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50 Cards in this Set
- Front
- Back
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The best treatment of this 80–year–old woman withvomiting retrosternal pain and a looped nasogastric tube in her left chestis:(A)Remove the tube because the patient is now well and discharged.
(B)Evaluate the esophageal myotomy to treat achalasia.Questions: 44–54 87 (C)Immediate left thoracotomy to treat perforation. (D) Consider surgical reductionof volvulus and diaphragmatic repair. (E)Do not consider any surgical repairbecause the patient is too old. |
(D)
Recurrent volvulus of the stomach into the chest is a serious condition that can lead to incar– ceration and gangrene. Every attempt should be made to repair this diaphragmatic hernia. |
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While landing at the end of flight a young woman develops shortness of breath and right– sided pressure chest pain. She is tall and thin. The pain, although less in intensity, occurs during her menstrual periods. She has not pre– viously consulted a doctor. Achest film is likely to show?
(A) Left pleural effusion (B) Pneumothorax (C) Dilated stomach (D) Widening of the mediastinum (E) Cardiomegaly |
(B)
The presentation itself should alert the clini– cian to the possibility of a pneumothorax (Fig 4–3). This condition is seen quite frequently with patients that are thin and tall. This lady presents with a catamenial pneumothorax syndrome.Figure 4–3.Spontaneous pneumothorax on right side. (Reproduced, with permission, from Doherty GM: Current Surgical Diagnosis and Treatment, 12th ed. 349. McGraw–Hill, 2006.) |
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And the treatment is:(A)Insertion of a chest tube(B) Immediate cardiology consult(C) Thoracentesis(D) Insertion of a nasogastric tube(E) A CAT scan
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(A)
This is the first documented pneumothorax on this patient. The treatment of choice is inser– tion of a chest tube. If the air leak persists forAnswers: 40–58 95more than 3 days or if she develops a recur– rence after discharge, a thoracoscopy, resection of bullae and pleurodesis becomes the treat– ment of choice. |
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55. DIRECTIONS (Questions 55 through 58): Each set of matching questions in this section consists of a list of lettered options followed by several num– bered items. For each numbered item, select the appropriate lettered option. Each lettered option may be selected once.(A)Transvalvular gradient of 50 mm or more
(B) History of congestive heart failure (C) Transient ischemic attacks (TIA) (D) Angina (E) Aortic insufficiency (F) Aortic dissection (G) Ventricular fibrillation (H) Mitral insufficiency(I) Acute MI\nA50–year–old man has a systolic heart murmur best heard in the second interspace on the right side. He is increasingly short of breath. Which of the above clinical settings would determine the decision to operate? SELECT ONE. |
(A)
The decision to operate in patients with aortic stenosis is based on transvalvular gradient. 50–mm gradient is termed critical aortic stenosis and the valve should be replaced in a symptomatic patient. |
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DIRECTIONS (Questions 55 through 58): Each set of matching questions in this section consists of a list of lettered options followed by several num– bered items. For each numbered item, select the appropriate lettered option. Each lettered option may be selected once.(A)Transvalvular gradient of 50 mm or more
(B) History of congestive heart failure (C) Transient ischemic attacks (TIA) (D) Angina (E) Aortic insufficiency (F) Aortic dissection (G) Ventricular fibrillation (H) Mitral insufficiency (I) Acute MI\n A68–year–old female with aortic stenosis needs a valve replacement. Which of the above might result in a poor result for this patient? SELECT ONE. |
(B)
Congestive heart failure. In patients with aortic stenosis, risk factors include a history of agina, stroke or TIAs, and a history of conges– tive heart failure, which indicates a compro– mised left ventricle. Of the three, congestive heart failure is the factor which is the greatest risk factor for patients undergoing surgery. |
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DIRECTIONS (Questions 55 through 58): Each set of matching questions in this section consists of a list of lettered options followed by several num– bered items. For each numbered item, select the appropriate lettered option. Each lettered option may be selected once.(A)Transvalvular gradient of 50 mm or more
(B) History of congestive heart failure (C) Transient ischemic attacks (TIA) (D) Angina (E) Aortic insufficiency (F) Aortic dissection (G) Ventricular fibrillation (H) Mitral insufficiency(I) Acute MI\nA 55–year–old man with a diastolic murmur heard in the second interspace on the right that radiates toward the apex of the heart. The cardiac index is normal at rest but decreases with exer– cise. The most likely diagnosis is? SELECT ONE. |
(E)
Aortic insufficiency. This is the murmur of a patient with aortic insufficiency. Typically, these patients will be well compensated at rest but will have decreased cardiac output with exercise. These patients should be operated on. |
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DIRECTIONS (Questions 55 through 58): Each set of matching questions in this section consists of a list of lettered options followed by several num– bered items. For each numbered item, select the appropriate lettered option. Each lettered option may be selected once.(A)Transvalvular gradient of 50 mm or more
(B) History of congestive heart failure (C) Transient ischemic attacks (TIA) (D) Angina (E) Aortic insufficiency (F) Aortic dissection (G) Ventricular fibrillation (H) Mitral insufficiency(I) Acute MI\nA45–year–old tall, thin, male has acute onset of chest pain radiating into the back. In the emer– gency room his right radial pulse is bounding but his femoral pluses are absent. The most likely diagnosis is? SELECT ONE. |
.(F)
Aortic dissection. This describes a patient with Marfan syndrome, who are typically at risk for aortic dissection. With dissection you may preserve right radial pulse but lose femoral pulses. (C) Adenocarcinoma, originated from islands of Barrett’s esophagus, is today the most common cancer of the esophagus in the United States. |
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In acute pancreatitis, surgery is indicated in which one of the following conditions ?
A) Acute fluid collection B) Acute pseudocyst C) Sterile pancreatic necrosis D) Infected pancreatic necrosisAnswer (Select an option above to get the answer):(Single Best Answer) |
D |
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The most common site of skeletal metastases in carcinoma of the breast is ?
A) Pelvis B) Skull C) Lumbar vertebrae D) Thoracic vertebraeAnswer (Select an option above to get the answer):(Single Best Answer) |
C |
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Among the following, which is the investigation of choice for evaluation of common bile duct (CBD) ?A) CECT Abdomen
B) MRCP C) HIDA scan D) UltrasonographyAnswer (Select an option above to get the answer):(Single Best Answer) |
B |
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A 27 year old male presented with a painless, non tender mass in the testis, with raised levels of alpha fetoprotein and beta HCG. The most likely diagnosis is ?
A) Hydrocele B) Varicocele C) Seminoma D) TeratomaAnswer (Select an option above to get the answer):(Single Best Answer) |
D |
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The Pain of Ureteric Colic in females may be referred to ?
A) Clitoris B) Groin C) Labia Majora D) Inguinal RegionAnswer (Select an option above to get the answer):(Single Best Answer) |
C |
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The Subclavian steal syndrome occurs due to ?A) Occlusion / stenosis of the vertebral artery
B) Occlusion / stenosis of the carotid artery C) Occlusion of the subclavian artery proximal to origin of vertebral artery D) Occlusion of the subclavian artery distal to origin of vertebral arteryAnswer (Select an option above to get the answer):(Single Best Answer) |
C |
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Regarding laparoscopic cholecystectomy, which of the following statements is correct ?
A) It is primarily done for cholecystitis in the third trimester of pregnancy B) It is associated with higher rate of bile duct injuries than open cholecystectomy C) It is contraindicated in acute cholecystitis D) It is safer than open cholecystectomy in patients with cardiorespiratory diseaseAnswer (Select an option above to get the answer):(Single Best Answer) |
B |
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Consider the following statements:Branchial cysts:1. are associated with tracks passing between the carotid bifurcation2. usually present in earloccur along the lower one-third of the anteromedial border of the sternocleidomastoid muscle4. develop from the vestigial remnants of the fourth branchail cleftWhich of the statements given above are correct ?
A) 2, 3 and 4 only B) 1, 3 and 4 only C) 1, 2, 3 and 4 D) 1, 2 and 3 onlyAnswer (Select an option above to get the answer):(Single Best Answer) |
B |
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The following statements regarding Meckels diverticulum in adults are true except ?
A) It is a remnant of omphalomesenteric duct B) It usually presents on the antimesenteric border of small intestine C) Bleeding is a common complication D) It should be removed if detected incidentally during an abdominal explorationAnswer (Select an option above to get the answer):(Single Best Answer) |
D |
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The complications of prolonged parenteral hyperalimentation may include the following except ?A) Cholestatic jaundice
B) Hyperphosphataemia C) Hyperosmolar acidosis D) HyperammonaemiaAnswer (Select an option above to get the answer) |
C |
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Carcinoid tumour of the appendix is associated with whatfeatures
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a most are asymptomatic
b tumours less than 2 cm in size require no further therapy other than appendicectomy d carcinoid syndrome arises when hepatic metastases\nhave occurred e synchronous carcinoid tumour in the distal ileum may\nbe present |
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What are appropriate managements for familial\nadenomatous polyposis
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a restorative proctocolectomy and ileoanal pouch anastomosis
b regular surveillance with flexible sigmoidoscopy c enrolment in a familial adenomatous polyposis registry d identification of presymptomatic carrier by molecular genetic testing |
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Tell me about FAP:
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a inheritance is in autosomal dominant fashion
c most affected individuals develop polyps by the age of 10 years d desmoid tumour is an association e all affected patients will develop colorectal carcinomas with time |
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The HNPCC syndrome:
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is linked to hereditary adenomatous polyposis
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Hamartomatous polyposis includes:
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need to find out
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A 72–year–old woman presents with left iliac fossa pain,fever and abdominal distension. Abdominal X–ray reveals two dilated loops of small bowel. The most likely diagnosis is:
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acute diverticulitis
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Diverticular disease of the colon is associated with:
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increased intraluminal pressure within the colon
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Surgical management of perforated diverticular disease with faecal peritonitis includes:
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Hartmann’s procedure and sigmoid end colostomy
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The complications of sigmoid diverticular disease include
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a sigmoid inflammatory phlegmon
b colonic bleeding c purulent peritonitis d colovaginal fistula doesn't cause colon ca |
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Extra–intestinal manifestations of ulcerative colitis include
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a pyoderma gangrenosum
b iritis c sacroileitis d sclerosing cholangitis |
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What features may occur in both ulcerative colitis and Crohn’s disease
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a proctitis
b erythema nodosum c toxic megacolon e response to mesalazine |
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Gimme a fact about Crohn’s disease
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adenocarcinoma of the small bowel is a recognised complication of Crohn’s disease
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Ulcerative colitis:
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toxic megacolon may be the initial manifestation
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Indications for restorative proctocolectomy in ulcerative colitis include:
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a 2–cm villous adenoma in the hepatic flexure of the colon
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Pathological findings in Crohn’s disease of the small bowel include:
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a cobblestone appearance of the bowel arising from fissuring of the mucosa and submucosal oedema
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Peutz–Jeghers syndrome The oncologic outcome of rectal cancer is:
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improved by pre–operative chemotherapy alone, if pre–operative endorectal ultrasound indicates that it is a T3 cancer
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Which of the factors listed below will adversely affect the risk of perioperative cardiac complications and reinfarction in the patient described above?
a. Greater than five premature ventricular beats per minute on EKG rhythm strip b. The anesthetic technique used c. Withdrawal of medical therapy with beta blockers and topical nitrates d. Length of surgical procedure less than three hourse. Known three vessel coronary artery disease |
Answer: a, c, e
The incidence of reinfarction is increased in patients undergoing intrathoracic or intra-abdominal procedures lasting longer than three hours. The site of surgery or anesthetic technique have not been shown to change the incidence of reinfarction if the procedure is less than three hours in duration. Patients with known three-vessel or left main coronary artery disease are at increased risk, while those who have undergone prior coronary artery bypass grafting are of substantially decreased risk of reinfarction. Prophylactic therapy with beta blockers, calcium channel agents, and nitrates has not been proven beneficial; however, withdrawal of these agents has been associated with perioperative ischemia, myocardial infarction, and death. CHF is the single most important factor predicting postoperative cardiac morbidity. Rhythm disturbances, particularly frequent premature ventricular beats, more than five beats/minute, are also independently associated with an increased risk of perioperative cardiac complications. |
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Anesthetic techniques used in the management of patients with significant pulmonary disease include:
a. Intubation at a deep level of anesthesia b. Choice of an anesthetic agent which produces bronchodilatation c. The use of epidural analgesia for postoperative pain control d. Perioperative use of intermittent positive pressure breathing |
Answer: a, b, c
Patients with significant pulmonary diseases require special anesthetic techniques. Obstructive pulmonary disease can either be chronic (COPD) or acute (asthma). In either case, the reversible component of obstruction should be reversed prior to elective surgery. In patients with reactive airway disease, the endotracheal tube may induce severe bronchospasm. Even in patients who are well treated preoperatively, reactive bronchospasm may complicate anesthetic induction and emergence from anesthesia. The principal method used to prevent or diminish this “foreign body” induced bronchospasm is intubation of the patient at a deep level of anesthesia when reflexes are blunted. The classic way of managing a patient with severe asthma is to induce with an agent that produces bronchodilatation and to ventilate the patient with an inhalation agent until deeply anesthetized prior to laryngoscopy and intubation. The patient should be extubated while spontaneously ventilating, but with the inhalation agent still in effect, bringing the patient to consciousness while ventilating by mask.Because of the potential adverse effects of systemic narcotics on respiratory drive, the use of epidural narcotics and local anesthetics for postoperative pain control has become very popular. These techniques allow the patient to be extubated earlier, and patients with intrathoracic and upper abdominal surgery, help restore pulmonary function toward preoperative values. Preoperative use of intermittent positive pressure breathing has not been demonstrated to decrease the incidence of postoperative pulmonary complications. |
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Narcotics are commonly used in the administration of general anesthesia. Which of the following statement(s) is/are true concerning this class of agents.
a. Narcotics have both profound analgesic and amnestic properties b. Narcotics can cause hypotension by direct myocardial depressive effects c. Naloxone should be used routinely for the reversal of narcotic analgesia d. Acutely injured hypovolemic patients are at significant risk for decreased blood pressure with the use of narcotic analgesicse. Propofol is a new intravenous short-acting narcotic used frequently in the outpatient setting |
Answer: d
Narcotics and synthetic analogues belong in the class of drugs called opioids. Narcotics produce profound analgesia and respiratory depression. They have no amnesic properties, no myocardial depressive effects, and no muscle relaxant properties. Narcotics may produce significant hemodynamic effects indirectly through the release of histamine and/or blunting of the patient’s sympathetic vascular tone due to analgesic properties. Acutely injured patients may be hypovolemic and in pain, with high sympathetic tone and peripheral resistance. Therefore, such patients can experience a dramatic drop in systemic blood pressure with minimal doses of opioids. All opioids can be reversed with naloxone. Naloxone reversal, however, can be dangerous because the agent acutely reverses not only the analgesic effects of the opioid but also analgesics effects of native opioids. Naloxone treatment has been associated with acute pulmonary edema and myocardial ischemia and should not be used electively to reverse the effects of narcotic. Propofol is a lipid-soluble substitute isopropyl phenol non-narcotic agent that produces rapid induction of anesthesia followed by awakening in four to eight minutes |
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Patient-controlled analgesia ( PCA) is a commonly used technique for postoperative analgesia. The following statement(s) is/are true for the use of PCA.
a. Satisfactory pain relief is provided by the administration of higher narcotic doses b. The technique is not applicable in the semiconscious or uncooperative patient c. PCA is as safe as conventional intramuscular administration of pain medication d. Excessive administration of narcotic medication can be limited by a lockout duration which controls administration of the narcotic |
Answer: b, c, d
The technique of patient-controlled analgesia is based on investigations that small intravenous bolus doses of narcotic on demand can provide patients with improved pain relief at the same or less total narcotic dose. The system requires some degree of sophistication and a conscious patient who has been instructed in the technique. Numerous studies have demonstrated that PCA is as safe as conventional IM medication. The patient can be restricted from receiving excessive agents via setting a lockout interval duration of several minutes during which time a dose of narcotic cannot be successfully administered. In addition, limits to the total hourly dose can be set. |
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Correct statement(s) concerning complications occurring in the post-anesthetic care unit include which of the following?
a. The use of nitrous oxide has been well documented to increase the incidence of postoperative nausea b. Perioperative myocardial ischemia is usually easily diagnosed in the early postoperative period c. Hypothermia results in a deleterious effect on drug metabolism therefore delaying recovery from anesthesia d. The serotonin antagonist, odansetron, holds promise as the superior antiemetic agent in the perioperative period |
Answer: c, d
Twenty-four percent of patients experience a post-anesthetic care unit complication. Nausea, vomiting and airway support comprise 70% of these complications. The need to maintain airway support is by far the most common respiratory complication. Hypothermia has a deleterious effect on altering drug metabolism and delaying recovery. Nausea and vomiting are rarely unifactorial and cause considerable discomfort to the patient. There is little evidence to favor one anesthetic or anesthetic technique over another. Nitrous oxide does not appear to increase incidence of nausea in well documented studies. The new serotonin antagonist, odansetron, has been shown in several studies to be superior to other agents as a perioperative antiemetic agent.Perioperative myocardial ischemia is an extremely important complication but difficult to recognize. Diagnosis is complicated by the fact that only 10—30% of patients suffering documented myocardial infarction will have pain and that postoperative EKG changes are often nonspecific. One must therefore look for secondary indications of on-going ischemia such as hypotension, arrhythmias, elevated filling pressures, or postoperative oliguria. |
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Over the last decade, the routine use of both invasive and noninvasive monitoring devices has been instituted for the administration of most anesthetics. The following statement(s) is/are true concerning monitoring of the surgical patient.
a. A pulse oximeter reading will reflect changes in PaO2 only below 80 mm Hg b. Monitoring of end tidal CO2 will reflect changes in ventilation but not cardiac output c. Intermittent, noninvasive systemic blood pressure monitoring using an oscillometric blood pressure cuff has essentially replaced clinical measurement by auscultation d. Pulmonary arterial catheter monitoring is generally reserved for critically ill patients with significant left ventricular dysfunction |
Answer: a, c, d
Pulse oximetry continuously, noninvasively and inexpensively provides arterial hemoglobin saturation and peripheral pulse determination. It must be remembered, however, that a pulse oximeter measures oxygen saturation and not arterial oxygen tension (PaO2). The PaO2 must drop below 80 mm Hg before any significant change in oxygen saturation will occur. End tidal CO2 monitoring reflects metabolism (the production of CO2), circulation (blood flow to the lungs), and ventilation (respiratory rate in an intact ventilatory circuit). It can be used as a surveillance monitor for both the respiratory circuit and the cardiovascular system. Any acute decrease in cardiac output will decrease output to the lung and increase alveolar dead space, causing an acute drop in end tidal CO2.Hemodynamic stability can be monitored in a variety of methods, the most basic of which is systemic arterial blood pressure measure. Intermittent, noninvasive measure of systemic blood pressure with an oscillometric blood pressure cuff has become the standard in the operating room with an accuracy equal to that of clinical measurement by auscultation. When tighter control is required in patients with significant hypertension, serious heart disease, or in patients who may suffer acute blood loss, invasive arterial monitoring is employed. In patients with left ventricular dysfunction who are undergoing extended surgical procedures with significant fluid shifts and potential blood loss, central venous pressure monitoring is frequently used, with pulmonary arterial catheter monitoring reserved for more critically ill patients and for those with significant left ventricular dysfunction |
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General anesthesia is not without risks. Which of the following statement(s) is/are true concerning the risk associated with general anesthesia.
a. Current estimates for mortality due to anesthesia alone are 1:10,000 b. Human error accounts for between 50 and 75% of anesthetic-related deaths c. Most anesthetic-related deaths are associated with overdose of analgesic agents d. The most common problems associated with adverse anesthetic outcomes are related to the airway |
Answer: b, d
Anesthetic agents effectively obtund or completely block nearly all physiologic protective mechanisms, therefore, there is an associated risk even without a surgical procedure. Fortunately, with the advent of newer agents and monitoring techniques, it is estimated the mortality due to anesthesia alone has decreased from approximately 1:10,000 in the 1950s to as low as 1:100,000 or less for healthy patients today. It has been estimated that between 50–75% of anesthetic-related deaths are due to human error and are preventable. The most common problems associated with adverse outcomes are related to the airway: inadequate ventilation, unrecognized esophageal intubation, unrecognized extubation, and unrecognized disconnection from the ventilator. |
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A 65-year-old gentleman with a history of coronary artery disease and a recent myocardial infarction requires an elective colon resection for a nonobstructing neoplasm. Which of the following statement(s) is/are true concerning the risks of general anesthetic in this patient?
a. The age of the previous infarct has no effect on the perioperative reinfarction risk b. The incidence of reinfarction appears to stabilize after six months c. Invasive hemodynamic monitoring has no effect on perioperative reinfarction rates d. Reinfarction has minimal effect on mortalitye. Perioperative infarction most frequently occurs after the first 72 hours from surgery |
Answer: b, d
The history of myocardial infarction is an important risk factor for general anesthesia. Large retrospective studies have found that the incidence of reinfarction is related to the time elapsed since the previous myocardial infarction. The incidence of reinfarction appears to stabilize at approximately 1% after six months, with the highest rate of reinfarction occurring in the first three months after the infarct. Mortality from reinfarction, for patients undergoing non-cardiac surgery, has been reported to be between 20–50% and usually occurs within the first 48 hours after surgery. Invasive hemodynamic monitoring with pulmonary artery catheters and aggressive pharmacologic intervention has been demonstrated to reduce reinfarction rates. |
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Local anesthetics are essential agents used in current surgical practice. Which of the following statement(s) is/are true concerning the use of local anesthetic agents.
a. Complications due to excessive plasma concentration can result only from inadvertent intravascular injection of the agent b. Bupivacaine is noted for a slow onset but long duration c. The addition of epinephrine to a local anesthetic agent will both lower the toxicity and increase the duration of local anesthesia d. Hypotension observed when a local anesthetic is administered in the form of a spinal epidural block, is the result of myocardial depression |
Answer: b, c
Local anesthetics constitute a class of drugs which produce temporary blockage of nerve conduction by binding to neuronal sodium channels. Adverse consequences associated with the use of local anesthetics fall into three categories: acute central nervous system toxicity due to excessive plasma concentration, hemodynamic and respiratory consequences due to excessive conduction block of the sympathetic or motor nerves, and allergic reactions. Whenever a local anesthetic has been injected, there may be inadvertent intravascular injection or an overdose of the drug due to rapid uptake from the tissues. All may produce seizures. Complications can be minimized by aspirating prior to injection to avoid intravascular injection and limiting the doses to the safe range. When local anesthetics are administered for a spinal or epidural block, there will be a progressive blockade of the sympathetic nervous system which will produce systemic vasodilatation. If the block travels along the thoracolumbar region, a sympathetic blockade will result in profound systemic vasodilatation and bradycardia with resultant hypotension.Local anesthetics are divided into two groups: esters and amides. Most commonly used agents, the amides, include lidocaine and bupivacaine. Lidocaine is noted for a fast onset of action but a short duration whereas bupivacaine has a slower onset with the duration lasting for four to 12 hours. The addition of epinephrine (100 µg) will lower the toxicity and increase the duration of the local anesthetic. |
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Muscle relaxants are a class of anesthetic agents used to prevent movement and facilitate surgical exposure. Which of the following statement(s) is/are true concerning the use of muscle relaxants in surgical procedures.
a. Succinylcholine produces rapid obvious muscle fasciculations b. Pancuronium can be reversed by increasing the acetylcholine concentration using an anticholinesterase inhibitor (neostigmine) c. Prolonged periods of muscle relaxation in patients requiring prolonged ventilation should be used in conjunction with analgesics and amnesic agents d. The best clinical test for complete reversal of neuromuscular blockad e is the ability of the patient to produce a large negative inspiratory force |
Answer: a, b, c
Neuromuscular blocking agents can be classified as depolarizing or nondepolarizing inhibitors of the neurotransmitter, acetylcholine at the neuromuscular junction. The only noncompetitive inhibitor employed clinically is succinylcholine. This drug rapidly binds to the neuromuscular junction and produces depolarization, clinically obvious as fine muscle fasciculations occurring approximately 60 seconds after injection. All other clinically useful muscle relaxants are termed competitive inhibitors and do cause depolarization when they attach to the neuromuscular junction. Since these agents compete with acetylcholine, the block produced is in direct proportion to the concentration of the agent relative to the concentration of acetylcholine. If the concentration ratio is low enough, competitive relaxants can be “reversed” if the concentration of acetylcholine is artificially elevated. Increase of acetylcholine concentration can be achieved by giving a drug which blocks metabolism of anticholinesterase (neostigmine).Nondepolarizing relaxants are frequently used in critically ill patients who are difficult to manage otherwise during prolonged periods of mechanical ventilation. It is imperative that these drugs be given in conjunction with analgesics and amnesic agents, since neuromuscular blocking agents have no analgesic or amnestic properties and only prevent motion of voluntary muscles. Patients may therefore be totally aware and in pain and unable to communicate. All muscles of the body do not have equal sensitivity in muscle relaxants. The diaphragm is both resistant to neuromuscular blockade while the neck and pharyngeal muscles that support the airway are most sensitive. It is possible for an intubated patient to spontaneously ventilate and even to produce a large negative inspiratory force and yet have complete airway obstruction when extubated due to effects of residual muscle relaxants on upper airway muscles. The definitive clinical test for complete reversal of neuromuscular blockade is the ability of the patient to sustain a head lift from the bed for five seconds. |
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Which of the following statement(s) is/are true concerning alterations in serum magnesium?
a. Renal failure is the primary cause of hypermagnesemia b. Hypomagnesemia may occur during prolonged periods of intravenous fluid replacement c. Symptoms of hypomagnesemia may mimic symptoms of hypocalcemia d. Intravenous administration of magnesium sulfate is usually the most efficient method of correction of magnesium deficiency |
Answer: a, b, c, d
Renal failure is the primary cause of hypermagnesemia. Because of the kidneys ability to excrete large magnesium loads, hypermagnesemia rarely occurs if renal function remains normal. Because the kidneys are able to conserve magnesium well in states of magnesium depletion, hypomagnesemia rarely occurs from poor intake alone. The combination of low intake and increased gastrointestinal loss may lead to hypomagnesemia. Prolonged periods of intravenous fluid replacement without magnesium replacement and the chronic use of loop diuretics or other medications such as cyclosporine or aminoglycosides can also result in hypomagnesemia. Deficiencies of magnesium may present signs and symptoms similar to hypocalcemia. Hypomagnesemia may be treated by the oral administration of magnesium however large doses frequently leads to diarrhea. Correction of major deficits is therefore best managed by intravenous administration of magnesium sulfate at a dose of 50 to 100 mEq/d. |
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Which of the following statement(s) is/are true concerning respiratory alkalosis?
a. Exposure to high altitudes can result in respiratory alkalosis b. Renal compensation for respiratory alkalosis is obtained by increasing excretion of bicarbonate c. Symptoms of respiratory alkalosis may mimic those of hypocalcemia d. The treatment of acute respiratory alkalosis may involve a brown paper bag |
Answer: a, c, d
A primary decrease in PCO2 resulting in an increase extracellular pH is referred to as respiratory alkalosis. Hyperventilation and the ensuing fall in PCO2 may be secondary to hypoxia, reflux simulation from decreased pulmonary compliance, drugs, mechanical ventilation, and other causes. The two most common causes of hypoxia resulting in respiratory alkalosis are pulmonary disease and exposure to high altitudes. Renal compensation for respiratory alkalosis is not achieved by increasing excretion of bicarbonate but by decreasing net acid excretion, primarily through the reduction in ammonia excretion and increases in organic anion excretion. Chronic respiratory alkalosis is generally asymptomatic. Acute respiratory alkalosis may cause sensations of breathlessness, dizziness, and nervousness and can result in circumoral and extremity parathesias, altered levels of consciousness, and tetany. These signs are related to decreased cerebral blood flow secondary to decreased PCO2 and decreased ionized calcium concentration secondary to increased blood pH. In acute symptomatic respiratory alkalosis rebreathing, by breathing in and out of a paper bag, can temporarily relieve the symptoms. |
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Clinical manifestations of acute metabolic acidosis include:
a. Decreased cardiac contractility b. Decreased catecholamine secretion c. Peripheral arteriolar dilitation d. Shift of the oxygen-hemoglobin disassociation curve to the left |
Answer: a, b, c
The major cardiovascular effects of acute metabolic acidosis are peripheral arteriolar dilitation, decreased cardiac contractility, and central venous constriction. These may lead to cardiovascular collapse and pulmonary edema. Catecholamine secretion is stimulated by metabolic acidosis and in mild cases, heart rate may be increased. In addition to these cardiovascular effects, metabolic acidosis may also affect oxygen delivery by shifting the oxygen-hemoglobin disassociation curve to the right. |
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An 11-year-old boy has experienced severe diarrhea for 10 days. He presents with decreased skin tungor, sunken eyes, orthostatic hypotension, and tachycardia. Which of the following statement(s) may be true concerning his diagnosis and treatment?
a. His hematocrit will likely be elevated b. His BUN may be elevated out of proportion to serum creatinine c. His serum sodium will be elevated d. Fluid resuscitation should begin with D5/.2 normal saline because of the expected high serum sodium associated with excessive fluid loss |
Answer: a, b
Chronic volume deficits may be manifested by decreased skin turgor, weight loss, sunken eyes, hypothermia, oliguria, orthostatic hypotension and tachycardia. Serum BUN and creatinine may be elevated, with a high BUN/creatinine ratio. The hematocrit may be elevated as well. Plasma sodium is not an indicator of intravascular volume, and if the loses have been isotonic, plasma sodium concentration remains normal. Fluid resuscitation for hypovolemia is initiated with an isotonic solution such as lactated Ringer’s solution. Urine flow in critically ill patients is monitored with an indwelling Foley catheter, with the goal of a urine output 0.5mL/kg/h desirable. |
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Which of the following statement(s) is/are true concerning parenternal electrolyte solutions? a. Lactated Ringer’s solution contains physiologic concentrations of all important electrolytes b. Glucose is added to hypotonic saline solutions to increase their tonicity c. About 1/2 of all exogenously administered albumin ends up in the extravascular space d. Normal saline solution provides excessive sodium and chloride which may lead to body sodium overload |
Answer: b, c, d
A number of electrolytes solutions are available for parenteral administration. Lactated Ringer’s solution is a physiologic solution containing many of the electrolytes found in plasma. The disadvantage of this solution is the relatively low sodium content (130 mEq/L) as compared to plasma. Hyponatremia can occur with extended use of lactated Ringer’s solution. Isotonic saline (0.9% or normal saline) contains 154 mEq of both sodium and chloride. The excess of both sodium and chloride can lead to electrolyte and acid-base disturbances. Infusion of large volumes of 0.9% saline can lead to total body sodium overload and hyperchloremia. The less-concentrated saline solutions are hypo-osmotic and have excess free water. In addition, 0.2% saline solution is hypotonic with respect to plasma and can result in red blood cell lysis if rapidly infused. For this reason, 5% dextrose is added to these solutions to increase the tonicity. Plasma expanders are commonly used in surgical patients. Plasma protein solutions such as 5% and 25% albumin act initially by increasing plasma oncotic pressures. Abnormalities in microvascular permeability such as those found in the pulmonary circulation in adult respiratory distress syndrome, in regional circulatory bed burns or infections, and in the systemic circulation in sepsis, may result in extravasation of these proteins into the interstitial space. About half of all exogenously administered albumin eventually ends up in the extravascular space. The half life of exogenously administered albumin is about 11 days. |
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Which of the following statement(s) is/are true concerning the postoperative fluid management in a surgical patient?
a. Standard formulas are available that essentially can direct the therapy for all patients b. Isotonic solutions containing potassium should be used throughout the entire postoperative period c. Urine output should be maintained at a level greater than 0.5 ml/kg/h d. A urine specific gravity of greater than 1.012 may indicate that the patient is dehydrated |
Answer: c, d
Fluid therapy during the postoperative period should be tailored to each patient and depends on the adequacy of patient’s volume status at the completion of the operative procedure, as well as ongoing fluid losses. Maintenance fluid should be supplemented by replacement of the additional fluids needed to replace the ongoing third space loss as well as losses from various tubes and drains. In general, isotonic solution should be used for volume resuscitation during the early postoperative period. It is best not to give potassium supplements during this period unless they are specifically required as indicated by serum electrolyte measurements. Monitoring fluid status during the postoperative period is best accomplished by careful monitoring of vital signs, urine output, and central venous pressure, if necessary. Urine output is maintained at a level greater than 0.5 mL/kg/h. A urine specific gravity of greater than 1.010 to 1.012 indicates that urine is being concentrated and the patient may not be receiving adequate hydration. |
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Which of the following statement(s) is/are true concern renal tubular acidosis?a. Renal tubular acidosis is primarily caused by reduction in ammonia excretionb. The renal tubular defect in renal tubular acidosis can either be at the distal or proximal renal tubulec. In distal renal tubular acidosis associated with hyperkalemia, the defect involves increased tubular permeability with backleak of secreted sodium and potassium into the tubular celld. Uremic acidosis occurs independently of protein intake
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Answer: a, b
The impaired ability of the kidney to excrete acid and hence generate bicarbonate may be secondary to a decrease in the number of functioning nephrons and is termed uremic acidosis or renal tubular acidosis. Renal tubular acidosis, which can occur both in acute and chronic renal failure, is primarily caused by reduction in ammonia excretion secondary to a reduction in the number of functioning proximal tubular cells. In addition, decreased proximal tubular bicarbonate reabsorption contributes to the development of acidosis. Although the onset of uremic acidosis is related to declining renal function, its appearance may be influenced by diet-dependent protein and organic anion ingestion. Renal tubular acidosis may be classified as distal or proximal, depending on the primary site of the renal tubular defect leading to acidosis. In renal tubular acidosis with hyperkalemia, the mechanism is decreased luminal negativity secondary to impaired sodium reabsorption. In distal renal tubular acidosis with hypokalemia, mechanisms including increased tubular permeability with backleak of secreted H+ into the tubular cell and reduced H+ pump activity are proposed mechanisms. |
