Rescue therapies in Thyroid storm

Q: All of the following has been used or suggested to have beneficial effects in the management of Thyroid storm except?

A) Plasmapheresis 
B) Lithium 
C) Cholestyramine 
D) Glucocorticoids 
E) Aspirin


Answer: E

The objective of the above question is to highlight the possible role of plasmapheresis and lithium in the management of thyroid storm as adjuvant use of steroid and cholestyramine are relatively known in this disease.

Also, it is universally known to stay away from aspirin in thyroid storm as it releases thyroxine from protein binding sites.

Plasmapheresis is particularly useful if a thyroid storm is caused by a drug overdose but it can be attempted as a last-ditch therapy. Plasmapheresis is suggested in thyroid storm as theoretically can remove cytokines, antibodies, and thyroid hormones from plasma. 1

Lithium can acutely block the release of thyroid hormone, and this side effect of lithium can be utilized in a thyroid storm. 2

#endocrine



References:

1. Muller C, Perrin P, Faller B, et al. Role of plasma exchange in the thyroid storm. Ther Apher Dial 2011; 15:522.

2. Carroll R, Matfin G. Endocrine and metabolic emergencies: thyroid storm. Ther Adv Endocrinol Metab. 2010;1(3):139-45.

Hypokalemia and hepatic encephalopathy

Q: How diuresis can directly contribute to hepatic encephalopathy in liver cirrhosis patients?



Answer: Diuresis lead to hypokalemia and contraction alkalosis.

1. Hypokalemia increases renal ammonia synthesis

2. Alkalemia increases the conversion of charged ammonium (NH4+) to unionized ammonia (NH3). Unionized ammonia can readily penetrate neurons and can deteriorate hepatic encephalopathy

#hepatology
#electrolytes


References:

Gabduzda GJ, Hall PW 3rd. Relation of potassium depletion to renal ammonium metabolism and hepatic coma. Medicine (Baltimore) 1966; 45:481.

'Massive' GI bleed

Q: How the "massive" upper or lower gastrointestinal (UGI/LGI) bleed is defined? 


 Answer: Unlike hemoptysis, it is hard to quantify the GI bleed. UGI or LGI bleed is considered 'massive' if requires transfusion of 4 units of blood or more in 24 hours period. Other definitions described are hemodynamic instability with systolic blood pressure (SBP) less than 90 mmHg, and the initial decrease in hematocrit of 6 g/dL or less.

#gastroenterology 




References:

1. Millward SF. ACR Appropriateness Criteria on treatment of acute nonvariceal gastrointestinal tract bleeding. J Am Coll Radiol 2008; 5:550. 

2. Zuccaro G Jr. Management of the adult patient with acute lower gastrointestinal bleeding. American College of Gastroenterology. Practice Parameters Committee. Am J Gastroenterol 1998; 93:1202.

Physical exam & stenosis of AV-Graft

Q: Which part of the hand is best to examine the "thrill" of an Arterio-venous graft (AVG) in hemodialysis (HD) patient?


Answer: Palm

A patent arteriovenous graft for HD patients should have a considerable thrill, which is best palpable with the palm. Although thrill should have both a systolic and a diastolic component, that's often hard to distinguish. It usually feels like a "soft, continuous, diffuse thrill." 

It is more pronounced near the arterial anastomosis, but in case, if it feels more accentuated at any other place of the course of the graft, it raises the possibility of stenosis.

#physicalexam
#nephrology



References: 

1.  Beathard GA. Physical examination of the dialysis vascular access. Semin Dial 1998; 11:231.

2. Leon C, Orozco-Vargas LC, Krishnamurthy G, et al. Accuracy of physical examination in the detection of arteriovenous graft stenosis. Semin Dial 2008; 21:85.

BNP in obese patients

Q: B-type natriuretic peptide (BNP) in obese patients tend to be? (select one)

A) Lower than non-obese patients 
B) higher than non-obese patients


Answer: A

Obese patients tend to have lower plasma BNP level than patients with normal Body Mass Index (BMI). Despite various studies the exact reason behind this disparity is not known.

Clinical significance: It may deceive a clinician with severity of heart failure.

#cardiology
#laboratory-medicine


References:

1. Das SR, Drazner MH, Dries DL, et al. Impact of body mass and body composition on circulating levels of natriuretic peptides: results from the Dallas Heart Study. Circulation 2005; 112:2163.

2. Mehra MR, Uber PA, Park MH, et al. Obesity and suppressed B-type natriuretic peptide levels in heart failure. J Am Coll Cardiol 2004; 43:1590. 

3. Wang TJ, Larson MG, Levy D, et al. Impact of obesity on plasma natriuretic peptide levels. Circulation 2004; 109:594. 

4. McCord J, Mundy BJ, Hudson MP, et al. Relationship between obesity and B-type natriuretic peptide levels. Arch Intern Med 2004; 164:2247. 

5. Horwich TB, Hamilton MA, Fonarow GC. B-type natriuretic peptide levels in obese patients with advanced heart failure. J Am Coll Cardiol 2006; 47:85. 

Dengue virus vaccination

Q; 53 years old male is recovering in ICU from severe dengue virus infection after his trip to Columbia. He asked for possible vaccination against Dengue virus (DENV). Infection from Dengue virus automatically provide lifelong immunity against it and doesn't require protection, and should only be administrated to people with no history or laboratory evidence of the previous infection.

A) True
B) False


Answer: B

Contrary to expectations, administration of Dengue vaccine to people without any previous exposure can do more harm than benefit. But it should be administrated to people with previous experience of DENV, as the chances of severity go up in the second infection.

Treatment is mostly preventive, and if acquired, supportive with fluid resuscitation. 


#infectiousdiseases


References:

http://www.who.int/immunization/diseases/dengue/q_and_a_dengue_vaccine_dengvaxia/en/ (World Health Organization)

On Plateau Pressure

Q: The plateau pressure (Pplat) on the ventilator should be measured with a pause at? (select one) 

A) end-inspiration 
B) end-expiration 


 Answer: A

Pplat is the reflection of static compliance of the whole respiratory system taking into account of lung parenchyma, chest wall, as well as an abdominal effect on respiratory mechanics, so the Pplat is measured while there is no airflow.

Knowing that Pplat should be measured at pause and at end-inspiration.

#pulmonary
#ventilators


References:

1. Stenqvist O. Practical assessment of respiratory mechanics. Br J Anaesth 2003; 91:92. 

2. Tobin MJ. Respiratory monitoring. JAMA 1990; 264:244. 

3. Marini, JJ. Lung mechanics determinations at the bedside: instrumentation and clinical applications. Respir Care 1990; 35:669.

eosinophilia in severe trichinellosis

Q: Absence of eosinophilia in severe trichinellosis is a? (select one) 

A) Good sign 
B) Bad sign 


 Answer: B 

 Massive eosinophilia which may go up to 90% of leucocytosis is a hallmark of clinical trichinellosis. It starts during the second week of the muscle stage and peaked at the third or fourth week. Said that there is no correlation between the clinical course of the disease and the severity of eosinophilia. Disappearance or absence of eosinophilia in severe clinical trichinellosis is actually a poor prognostic sign.

#infectiousdiseases
#laboratory-medicine



References:

1. Kociecka W. Trichinellosis: human disease, diagnosis and treatment. Vet Parasitol 2000; 93:365.

2. Vu Thi N, Trung DD, Litzroth A, et al. The hidden burden of trichinellosis in Vietnam: a postoutbreak epidemiological study. Biomed Res Int 2013; 2013:149890.

Colorimetric capnography in NGT placement

Q: Colorimetric capnography is a reliable method to identify misplacement of nasogastric tube (NGT) position in mechanically ventilated patients? 

A) Yes 
B) No 


Answer: A 

Although not frequently used for this purpose, a  meta-analysis of five studies showed a colorimetric capnography to have a sensitivity of 88 to 100 percent and a specificity of 99 to 100 percent to identify misplacement of the nasogastric tube into the airway in mechanically ventilated patients.

#nutrition
#procedure
#pulmonary


Reference:

Bennetzen LV, Håkonsen SJ, Svenningsen H, Larsen P. Diagnostic accuracy of methods used to verify nasogastric tube position in mechanically ventilated adult patients: a systematic review. JBI Database System Rev Implement Rep 2015; 13:188.

Horner Syndrome

Q: Horner Syndrome associated with Arm pain, hand weakness (typical of brachial plexus type lesions) suggest lesion at? 

 A) brainstem 
 B) cervicothoracic cord 
C) lung apex 
D) cavernous sinus 
E) internal carotid dissection


Answer: C

The classic triangle of Horner syndrome is

• ptosis
• miosis
• anhidrosis

Although in about 40 percent of cases no reason can be identified, it can be a manifestation of a serious underlying lesion/disease. Associated features help in locating the lesion site.

•  Brainstem lesion is marked by diplopia, vertigo, ataxia, and lateralized weakness
•  Lesion in cervicothoracic cord gives myelopathic features like bilateral or ipsilateral weakness, long tract signs, and bowel and bladder impairment 
•  Lesions in the apex of the lung is associated with arm pain and/or hand weakness typical of brachial plexus lesions 
•  Lesion in cavernous sinus gives Ipsilateral extraocular pareses, particularly a sixth nerve palsy, in the absence of other brainstem signs 
•  An isolated Horner syndrome accompanied by neck or head pain is probably due to internal carotid dissection

#physicalexam
#neurology

Reference:

Maloney WF, Younge BR, Moyer NJ. Evaluation of the causes and accuracy of pharmacologic localization in Horner's syndrome. Am J Ophthalmol 1980; 90:394.

Definition of neutropenic fever

Q: What is the definition of fever in neutropenic patients per the Infectious Diseases Society of America? 


 Answer: The Infectious Diseases Society of America defines fever in neutropenic patients as either

• a single oral temperature of 101°F, or 
• a temperature of 100.4°F sustained over 60 minutes

#infectiousdiseases



Reference:

Freifeld AG, Bow EJ, Sepkowitz KA, et al. Clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer: 2010 update by the infectious diseases society of america. Clin Infect Dis 2011; 52:e56.

Obstetrics Critical Illnesses

Q: All of the following favors the diagnosis of preeclampsia except?

A) Severe elevation of LDH
B) significant hypertension 
C) severe liver dysfunction 
D) severe elevation of AST 
E) illness after a gestation age of 20 weeks


Answer: A

In obstetric emergencies sometimes it is difficult to recognize the difference between look-alike clinical conditions. But few features are pathognomic to certain conditions.

Thrombotic thrombocytopenic purpura (TTP) is technically defined by a less than 10% activity of ADAMTS13 (but the test may take few weeks to be available). Similarly, hemolytic uremic syndrome (HUS) is dominant by a clinical feature of acute renal failure. 

One of the major differentiation between preeclampsia and TTP/HUS can be done on the basis of two relatively simple laboratory tests i.e. Lactate Dehydrogenase (LDH) and aminotransferase (AST). LDH is usually severely elevated in TTP/HUS while the severe elevation of AST is the feature of preeclampsia.

#obstetrics
#hepatology  



References: 

1.  Fyfe-Brown A, Clarke G, Nerenberg K, et al. Management of pregnancy-associated thrombotic thrombocytopenia purpura. AJP Rep 2013; 3:45. 

2. Allford SL, Hunt BJ, Rose P, et al. Guidelines on the diagnosis and management of the thrombotic microangiopathic haemolytic anaemias. Br J Haematol 2003; 120:556.

2 other essentials of CVA

Q: All of the following should be confirmed prior to administration of alteplase in acute stroke except? 

 A) The time window is met 
B) Eligibility criteria is fulfilled 
 C) Hypoglycemia is ruled out 
D) Two intravenous lines, preferably 2 large bores, are placed 
E) Ideal body weight is measured


 Answer: E 

 Besides all the 'checklist' marked for the administration of alteplase, there are two other essentials that should be checked 

 1) A dedicated intravenous line is required for alteplase. 
 2) The dose should be calculated of actual body weight. 

 The dose of alteplase dose is 0.9 mg/kg, with a maximum dose of 90 mg, 10% of which is given as an upfront bolus and the remainder is infused over next hour. 

 #neurology
 #pharmacology 


 Reference: 

 Michaels AD, Spinler SA, Leeper B, et al. Medication errors in acute cardiovascular and stroke patients: a scientific statement from the American Heart Association. Circulation 2010; 121:1664.

"Dig effect on EKG"

Q: Describe the effects of Digoxin on EKG? 

Answer: Following could be the EKG effects secondary to Digoxin, popularly known as "Dig. effect". One or more may be present. 

• ST depression with a characteristic “sagging” appearance 
• Flattened, inverted, or biphasic T waves. 
• Shortened QT interval 
• Mild PR interval prolongation of up to 240 ms
• Prominent U waves 
• Peaking of the terminal portion of the T waves 
• J point depression

#cardiology

Reference:

Heather Wetherell. Digoxin and the heart. August 2015. Br J Cardiol 2015;22:96–7

Murmur of Aortic Dissection

Q:  Murmur of acute aortic dissection can be best heard at? (select one)

A) right sternal border 
B) left sternal border 


 Answer: A

The objective of the above question is to bring into light the 'location difference' of aortic regurgitation murmur secondary to aortic dissection and primary aortic valve disease. 

•  The murmur of aortic regurgitation due to the aortic dissection is best audible along the right sternal border 
• The murmur of aortic regurgitation due to the primary aortic valve disease is best audible along the left sternal border 

 Other clinical signs help to distinguish between the two clinical conditions, as the presentation of acute aortic dissection is relatively dramatic associated with acute sharp tearing chest pain often radiating to back, a wide pulse pressure, hypotension, possible pulse deficit, and neurological symptoms.

#cardiology
#surgicalcriticalcare


References: 

1. Nienaber CA, Eagle KA. Aortic dissection: new frontiers in diagnosis and management: Part I: from etiology to diagnostic strategies. Circulation 2003; 108:628. 

2. Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA 2000; 283:897.

ACE inhibitors or ARBs as an adjuvant Rx for atrial fibrillation

Q: ACE inhibitors or angiotensin receptor blockers (ARBs) have been used as an adjuvant treatment to prevent new onset and recurrent atrial fibrillation (AF)? How these drugs directly help in the treatment of AF? 


 Answer: By preventing the formation of atrial fibrosis 

Fibrosis in the atrial myocardium is one of a component of the substrate necessary for AF. Atrial fibrosis is stimulated by angiotensin-II. ACE inhibitors and angiotensin receptor blockers reduce the effect of angiotensin-II.

#cardiology


Reference: 

1. McEwan PE, Gray GA, Sherry L, et al. Differential effects of angiotensin II on cardiac cell proliferation and intramyocardial perivascular fibrosis in vivo. Circulation 1998; 98:2765. 

target plateau airway pressure on ventilator with ECMO

Q: What should be the target plateau airway pressure on ventilator settings once Extra-Corporeal Membrane Oxygenation (ECMO) is initiated in Acute Respiratory Distress Syndrome (ARDS) patient? 


 Answer: Ideally less than 20 cm H2O but at least should be less than 30 cm H2O 

 The primary goal of Extra-Corporeal Membrane Oxygenation (ECMO) in Acute Respiratory Distress Syndrome (ARDS) is to minimize the burden on lung via minimizing (as much as possible) the barotrauma and volutrauma. The best target to keep check of stress on lungs is to keep plateau airway pressure less than 20 cm H2O.

#ARDS
#ECMO
#Pulmonary


Reference: 

Zhang Z, Gu WJ, Chen K, Ni H. Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure. Can Respir J. 2017;2017:1783857.

Heart in ARDS

Q: During prone positioning of patients in Acute Respiratory Distress Syndrome (ARDS), the compression of heart on lungs? (select one)

A) Increases
B) Decreases


Answer:  B

Although well known since last two decades but rarely mentioned is one of the accessories but significant advantage of prone positioning in ARDS via decreased compression of heart on both the lungs. During the prone positioning, heart shifts its dependence from the posterior and medial aspects of lungs to the sternum providing more physiologic space for lungs to expand.

#pulmonary
#ARDS


Reference:

Agostoni E, Mead J. Statics of the respiratory system. In: Handbook of Physiology, Macklem P, Mead J (Eds), American Physiologic Society, Bethesda 1986. p.387.

Hemodialysis and Priapism

Case: 23 year old male is admitted to ICU after his hemodialysis session for extremely painful priapism.

Answer; Priapism is a rare and almost unheard complication of hemodialysis. Although exact pathophysiology is not known, the proposed mechanisms include epoetin alfa administration resulting in high hemoglobin levels and possibly heparin effect as anticoagulants have been known to cause priapism.

Other less known causes of priapism include spinal shock, antidepressants, malaria, spider toxins, total parenteral nutrition, and amyloidosis.

#nephrology
#vasculardiseases


Reference: 

Shih WV, Wong C.- Priapism and hemodialysis: Case report and literature review. Clin Nephrol. 2018 Jul;90(1):64-70. doi: 10.5414/CN109416.

Bouveret syndrome

Q: 43 year old female is admitted to ICU via ED with severe epigastric pain associated with nausea and vomiting. On CT scan radiologist suspected Bouveret syndrome. What is Bouveret syndrome?


Answer: Bouveret syndrome is named after a nineteenth-century French physician Léon Bouveret.  It is a gastric outlet obstruction (GOO) due to impaction of a gallstone in the pylorus or proximal duodenum. This is a very proximal form of gallstone ileus. Endoscopic removal may be attempted before surgical intervention. 

#surgicalcriticalcare
#gastroenterology


References:

1. Singh AK, Shirkhoda A, Lal N et-al. Bouveret's syndrome: appearance on CT and upper gastrointestinal radiography before and after stone obturation. AJR Am J Roentgenol. 2003;181 (3): 828-30.

2. Nabais C, Salústio R, Morujão I et-al. Gastric outlet obstruction in a patient with Bouveret's syndrome: a case report. BMC Res Notes. 2013;6 (1): 195. 

3. Guilherme P. Ramos, M.D., and Nian-En Chiang, M.D., Bouveret’s Syndrome, April 5, 2018, N Engl J Med 2018; 378:1335

"Crushed ping pong balls"

Q: "Crushed ping pong balls" reminds you of which disease? 


Answer: PCP (Pneumocystis pneumonia)

 The diagnosis of PCP can be definitively confirmed by histological identification of the causative organism in sputum or bronchio-alveolar lavage (BAL). Special staining will show the characteristic cysts. The cysts resemble crushed ping-pong balls and are present in aggregates of 2 to 8. In contrast, Histoplasma or Cryptococcus, typically do not form aggregates of spores or cells.

 #infectiousdiseases
#pulmonary



 Reference:

 Jeong Hyeon Lee, Ji Young Lee, Mi Ran Shin, Hyeong Kee Ahn, Chul Whan Kim, Insun Kim - Immunohistochemical Identification of Pneumocystis jirovecii in Liquid-based Cytology of Bronchoalveolar Lavage - Nine Cases Report -, The Korean Journal of Pathology 2011; 45: 115-118

Gastrografin in A-SBO

Q: Diatrizoate meglumine-diatrizoate sodium, also known as Gastrografin (GGF) do all of the following in adhesive small bowel obstruction (ASBO) except? 

A) Predicts resolution of bowel obstruction without surgery 
B) Accelerates resolution of bowel obstruction 
C) Reduces the need for surgical intervention 
D) Reduces the length of stay (LOS) 
E) All of the above


Answer: C

It is important to understand the definition of adhesive small bowel obstruction (ASBO) to know the role of GGF in ASBO.  As the name implies, ASBO is any small bowel obstruction which occurs in a patient with a history of previous abdominal surgery causing adhesions and without any alternate explanation or cause for bowel obstruction, particularly hernia, malignancy, or inflammation. 

GGF is basically an oral water-soluble radiological contrast agent, which is used therapeutically in ASBO. It has a very high osmolarity. It moves the water into the small bowel lumen by osmosis, decreases the edema of the small bowel wall and consequently regenerates the peristalsis of the bowel, and so accelerates the resolution of ASBO (choice B). If it appears in the colon within 24 hours of its administration, it predicts the resolution of ASBO without surgery (choice A). But, it does not resolve the need for surgery in ASBO., if requires.

With its early effect, it helps in decreasing the LOS in the hospital (choice D).


#surgicalcriticalcare
#gastroenterology


References / further reading:

1. Abbas S, Bissett IP, Parry BR. Oral water soluble contrast for the management of adhesive small bowel obstruction. Cochrane Database Syst Rev 2007; :CD004651. 

2. Di Saverio S, Catena F, Ansaloni L, et al. Water-soluble contrast medium (gastrografin) value in adhesive small intestine obstruction (ASIO): a prospective, randomized, controlled, clinical trial. World J Surg 2008; 32:2293. 

3. Burge J, Abbas SM, Roadley G, et al. Randomized controlled trial of Gastrografin in adhesive small bowel obstruction. ANZ J Surg 2005; 75:672. 

4. Ceresoli M, Coccolini F, Catena F, et al. Water-soluble contrast agent in adhesive small bowel obstruction: a systematic review and meta-analysis of diagnostic and therapeutic value. Am J Surg 2016; 211:1114. 

5. Farid M, Fikry A, El Nakeeb A, et al. Clinical impacts of oral gastrografin follow-through in adhesive small bowel obstruction (SBO). J Surg Res 2010; 162:170.

cerebral hyperperfusion syndrome

Q: What is cerebral hyperperfusion syndrome? 


 Answer: After carotid artery stenting or carotid endarterectomy (CEA), patient may experience headache on the ipsilateral side of the procedure, which usually improved in upright posture due to gravity. If it continues, patient may develop seizure or even Intra-Cerebral hemorrhage (ICH). The best prevention is blood pressure control. 

 Mechanism of action: Due to long standing carotid stenosis prior to surgery small vessels in the brain compensate with dilatation. Resolution of carotid stenosis leads to elevated perfusion pressure as there is a chronic loss of cerebral blood flow autoregulation. This again emphasis the need of keeping Systolic 

Blood Pressure less than 140 mm Hg post carotid intervention.

#neurology
#surgicalcriticalcare




References:

1. Coutts SB, Hill MD, Hu WY. Hyperperfusion syndrome: toward a stricter definition. Neurosurgery 2003; 53:1053. 

2.  Bouri S, Thapar A, Shalhoub J, et al. Hypertension and the post-carotid endarterectomy cerebral hyperperfusion syndrome. Eur J Vasc Endovasc Surg 2011; 41:229. 

3.  Piepgras DG, Morgan MK, Sundt TM Jr, et al. Intracerebral hemorrhage after carotid endarterectomy. J Neurosurg 1988; 68:532. 

4.  Karapanayiotides T, Meuli R, Devuyst G, et al. Postcarotid endarterectomy hyperperfusion or reperfusion syndrome. Stroke 2005; 36:21.

EPS in anti-psychotics

Q: Among the second-generation antipsychotics (SGAs) (atypical antipsychotics), which of the following has the highest risk of Extrapyramidal side effects (EPS)?

A) risperidone 
B) aripiprazole 
C) asenapine 
D) quetiapine 
E) clozapine


Answer: A

Out of all the SGAs, risperidone carries the highest risk of EPS. Ideally, it should not be used beyond 4 mg/day. Aripiprazole, asenapine, cariprazine, lurasidone, and paliperidone also carries some risk for EPS but less than risperidone.

Quetiapine and clozapine are considered the safest.


#neurology
#psychiatry
#pharmacology



References:

1. Marder SR, Meibach RC. Risperidone in the treatment of schizophrenia. Am J Psychiatry 1994; 151:825. 

2. Peuskens J. Risperidone in the treatment of patients with chronic schizophrenia: a multi-national, multi-centre, double-blind, parallel-group study versus haloperidol. Risperidone Study Group. Br J Psychiatry 1995; 166:712. 

3. Seppi K, Weintraub D, Coelho M, et al. The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the non-motor symptoms of Parkinson's disease. Mov Disord 2011; 26 Suppl 3:S42.

elevated troponin levels but a normal coronary angiogram

Q; Which of the following is found to be the most common cause of elevated troponin levels but a normal coronary angiogram?

A) Tachycardia 
B) Pericarditis 
C) Heart failure 
D) Strenuous exercise 
E) No clear reason



Answer: E

Although elevation of troponin seems to be very specific for cardiac ischemia, there is still a huge laundry list of non-cardiac causes of elevated troponin. Few very important ones and clinically relevant ones are

• Sepsis 
• Acute neurological events, including subarachnoid hemorrhage 
• Pulmonary embolism 
• Severe pulmonary hypertension 
• Aortic dissection 
• Hemochromatosis 
• Scleroderma 
• Snake venom 
• More than 25% of body surface area burns

Interestingly, in one albeit small study, nearly half of the patients were found to have no clear-cut reason for elevated troponin. It is assumed that some sort of myocardium damage occurs due to increase demand.

#cardiology

Reference:

Bakshi TK, Choo MK, Edwards CC, et al. Causes of elevated troponin I with a normal coronary angiogram. Intern Med J 2002; 32:520.

The most common location of Boerhaave syndrome

Q: What is the most common location of esophageal perforation in Boerhaave syndrome? 


 Answer: The left posterolateral aspect of the distal esophagus

Although Boerhaave syndrome can occur in any patient but it should led physician to think of previously underlying undiagnosed conditions like eosinophilic esophagitis, Barrett's esophagus, infectious ulcers or non-infectious ulcers from pills/other objects. 

Without any underlying pathology, other possible causes of esophageal perforation in Boerhaave syndrome are usually due to "sudden increase in intraesophageal pressure combined with negative intrathoracic pressure" and include severe straining (defecation in constipation, weightlifting), vomiting, childbirth, seizure, forceful coughing or laughing, and others. Perforation is mostly a longitudinal esophageal tear at the left posterolateral aspect of the distal esophagus.

#surgicalcriticalcare
#gastroenterology



References:

1. Pate JW, Walker WA, Cole FH Jr, et al. Spontaneous rupture of the esophagus: a 30-year experience. 

2. Ann Thorac Surg 1989; 47:689. Herbella FA, Matone J, Del Grande JC. Eponyms in esophageal surgery, part 2. Dis Esophagus 2005; 18:4.

Water loss via stool

Q: Water loss via stool in ICU should be documented as? (select one)

A) Insensible loss
B) Sensible loss 


Answer: A

There are four venues for insensible loss of water from human body, as they can't be objectively measured.

• Urine 
•  Skin 
•  Respiratory tract 
•  Stool

Amount dedicated to insensible loss via stool in a patient without diarrhea is about 200 mL per day.

#fluidbalance


Reference: 

Walter F. Boron (2005). Medical Physiology: A Cellular And Molecular Approach. Elsevier/Saunders. Page 829 (ISBN 1-4160-2328-3).

SVC syndrome - immediate relief

Q: The best initial corrective course of action for patients presenting with life-threatening superior vena caval (SVC) syndrome is (select one) 

 A) endovenous recanalization of SVC 
 B) Immediate Radiation therapy (RT)


 Answer: A

Symptomatic life-threatening SVC syndrome is a true medical emergency as the risk of sudden airway compromise or cerebral edema, resulting in death is very high.

In the past, after securing airway, conventional teaching was to perform immediate RT to provide rapid relief. Since endovenous recanalization stent placement is widely available, it should be considered a first line of treatment for the relief of immediate symptoms. RT if given prior to biopsy may obscure the histologic diagnosis, which should be a priority in these cases.

#surgicalcriticalcare
#oncology




Reference:

Loeffler JS, Leopold KA, Recht A, et al. Emergency prebiopsy radiation for mediastinal masses: impact on subsequent pathologic diagnosis and outcome. J Clin Oncol 1986; 4:716.

HRCT in prone position

Q: 68 year old male is admitted to ICU with SOB. Patient required intubation. Pulmonary service after reviewing history, exam and available data suggested High Resolution CT (HRCT) scan in prone position. In which of the pulmonary conditions, HRCT scan in prone position is preferred? 

A) Acute interstitial pneumonia 
B) Lymphocytic interstitial pneumonia 
C)  Cryptogenic organizing pneumonia
D) Asbestosis 
E)  Langerhans cell histiocytosis 




Answer: D 

Fibrosis in asbestosis  predominantly effects basal and dorsal lung parenchymal. Prone HRCT in  asbestosis better display the fixed, nongravitational changes at the lung bases. Another differentiating point between asbestosis and Interstitial Pulmonary Fibrosis (IPF) is more parenchymal bands or long scars in asbestosis than IPF. 

#pulmonary
#radiology


Reference: 

Gamsu G, Salmon CJ, Warnock ML, Blanc PD. CT quantification of interstitial fibrosis in patients with asbestosis: a comparison of two methods. AJR Am J Roentgenol 1995; 164:63.

Cardiac devices and MRI safety

Q: All of the following devices are "MRI safe" except?

A) Coronary artery stents 
B) Mechanical cardiac valves 
C) Sternal wires 
D) Inferior vena cava filters 
E) Pulmonary artery catheters (PAC) (Swan-Ganz catheter)


Answer: E

Devices and implants have been divided into three categories 

 1) MR safe - no known hazards 
2) MR conditional - no known hazards in a specified MR imaging environment with specified conditions of use. 
3) MR unsafe - known to pose hazards 

 Most of the known devices including sternal wires in immediate post surgical patients in ICU are usually MR safe, but a very commonly used PAC is not! 

Other unsafe devices include temporary pacemaker external pulse generators and transvenous temporary pacing leads. 

 Patients with Permanent pacemakers and implantable cardioverter-defibrillators (AICD) may undergo programming changes, asynchronous pacing, decrease pacing output, and heating of lead wires in the MR environment.

#radiology
#cardiology
#patient-safety 



References: 

1. American Society for Testing and Materials (ASTM) International. ASTM F2503-05: Standard Practice for Marking Medical Devices and Other Itmes for Safety in the Magnetic Resonance Environment. ASTM International ,West Conshohocken, PA. 2005. Available at: http://www.astm.org. 

2. Levine GN, Gomes AS, Arai AE, et al. Safety of magnetic resonance imaging in patients with cardiovascular devices: an American Heart Association scientific statement from the Committee on Diagnostic and Interventional Cardiac Catheterization, Council on Clinical Cardiology, and the Council on Cardiovascular Radiology and Intervention: endorsed by the American College of Cardiology Foundation, the North American Society for Cardiac Imaging, and the Society for Cardiovascular Magnetic Resonance. Circulation 2007; 116:2878. 

3. American College of Cardiology Foundation Task Force on Expert Consensus Documents, Hundley WG, Bluemke DA, et al. ACCF/ACR/AHA/NASCI/SCMR 2010 expert consensus document on cardiovascular magnetic resonance: a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents. J Am Coll Cardiol 2010; 55:2614.