Q: What caution should be taken if lipids emulsion is added in total parenteral nutrition (TPN)?


Answer: Check for egg allergy

Lipid emulsion consists of omega-6 triglycerides, which are then emulsified using egg phospholipids and glycerin. Though allergy is rare but caution should be exercised and nutritionist should be consulted for other options.

Q: All of the following may help in post-operative shivering except?

A) Meperidine
B) Clonidine
C) Dexmedetomidine
D) Doxapram 
E) IVF at room temperature


Answer: E

Actually, IVF at room temperature is one of the risk factor for post-operative shivering along with OR's cold environment, inhaled anesthetics, impairment of the hypothalamic thermostat due to anesthesia, exposure of body cavities to room temperature and others. Meperidine, clonidine, dexmedetomidine and doxapram helps in resolving post-operative shivering.

Q: Why it may help to know the history of motion sickness before any surgical procedure?


Answer: Postoperative nausea or vomiting, popularly known as PONV, is the most common complication in the recovery room. One of the risk factor of PONV is history of motion sickness. Other risk factors include younger age, female gender, absence of a history of smoking and type of surgery.

Q: Epinephrine causes (select one)?

A) Hypokalemia
B) Hyperkalemia


Answer: Hypokalemia

Epinephrine enhances driving of potassium into the cells, causing or worsening preexisting hypokalemia.

Q: What is Lille score?


Answer: The Lille score is specifically designed to see if patients with severe alcoholic hepatitis are responding to glucocorticoid therapy. It looks into Day # 0

•  age
• renal insufficiency 
•  albumin
• prothrombin time
• bilirubin 

and

Day # 7 bilirubin

In this model, survival probability at 6 months is defined by the 0.45-cutoff.

Calculator is available at http://www.lillemodel.com/lillept.asp

Case: 54 year old female admitted to ICU with severe exacerbation of asthma but responded pretty well to intravenous glucocorticoids and symptoms resolved completely within 24 hours. How long should steroids be continued?


 Answer:  5 to 10 days

Intravenous  glucocorticoids should be converted whenever possible to oral form and should be continued for at least about a week, despite resolution of the symptoms. This prevents the recurrence of another exacerbation within next 2 weeks and found to be more effective than a day or two of treatment. Oral form has same efficacy and same bioavailability and is quickly absorbed, and there is no reason to continue IV steroid if patient can tolerate oral prednisone.




Reference: 

National Asthma Education and Prevention Program: Expert Panel Report III: Guidelines for the diagnosis and management of asthma. Bethesda, MD. National Heart, Lung, and Blood Institute, 2007. (NIH publication no. 08-4051)

Q: Heliox (Helium plus oxygen) works by all of the following mechanisms except?

A) Advantage of low density 
B) Ability to increase the proportion of turbulent air flow relative to laminar airflow
C) Reduction in airway resistance, 
D) Reduction in pleural pressures swings
E) Reduction in work of breathing


Answer:  B

Heliox actually works by decreasing the proportion of turbulent air flow relative to laminar airflow. It is an objective which gets achieve by inertness and low density of helium gas. Due to laminar flow it reduces the airway resistance, pleural pressures swings and consequently work of breathing.

A note on use of carbon dioxide as a contrast

Contrast induced nephropathy remained a constant issue of  concern in issue and calls for a sharp call of clinical decision in patients with compromised renal function. Though not very popular but in non-neurological radiology workup carbon dioxide can be a good agent which can actually be combined with iodinated contrast to keep its quantity low. Carbon dioxide has almost negligible renal effects. It cannot be used in neurological workup as it carries risk of neurotoxicity.

Rule of thumb: Carbon dioxide can be use as contrast for below diaphragm procedures. 



Related Article at emedicine/Medscape: (click)

Carbon Dioxide Angiography
 Kyung J Cho, MD, FACR, FSIR; Chief Editor: Eugene C Lin, MD

Web-link: http://emedicine.medscape.com/article/423121-overview

On "contrast-induced transient cortical blindness"

After receiving contrast for procedures like cardiac angiogram, some patients may experience contrast-induced transient cortical blindness, usually associated with headache. Any patient who complains of blurred vision after contrast added procedure should be suspected of contrast-induced transient cortical blindness. Blurring of vision may be the prologue of full blindness. It may be associated with nausea, vomiting, aphasia or limb weakness mimicking stroke. Interestingly, CT and MRI findings may be impressive with different findings. Clue to diagnosis is symmetrical white matter edema in the posterior cerebral hemispheres. Most deceiving (if little contrast extravasation occurs) is appearance of either subarachnoid hemorrhage or intracerebral hemorrhage, on noncontrast head CT scan, which is usually done as a first line of workup in such circumstances. Fortunately, symptoms and radiological findings resolve over few next days. Some experts cout this as a form of posterior reversible encephalopathy syndrome (PRES).  Despite all typical symptoms, high vigilence should be kept for any real CVA.



References:

1. Borghi C, Saia F, Marzocchi A, Branzi A. The conundrum of transient cortical blindness following coronary angiography. J Cardiovasc Med (Hagerstown) 2008; 9:1063.

2. Saigal G, Bhatia R, Bhatia S, Wakhloo AK. MR findings of cortical blindness following cerebral angiography: is this entity related to posterior reversible leukoencephalopathy? AJNR Am J Neuroradiol 2004; 25:252. 

3. Velden J, Milz P, Winkler F, et al. Nonionic contrast neurotoxicity after coronary angiography mimicking subarachnoid hemorrhage. Eur Neurol 2003; 49:249. 

Q: What is the major hurdle for cardiopulmonary resuscitation (CPR)in severe hypothermic patients?


Answer: A frozen chest wall

Severe hypothermia may cause chest wall to freeze up to the point that it is not compressible. In such instances, bedside echocardiography combining with doppler ultrasound may help. If cardiac contractions can be seen with 'echo' and if pulses can be detrmined by 'doppler' - it may be more safe to avoid CPR. Endotracheal intubation to assist chest wall movement may help, along with hhumidified oxygen to rewarm the patient. Severly hypothermic patients who are in cardiac arrthymias actually may respond better to bretylium.

Q: All of the following are absolute contraindications for having Magnetic Resonance Imaging (MRI) except? 

A) Defibrillator (AICD)
B) Metallic foreign body
C) Deep brain stimulator (DBS)
D) Swan-Ganz catheter (PAC)
E) Implanted drug infusion device


Answer: E

The Objective of above question is to emphasize the need of understanding of absolute contraindications of MRI from very common conditions/devices in ICU like DBS, PAC and AICD. Though MRI technicians are thoroughly trained and all radiological departments have extreme scrutiny before initiating MRI, an ultimate responsibility falls on ordering physician. 

Aneurysm stents, implanted drug infusion devices, wire sutures, ocular prosthesis, penile prosthesis, joint prosthesis etc. are relative contraindications and if the benefit of obtaining MRI is higher than risks, they can be worked out between an ordering physician and a radiologist.

Q: Which of the vascular condition may present as an acute scrotal pain and may be fatal if missed?


Answer:  AAA (abdominal aortic aneurysm)

It is unlikely but if no reason could be found for acute scrotal pain in an adult male, it could be a referred pain. Out of all conditions which may present as a referred pain, AAA is a dreaded one to miss. Others are urolithiasis, lower lumbar or sacral nerve root impingement and retrocecal appendicitis. Another condition which should be considered if patient cont. to c/o scrotal pain without any major finding is retroperitoneal tumor.


Referrence:  

 McGee SR. Referred scrotal pain: case reports and review. J Gen Intern Med 1993; 8:694.

Q; What is Hamman's sign?


Answer:  Hamman's sign, also known as, Hammond's sign or Hammond's crunch - as the name implies is a crunching sound on the chest wall. It is mostly synchronous with the heartbeat. It is due to spontaneous mediastinal emphysema. It is produced due to cardiac beats against air-filled subcutaneous tissues. It is best demonstrated by the patient at the left lateral position. The distinguishing feature are the crackles that correlate with the heart beat and not the respiratory cycle.

Clinical significance: If heard on an exam in a patient with respiratory distress, it points towards localized  spontaneous pneumothorax; but not a total lung collapse, on the left side. If severe, it can be visualized too.

Hamman's sign is little different though related to Hamman syndrome, which is a spontaneous pneumomediastinum and SQ emphysema, mostly happening either peri or postpartum. The condition is usually benign and self-resolving, but clinicians tend to confuse with  Boerhaave syndrome.



References:

1. Hadjis T, Palisaitis D, Dontigny L, Allard M (March 1995). "Benign pneumopericardium and tamponade". Can J Cardiol 11 (3): 232–4

2. Bonin MM. Hamman's syndrome (spontaneous pneumomediastinum) in a parturient: a case report. J Obstet Gynaecol Can. 2006;28 (2): 128-31

A note on use of 'Nitropaste' in cerebral vasospasm

Nitropaste is a very safe and simple adjuvant treatment to reduce some degree of intracranial vasospasm resulting from subarachnoid hemorrhage (SAH). Each inch of Nitropaste contains 15 mg of nitroglycerin. For adults, 2–5 inches  of Nitropaste is recommended depending on patient's BMI, alike treatment of angina pectoris. It takes about 30 minutes for paste to show effects. It has shown documented mild to moderate improvement of vasospasm by angiography in all patients.



Reference:

Walter S. Lesley, Al Lazo, John C. Chaloupka and John B. Weigele - AJNR 2003 24: 1234-1236

Q: In normal circumstances ultrasound is an excellent modality to diagnose pneumothorax at bedside. Studies have shown it to be superior to chest X-ray for diagnosis of pneumothorax in experienced hands. In which ondition, ultrasound can be deceiving and should be use with clinical picture and in combination of other modality for diagnosis of pneumothorax?


Answer:  COPD

Emphysematous lungs may mimic a pneumothorax. Caution should be exercised before embarking onto adventure of putting chest tube.



Reference: 

 Slater A, Goodwin M, Anderson KE, Gleeson FV. COPD can mimic the appearance of pneumothorax on thoracic ultrasound. Chest 2006; 129:545.

Q; How many days usually it take for Thrombocytopenia to resolve after withdrawal of Heparin in Heparin-Induced-Thrombocytopenia (HIT)?


Answer: Seven

Thrombocytopenia usually resolves within a week following withdrawal of heparin in HIT. Persistent thrombocytopenia may give clue to look for other reasons of Thrombocytopenia in same patient. HIT antibodies continue to persist for about three months, reason behind treatment with non-heparin anticoagulation for three months.

Q: What are the advantages and disadvantages of Right subclavian central venous catheter over Left subclavian central venous catheter?


Answer:

Advantages

• lower risk of pneumothorax due to the lower pleural apex 
• no risk of thoracic duct injury due to its absebce on this side

Disadvantages

• Higher chances of catheter malposition 
• Higher chances of vessel trauma 

Reference: 

 The clinical anatomy of several invasive procedures. American Association of Clinical Anatomists, Educational Affairs Committee. Clin Anat 1999; 12:43.

Q; A 20-year-old male admitted in the month of August to ICU with chest pain, shortness of breath and palpitations. Patient's EKG in ED showed second-degree AV block. In ICU,  he is in intermittent AV block. The Patient recently started his college in the State of Maryland. What is your most probable diagnosis?


Answer: Lyme Carditis

Sudden cardiac death is the most dreaded complication in young healthy males. For reasons, not completely understood, it strikes young healthy males. Any young healthy male with unexplained AV blocks and travel or residence in states of Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota and New Hampshire, is suspected of Lyme carditis,  proved otherwise! It classically presents in the months of summer or early fall. Treatment is 2-3 weeks course of PO Amoxicillin or Doxycyclin. Severe disease requires IV infusion  of ceftriaxone or cefotaxime for 2-3 weeks.


Further Reading: 

Peter J. Krause, MD; Linda K. Bockenstedt, MD -

 Lyme Disease and the Heart 

Circulation, 2013; 127: e451-e454

Weblink: http://circ.ahajournals.org/content/127/7/e451.full

Q: After thoracentesis, patient's pleural fluid reported no glucose in pleural fluid. Which 2 conditions should be considered strongly?



Answer:  A low pleural fluid/serum glucose ratio less than 0.5 easily narrows the differential diagnosis to rheumatoid pleurisy, empyema, malignant effusion, tuberculous pleurisy, lupus pleuritis and esophageal rupture. Of all, pleural fluid in rheumatoid pleurisy and empyema many times comes with no glucose. This is due to decreased transport of glucose from blood to pleural fluid.

Q: All of the following drugs if given as pretreatment increases the chance of atrial fibrillation conversion to normal sinus rhythm except? 

A) Aamiodarone
B) Flecainide
C) Sotalol
D) Digoxin
E) Ibutilide



Answer:  D 

Pretreatment with amiodarone, flecainide, propafenone, ibutilide, or sotalol enhances success and prevent recurrent atrial fibrillation. 

Q: Ideally tip of transhepatic dialysis catheter should be located at

A) Right Atrium

B) Right Ventricle

C) Subclavian vein

D) Hepatic Vein

E) Iliac Vein

Answer: A

Transhepatic dialysis catheter is usually inserted as a last resort or as an emergent temporary measure.  The Catheter is placed under radiology surveillance transcutaneously and via hepatic vein into the right atrium. Catheters can be placed inferiorly into inferior cava in special circumstances but ideally, tip should lie in right atrium.

Q: What is the usual standard for drawing cerebrospinal fluid (CSF) during management of Intra-Cranial Pressure (ICP) management?


Answer: Ventricular CSF drainage is usually done as the first line of invasive management particularly when ICP goes above 20 mmHg. CSF should be drained at a rate of approximately 1-2 cc/minute for 2 minutes. If further removal is required, the interval of at least 2 minutes should be given in between drainages until the desirable ICP is achieved.


Reference: 

Brain Trauma Foundation, American Association of Neurological Surgeons, Congress of Neurological Surgeons, et al. Guidelines for the management of severe traumatic brain injury. VIII. Intracranial pressure thresholds. J Neurotrauma 2007; 24 Suppl 1:S55.

Q: Which of the following two inotrope, is of choice in cardiogenic shock due to Right Ventricle dysfunction? (select one)

1) Dopamine 
2) Dobutamine


Answer:  Dopamine

Dopamine is usually more effective than Dobutamine in cardiogenic shock due to right ventricular dysfunction. It can be started 5 mcg/kg/minute, and titrated up with close watch for tachycardia. Though Dobutamine is an excellent inotrope, it decreases systemic vascular resistance, which may become detrimental in shock situation.

Q: How upper gastrointestinal bleed (UGIB) can be differentiated from lower gastrointestinal bleed (LGIB) by looking at Basic Metabolic Profile (BMP)?


Answer:  Patients with acute lower GI bleeding, and with normal kidney function, usually have a normal blood urea nitrogen (BUN)-to-creatinine (Cr). In contrast, patients with acute upper GI bleeding with normal renal function will have higher BUN/Cr ratio.


 Reference: 

Mortensen PB, Nøhr M, Møller-Petersen JF, Balslev I. The diagnostic value of serum urea/creatinine ratio in distinguishing between upper and lower gastrointestinal bleeding. A prospective study. Dan Med Bull 1994; 41:237.

Q: Which of the following is regarded as antidote for valproic acid overdose?

A) N-acetylcysteine 
B) L-carnitine
C) Vitamin B6
D) Naloxone
E) Sodium Bicarbonate


Answer:  B 

Valproic acid toxicity which usually causes  hyperammonemia and  liver injury is in part mediated by carnitine deficiency. Various drug regimens  have been described. Literature clearly shows the reversal or prevention of toxic effects of valproic acid with carnitine administration. 





Reference: 

Perrott J, Murphy NG, Zed PJ. L-carnitine for acute valproic acid overdose: a systematic review of published cases. Ann Pharmacother 2010; 44:1287.

Q:  24 year old male is admitted to ICU because of  huge load of deep vein thrombosis (DVT) of right upper arm. Symptoms started after playing long session of racquetball. Patient is c/o severe arm pain, and on exam extremity is reddish-blue, tender, warm and swelled. Your diagnosis?  



Answer: Paget–von Schrötter disease

Paget–von Schrötter disease, is a form of upper extremity deep vein thrombosis (DVT), involving axillary or subclavian veins. It is also known as "effort-induced thrombosis" as it mostly occurs after repetitive upper arm movements, putting excessive pressure against the brachiocephalic and external jugular veins. In some cases may occur without any repetitive movements or after clavicular trauma. It is an expression of thoracic outlet syndrome. It is important to understand that they are not catheter related.



Reference:

1.  Flinterman LE; Van Der Meer FJ; Rosendaal FR; Doggen CJ (Aug 2008). "Current perspective of venous thrombosis in the upper extremity". Journal of Thrombosis and Haemostasis 6 (8): 1262–6

2. Peivandi, Mohammad Taghi; Nazemian, Zohreh. "Clavicular Fracture and Upper-Extremity Deep Venous Thrombosis". Orthopedics 34 (3): 227–227

3. Thompson, J. F.; Winterborn, R. J.; Bays, S.; White, H.; Kinsella, D. C.; Watkinson, A. F. (2011-10-01). "Venous thoracic outlet compression and the Paget-Schroetter syndrome: a review and recommendations for management". Cardiovascular and Interventional Radiology 34 (5): 903–910

Q: During management of hypothermia, intravenous fluid (IVF) should be warmed upto what temerature?


Answer: 40-42 degree centigrades

During management of hypothermia, intravenous fluid (IVF) should be warmed upto 40-42 degree centigrades, as these patients usually require high IVF infusions, and infusion of IVF even at room-temperature can worsen hypothermia. Some experts suggest even rewarming IVF up to 45 degree centigrades.

Q: How volume expansion works in Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS)?


Answer: 

Volume expansion causes fall in serum glucose primarily via 2 mechanisms.

1) dilution, and
2) Urinary loss as renal perfusion improved

Just volume repletion alone (without insulin) can reduce the serum glucose by 35 to 70 mg/dL per hour.

Q: All of the following are causes of D-lactic acidosis except?

A) Short gut syndrome
B) Diabetic ketoacidosis
C) Propylene glycol 
D) Metformin



Answer: D

D-lactic acidosis is the most uncommon of Type A, B or D Lactic acidosis. It can be seen in people with short gut syndrome consuming high carbohydrate diet. Large amounts of carbohydrate gets fermented by intestinal bacteria and produce D-lactic acidosis. By default, humans metabolize D-lactic acid very slowly, and causes high plasma D-lactate levels and consequently metabolic acidosis. Other major reason of D-lactic acidosis in ICUs is infusion of propylene glycol, which is use as a solvent for many intravenous medications. D-Lactic acidosis also occurs in diabetic ketoacidosis via accumulating metabolites.

Metformin causes Type B lactic acidosis which is due to mitochndrial dysfunction. Other well-known drug to in ICU to do this is Linezolid.

Type A lactic acidosis is from ischemia and anaerobic metabolism of cells.

Q: Which of the following vessel is usually involved in Locked-in syndrome? 

A) Basilar artery 
 B) Middle Cerebral artery 
C) Anterior Cerebral artery 
D) Internal Jugular artery 
E) Aortic multiple emboli (showering) 


Answer: A

Ventral pons infarction is the most common cause of locked-in syndrome due to basilar artery involvement. Other major cause of Locked-in syndrome is pontine hemorrhage, due to hypertension or vascular malformations. Other reported causes include trauma, infection (abscess), tumors, central pontine myelinolysis, and drug abuse.