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50 Cards in this Set
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A 68-year-old male who underwent a repair of an abdominal aortic aneurysm 5 days ago, develops tachycardia, tachypnea, hypotension with cool, pale, mottled cyanotic extremities. He is agitated and complains of shortness of breath. Which of the following statement(s) is/ are correct concerning his diagnosis and management?
a. Myocardial ischemia secondary to preexisting coronary artery disease is most likely the underlying cause of this problem b. Invasive hemodynamic monitoring with a Swan-Gantz catheter will demonstrate a low cardiac output, a high systemic vascular resistance, and elevated cardiac filling pressures c. The use of morphine sulphate and nitrates should be part of the initial management d. The primary pharmacologic treatment involves the use of moderate doses of inotropic agentse. Afterload reduction with nitroprusside is absolutely contraindicated |
Answer: a, b, d
Intrinsic cardiogenic shock results from failure of the heart as an effective pump. Coronary artery disease is the most common cause of myocardial insufficiency, but contractile dysfunction may also rise as a consequence of cardiomyopathy, myocarditis, or metabolic abnormalities. Invasive hemodynamic monitoring often establishes a specific nature of shock and allows appropriate treatment to be delivered in an effective and expedient manner. Hemodynamic findings consistent with cardiogenic shock include a low cardiac output and high systemic vascular resistance, with elevated cardiac filling pressures. The initial measures in the management of cardiogenic shock include the administration of supplemental oxygen, mechanical ventilation (as needed), and appropriate treatment of dysrhythmias. Hypotension usually precludes the use of morphine sulfate and nitrates, drugs typically used in simple congestive heart failure to alleviate cardiac pain and ameliorate pulmonary vascular congestion. The use of beta-adrenergic agonists such as dopamine and dobutamine, in moderate doses, offers positive inotropic support without excessive alpha-adrenergic activity. Increasing the inotropic state of the heart shifts the entire Starling curve upward, resulting in increased cardiac output for each level of cardiac filling. Afterload reduction may prompt increases in cardiac output through decreases in resistance to flow. The use of nitroprusside or other dilators requires relative blood pressure stability and close hemodynamic monitoring. Infusion of afterload-reducing agents can be administered in conjunction with inotropic support. |
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Which of the following physical findings are associated with the various classes of hemorrhagic shock?
a. Mild shock (< 20% blood volume): Pallor, cool extremities, diminished capillary refill and diaphoresis b. Moderate shock (20%–40% blood volume): All of the above plus tachycardia and hypotension c. Severe shock (> 40% blood volume): Systemic hypotension, changes in mental status, tachycardia, oliguria d. All of the above |
Answer: a, c
PHYSICAL FINDINGS IN HEMORRHAGIC SHOCK* Moderate Mild (<20% (20%-40% Severe(>40%Blood Volume) Blood Volume) Blood Volume)Pallor Pallor PallorCool extremities Cool extremities Cool extremitiesDiminished capillary Diminished capillary Diminished capillaryrefill refill refillDiaphoresis Diaphoresis DiaphoresisCollapsed Collapsed Collapsedsubcutaneous subcutaneous subcutaneousveins veins veinsTachycardia TachycardiaOliguria OliguriaPostural Hypotensionhypotension Mental statuschanges* Alcohol or drug intoxication may alter physical findings. |
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Which of the following statement(s) is/are correct concerning the immunoinflammatory response to shock?
a. The anaphylactoxins, C3a and C5a, are products of activation of only the classical pathway of the compliment cascade b. Eicosanoids, such as prostaglandins are stored in platelets and endothelial cells and released in response to inflammatory stimuli c. Thromboxane and PGI2 have similar effects d. Platelet-activating factor can be released by both circulating and fixed tissue cells |
Answer: d
Inflammatory mediators have recently been recognized as playing a significant role in the clinical manifestations and progression of shock and the development of subsequent complications. These mediator systems function primarily as parcrine and autocrine agents in the local environment and are not usually detectable systemically. The over-expression and systemic dissemination of these mediators produces the toxic autodestructive processes underlying multiorgan failure syndrome with attendant high mortality. The compliment cascade is activated in shock and tissue injury through both the classical and alternative pathways. Activation of either pathway results in generation of the anaphylatoxin, C3a and C5a, soluble products with potent systemic hemodynamic effects. The eicosanoids, which include the prostaglandins and leukotrienes are formed acutely from arachidonic acid released from the membrane phospholipid by phospholipase A2. Eicosanoids are not stored in any measurable level and are generated as needed from readily available arachidonic acid in response to various inflammatory phenomena. Platelets, white cells, and endothelial cells are a rich source of these compounds. Thromboxane (TXA2) is the major arachidonic acid metabolite elaborated by platelets. TXA2 induces intense vasoconstriction, platelet aggregation and degranulation, neutrophil margination in the microcirculation and bronchial constriction. PGI2, the major arachidonic acid metabolite formed by endothelial cells, serves a check against actions of TXA2. PGI2 is a vasodilator and a potent inhibitor of platelet aggregation. Platelet aggravating factor is a potent phospholipid mediator released by neutrophils, platelets, macrophages and endothelial cells in response to ischemia, tissue injury and sepsis. Its effects include decreased cardiac function, increased pulmonary vascular resistance, bronchoconstriction, peripheral vasodilatation, and increased vascular permeability. |
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223 Which of the following statement(s) is/are true concerning tumor necrosis factor (TNF)?
a. TNF is a product of activated macrophages secreted in response to contact with endotoxin or lipopolysaccharide, antibody complexes, or inflammatory stimuli b. The liver and gut appear to be a major source of TNF following hypoperfusion c. Circulating levels of TNF correlate well with severity of tissue injury in shock d. Recently completed clinical trials of anti-TNF antibody in septic patients shows a marked improvement in survival |
Answer: a, b
Tumor necrosis factor (TNF), a protein product of activated macrophages, is secreted in response to contact with endotoxin or lipopolysaccharide, antibody complexes, or other inflammatory stimuli. Elevation of serum levels of TNF have been reported shortly after experimental trauma and shock, however, documentation of elevated circulating levels of TNF in human shock is less clear. Furthermore, circulating levels of TNF cannot be correlated with severity of tissue injury or shock. This variability is thought to be due to rapid clearance and uptake by membrane receptors and by soluble membrane receptors that are released from multiple cells following stress and injury. Following hypoperfusion the liver and gut appear to be the major source of TNF that is rapidly cleared but responsible for inducing hepatocyte changes following shock. The release of breakdown products and escape of bacterial and endotoxin through the damaged mucosal barrier of the gut following shock allows or induces activation of tissue-fixed macrophage (Kupffer cell) of the liver which then produces secondary inflammatory mediators contributing to the post-resuscitation clinical response and inflammatory mediator activation seen in the systemic inflammatory response syndrome.TNF is central to inflammatory response, particularly in sepsis and following endotoxemia or bacteremia. TNF also induces secondary inflammatory responses through direct interaction with specific membrane receptors, TNF-r. Treatment with anti-TNF antibody in the experimental setting protects animals from the deleterious effects of lethal bacteremia and endotoxemia. However, recently completed clinical trials in septic patients utilizing infusion of monoclonal antibodies to the TNF molecule have shown no overall survival benefit. |
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Which of the following statement(s) is/are true concerning septic shock?
a. The clinical picture of gram negative septic shock is specifically different than shock associated with other infectious agents b. The circulatory derangements of septic shock precede the development of metabolic abnormalities c. Splanchnic vascular resistance falls in similar fashion to overall systemic vascular resistance d. Despite normal mechanisms of intrinsic expansion of the circulating blood volume, exogenous volume resuscitation is necessary |
Answer: d
The clinical findings in sepsis and septic shock represent the host response to infection. Gram-positive and gram-negative bacteria, viruses, fungi, rickettsiae, and protozoa have all been reported to produce a clinical picture of septic shock, but the overall response is independent of the specific type of invading organism. Septic shock develops as a consequence of the combination metabolic and circulatory derangements accompanying the systemic infection. It appears that the circulatory deficits are preceded by the metabolic abnormalities induced by infection. In fact, the circulatory changes in hyperdynamic sepsis appear to be an adaptive response to the underlying metabolic dysfunction. Cardiac output is high and systemic vascular resistance low in hyperdynamic septic shock. However, splanchnic vasoconstriction is pronounced even in the absence of systemic hypotension and even though systemic vascular resistance is reduced. Expansion of circulating blood volume can occur through either transcapillary refill or fluid resuscitation. Due to the ongoing inflammatory mediator-induced increases in capillary permeability and continued loss of intravascular volume, exogenous volume resuscitation must be provided to restore venous return and ventricular filling. |
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A 32-year-old man suffers a spinal cord injury with a resultant paraplegia in a motorcycle accident. He presents to the emergency room with hypotension. Which of the following statement(s) is/are true concerning his diagnosis and management?
a. The low blood pressure can be assumed to be due to neurogenic shock b. The sole cause of hypotension is the loss of sympathetic input to the venous system c. Despite significant hypotension, secondary organ injury will be uncommon d. There is no role for pharmacologic intervention to maintain blood pressure |
Answer: c
Neurogenic shock results from interruption of sympathetic vasomotor input and develops after spinal cord injury, spinal anesthesia, and severe head injury. Under normal conditions, baseline sympathetic activity establishes a degree of arteriolar and venous constriction. Ablation of this tone results in decreased systemic vascular resistance and a dramatic increase in venous capacity, causing hypotension due to relative hypovolemia. Arteriolar dilatation not only lowers the systemic vascular resistance but also allows previously unopened vascular beds to be perfused, greatly expanding venous capacity. Removal of sympathetic inputs to innervated portions of the venous system allows further venodilatation. Restoration of an effective, albeit expanded, intravascular volume may require extremely large volumes of resuscitation fluid to restore normal cardiac filling pressures. This will restore cardiac output and reverse hypotension. However, pharmacologic intervention with vasoactive drugs may be necessary and is preferable to excessive volume resuscitation. Post-shock sequelae are infrequent. Although there is significant hypotension with neurogenic shock, there is usually little if any hypoperfusion. Thus, activation of inflammatory cascade and subsequent organ injury rarely occur.A major pitfall in the management of neurogenic shock arises when there is coexistent hemorrhage or ongoing volume loss that is not appreciated. This is not an unusual situation because cervical spine trauma causing paraplegia or severe head injury is frequently associated with multiple injuries. Thus, in trauma the initial response to neurogenic shock is large volume resuscitation regardless of the presumed etiology. If hemodynamic instability persists after initial trauma resuscitation, one must assume that the cause is not neurogenic and search for occult blood loss or cardiogenic causes of shock. |
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A 22-year-old man sustains a single stab wound to the left chest and presents to the emergency room with hypotension. Which of the following statement(s) is/are true concerning his diagnosis and management?
a. The patient likely is suffering from hypovolemic shock and should respond quickly to fluid resuscitation b. Beck’s triad will likely be an obvious indication of compressive cardiogenic shock due to pericardial tamponade c. Echocardiography is the most sensitive noninvasive approach for diagnosis of pericardial tamponade d. The placement of bilateral chest tubes will likely resolve the problem |
Answer: c
Shock from cardiac compression occurs when external pressure on the heart impairs ventricular filling. Because ventricular filling is a function of venous return and myocardial compliance, any process that places pressure on the heart can cause compressive cardiogenic shock. Included among these are pericardial tamponade, tension pneumothorax, mediastinal hematoma, and positive pressure from mechanical ventilation. Any patient with hypotension after a wound in proximity of the heart should be considered to have compressive cardiogenic shock until proven otherwise. The classical clinical findings of pericardial tamponade include Beck’s triad of hypotension, neck vein distention and muffled heart sounds. Pulses paradoxus may be noted (this involves a decrease rather than the normal increase of systolic blood pressure with inspiration; values 10mmHg are significant). These findings, however, may be obscured in a noisy emergency room environment by positive pressure ventilation or by associated injuries. Placement of a CVP catheter confirms the elevation of right-sided filling pressure. If a pulmonary artery catheter has been placed, findings consistent with tamponade or other forms of cardiac compression are a trend toward equalization of chamber pressures as hypotension progresses. In the patient at risk, echocardiography is an extremely sensitive and noninvasive approach to demonstrate pericardial fluid and the need for operation. Pericardial tamponade must be relieved urgently and cardiac injuries require emergent sternotomy. Chest tube placement would not be appropriate as the sole treatment in this patient. |
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Which of the following statement(s) is/are true concerning the neuroendocrine responses to shock?
a. Sympathetic nerve endings release epinephrine which is responsible for greater than 80% of systemic vascular resistance b. Endogenous epinephrine is the primary contributor to systemic vascular resistance c. Increased pancreatic secretion of glucagon contributes to glucose intolerance associated with injury and sepsis d. The renin-angiotensin axis further augments the sympathetic-mediated vasoconstriction |
Answer: c, d
The neuroendocrine response to shock attempts to achieve restoration of effective blood volume, mobilization of metabolic substrates, and maintenance of central profusion. Both peripheral and central afferent stimuli to the central nervous system are involved in inducing this response. Hypotension, associated with a decrease in impulses from the aortic and carotid baroreceptors, disinhibits the vasomotor center. This disinhibition results in increased adrenergic output and decreased vagal activity. Sympathetic nerve endings release norepinephrine, inducing peripheral and splanchnic vasoconstriction which is responsible for greater than 80% of systemic vascular resistance and is a major contributor to maintenance of central organ perfusion and venous return. Plasma levels of both epinephrine and norepinephrine are elevated with injury, and the degree of the catecholamine elevation corresponds to the magnitude of injury. In shock the effects of endogenous epinephrine are largely metabolic. In addition to initiating autonomic nervous activity, the hypothalamus secretes releasing hormones, which induce the stress hormone release of the pituitary. As part of this response, adrenocorticotropic hormone (ACTH) secretion by the anterior pituitary is increased stimulating cortisol secretion by the adrenal cortex. In conjunction with elevated plasma levels of cortisol and epinephrine, increased pancreatic secretion of glucagon accelerates hepatic gluconeogenesis and further aggravates the glucose intolerance that follows injury and sepsis. The secretion of renin is increased in responses to adrenergic discharge and decreased perfusion of the juxtaglomerular apparatus in the kidney. Renin allows formation of angiotensin I in the liver, which is then converted to angiotensin II in the lungs. Angiotensin II is an extremely effective vasoconstrictor that further augments sympathetic-mediated vasoconstriction. |
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Which of the following statement(s) is/are true concerning the diagnosis and management of hypovolemic shock?
a. A fall in hematocrit or hemoglobin always accompanies hemorrhagic shock b. The treatment of shock is generic regardless of the etiology c. Pharmacologic intervention to increase myocardial contractility in hypovolemic shock is an important part the early management d. Complications are less frequent after treatment of hemorrhagic shock than septic or traumatic shock |
Answer: d
Hypovolemic shock is readily diagnosed when there is an obvious source of volume loss and overt signs of hemodynamic instability and increased adrenergic output are present. After acute hemorrhage, hemoglobin and hematocrit values do not change until compensatory fluid shifts have occurred or exogenous fluid is administered. These values decrease once transcapillary refill, osmotic-induced shifts, or non-RBC volume resuscitation expands the blood volume. It is imperative that the distinction be made between hypovolemic and cardiogenic forms of shock, because appropriate therapy differs dramatically. Restoration of perfusion in hypovolemic shock requires reexpansion of circulating blood volume in conjunction with necessary interventions to control ongoing volume loss. Continued hemodynamic instability after fluid resuscitation implies that shock has not been reversed or that there is ongoing blood or volume loss. In severe, prolonged hypovolemia, ventricular contractile function may itself become depressed and require inotropic support to maintain ventricular performance, but in general, pharmacologic interventions directed toward increased contractility in situations of inadequate preload are ineffective, further complicate metabolic derangements, and are not indicated until adequate volume replacement has been completed. Complications are less frequent after treatment of hemorrhagic shock than in situations of septic or traumatic shock. In the later circumstances, the massive activation of inflammatory mediator response systems and consequences of their disseminated, indiscriminate cellular injury can be quite profound. |
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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 |
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 lung mechanics, and acute lung injury or ARDS due to sepsis. Pulmonary function may be further compromised by pathology intrinsic to the lung itself, including pulmonary contusion, aspiration, airway obstruction, pneumonia, pneumothorax, hemothorax, and atelectasis. The acute pulmonary vascular response to shock largely parallels that of the systemic vasculature. The increase in pulmonary vascular resistance, which may proportionally exceed that of the systemic circulation, transiently accompanies the systemic adrenergic response. ARDS is a syndrome of progressive lung injury that may arise as a direct consequence of shock or other disease processes. The characteristic findings of ARDS are the presence of pulmonary edema, hypoxemia, and significantly decreased lung compliance. The pulmonary edema is noncardiac in origin and occurs in the face of normal left heart pressures. The hypoxemia results from the development of intrapulmonary shunting and perfusion of under and nonventilated alveoli. The decrease in lung compliance results from the loss of surfactant and lung volume in combination with the presence of interstitial fluid and alveolar edema. Progressive histologic changes of ARDS become apparent in pulmonary capillaries, interstitium, and alveoli. Initially, interstitial edema develops with swelling of the capillary endothelial cells and the type I pneumocytes. The type I pneumocytes subsequently slough, and alveolar edema ensues. Functional surfactant is lost with a significant increase in alveoli opening pressure and decrease in alveolar surface tension. Mechanisms proposed in the pathogenesis of ARDS include injury from mediators of inflammation elaborated elsewhere, and from activated cellular blood elements. |
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216 Which of the following statement(s) is/are true concerning the microvascular and cellular response to shock?
a. Osmodically induced mobilization of intracellular fluid is the initial response to restore intravascular volume b. With larger volume hemorrhagic shock deterioration of normal cellular transmembrane potential occurs resulting in an increase in extracellular sodium and water c. The accumulation of anaerobic metabolites override normal homeostatic vasomotor tone and contribute to the maladaptive vasodilatation d. Abnormal intracellular calcium homeostasis may contribute to the cellular dysfunction of shock |
Answer: c, d
Moderate hypovolemia results in a relatively rapid spontaneous restitution of intravascular volume through expansion of the plasma space. This plasma expansion by erythrocyte free fluid occurs within one hour as a result of alterations in pressure and osmolarity and produces an associated hemodilution. Sympathetic discharge, associated arteriolar constriction, and induced metabolic changes in osmolarity initiate the compensatory events at the microcirculatory level. The initial pressure-related phase of restitution of blood volume in shock is overlapped by a second phase involving osmotically induced mobilization of intracellular fluid. Osmotic mechanisms contributing to the restitution of blood volume after moderate hemorrhage are not adequate in hemorrhage of greater magnitude. In larger hemorrhages (over 25% blood volume), there is also deterioration of the normal cellular transmembrane potential, an increase in intracellular sodium and water, and a concomitant decrease in extracellular fluid volume. Tissue hypoxia results, anaerobic metabolites accumulate, and the cell cannot maintain the normal cell membrane potential. Accumulation of hydrogen ion, lactate, and other products of anaerobic metabolism override homeostatic vasomotor tone and contribute to a maladaptive vasodilatation, further augmenting hypotension and hypoperfusion. The uptake of fluid by the “failing” cell is a major source of food sequestration following shock. Loss of membrane function is proportional to both the extent and duration of shock or degrees of sepsis. The etiology of membrane failure is unclear but appears multifactorial. Loss of intracellular ATP energy stores during hypoperfusion or direct toxicity during sepsis may inhibit the membrane sodium-potassium pump. Cellular dysfunction also appears to be related to abnormal intracellular calcium homeostasis. |
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215 Which of the following statement(s) is/are true concerning metabolic derangements in sepsis and the systemic inflammatory response syndrome which may follow progressive shock?a. Alterations in glucose metabolism lead to the development of efficient substrate utilization
b. A progressive rise in serum triglyceride levels result from less efficient clearance and increased hepatic lipogenesis c. A net negative nitrogen balance occurs due to the oxidative metabolism of proteins to meet energy needs d. The serum aromatic amino acids fall rapidly as they are actively used in oxidative metabolism |
Answer: b, c
A broad spectrum of metabolic abnormalities become apparent in sepsis and the systemic inflammatory response syndrome following shock. Disruption of the normal cycles of carbohydrate, lipid, protein, and oxygen metabolism occur as hypermetabolism develops. Through the Cori cycle, lactate from the periphery is shuttled back to the liver, where it is used in the production of glucose. Because pyruvate is converted to alanine in the periphery, flux of alanine also contributes to hepatic gluconeogenesis. The glycolytic oxidation of glucose to pyruvate and its subsequent glugoneogenic regeneration from lactate is an inefficient cycling of substrate. There is no net energy production, but heat is released in significant quantities. Alterations in lipid metabolism cause a progressive rise in the serum triglyceride level as a result of less efficient clearance of exogenous triglycerides coupled with increased hepatic lipogenesis. Profound alterations in protein and amino acid metabolism develop with characteristic changes in amino acid levels, nitrogen balance, and skeletal muscle mass. Initially levels of the branch chain amino acids are reduced, whereas those of the aromatic amino acids are elevated. There is an increase in the oxidative metabolism of protein to meet energy needs and a tremendous mobilization of nitrogen with net negative nitrogen balance. The branch chain amino acids are preferentially utilized in the TCA cycle to maintain an activity that otherwise would be lost from the diminished entry of carbohydrate-and fatty acid-generated acetyl coenzyme A. This results in reduced serum level of leucine, isoleucine and valine. |
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Which of the following statement(s) is/are true concerning the various types of shock?
a. Traumatic shock is more commonly associated with subsequent organ injury and multiorgan failure syndrome than hemorrhagic shock b. Cardiogenic shock can be of either an intrinsic or compressive nature c. Hypodynamic septic shock is associated with a decreased mortality risk when compared with hyperdynamic septic shock d. Hypoadrenal shock usually responds quickly to resuscitatione. Neurogenic shock occurs with the absence of sympathetic activity |
Answer: a, b, d, e
Classification schemes of shock based on cause have been developed for the seemingly dissimilar processes leading to circulatory collapse and the shock state. Hypovolemic shock, the most common, is the result of intravascular volume depletion through loss of red blood cell mass or plasma volume. Microvascular hypotension results from a combination of low intravascular blood volume, diminished cardiac output, and compensatory sympathetic peripheral vasoconstriction. Shock associated with trauma (traumatic shock) arises from the consequences of hypovolemia due to hemorrhage in conjunction with direct soft tissue injury and bone fracture. Hypovolemia caused by blood loss and fluid extravasation into injured tissues is compounded by activation of maladaptive inflammatory cascades initiated by the tissue injury. In contrast to pure hemorragic shock, subsequent organ injury and multiorgan failure syndrome (MOFS) occurs much more frequently following traumatic shock due to the over-expression of these immuno-inflammatory cascades. Cardiogenic shock is the result of failure of the heart as an effective pump, resulting in inadequate cardiac output, tissue perfusion and oxygen delivery. Intrinsic causes include myocardial infarction, cardiomyopathy, valvular heart disease, or rhythm disturbances. Compressive cardiogenic shock is a discrete entity that results when extrinsic compression of the heart limits diastolic filling and thus systolic ejection and cardiac output. Septic shock refers to hypotension and circulatory insufficiency developing as a consequence of infection and the systemic response to that infection. In its hyperdynamic form, septic shock is marked by diminished peripheral vascular resistance and generalized vasodilatation causing relative hypovolemia. In contrast, hypodynamic septic shock occurs in situations of inadequate resuscitation or preterminal cardiovascular decompensation, and is associated with vasoconstriction and a greatly increased mortality risk. Sympathetic denervation through spinal cord injury, spinal anesthesia, or severe head injury produces generalized arterial vasodilatation and venodilation. Shock occurs when the normal blood volume fails to fill the available intravascular space and severe relative hypovolemia exists. Despite hypotension, there is a noteworthy absence of sympathetic activity, as occurs in hypovolemia or cardiogenic shock. Profound shock can occur in surgical patients following stress due to the loss of the homeostatic corticosteroid response. Hemodynamic instability may develop after an operative procedure or coincident with an unrelated illness. The profound circulatory collapse is often refractory to vigorous resuscitation with fluids and pressor agents. The response to exogenous corticosteroids is usually dramatic and potentially life-saving. |
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The following statement(s) is/are true concerning gram-negative bacterial sepsis.
a. Mortality due to this condition has almost been eliminated due to therapeutic intervention with antibiotics, aggressive hemodynamic monitoring and fluid resuscitation b. Recent series have noted a decrease in the incidence of this condition c. Predisposing factors include old age, malnutrition, and immunosuppression d. Pseudomonas bacteremia is the most common cause of gram-negative sepsis e. Polymicrobial sepsis is generally considered a more serious problem than sepsis due to a single organism |
Answer: c, e
Gram-negative bacterial sepsis is a serious disease process that produces substantial morbidity and mortality in both normal and immunocompromised patients (10% to 20% and 30% lethality, respectively), despite therapeutic intervention with antimicrobial agents, aggressive hemodynamic monitoring, fluid resuscitation, and metabolic support. During the past several decades, nosocomial infections due to gram-negative pathogens have increased in frequency with resultant increase in the incidence of gram-negative bacteremia to between 3 and 13 cases per 1000 hospital admissions. Factors that predispose to these infections include: 1) underlying host disease processes such as malignancy, diabetes; 2) old age and disability; 3) malnutrition; 4) previous or concurrent antimicrobial antibiotic therapy; 5) major operations; 6) respiratory or urinary manipulation or intubation; and 7) immunosuppression.Although many different organisms cause this form of sepsis, E. coli predominates in overall frequency. Also common are isolates of Klebsiella, Enterobacter and Serratia; Pseudomonas bacteremia is less common. Some studies, however, have suggested that Pseudomonas sepsis is associated with the highest lethality. In several series, 10% to 20% of patients have had polymicrobial series, and most investigators agree that polymicrobial sepsis is more lethal than infection with a single organism. |
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A 67-year-old male presents with an intraabdominal abscess secondary to perforated sigmoid diverticulitis. The following statement(s) is/are true concerning his intraabdominal abscess.
a. Culture will likely reveal a solitary organism b. Both aerobic and anaerobic islets are encountered in 50% of specimens c. The most common aerobic islet will be likely E. coli and other gram-negative enteric bacilli d. The most common anaerobic islet will be a Bacteroides species |
Answer: b, c, d
Typically an intraabdominal infection results in perforation of a hollow viscus and the ensuing contamination of a normally sterile peritoneal cavity. The normal bacterial flora found in that particular location of the alimentary tract thus determines the initial inoculum. In parallel with the overall quantity of microorganisms, (both aerobes but predominantly anaerobes) perforations of the lower small bowel and colon produce a high frequency of infections that contain anaerobic microorganisms. Certain predictable patterns of bacterial islets are found, but on average four to five islets occur in patients with established intraabdominal infection, more than half of which are anaerobes. Both aerobes and anaerobes are encountered in 80% to 90% of specimens. Commonly encountered aerobes isolated are E. coli and other gram-negative enteric bacilli such as Enterobacter, Klebsiella. Among the anaerobes, Bacteroides species (especially B. fragilis, Clostridium), and anaerobic cocci are most consistently isolated. |
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The following statement(s) is/are true concerning host defense mechanisms to intraabdominal infection.
a. Bacterial clearance can occur via translymphatic absorption b. Phagocytic activity and bacterial killing can occur via resident phagocytic cells and an influx of PMNs c. A fibrinogen-rich inflammatory exudate is released into the peritoneal cavity, trapping large numbers of bacteria and other particulate matter d. Perforations of a bowel may be walled off but are seldom sealed by the omentum and other mobile viscera |
Answer: a, b, c
The introduction of microorganisms into the normally sterile peritoneal environment invoke several potent specialized host antimicrobial defense mechanisms. Bacterial clearance, also termed translymphatic absorption, occurs through specialized structures found only on the peritoneal mesothelium on the underside of the diaphragm that act as conduits for both fluid and particulate matter. Lymphatic channels eventually form which drain into the venous circulation via the thoracic duct. Bacteria not cleared via translymphatic absorption are rapidly engulfed by resident and recruited phagocytic cells including resident macrophages on the peritoneal surface and omentum and attracted PMNs. The final primitive host defense mechanism is sequestration by which a fibrinogen-rich exudate containing plasma oposonins appears during peritoneal infection and fibrin polymerization occurs. Fibrin has the capacity to trap large numbers of bacteria and other particulate matter. Acting in conjunction with omentum and other mobile viscera, perforations are sealed and the contaminated enteric contents walled off, preventing continued soilage of the peritoneal cavity. |
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The treatment of the following patient should include:
a. Initial empiric therapy directed against both aerobes and anaerobes b. The addition of anti-fungal therapy in an elderly patient c. A minimum of two weeks of antibiotic therapy is indicated d. The addition of appropriate antibiotic therapy has made surgical therapy unnecessary in such cases e. Either a single agent or combination therapy is appropriate if the agents selected possess activity against both aerobic and anaerobic bacteria |
Answer: a, e
The primary treatment for a perforated viscus is surgical, however antimicrobial therapy is an extremely important adjunct. Empiric antibiotic therapy for secondary bacterial peritonitis and intraabdominal abscess should be directed against both aerobes and anaerobes. Administration of an agent directed against only one component of the infection or the other is inferior to combined therapy. Several studies indicate that the results of using several agents in combination is equivalent to the use of a single agent therapy as long as the agents selected possess activity against both components of the infection. The addition of antientercoccal or antifungal agents as initial therapy has not been substantiated. The most beneficial duration of antibiotic therapy must be based on the setting for the specific patient. Minimal peritoneal contamination with adequate surgical treatment may be treated with a three-to five-day course of antibiotics, whereas longer periods are indicated for immunosuppressed patients and with patients with extensive contamination. |
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Antibacterial agents can be classified with regard to their structure, mechanism of action, and activity pattern against various types of bacterial pathogens. Which of the following statement(s) is/are true concerning antimicrobial classes?
a. Penicillins and cephalosporins share the compound structure of a b-lactam ring which binds to bacterial division plate proteins b. Tetracyclines and macrolides such as erythromycin inhibit bacterial ribosomal activity and therefore protein synthesis c. Aminoglycosides act in a similar fashion to tetracyclines and therefore are both bacteriostatic d. Sulfonamides and trimethoprim act synergistically to inhibit purine synthesis |
Answer: a, b, d
Penicillins, cephalosporins, and monobactams possess a b-lactam ring of some type and act to bind bacterial division plate proteins, thus inhibiting cell wall peptidoglycan synthesis and either causing or inducing autolytic bacteriolysis. Because gram-positive and gram-negative bacteria possess different types of division plate proteins, many of these agents exhibit differential activity between these two types of microorganisms. Tetracyclines, chloramphenicol, and macrolides inhibit bacterial ribosomal activity, and thus overall protein synthesis by a variety of different mechanisms. Aminoglycosides act to inhibit protein synthesis and also presumably act on a different target site, a supposition based on the fact that aminoglycosides are bacteriolytic and the other agents are bacteriostatic. Vancomycin inhibits assembly of peptidoglycan polymers, whereas quinolones bind to DNA helicase proteins and inhibit bacterial DNA synthesis. Sulfonamides and trimethoprim act in different mechanisms to inhibit protein synthesis, therefore two agents in combination act synergistically. |
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New treatment modalities designed to modulate host defense mechanisms that have been demonstrated conclusively to be of benefit include:
a. Gut decontamination b. Anti-LPS antibody c. Anti-TNF antibody d. Thymopentin e. None of the above |
Answer: e
Selective gut decontamination involves the use of orally administered antibiotics that achieve a high intraluminal level directed against gram-negative aerobes and yeast, leaving the host anaerobic intestinal microflora relatively undisrupted. Although a reduction and alteration of the microorganisms responsible for infectious episodes have been demonstrated in certain groups of patients, a clear-cut impact on host mortality has not been shown. Because LPS may be responsible for toxicity both directly and through host mediator systems, the availability of agents to bind against this portion of the gram-negative bacteria to reduce mortality has been intensively examined. Unfortunately, large multicenter randomized trials provide no evidence of benefit for this treatment. Similarly, since many of the systemic manifestations of gram-negative bacteremia are mediated by cytokines, the effect of an anti-TNF antibody preparation is currently in clinical trial. No proven benefits have yet been identified. Finally, the use of immunostimulants to enhance the state of activation of host defenses has been proposed. Thymopentin is a peptide that contains active thymopoetin, a thymic molecule that acts to stimulate T-lymphocyte activity. Preliminary trials indicate that this agent ameliorates host septic response after major operations and trauma but conclusive evidence that concurrent reduction of infection-related mortality occurs is not available. |
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The following statement(s) is/are true concerning necrotizing fascitis.
a. Mortality rates as high as 40% can be expected b. The infection involves only the superficial fascia, sparing the deep muscular fascia c. An impaired immune system is a common factor predisposing to this condition d. The infection is usually polymicrobial e. Necrotizing fascitis is most likely to develop in the face of impaired fascial blood supply |
Answer: a, c, d, e
Necrotizing fascitis is an uncommon infection of the deep and superficial fascia that is associated with mortality as high as 40% in many series. Although many underlying disease processes predispose patients to necrotizing fascitis, three common factors are almost invariably present: 1) impairment of the immune system; 2) compromise of fascial blood supply, and 3) the presence of microorganisms that are able to proliferate within this environment. Infections of this type are usually polymicrobial in nature, with gram-positive organisms such as staphylococci and streptococci, gram-negative enteric bacteria, and gram-negative anaerobic being frequently identified. These polymicrobial cultural results are assuredly indicative of the occurrence of a synergistic process, perhaps in large part accounting for the severity of these infections. Some microorganisms possess virulence factors that, in conjunction with an underlying host predisposition, allow this disease process to occur without dependence on other bacteria. Examples of such bacteria include Clostridium, Pseudomonas, and Aeromonas. In these patients, the process is often fulminant and is frequently associated with cellulitis, myositis, fascitis, and bacteremia with attendant high mortality. |
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Question 201:
The structures removed in radical neck dissection include 1. Sternomastoid muscle2. Submandibular gland3. Internal jugular vein4. Recurrent laryngeal nerveSelect the correct answer using the code given below: A) 1, 2 and 3 only B) 1 and 3 only C) 2 and 4 only D) 1, 2, 3 and 4 |
A |
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Question 202:
The following are the indications for carrying out a sympathectomy except ? A) Hyperhydrosis B) Venous ulcer of leg C) Causalgia D) Raynauds disease |
B |
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Question 203:
A 32 year-old male patient presents in casualty department with history of RTA one-hour back; on examination is found that BP is 90/50 mm Hg, pulse rate 110 beats per minute, with fracture left lower ribs, and generalized distension of abdomen with guarding and rigidity. He also complained of pain on the tip of the left shoulder. As a casualty Medical Officer you must exclude which one of the following clinical conditions on the primary basis ? A) Cardiac tamponade B) Inestinal perforation C) Rupture left lobe of liver D) Splenic rupture |
D |
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Question 204:
Femoral hernias are more common in females because ? A) femoral canal is long B) femoral canal is wide C) ligaments of femoral canal neck are weak D) weakness of post Inguinal wall |
B |
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Question 205:
Pelvic abscess can present with all symptoms except ? A) fever B) pain abdomen C) bleeding rectum D) diarrhea with mucus discharge |
C |
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Question 206:
Consider the following statements in respect of prostatic carcinoma :1. Most originate from peripheral zone2. Prostatic needle biopsy is better performed under trans rectal ultrasound3. Prostate specific antigen is the specific test4. L.H.R.H. analogues are used as medical treatment for metastatic diseaseWhich of the statements given above is / are correct ?A) 1 and 2 only B) 2, 3 and 4 C) 1 and 3 D) 1, 2 and 4 |
D |
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Question 207:
Regarding varicocele, all of the following are true except ? A) Varicosity of cremasteric veins B) Left side is affected usually C) Feels like a bag of worms D) May lead to infertility |
A |
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Question 208:
The most frequent complication of fracture pelvis is injury to ? A) penile urethra B) membranous urethra C) urinary bladder D) rectum |
B |
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Question 209:
Burns involving the head and neck region are particularly dangerous because ? A) Face is a very vascular area B) There may be thermal damage to the respiratory passage C) Renal failure is more frequent D) Blood loss may be more severe |
B |
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Question 210: The term debridement of the wound refers to ?
A) Clean excision of at least 1 mm of skin from the edge of the wound B) The irrigation and cleaning of the wound C) Laying open all layers to the wound and excision of the devitalized tissue D) Closure of wound in layers |
C |
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Question 211:
Which of the following statements is true regarding wound contracture ? A) It is a primary process affecting the closure of sutured wounds B) Bacterial colonization of a wound slows the process of contraction C) It is the function of specialised fibroblasts that cotain actin myofilaments D) It may account for a maximum of 40% decrease in the size of a wound |
C |
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Question 212:
The scolicidal agents used in the surgery of a hydatid cyst include all of the following except ? A) 0.5% silver nitrate B) 20% (Hypertonic) saline C) 15% gluteraldehyde D) Absolute alcohol |
A |
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Question 213:
Which one of the following is an example of a chemodectoma ? A) Cocks peculiar tumour B) Cystosarcoma phylloides C) Carotid body tumour D) Keratoacanthoma |
C |
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Question 214:
Consider the following conditions in blunt trauma of the chest:1. Flail chest2. Drainage of 1 litre of blood from the chest tube3. Cardiac tamponade4. Rupture of oesophagus Which of the above are the indications of emergency thoracotomy ? A) 1, 2 and 3 only B) 2 and 4 only C) 2, 3 and 4 only D) 1, 2, 3 and 4 |
D |
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Question 215:
Which type of breast cancer is most likely to be bilateral ? A) Infiltrating duct carcinoma B) Paget's disease of breast C) Lobular carcinoma of breast D) Medullary carcinoma of breast |
C |
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Question 216: Surgery for undescended testis is done at ?
A) 6 months B) 9 months C) 12 months D) 24 months |
C |
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Question 217:
Which one of the following is not a component of Charcoat's triad ? A) Pain B) Fever C) Vomiting D) Jaundice |
C |
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Question 218: 'Double duct' sign is diagnostic of ?A) periampullary carcinoma
B) gall bladder carcinoma C) klatskin's carcinoma D) hepatocellular carcinoma |
A |
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Question 219:
Match List I with List II and select the correct answer using the code given below the lists : List I(Condition) A. Viral hepatitis B. Amoebic liver abscess C. Ascending cholangitis D. Hydatid liver diseaseList II(Causative Agent)1. Enteric bacteria2. Echinococcus granulosus3. Hepatitis A, B, C4. Entamoeba histolyticaCode: A) A3 B4 C1 D2 B) A3 B1 C4 D2 C) A2 B4 C1 D3 D) A2 B1 C4 D3 |
A |
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Question 220:
What is the most common hernia in females ? A) Femoral hernia B) Spigelian hernia C) Inguinal hernia D) Obturator hernia |
C |
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Question 221:
Dysphagia lusoria is a condition which results from ? A) oesophageal atresia B) aberrant right subclavian artery C) oesophageal web D) corrosive stricture |
B |
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Question 222:
Dumping syndrome can occur after ? A) Billroth II operation B) Heller's operation C) Whipple's disease D) Nissen fundoplication |
A |
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Question 223:
With reference to Le Fort I fracture, consider the following statements:1. Fracture line separates alveolus and palate from the facial skeleton2. Fracture line passes from the pyriform aperture3. Fracture line runs posteriorly to include pterygoid plates4. Fracture line passes through orbitWhich of the statements given above are correct ? A) 1 and 2 only B) 1, 2 and 3 C) 1 and 3 only D) 2, 3 and 4 |
D |
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Question 224:
A four-month-old baby has cleft lip and palate. How would you manage the baby ? A) Immediate repair of the lip B) Immediate repair of the lip and palate C) Delayed repair of the lip and palate until 2 years D) Delayed repair of the lip and palate until pre-school age |
B |
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Question 225:
A man falls astride a penetrating object. He develops retention of urine, perineal hematoma and bleeding from urinary meatus. The nature of injury would be ? A) rupture of membranous urethra B) rupture of bulbar urethra C) intraperitoneal rupture of bladder D) extraperitoneal rupture of bladder |
A |
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Question 226:
Renal carcinoma with solitary lung secondary is best treated by ? A) Radiotherapy B) Surgery C) Chemotherapy D) Immunotherapy |
B |
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Question 227:
Priapism in a young male could occur because of ? A) Testicular cancer B) Carcinoid tumor of appendix C) Leukemia D) Penile cancer |
C |
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Question 228:
Pneumobilia can be seen in ? A) Mirrizi's syndrome B) Acute pancreatitis C) Gallstone ileus D) Carcinoma Gallbladder |
A |
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Question 229:
Treatment with herceptin in breast cancer is indicated for ? A) ER receptor +ve tumors B) PR receptor +ve tumors C) K:67 stain +ve tumors D) Tumors with over expressed C-erb B-2 protein |
D |
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Question 230:
Which of the following does not alter the 'T' stage in breast cancer ? A) Peau d'orange B) Skin ulceration C) Pectoral muscle involvement D) Serratus anterior muscle involvement |
D |
