Sunday, January 31, 2016

Q: 28 year old female who has recently started her care for severe Anorexia nervosa on an outpatient basis presented with the complaint of "not feeling well". ER physician wants to admit her to the ICU for observation. Today, the patient's physical exam appears to be unchanged from the description of previous outpatient visits, but you notice that even though today her heart rate is normal, she was consistently bradycardic in heart rate of 40s during her previous outpatient visits.


 Answer:  Bradycardia is a normal finding in patients with severe Anorexia nervosa and should be treated as normal. Hospital admission is required for bradycardia only if heart rate is less than 40 to rule out any pathology. On the contrary, normal heart rate in patients with severe known Anorexia nervosa should be taken very seriously as this represents “relative tachycardia” in these patients, and may be a clinical symptom of impending heart failure or early sign of refeeding syndrome, both of which can have significant clinical implications.




References:

1. Krantz MJ, Mehler PS. Resting tachycardia, a warning sign in anorexia nervosa: case report. BMC Cardiovasc Disord 2004; 4:10. 

2. Galetta F, Franzoni F, Prattichizzo F, et al. Heart rate variability and left ventricular diastolic function in anorexia nervosa. J Adolesc Health 2003; 32:416. 

3. Derman T, Szabo CP. Why do individuals with anorexia die? A case of sudden death. Int J Eat Disord 2006; 39:260.

Saturday, January 30, 2016

Q: In ICUs what is the most common cause of falsely positive Ant-Xa assay level?


Answer:  In ICUs Anti-Xa assay is usually obtained on patients who are getting infusion of IV Heparin. If level is drawn from the same line or nearby ports running Heparin, Anti-Xa assay would be falsely elevated. Second major cause of falsely elevated Anti-Xa  assay is compromised renal function.



Friday, January 29, 2016

Q: What are the three desired end effect of Intra-Aortic Balloon Pump (IABP)? 


 Answer:

  1. Decrease myocardial oxygen consumption, 
  2. Increase cardiac output, and 
  3. Lower peak left ventricular wall stress
(Objective of above question is to emphasize the third effect, which often go undescribed).



Reference: 

Kern MJ. Intra-aortic balloon counterpulsation. Coronary Artery Disease. 1991. 2(6):649-660.

Thursday, January 28, 2016

Q: How Idarucizumab, reversal of  Dabigatran works?


Answer: Idarucizumab is a dabigatran-specific antidote and is a humanized monoclonal antibody fragment, also called Fab.

Dabigatran is an oral anticoagulant and is a direct thrombin inhibitor. It is used as an oral therapy in patients with atrial fibrillation to prevent CVAs,  deep venous thrombosis (DVT) and pulmonary embolism (PE). It carries risk of life threatening bleeding and was avoided by many physicians as no effective reversal was available. 

In October 2015, FDA approved Idarucizumab. The recommended dose is one time IV use of 5 gram (or two pre-mix vials).

Wednesday, January 27, 2016

Q: Most of the C-reactive Protein (CRP) gets synthesized in (One best answer)? 

A) Kidney 
B) Muscles 
C) Endothelium 
D) Liver 
E) Macrophages


Answer:  CRP is mostly synthesized in the liver.

Clinical significance: CRP production gets unreliable in liver failure.  Any moderate CRP increase in patients with  liver insufficiency should get consideration to start empiric antibiotics. 



 Reference / further reading: 

1. Pepys MB, Hirschfield GM (Jun 2003). "C-reactive protein: a critical update". The Journal of Clinical Investigation 111 (12): 1805–12.


2. Bota DP, van Nuffelen M, Zakariah AH, Vincent JL. Serum level of C-reactive protein and procalcitonin in critically ill patients with cirrhosis of the liver. J Lab CLin Med. 2005;146:347–351


3. Janum SH, Søvsø M, Gradel KO, Schønheyder HC, Nielsen H. C-reactive protein level as a predictor of mortality in liver disease patients with bacteremia. Scand J Gastroent. 2011;46:1478–1483


4. Mackenzie I, Woodhouse J. C-reactive protein concentrations during bacteraemia: a comparison between patients with and without liver dysfunction. Intensive Care Med. 2006;32:1344–1351.


5. Li CH, Yang R, Pang JH, et al. Procalcitonin as a biomarker for bacterial infection in patients with liver cirrhosis in the emergency department. Acad Emerg Med. 2011;18:121–126


Tuesday, January 26, 2016

Q: Why all patients with Neurocysticercosis should have obligated detailed eye exam?


Answer:  Ocular cysticercosis is endemic and actually in some areas rate is reported higher than Neurocysticercosis. Timely exam and surgical intervention can save vision and should be carried out ASAP and preferably before the start of treatment as inflammation around degenerating cysticerci may cause chorioretinitis or retinal detachment.


 Reference: 

Sharma T, Sinha S, Shah N, et al. Intraocular cysticercosis: clinical characteristics and visual outcome after vitreoretinal surgery. Ophthalmology 2003; 110:996.





Monday, January 25, 2016

Q: What advantage fidaxomicin has over oral vancomycin or metronidazole in treatment of C. difficile infection?


Answer: Fidaxomicin has a narrower antimicrobial spectrum than other antibiotics for treatment of clostridium difficile colitis which leads to less disruption of the normal colonic anaerobic microflora. Though cure rate remained same but recurrence rate is significantly lower, and that is why it is used as a reserve for patients with recurrent C. difficile infection.



References: 

Venugopal AA, Johnson S. Fidaxomicin: a novel macrocyclic antibiotic approved for treatment of Clostridium difficile infection. Clin Infect Dis 2012; 54:568. 

Cornely OA, Nathwani D, Ivanescu C, et al. Clinical efficacy of fidaxomicin compared with vancomycin and metronidazole in Clostridium difficile infections: a meta-analysis and indirect treatment comparison. J Antimicrob Chemother 2014; 69:2892. 

Eyre DW, Babakhani F, Griffiths D, et al. Whole-genome sequencing demonstrates that fidaxomicin is superior to vancomycin for preventing reinfection and relapse of infection with Clostridium difficile. J Infect Dis 2014; 209:1446.

Sunday, January 24, 2016

Q: Why Clindamycin continue to be main stay of treatment for Necrotizing fasciitis?


Answer: In Necrotizing fasciitis, clindamycin continue to show superiority over other antibiotics. It remained part of all combination regimens due to it's antitoxin effects against toxin-elaborating strains of streptococci and staphylococci. Moreover, it can modulate the immune response.


 References:

1. Stevens DL, Gibbons AE, Bergstrom R, Winn V. The Eagle effect revisited: efficacy of clindamycin, erythromycin, and penicillin in the treatment of streptococcal myositis. J Infect Dis 1988; 158:23.

2. Zimbelman J, Palmer A, Todd J. Improved outcome of clindamycin compared with beta-lactam antibiotic treatment for invasive Streptococcus pyogenes infection. Pediatr Infect Dis J 1999; 18:1096.

 3. Edlich RF, Winters KL, Woodard CR, Britt LD, Long WB 3rd. Massive soft tissue infections: necrotizing fasciitis and purpura fulminans. J Long Term Eff Med Implants. 2005. 15(1):57-65.

Saturday, January 23, 2016

Q: Why extra care should be taken to prevent air embolism in arterial lines?


Answer: Extra care should be taken to prevent air embolism in arterial lines because in contrast to venous lines which have pulmonary capillaries sitting as filter before emboli travel to arterial sides, "A-Lines" have no such natural protection. Experiment has shown that even if 2 cc of air get injected in radial artery with a standard pressurized infusion apparatus can cause significant clinical cerebral air emboli. 2 major risk factors for air emboli from arterial lines are smaller size patients and patients who are sitting upright. 


Reference: 

Chang C, Dughi J, Shitabata P, et al. Air embolism and the radial arterial line. Crit Care Med 1988; 16:141.

Friday, January 22, 2016

Q: Where is the best place to find conjunctival hemorrhage in infective endocarditis? 


Answer: The best way to find conjunctival hemorrhage in infective endocarditis is by eversion of the upper or lower eyelids.

Thursday, January 21, 2016

Q: 52 year old male admitted to ICU with upper gastrointestinal (UGI) bleed. Patient stabilized with resuscitation, pRBC transfusions, and IV proton pump inhibitor drip. UGI scope performed and revealed adherent clot. What are the chances of rebleed during hospitalization?

A) 80%
B) 50%
C) 25%
D) none as clot is already formed
E) there is no way to predict it


Answer: C

Forrest classification is developed to predict  risk of recurrent bleeding depending on endoscopic findings, and also known as stigmata of recent hemorrhage,


  • Class Ia – Spurting hemorrhage  - 90% chances of rebleed
  • Class Ib – Oozing hemorrhage  - 10-20% chances of rebleed 
  • Class IIa – Visible vessel - 50% chances of rebleed
  • Class IIb – Adherent clot  - 25-30% chances of rebleed
  • Class IIc – Flat pigmented spot - 7-10% chances of rebleed
  • Class III – Clean ulcer base - 3-5% chances of rebleed


References:

1. Forrest JA, Finlayson ND, Shearman DJ. Endoscopy in gastrointestinal bleeding. Lancet 1974; 2:394.


2. Heldwein W; Schreiner J; Pedrazzoli J; Lehnert P (Nov 21, 1989). "Is the Forrest classification a useful tool for planning endoscopic therapy of bleeding peptic ulcers?". Endoscopy 21 (6): 258–62.

Wednesday, January 20, 2016

Q: What is the significance of "calcium ratio" during Continuous Renal Replacement Therapy (CRRT)?


Answer: If the ratio of total serum calcium to ionized calcium concentration exceeds 2.5, when both total and ionized calcium are measured in mmol/l or exceeds more than 10 if total calcium is measured in mg/dl., is a strong indicator of citrate toxicity. Treatment is the discontinuation of Citrate.



Reference: 

 Meier-Kriesche HU, Gitomer J, Finkel K, DuBose T. Increased total to ionized calcium ratio during continuous venovenous hemodialysis with regional citrate anticoagulation. Crit Care Med 2001; 29:748. 

Bakker AJ, Boerma EC, Keidel H, et al. Detection of citrate overdose in critically ill patients on citrate-anticoagulated venovenous haemofiltration: use of ionised and total/ionised calcium. Clin Chem Lab Med 2006; 44:962.

Tuesday, January 19, 2016

Q: Why calcium gluconate is preferred over calcium chloride in usual elemental replacement protocols in ICUs?


Answer: Particularly when intravenous peripheral lines are used for infusion, calcium gluconate is preferred because extravasation causes less tissue necrosis. Moreover, it should be well diluted either in D5W or NS because concentrated calcium is very irritating to veins. Asymptomatic hypocalcemia usually don't require treatment but asymptomatic patients should get replacement if corrected calcium  is less than 7.5 mg/dL as untreated hypocalcemia at this level may cause life threatening complications.



Monday, January 18, 2016

Q: What is the biggest risk factor for development of Vancomycin induced "Red-Man Syndrome"?



Answer:  Vancomycin related "Red-Man Syndrome" is a mast cell activation phenomenon so any medicine which predispose mast cell activation concomitantly with vancomycin may increase the risk. In ICU, two most common offenders are opioids and radiocontrast dye. Also, two other commonly used drugs in ICU found to increase the risk for similar reasons, are Ciprofloxacin and Succinylcholine. 



References: 

1. Polk RE, Healy DP, Schwartz LB, et al. Vancomycin and the red-man syndrome: pharmacodynamics of histamine release. J Infect Dis 1988; 157:502. 

2. Wong JT, Ripple RE, MacLean JA, et al. Vancomycin hypersensitivity: synergism with narcotics and "desensitization" by a rapid continuous intravenous protocol. J Allergy Clin Immunol 1994; 94:189.

Sunday, January 17, 2016

Q: 54 year old male with history of double lung transplant two years ago, is admitted to ICU with septic shock. Patient also has underlying comorbidity of diabetes mellitus secondary to steroid therapy. Patient was intubated in ER and required pressors. Respiratory Therapist reports "greenish" sputum sample. On clinical exam, patient also noted to have swollen right knee. Patient has documented severe allergy to Penicillin. Also, at least on two occasions previously, patient thought to develop "Red-Man Syndrome" from Vancomycin.  From the following, which antibiotic regimen would be appropriate beside joint drainage?

A) Clindamycin and Ciprofloxacin
B)  Linezolid,  Ciprofloxacin and Gentamicin
C)  Daptomycin and Ceftazidime 
D) Slow infusion of Vancomycin and later adjustment of antibiotics depending on culture
E)   Linezolid,  Daptomycin and Clindamycin


Answer: B

Patient  at this stage requires full broad spectrum antibiotic coverage. Patient may be immunocompromised due to immunosuppressive therapy post lung transplant. Also, patient has a risk factor of diabetes mellitus. With massive septic shock, and report of greenish sputum, pseudomonas aeruginosa need to be covered at least in the beginning.

Now with given severe allergy to penicillin as well as high intolerance to vancomycin -

C) is not a good choice as ceftazidime is a cephalosporin and patient with septic shock may not be able to sustain any further vasoplegia from allergic reaction.

D) is a wrong choice as monotherapy as in septic shock patient, it is not sufficient.

E) is inappropriate as all three drugs cover only gram positive organisms.

A) can be a choice but in severely septic patient with high suspicion of gram negative sepsis, double coverage with added gentamicin would be a better choice. Moreover, with patient's history of previous hospitalizations, methicillin-resistant S. aureus (MRSA) need to be covered, and neither clindamycin nor ciprofloxacin covers it.



 Reference: 

Sharff KA, Richards EP, Townes JM. Clinical management of septic arthritis. Curr Rheumatol Rep 2013; 15:332.

Saturday, January 16, 2016

Picture Diagnosis 

 Q: Which are these 2 cannulas in Inferior Vena Cava. Hint: Upper cannula is upto cardiac level?


Answer:   Femoral - Femoral Venous - Venous Cannulas

Upper Cannula is inflow cannula and lower one is outflow cannula to collect deoxygenated blood

Friday, January 15, 2016

Q: Putting following five together, which diagnosis comes to mind? 

  • Hypercalcemia
  • Elevated 1, 25-dihydroxyvitamin D level
  • 3rd degree AV block, particularly in a Japanese person 
  • Hyperprolactinemia
  • Elevated alkaline phosphatase level, when liver is involved



Answer: Sarcoidosis

Though ACE levels is widely described as a marker for Sarcoidosis, neither it is very sensitive nor specific, and so has poor prognostic value.Sarcoidosis is a generalized disease process and has been described depending on the organ involvement. Above five are other few classics found to be associated with Sarcoidosis.

Thursday, January 14, 2016

Q: 64 year male presented to ER with abdominal pain. Patient is send to CT scan. You received call from radiologist that patient has a "Crescent sign". What does it means?


Answer:  Impending AAA rupture 

 If a hyper-dense crescent can be appreciated within the thrombus of AAA, it implies probable impending AAA rupture. It means a loss in the ability of the thrombus to protect the aneurysm from rupture.

Wednesday, January 13, 2016

Q: 25 year old female is admitted to ICU with acute Acetaminophen toxicity. Patient is extremely lethargic and appears to be in acute hepatic encephalopathy. Resident decided to try lactulose to see if "intubation" can be saved by improving hepatic encephalopathy via lactulose. Simultaneously liver team is evaluating patient for possible transplant. What should be your next step?


Answer:  Stop administration of lactulose 

Benefits of lactulose in acute hepatic encephalopathy is not defined, rather it can be harmful. Lactulose can cause significant bowel distension which may hamper liver transplantation. Intubation in such situations is a safer approach, particularly when plans for surgery are underway.


Reference: 

Alba L, Hay JE, Lee WM. Lactulose therapy in acute liver failure. J Hepatol 2002; 36:33A.

Tuesday, January 12, 2016

Q: 63 year old male after partial pneumonectomy for lung cancer developed chylothorax. Patient is initially managed on TPN (Total Parenteral Nutrition). What dietary modification may help in such situation to transit to enteral feed? 


Answer:  Reduced fat diet 

 Reduced fat diet preferably less than ten grams/day may play the trick by decreasing the flow of chyle through the thoracic duct and helps in spontaneous closure of a thoracic duct leak. Reduced fat diet can be supplemented by medium chain triglycerides which are absorbed directly into intestinal cells and transported directly to the liver via the portal vein, bypassing the thoracic duct. 


 Reference: 

 Takuwa T, Yoshida J, Ono S, et al. Low-fat diet management strategy for chylothorax after pulmonary resection and lymph node dissection for primary lung cancer. J Thorac Cardiovasc Surg 2013; 146:571.

Monday, January 11, 2016

Q: In which drug toxicity, intubation may result in death and should be done "only and only" if there is a clear indication of respiratory failure, otherwise tachypnea should be allowed to continue?


Answer:  Salicylate poisoning

During severe salicylate poisoning, one of the most difficult clinical decision physician may have to make is oral intubation due to tachypnea. 'Intubation' should be performed ONLY if there is a clear sign of life threatening respiratory failure. Tachypnea usually resolves with alkalinization, and if indicated with hemodialysis. Supplemental oxygen usually is sufficient to keep oxygenation intact. Adequate Alkalinization can be achieved with sodium bicarbonate 100 mEq IV push over 5 minutes  followed by drip of  150 mEq sodium bicarbonate in 1 Litre of D5W, run over four hours. Target should be urine alkalinization upto PH of 7.5-8. Even alkalotic PH on ABG/VBG is not a contraindication to bicarbonate treatment.

Alkalosis is a friend in salicylate toxicity. Increase respiratory rate is a body's natural mechanism against poisoning. Alkalosis prevents salicylate anions from crossing into the brain. During oral intubation, with administration of sedatives and/or neuromuscular blockades, alkalosis may ensue into respiratory acidosis allowing salicylate anions to cross blood brain barrier and play havoc. In case, if intubation becomes necessary, it is absolutely necessary to keep alkalosis intact with high minute ventilation.


Reference: 

Greenberg MI, Hendrickson RG, Hofman M. Deleterious effects of endotracheal intubation in salicylate poisoning. Ann Emerg Med 2003; 41:583.

Sunday, January 10, 2016

Q: All of the following are used in Thyroid storm except?

A) Propranolol 

B) Propylthiouracil (PTU)
C) Iodine 
E) Cholestyramine
E) Aspirin


Answer:  E

Aspirin should be strictly avoided in thyroid storm as antipyretic because it can increase serum free T4 and T3 concentrations by interfering with their protein binding. If requires Acetaminophen should be used as antipyretic.

Choice A,B and C are  integral part of thyroid storm management. Cholestyramine are used in thyroid storm as they reduce enterohepatic circulation of thyroid hormone. 

Saturday, January 9, 2016

 Picture Diagnosis


Total Artificial Heart (TAH)

2 valves bilaterally with empty space below (air) and nice rim of air around heart with no cannulas going to aorta or pulmonary vessels signifies total artificial heart.

TAH works on the principal of "Full eject, Partial fill" which gives good 2 pockets of air below valves. TAH works via air pump with negative vacuum pressure and cannulas come out from TAH to machine, in contrast to assist devices where big vessels get cannulated.

Friday, January 8, 2016

Q: What does SCIWORA means in trauma?


Answer: Spinal Cord Injury Without Radiographic Abnormality 

It is the presence of neurologic deficits in the absence of technically adequate radiological workup including MRI. It may be due to ligamentous injuries, disc prolapse or cervical spondylosis. It is thought to be limited to pediatric patients but more and more cases have been described now in adults.

Clinical significance; Patient complain of pain and clinical findings take precedence over any radiological workup and strong vigilance, precaution and management should ensue to minimize damage from spinal cord injury.



Reference: 

Yucesoy K, Yuksel KZ. SCIWORA in MRI era. Clin Neurol Neurosurg 2008; 110:429.

Thursday, January 7, 2016

Q: What are the dosing guidelines for the titration of intravenous (IV) nitroglycerine in ST elevation myocardial infarction (STMI)?


Answer:
According to American College of Cardiology/American Heart Association (ACC/AHA) guidelines on ST elevation myocardial infarction (STEMI), "IV Nitro" can be started at very low dose from 5-10 µg/min and titrated slowly up with caution  by 5-20 µg/min every 10 minutes till either chest pain (and related symptoms) resolved or a mean arterial blood pressure (MAP) 10 percent below baseline in normotensive patients and up to 25-30 percent in hypertensive patients is achieved. Ideally, systolic pressure should not fall below 90 mmHg or by more than 30 mmHg.

Maximum effective dose is around 400 µg/min. 



Reference: 

O'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation 2013; 127:e362.

Wednesday, January 6, 2016

Q: Methylene blue should be use witth high caution in which sets of patient? 


Answer: Methylene blue is lately getting very popular in ICUs and ORs for refractory vasoplegia. But methylene blue should be avoided or be given with high caution in patients with

  • pulmonary hypertension
  •  glucose-6-phosphate dehydrogenase (G6PD) deficiency
  • acute lung injury

Tuesday, January 5, 2016

Q: "Pistol shot" pulsation is the hallmark of which disease?


Answer: Aortic Regurgitation

Wide pulse pressure in patients with Aortic Regurgitation gives some interesting findings which are also diagnostic of disease. 

A pistol shot pulse, also known as Traube's sign is an audible systolic and diastolic sounds heard over the femoral arteries. It is accompanied by a systolic and diastolic bruit audible when the femoral artery is partially compressed with stethoscope, known as Duroziez's sign. One famous and widely described clinical sign in this regard is Corrigan pulse, also known as 'water hammer or 'collapsing pulse', which is felt as a rapidly swelling and falling arterial pulse at radial, brachial or the carotid arteries. Also, capillary pulsations can be seen or feel at the fingertips or lips and known as Quincke's pulses. One dramatic and exotic physical finding is visible pulsations of the retinal arteries and pupils, known as Becker's sign. Also, pulsations can be felt at liver and spleen. Patient classically give description of "head bob occurring with each heart beat". 

On heart sounds, Austin flint murmur remained one widely described heart sound associated with aortic regurgitation.

Monday, January 4, 2016

A note on rebound hypotension post vasopressin drip

Vasopressin has been used with different doses in different ICUs depending on local culture - and this is mostly due to the fact that vasopressin has dose dependent effect. Dose for vasopressin is not recommended beyond  0.03 units/min but definitely higher dose has been shown to be more effective to counter hypotension. Though at least one study has shown its safety upto dose of 0.06 units/min but general consensus is to avoid it beyond 0.03 units/min as coronary, dermal and mesenteric ischemia has been clearly associated with use of vasopressin. One seldom mentioned aspect of vasopressin therapy is rebound hypotension at the abrupt discontinuation of drip. Drip should be titrated down very slowly by 0.01 units/min.



References:

1. Polito A, Parisini E, Ricci Z, et al. Vasopressin for treatment of vasodilatory shock: an ESICM systematic review and meta-analysis. Intensive Care Med 2012; 38:9. 

2. Malay MB, Ashton JL, Dahl K, et al. Heterogeneity of the vasoconstrictor effect of vasopressin in septic shock. Crit Care Med 2004; 32:1327. Kahn JM, Kress JP, Hall JB. 

3. Dünser MW, Mayr AJ, Tür A, et al. Ischemic skin lesions as a complication of continuous vasopressin infusion in catecholamine-resistant vasodilatory shock: incidence and risk factors. Crit Care Med 2003; 31:1394.

Sunday, January 3, 2016

Q: What is the pathological basis behind "Big No No" for renal dose dopamine in Acute Kidney Injury (AKI)?


Answer: 

In normal individual renal-dose dopamine (1-2 mcg/kg per minute) increases the renal blood flow but in patients with AKI it is shown to increase the renovascular resistance and consequently to decrease the renal blood flow. So low-dose dopamine is not only ineffective in AKI, it may actually harm the patient.



Reference:

Lauschke A, Teichgräber UK, Frei U, Eckardt KU. 'Low-dose' dopamine worsens renal perfusion in patients with acute renal failure. Kidney Int 2006; 69:1669.

Saturday, January 2, 2016

Q: 40 year old male is in ICU after spontaneous pneumothorax four days ago which was successfully drained with thoracostomy (chest tube). Since last night there is no "air leak" despite chest tube on suction. Clamp is applied to chest tube. Patient remained asymptomatic. How long should you wait to repeat CXR and discontinue (pull out) chest tube?


Answer:  At least 12 hours

Ideally, chest tube should be left in clamped position for twelve hours after the lung is fully expanded  on CXR and there is no detectable "air leak" on chest drainage system (aka Pleurovac). Repeat CXR without change  and no clinical symptom in 12 hours after the chest tube is clamped warrants safe removal of tube.