hours

Description : Which of the following statement(s) is/are true concerning translation of the mRNA message to protein synthesis? a. An adaptor molecule, tRNA, recognizes specific nucleic acid bases and unites them ... and the free amino acid occurs in the free cytoplasm d. Complete protein synthesis takes hours

Last Answer : Answer: a, b The synthesis of protein involves conversion from a four-letter nucleotide language to one of 20 chemically distinct amino acids. This process is referred to as ... translation and be moving down the mRNA molecules simultaneously, thus increasing the rate of protein synthesis

Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the cell membrane contains specialized transport proteins which maintain the intracellular ionic milieu different from the extracellular fluid c. Plasma membrane proteins extend externally and bear phospholipid moieties which contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent

Description : Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the ... contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent

Last Answer : Answer: a, b, d The plasma membrane defines the boundary of the cell and serves to contain and concentrate enzymes and other macromolecule constituents. The plasma membrane is ... and bear carbohydrate moieties primarily as oligosaccharide chains that contribute to the cell coat or glycocalyx

Which of the following statement(s) is/are true concerning the assessment of protein reserve? a. Conventional serum proteins such as albumin and globulin are early indicators of malnutrition b. The total lymphocyte count reflects immune status and not nutrition c. Antigen skin testing reflects patient immunity and not nutrition d. Measurement of urea excretion in urine can be used as a measurement of protein breakdown

Description : Which of the following statement(s) is/are true concerning the assessment of protein reserve? a. Conventional serum proteins such as albumin and globulin are early indicators of malnutrition b. The ... d. Measurement of urea excretion in urine can be used as a measurement of protein breakdown

Last Answer : Answer: d Since protein is the functional and structural chemical of the body, most nutritional assessment techniques are estimates of protein reserves. The actual nitrogen balance can ... patients convert from reactive to anergic, and reactivity can be restored by nutritional repletion

Which of the following statement(s) is/are true concerning the pathophysiology of gas exchange? a. Hypoventilation in relation to perfusion can result in an oxygen saturation of less than 100% b. Diffusion block and / mismatch can almost completely be overcome by breathing 100% oxygen c. Transpulmonary shunting does not occur under normal circumstances d. The normal arterial oxygen saturation should be 100%

Description : Which of the following statement(s) is/are true concerning the pathophysiology of gas exchange? a. Hypoventilation in relation to perfusion can result in an oxygen saturation of less than 100% ... does not occur under normal circumstances d. The normal arterial oxygen saturation should be 100%

Last Answer : Answer: a, b Under normal conditions, red blood cells in the pulmonary capillaries become fully saturated and oxygen dissolves in plasma resulting in blood PO2 of 100 and O2 saturation of 100%. This ... the fact that normal arterial PO2 is 90-100 mm Hg and the normal O2 saturation is 98%

A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance of these differences is/are true? a. The cell membrane is able to maintain a 10,000 fold gradient between the extracellular concentration of ionized calcium and the intracellular concentration b. The key to these differences is the fact that the plasma membrane is normally impermeable to sodium, potassium and calcium c. The selectivity of biologic membranes is highly consistent and seldom changes d. The selectivity of cell membranes relates only to ions and not organic compounds

Description : A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance ... d. The selectivity of cell membranes relates only to ions and not organic compounds

Last Answer : Answer: a The survival of the cell requires that cytosolic composition be maintained within narrow limits, despite the constant influx of nutrients and the simultaneous outflow of waste. A ... be altered drastically as a result of regulatory or signaling processes that occur within the cell

A 55-year-old renal transplant patient has been hospitalized in a Surgical Intensive Care Unit, receiving a prolonged course of antibiotics following an attack of acute cholecystitis. The following statement(s) is/are true concerning his management. a. Due to the potential risk of Candida infection, prophylaxis with oral nystatin should be instituted early in the patient’s course b. A Candida urinary tract infection should be treated with systemic amphotericin B c. Changes of Candida retinitis are of little significance d. The presence of a virulent Candida bacteremia should suggest a dosage reduction in immunosuppressive agents until the infection can be adequately controlled

Description : A 55-year-old renal transplant patient has been hospitalized in a Surgical Intensive Care Unit, receiving a prolonged course of antibiotics following an attack of acute cholecystitis. The ... suggest a dosage reduction in immunosuppressive agents until the infection can be adequately controlled

Last Answer : Answer: a, d Infections due to fungal pathogens have become increasingly common during the past decade, frequently occurring in patients undergoing prolonged hospitalization in the Surgical ... agents should be discontinued until evidence of infection is absolutely controlled or is eradicated

Bleeding complications are frequently associated with fibrinolytic therapy. Which of the following statement(s) concerning complications of fibrinolytic therapy is/are true? a. Careful monitoring of prothrombin time and aPTT time are necessary to avoid bleeding complications b. A level of serum fibrinogen less than 100 mg/dl is associated with an increased risk of bleeding c. Recent (less than 10 days) major surgery is a contraindication to systemic but not regional fibrinolytic therapy d. A patient with a cerebrovascular event occurring less than two months ago can be treated with fibrinolytic therapy if head CT scan is normal

Description : Bleeding complications are frequently associated with fibrinolytic therapy. Which of the following statement(s) concerning complications of fibrinolytic therapy is/are true? a. Careful monitoring of prothrombin time ... months ago can be treated with fibrinolytic therapy if head CT scan is normal

Last Answer : Answer: b Fibrinolytic therapy induces a hemostatic defect through a combination of factors. Hypofibrinogenemia and fibrin degradation products inhibit fibrin polymerization and, in combination ... is considered a major relative contraindication to either regional or systemic thrombolytic therapy

Which of the following statements about delivery-dependent oxygen consumption are true? A. Below the critical oxygen delivery (D(overdot)O 2crit), one would expect to see a decrease in the lactate-pyruvate ratio. B. D(overdot)O 2crit may be increased in patients with sepsis. C. A desirable goal in the treatment of shock is to achieve delivery-independent oxygen consumption. D. The oxygen extraction ratio remains constant as long as oxygen delivery remains above D(overdot)O 2crit.

Description : Which of the following statements about delivery-dependent oxygen consumption are true? A. Below the critical oxygen delivery (D(overdot)O 2crit), one would expect to see a decrease in the ... oxygen extraction ratio remains constant as long as oxygen delivery remains above D(overdot)O 2crit.

Last Answer : Answer: BC DISCUSSION: Oxygen consumption is said to be delivery dependent below a critical point, D(overdot)O 2crit, at which anaerobic metabolism supervenes. Above this point, oxygen ... the therapeutic benefit of trying to achieve supranormal oxygen delivery has not been firmly established

Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and chemical barriers at the mucus membrane level c. Most of the microorganisms found in the oropharynx eventually pass into the intestine d. In the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Description : Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and ... the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Last Answer : Answer: b, d The composition of the gut microflora is established in neonates after ingestion of microbes that are acquired during contamination from the birth canal and during initial feeding, and ... small number of aerobes are present, these microbes being outnumbered 100-300 to 1 by anaerobes

Which of the following statement(s) is/are true concerning ischemia reperfusion injury? a. During ischemia, ATP degradation results in increased plasma and intracellular levels of hypoxanthine and xanthene b. Oxygen free radicals such as the superoxide radical are involved in the expression of the proinflammatory phenotype of endothelial cells, macrophages and neutrophils c. The intracellular adhesion molecule-1 (ICAN-1) contributes to injury and disruption of the endothelial lining, with extensive capillary leak and resultant interstitial edema d. Animal models have demonstrated that passive immunization with antibodies to neutrophil adhesive complex lessen the ischemic/reperfusion microvascular injury

Description : Which of the following statement(s) is/are true concerning ischemia reperfusion injury? a. During ischemia, ATP degradation results in increased plasma and intracellular levels of ... immunization with antibodies to neutrophil adhesive complex lessen the ischemic/reperfusion microvascular injury

Last Answer : Answer: a, b, c, d During the ischemia and hypoperfusion phase, degradation of ATP stores essential to maintain cell integrity and significant loss of diffusible ... either the neutrophil adhesive complex or the endothelial selectins dramatically lessens ischemia/reperfusion microvascular injury

The complement system consists of a series of serum proteins that exist in a quiescent or very low-level state of activation in the uninfected host. Which of the following statement(s) is/are true concerning complement activation? a. The alternate (properdin) pathway of complement activation can occur directly through contact with fungal or bacterial cell wall compounds b. Complement component fragments may serve to decrease vascular permeability c. Excessive complement activation can produce deleterious effects d. Fragments of certain complement components serve as chemoattractants to additional cellular components of the host defense mechanism

Description : The complement system consists of a series of serum proteins that exist in a quiescent or very low-level state of activation in the uninfected host. Which of the following ... certain complement components serve as chemoattractants to additional cellular components of the host defense mechanism

Last Answer : Answer: a, c, d Complement activation can occur through either classic or alternate (properdin) pathways, both of which eventuate in deposition of terminal complement pathway components on the ... and release of lysosomal enzymes that can directly damage certain target tissues, such as the lung

Which of the following statement(s) is/are true concerning heparin-associated thrombocytopenia? a. Heparin-associated thrombocytopenia occurs only in the face of over anticoagulation with heparin b. Severe thrombocytopenia (platelet count less than 100,000) is seen in less than 10% of patients treated with heparin c. Heparin-associated thrombocytopenia is due to the aggregation of platelets and may result in thrombosis or embolic episodes d. Heparin-associated thrombocytopenia may be seen within hours of initiation of heparin therapy

Description : Which of the following statement(s) is/are true concerning heparin-associated thrombocytopenia? a. Heparin-associated thrombocytopenia occurs only in the face of over anticoagulation with heparin b. ... d. Heparin-associated thrombocytopenia may be seen within hours of initiation of heparin therapy

Last Answer : Answer: b, c Heparin-associated thrombocytopenia occurs in 0.6% to 30% of patients who receive heparin, although severe thrombocytopenia (platelet counts less than 100,000) is seen in ... as coating on pulmonary artery catheters or low rate infusion into arterial catheters may cause this syndrome

Which of the following statement(s) is/are true concerning the physiology of the microvascular system? a. Filtration of capillary fluid into the interstitial and the subsequent reabsorption is influenced by Starling’s law of ultrafiltration b. The most important variable controlling blood to a capillary bed is the length of the vessel c. Most of the resistance to systemic blood flow occurs at the arteriolar level d. Adrenergic vasoconstriction can arrest blood flow to an entire capillary bed

Description : Which of the following statement(s) is/are true concerning the physiology of the microvascular system? a. Filtration of capillary fluid into the interstitial and the subsequent reabsorption is ... the arteriolar level d. Adrenergic vasoconstriction can arrest blood flow to an entire capillary bed

Last Answer : Answer: a, c, d Exchange of material between the vascular space and the cell of various tissues via the interstitial space is essential for organ viability and occurs at the ... contractions are potent enough that blood flow to entire capillary beds can be arrested by adrenergic vasoconstriction

Which of the following statement(s) is/are true concerning wound contraction? a. Wound contraction accounts for similar rates of reduction of wound size regardless of their location b. The fibroblast, at the cellular level, is the primary force driving wound contraction c. Excessive wound contraction, when occurring over a joint, may lead to disability d. Actin microfillaments are found in fibroblasts and may play a role in wound contracture

Description : Which of the following statement(s) is/are true concerning wound contraction? a. Wound contraction accounts for similar rates of reduction of wound size regardless of their location b. The fibroblast ... d. Actin microfillaments are found in fibroblasts and may play a role in wound contracture

Last Answer : Answer: b, c, d Wound contraction is an important event which contrasts healing open wounds and closed incisions. When open wounds contract, the surrounding skin is pulled over the open wound ... number in contracting wounds and are felt to play an active role in the process of wound contraction

Which of the following statement(s) is/are true concerning the cell function of phagocytosis? a. Phagocytosis is a mechanistically distinct process of endocytosis performed by special cells to take up larger particles such as bacteria or erythrocytes b. Lymphocytes are the primary blood cell involved with this process c. The process involves a coating of the cytoplasmic surface known as clathrin d. Phagocytosis is performed only by white blood cells and tissue macrophages

Description : Which of the following statement(s) is/are true concerning the cell function of phagocytosis? a. Phagocytosis is a mechanistically distinct process of endocytosis performed by special cells to take ... known as clathrin d. Phagocytosis is performed only by white blood cells and tissue macrophages

Last Answer : Answer: a Phagocytosis is a specialized form of endocytosis by which large particles are internalized by specialized cells primarily macrophages and neutrophils. To be phagocytosed, particles ... the lumen of the thyroid follicle, thereby releasing the thyroid hormones, thyroxine triiodothyronine

Which of the following statements concerning perioperative nutrition is true concerning the above-described patient? a. Since the patient’s weight had been stable with no preoperative nutritional deficit, 5% dextrose intravenous solutions are adequate for the initial postoperative source of nutrition b. Preoperative immunologic status should be determined including total peripheral lymphocyte count and delayed hypersensitivity reaction to determine skin-test response to common antigens c. Routine postoperative fluid administration with intravenous 5% glucose solutions can provide the calories to meet basal energy requirements d. A jejunal feeding catheter should be placed at the time of surgery for postoperative enteral feeding

Description : Which of the following statements concerning perioperative nutrition is true concerning the above-described patient? a. Since the patient's weight had been stable with no preoperative nutritional deficit ... feeding catheter should be placed at the time of surgery for postoperative enteral feeding

Last Answer : Answer: a Most patients undergoing elective operations are adequately nourished. Unless the patient has suffered significant preoperative malnutrition, characterized by weight loss greater than ... gastrointestinal surgery, this technique would not appear indicated in the patient described above

Which of the following statement(s) is/are true concerning the outcome in patients with acute renal failure? a. Mortality for ischemic acute tubular necrosis without other organ failure is approximately 6% b. Multiple organ failure complicated with acute renal failure is associated with mortality ranging from 50% to 90% c. Recovery of renal function after six weeks is unlikely d. There is no difference in survival between oliguric and nonoliguric renal failure

Description : Which of the following statement(s) is/are true concerning the outcome in patients with acute renal failure? a. Mortality for ischemic acute tubular necrosis without other organ failure is ... is unlikely d. There is no difference in survival between oliguric and nonoliguric renal failure

Last Answer : Answer: a, b, c Survival of patients with acute renal failure is a function of the successful treatment of the primary disease from which the renal failure was derived. The mortality ... is unlikely. Nonoliguric renal failure is usually limited in its extent and is almost always reversible

Which of the following statement(s) is/are true concerning pharmacologic agents used in the treatment of shock? a. The primary difference between dopamine and dobutamine is the absence of significant a adrenergic activity b. The renal and mesenteric vasoconstrictive effects of norepinephrine complicate and sometimes restrict its use c. The apparent paradoxical use of vasodilators, such as nitroprusside, in shock is indicated as a means to augment cardiac function d. Isoproterenol with its potent b-adrenergic effect, is a particularly useful agent in the treatment of all forms of shock

Description : Which of the following statement(s) is/are true concerning pharmacologic agents used in the treatment of shock? a. The primary difference between dopamine and dobutamine is the absence of significant a ... b-adrenergic effect, is a particularly useful agent in the treatment of all forms of shock

Last Answer : Answer: a, b, c Therapeutic adjustments of intravascular volume (preload) and systemic vascular resistance (afterload) form the basis of the treatment strategies for all ... careful constant monitoring of arterial pressure and repeated hemodynamic measurements with a pulmonary artery catheter

The first line of host defense is the barrier presented to the external environment. Which of the following statement(s) is/are true concerning host barriers? a. Sebaceous glands secrete chemical compounds that maintain a relatively high pH, providing effective bacterial stasis b. Within the respiratory tract, ciliary function serves to extrude microorganisms trapped within the mucus secretion layer c. The low pH within the stomach markedly decreases bacterial content of the upper gastrointestinal tract d. Gut peristalsis serves to prevent microbial adherence and invasion

Description : The first line of host defense is the barrier presented to the external environment. Which of the following statement(s) is/are true concerning host barriers? a. Sebaceous glands secrete ... of the upper gastrointestinal tract d. Gut peristalsis serves to prevent microbial adherence and invasion

Last Answer : Answer: b, c, d The skin, mucus membranes, and epithelial layers of various organs of the body constitute effective physical barriers against microbial invasion. In certain portions of the ... very low pH within the stomach and gut peristalsis both serve to prevent microbial adherence and invasion

External pneumatic compression has been advocated for the prevention of deep venous thrombosis during operative procedures. Which of the following statement(s) concerning the use of external pneumatic compression devices is/are true? a. Intermittent pneumatic compression is as effective as low-dose heparin in prevention of venous thrombosis b. These devices function by compressing the lower extremities therefore augmenting venous return c. Pneumatic compression devices may also exhibit their antithrombotic effect through stimulating local and systemic fibrinolysis d. The length of time that intermittent pneumatic compression should be used includes through the operation and for at least several days in the postoperative period

Description : External pneumatic compression has been advocated for the prevention of deep venous thrombosis during operative procedures. Which of the following statement(s) concerning the use of external pneumatic ... includes through the operation and for at least several days in the postoperative period

Last Answer : Answer: b, c, d In many well-controlled studies of venous prophylaxis, intermittent pneumatic compression has been found to be as effective as low-dose heparin therapy. In addition to augmentation ... be used through the operation and for at least five days in the face or prolonged immobilization

Which of the following statement(s) is/are correct concerning the cardiovascular response to shock? a. Changes in cardiac contractile function shift the Frank Starling curve up and down b. Venoconstriction from skeletal muscle is a significant contributor to the restoration of blood volume with shock c. Arterial vasoconstriction affects all vascular beds equally d. The total circulating blood volume is equally split between the arterial and venous system

Description : Which of the following statement(s) is/are correct concerning the cardiovascular response to shock? a. Changes in cardiac contractile function shift the Frank Starling curve up and down b. ... d. The total circulating blood volume is equally split between the arterial and venous system

Last Answer : Answer: a Central in the general cardiovascular response to shock is the action of the heart itself. The principle determinants of cardiac function in the normal heart are the volume of blood ... Blood flow to the skin is sacrificed early, followed by that to the kidneys and splanchnic viscera

Antithrombin III deficiency is a commonly observed hypercoaguable state. Which of the following statement(s) is/are true concerning this condition? a. A patient with this deficiency usually presents with thrombosis while on heparin or exhibits an inability to become adequately anticoagulated with heparin b. This deficiency may be either congenital or acquired c. Thrombotic episodes are related to predisposing events such as operations, childbirth, and infections d. Treatment involves acutely the administration of fresh frozen plasma followed by long-term treatment with Coumadin

Description : Antithrombin III deficiency is a commonly observed hypercoaguable state. Which of the following statement(s) is/are true concerning this condition? a. A patient with this deficiency usually ... involves acutely the administration of fresh frozen plasma followed by long-term treatment with Coumadin

Last Answer : Answer: a, b, c, d Antithrombin III deficiency accounts for about 2% of venous thrombotic event. This deficiency has been described in patients with pulmonary embolism, mesenteric venous ... is established, fresh frozen plasma should be administered followed by long-term treatment with Coumadin

Which of the following statement(s) concerning laboratory studies used in monitoring a patient with intravenous heparinization is/are correct? a. The platelet count should be followed because of the risk of heparin-associated thrombocytopenia b. The prothrombin time should be observed if prolonged treatment is necessary c. The activated partial thromboplastin time (aPTT) should be maintained at approximately 1.5 times normal d. The serum creatinine should be measured daily to allow adjustments in dose based on renal function

Description : Which of the following statement(s) concerning laboratory studies used in monitoring a patient with intravenous heparinization is/are correct? a. The platelet count should be followed because of the ... serum creatinine should be measured daily to allow adjustments in dose based on renal function

Last Answer : Answer: a, c In monitoring the effect of heparin, an activated partial thromboplastin time (aPTT) of 1.5 control or a thrombin clotting time (TCT) of 2 times control reflects adequate ... system. Therefore the dose of heparin need not be adjusted in cases of liver or renal dysfunction

Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results in selective thrombolysis at the fibrin clot surface. Which of the following statement(s) is/are true concerning agents used in thrombolytic therapy? a. Streptokinase is a bacterial protein which is antigenic in humans, resulting in allergic reactions in up to l5% of cases b. Tissue plasminogen activator acts directly on plasmin without an intermediate drug–plasmin complex c. The half-life of urokinase, streptokinase, and TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA

A 55-year-old male undergoes a total abdominal colectomy. Which of the following statement(s) is/are true concerning the hormonal response to the surgical procedure? a. Adrenocorticotropic hormone (ACTH) is secreted from the anterior pituitary gland b. ACTH stimulation results in elevation of serum cortisol levels for up to a week after the operation c. An increased secretion of aldosterone and ADH may contribute to postoperative fluid retention d. An increase in serum insulin and a fall in glucagon accelerate hepatic glucose production and maintain gluconeogenesis

Description : A 55-year-old male undergoes a total abdominal colectomy. Which of the following statement(s) is/are true concerning the hormonal response to the surgical procedure? a. Adrenocorticotropic ... in serum insulin and a fall in glucagon accelerate hepatic glucose production and maintain gluconeogenesis

Last Answer : Answer: a, c One of the earliest consequence of a surgical procedure is the rise in levels of circulating cortisol that occur in response to a sudden outpouring of ACTH ... hepatic glucose production, and, with other hormones (epinephrine and glucocorticoids), gluconeogenesis is maintained

Which of the following statement(s) is/are true concerning methods of nutritional support? a. Optimal results for enteral feedings are achieved with approximately half of calories supplied as carbohydrate and half as fat b. Diarrhea is the most common complication of enteral feeds and is due to the high osmolarity of the carbohydrate components c. The hyperosmolar nature of parenteral fat solutions requires central venous administration d. Approximately 25–50% of calories should be provided as fat emulsion in patients receiving total parenteral nutrition

Description : Which of the following statement(s) is/are true concerning methods of nutritional support? a. Optimal results for enteral feedings are achieved with approximately half of calories supplied as ... -50% of calories should be provided as fat emulsion in patients receiving total parenteral nutrition

Last Answer : Answer: a, b, d Most formulas for enteral feeding range from 1.0 to 2 cal/ml and include 3 to 7% protein. Most of the calories are supplied as glucose or sucrose, so that the solutions ... up to 25 to 50% of calories each day as fat emulsion may optimize the delivery of this caloric delivery

Which of the following statement(s) is/are true concerning the treatment of MOFS? a. Prevention and therapy of MOFS requires control of the infectious or inflammatory source b. Restoration of normal clinical parameters such as blood pressure, pulse rate, and urine output ensures optimal resuscitation in most patients c. Branch chain amino acids play and important role in the nutritional support of the patient d. Because of the nature of gut injury, total parenteral nutrition is preferred for most patients with MOFS

Description : Which of the following statement(s) is/are true concerning the treatment of MOFS? a. Prevention and therapy of MOFS requires control of the infectious or inflammatory source b. Restoration of normal ... of the nature of gut injury, total parenteral nutrition is preferred for most patients with MOFS

Last Answer : Answer: a, c The therapy of MOFS is directed towards interrupting the involving pathophysiologic process and providing an optimal physiologic environment for healing and recovery. ... Enteral absorption and processing of nutrients appears superior to TPN and lessens overall complications

Which of the following statement(s) is/are true concerning hypoadrenal shock? a. In the United States, idiopathic adrenal atrophy (Addison’s disease) is the most common cause b. Laboratory abnormalities include hyponatremia, hypochloremia, and hyperkalemia c. Fever may be seen with hypoadrenal shock d. ACTH stimulation test is the diagnostic test of choice to confirm hypoadrenal shock

Description : Which of the following statement(s) is/are true concerning hypoadrenal shock? a. In the United States, idiopathic adrenal atrophy (Addison's disease) is the most common cause b. Laboratory ... hypoadrenal shock d. ACTH stimulation test is the diagnostic test of choice to confirm hypoadrenal shock

Last Answer : Answer: b, c, d Shock of a dramatic nature, poorly responsive to resuscitation, may develop as a consequence of adrenal insufficiency. In this country, adrenal insufficiency most ... of an ACTH stimulation test. A significant major cortisol response should be elicited by ACTH administration