Q: 52 year old male is in refractory hypoxemia due to ARDS. Patient is not an ECMO candidate due to very recent neuro bleed. Pt. didn't respond to prone positioning either. In last 24 hours pulmonary artery catheter reading is showing progressive increase in pulmonary pressure. you requested iNO (inhaled nitric oxide). RT (Respiratory Therapy) service informed you that no iNO  machine is available. What could be your alternative?

Answer: Inhaled aerosolized prostacyclin 

Inhaled aerosolized prostacyclin (iAP), is an effective alternative to inhaled nitric oxide (iNO) for refractory hypoxemia and severe pulmonary hypertension. Tradiotionally, iNO is used in patients with pulmonary hypertension and acute respiratory distress syndrome (ARDS), but both iNO and iAP have been shown to reduce pulmonary vascular pressure and improve oxygenation in patients with ARDS. Moreover, it is more cost-effective also.


Reference:

Walmrath D, Schneider T, Schermuly R, Olschewski H, Grimminger F, Seeger W. - Direct comparison of inhaled nitric oxide and aerosolized prostacyclin in acute respiratory distress syndrome. -  Am J Respir Crit Care Med. 1996 Mar;153(3):991-6.

Q: What is pulsatile hepatomegaly?

Answer: In pulsatile hepatomegaly, the pulsations can be felt clinically over liver area. They can also be confirmed by external hepatic recordings. These pulsations conformed almost identically to the jugular venous pulsations in the neck. This is one of the classic sign seen in constrictive pericarditis. They should disappear after surgical treatment of constrictive pericarditis. Persistence of the hepatic pulsations after treatment signifies failure of surgical treatment.

Q: Which side of the chest is likely to have pneumothorax in  Catamenial pneumothorax?

Answer: Right

Catamenial pneumothorax may occur in women between age 30-40 years within 48 hours of menstruation. It usually occurs on right-side and have tendency to recur.

Q: Which atypical anti-psychotic drug can also be used as an anti-emetic in chemotheray induced nausea and vomitting?

Answer: Olanzapine

Olanzapine can be use as an anti-emetic, particularly in chemotherapy-induced nausea and vomiting. It is highly effective if use as a cocktail with palonosetron and dexamethasone. 

Reference:

Navari RM, Einhorn LH, Loehrer PJ, Passik SD, Vinson J, McClean J, Chowhan N, Hanna NH, Johnson CS (2007). "A phase II trial of olanzapine, dexamethasone, and palonosetron for the prevention of chemotherapy-induced nausea and vomiting: A Hoosier oncology group study". Supportive Care in Cancer 15 (11): 1285–91.

Q: 48 year old male is going for coronary stents placement after non-ST MI. Patient has previous history of severe GERD which is responsive only to Omeprazole (proton-pumo inhibitor). Which anti-platelet would be recommended?

Answer: Prasugrel

Clopidogrel (plavix) is the most commonly used anti-platelet agent along with aspirin in patients requiring coronary stents. But, clopidogrel has shown to have decreased effect in patients using proton pump inhibitors (PPI)  particularly omeprazole or esomeprazole (pantoprazole appears to be relatively safe).

Prasugrel has minimal interaction with PPIs, hence considered to be better choice in patients who are on PPIs and require coronary stents.

Types of Myocardial Infarction

Type 1: Ischemic myocardial necrosis due to plaque rupture ( ACS) 

 Type 2: Ischemic myocardial necrosis due to supply-demand mismatch, e.g. coronary spasm, embolism, low or high blood pressures, anemia, or arrhythmias. 

 Type 3: sudden cardiac death 

 Type 4: procedure related, post PCI or stent thrombosis 

 Type 5:  post CABG

Q: 60-year old patient presented with the compliant of shortness of breath. Patient has 60 pack-year history of smoking. Patient 

sodium is 140meq/l,
 potassium is 4meq/l, 
chloride is 94meq/l, and 
HCO3 is 36meq/l. 

 Patient abg revealed 

pCO2 is 70 and 
pH is 7.31.

 What is the acid base disturbance. 

 A) Metabolic acidosis
 B) Acute Respiratory acidosis 
 C) Chronic Respiratory acidosis 
 D) Mixed Metabolic and Respiratory acidosis 


 Answer: C

Rationale: Patient anion gap is 10 that rules out metabolic acidosis.  For every 10 Torr change in CO₂ change in ph is 0.3 for chronic and 0.8 for acute.  Since the change in torr of CO₂ in this case is 30, and ph is 7.31 that makes it chronic respiratory acidosis.  If it would have been acute that the ph should have been 7.16 (0.08x3=0.24; 7.4-.24=7.16)

Q; 30-year old patient with history of diabetes, presented to the hospital with c/o nausea and vomiting. Patient 

sodium was 140meq/l, 
potassium was 4meq/l, 
chloride was 105meq/l, 
HCO3 was 5meq/l. 

 On ABG 

pCO2 was 16 and 
pH was 7.11. 

 What is the acid base disturbance? 

 A) Metabolic acidosis 
 B) Respiratory acidosis 
 C) Mixed metabolic and respiratory acidosis 
 D) Triple acid-base disturbance 



Answer: A 

 Rationale: Patient anion gap is high (30) suggestive of metabolic acidosis. Patient CO2 is low, not supporting the notion of respiratory acidosis. Expected CO2 is (pCO2=1.5(HCO3) +8 +/-2; 1.5x5+8+/-2=13.5-17.5) within normal range.

Q; Patient with history of hypertension and anxiety presented to the hospital with tachypnea. Patient 

sodium was 140meq/l, 
potassium was 3meq/l, 
chloride was 94meq/l and 
HCO3 was 34. 

 On arterial blood gas, 

PH was 7.67 and 
pCO2 was 30. 

 What is the acid base disturbance? 

 A) Respiratory alkalosis 
 B) Metabolic alkalosis 
 C) Respiratory and metabolic alkalosis 
 D) Hyperchloremic non-anion gap metabolic acidosis 



Answer: C 

 Rationale: Patient HCO3 is high suggestive of metabolic alkalosis. Patient expected CO2 should be (pCO2=HCO3x0.9+9; 34x0.9+9=39.6); CO2 is 30, which is lower than expected pCO2, suggestive of mixed respiratory and metabolic alkalosis.

Patient presented to ED with complaint of vomiting and was found to be hypotensive. Patient sodium was 140meq/l, potassium was 3meq/l, chloride was 92meq/l and HCO3 was 29. On arterial blood gas the patient ph was 7.61 and pCO2 was 30. What is the underlying acid-base disturbance? 

 A) Mixed respiratory and metabolic alkalosis 
 B) Mixed respiratory alkalosis and metabolic acidosis 
 C) Respiratory alkalosis, metabolic acidosis and metabolic alkalosis 
 D) Respiratory acidosis and Respiratory alkalosis 


 Answer: C 

 Rationale: Patient PH is high suggestive of alkalosis. Patient HCO3 is high suggestive of metabolic alkalosis, the PCO2 should be high to compensate, but it is low, suggestive of concurrent respiratory alkalosis. Patient anion gap is 19 suggestive of metabolic acidosis. Hence the picture is consistent with metabolic acidosis, metabolic alkalosis and respiratory alkalosis. Patient cannot have respiratory acidosis and respiratory alkalosis together, as one cannot breath slowly and fast at the same time.

Case: The patient underwent serum chemistry and arterial blood gas. Patient was found to have Na of 139 meq/l, K 3 meq/l, CL 93 meq/L and HCO₃ of 35. Patient pH was 7.49 and pCO₂ was 41. What is the underlying acid base disturbance.

A) Mixed Respiratory and Metabolic Alkalosis
B) Respiratory Alkalosis
C) Hyperchloremic non-anion gap metabolic acidosis  
D) Metabolic Alkalosis




Answer: D. Metabolic alkalosis

Rationale: Patient has pH of 7.49 suggestive of alkalosis. pCO₂ is within normal range excluding respiratory alkalosis. The pH is high and chloride is 93 meq/L showing no indication of hyperchoremic metabolic acidosis. HCO₃ is high and expected pCO₂is within normal range (Expected CO₂=0.9 x HCO₃+9; .9X35+9=40.5) suggestive of simple compensated metabolic alkalosis as seen with diuretic therapy.

Case: 30-year female presented with complain of mild shortness of breath. Patient sodium was 139 meq/l, Potassium was 3.5meq/l, Chloride was 107meq/l, bicarbonate was 20. Patient pH on arterial blood gas revealed pCO₂of 25 and pH of 7.45. What is the underlying acid base disturbances.

   
A) Metabolic acidosis
B) Metabolic Alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis

Answer: D.  -  Respiratory Alkalosis

Rationale: Patient ph is 7,45 making it alkalosis, and the bicarbonate is not high, whereas the pCO₂ on arterial blood gas is low suugestive of respiratory alkalosis, as can be seen in the pregnant patient or in severe acute anxiety.

Q: 36 year old female, who is now recouping from exacerbation of Asthma in ICU and just finished her breakfast with large cup of coffee went into sustained SVT with heart rate of 240. You decided to administer Adenosine. What would be your concern?

Answer: Patient may need higher dose

Theophylline (which this patient may have use for Asthma) and caffeine antagonize adenosine's effects, so standard dose of 6 mg IV bolus may not work and an increased dose of adenosine may be required. On the contrary, Dipyridamole potentiates the action of adenosine, requiring the use of half of the standard dose.

Q: How just eye balling pulse oximetry on monitor can help in diagnosis of patient having suspicion of cardiac tamponade?


Answer: Patients with suspicion of cardiac tamponade, usually show increased respiratory variability in pulse-oximetry waveform.


Reference:

Stone MK, Bauch TD, Rubal BJ. Respiratory changes in the pulse-oximetry waveform associated with pericardial tamponade. Clin Cardiol. Sep 2006;29(9):411-4

Q: How much water need to be mixed to prepare one vial of Dantrium?

Answer: 60 cc

Each vial of Dantrium Intravenous should be reconstituted by adding 60 mL of sterile water and the vial shaken until the solution is clear. 5% Dextrose or 0.9% Sodium Chloride are not compatible with Dantrium Intravenous.

Dantrium is used for the prophylaxis and treatment of Malignant Hyperthermia (MH). The recommended prophylactic dose of Dantrium Intravenous is 2.5 mg/kg, starting approximately 60-75 minutes before anticipated anesthesia. It requires infusion over approximately 1 hour.

In post crisis intravenous Dantrium is used to attenuate malignant hyperthermia. The i.v. dose of Dantrium in the postoperative period starts with 1 mg/kg or more as the clinical situation dictates.

Q: Which pericarditis does not usually presents with classic ST elevations on EKG

Answer: Uremic pericarditis

In Uremic Pericarditis, classic finding of diffuse ST elevations are rare; rather more commonly, non- specific repolarization changes are present. This is due to the relative lack of  epicardial electrical injury. Also, pericardial fluid  is enriched with  oppositely charged uremic molecules  which neutralizes the electrical gradient.

Q: What is the difference between hypertensive urgency and hypertensive emergency?

Answer: 

Hypertensive urgency: is defined as severely elevated blood pressure (ie, systolic >180-220 mm Hg or diastolic >110- 120 mm Hg) with no evidence of target organ damage.

Hypertensive emergency: is defined as a recent significant increase over baseline blood pressure that is associated with target organ damage causing CVA, acute MI or angina, Renal insufficiency, Aortic dissection, Pulmonary edema, Eclampsia etc.

Clinical significance: Hypertensive emergencies require immediate therapy. In contrast, no evidence suggests a benefit from rapidly reducing blood pressure in patients with hypertensive urgency. In fact, such aggressive therapy may harm the patient, causing organ hypoperfusion.

Q: Why inhaled intrinsic Nitric oxide should always be weaned instead of abrupt discontinuation

Answer:  Abrupt discontinuation of inhaled NO may cause severe rebound pulmonary hypertension, an increase in intrapulmonary right-to-left shunting, and a decreased PaO2.

Exact mechanism is not known but It has been suggested that downregulation of endogenous NO synthesis and/or elevated endothelin-1 levels by inhaled NO is probably responsible for this rebound.

Slow stepwise weaning of the inhaled NO concentration is recommended.

References;

1. Rossaint R, Falke KJ, Lopez F, et al. Inhaled nitric oxide for the adult respiratory distress syndrome. N Engl J Med. 1993; 328: 399–405.

2. Black SM, Heidersbach RS, McMullan DM, et al. Inhaled nitric oxide inhibits NOS activity in lambs: potential mechanism for rebound pulmonary hypertension. Am J Physiol Heart Circ Physiol. 1999; 277: H1849–H1856.

3. McMullan DM, Bekker JM, Johengen MJ, et al. Inhaled nitric oxide-induced rebound pulmonary hypertension: role for endothelin-1. Am J Physiol Heart Circ Physiol. 2001; 280: H777–H785.

Q: Can sildenafil be given as IV in the treatment of pulmonary hypertension?

Answer:  Yes

IV sildenafil as a bolus in dose from 2.5 mg to 10 mg (tid) has been shown as a potent dilator in pulmonary hypertension. At least one study in children has shown it to be as effective as iNO.

Reference:

Ingram Schulze-Neick, MD; Paulina Hartenstein, BSc; Jia Li, MD; Brigitte Stiller, MD; Nicole Nagdyman, MD; Michael Hübler, MD; Ghazwan Butrous, MD; Andy Petros, MD; Peter Lange, MD; Andrew N. Redington, MD - Intravenous Sildenafil Is a Potent Pulmonary Vasodilator in Children With Congenital Heart Disease -  Circulation. 2003; 108: II-167-II-173

Q: Which one disease process need to be ruled out in severe pruritus associated with kidney failure, also known as Uremic pruritus?

Answer:  Hyperparathyroidism

If despite symptomatic treatment and increasing the dose/frequency of dialysis - uremic pruritus is not resolving, other disease processes particularly hyperparathyroidism need to be ruled out. Data is almost 45 years old but still is clinically relevant. 

References:

1. Massry S, Popovzer MM, Coburn JM, Mokoff DL, Maxwell MH, Kleeman CR. Interactable pruritus as a manifestation of secondary hyperparathyroidism in uremia. N Engl J Med1968; 279: 697–700

2. Hampers CL, Katz AI, Wilson RE, Merrill JP. Disappearence of uremic itching after subtotal parathyreoidectomy. N Engl J Med1968; 279: 695–697

3. Stahle‐Bäckdahl M, Hägermark O, Lins LE, Törring O, Hilliges M, Johansson O. Experimental and immunohistochemical studies on the possible role of parathyroid hormone in uremic pruritus. J Intern Med1989; 225: 411–415

Q: 56 year old male with ESRD is admitted to ICU with VRE pneumonia and sepsis.  Due to hemodynamic compromise, initially patient was put on CRRT. Patient responded well to Linezolid and is now switched to regular hemodialysis (HD). What care should be taken to maintain efficacy of Linezolid?

Answer:  Administer linezolid after HD session.

HD removes 30–40% of a dose of Linezolid so it should be given after HD session on the day of dialysis.  In CRRT no adjustment is needed but every 8 hours administration instead of every 12 hours of total daily dose is advisable.

Q: Can SLEDD (sustained low-efficiency daily dialysis) be done via AV fistula?

Answer:  Yes.

One advantage of SLEDD over CRRT (continuous renal replacement therapy) is that it can be done over AV fistula - and placement of dialysis catheter is not required.

Q: Can CPR be done in Prone position?

Answer:  Yes.

Also known as reverse CPR, has actually shown to generates higher mean Systolic blood pressure and higher Mean Arterial Pressure during circulatory arrest than standard CPR. It can be done by turning the head to the side and compressing the back. 

References:

1. Mazer SP, Weisfeldt M, Bai D, Cardinale C, Arora R, Ma C, Sciacca RR, Chong D, Rabbani LE.- Reverse CPR: a pilot study of CPR in the prone position. - Resuscitation. 2003 Jun;57(3):279-85.

2. Wei J, Tung D, Sue SH, Wu SV, Chuang YC, Chang CY (21 July 2005). "Cardiopulmonary resuscitation in prone position: a simplified method for outpatients" (PDF). Journal of the Chinese Medical Association (Elsevier, published May 2006) 69 (5): 202–206.

Q: 74 year old male with Parkinson's Disease is admitted to ICU with Urosepsis. Patient is recovering well. A night before transfer to floor, patient start displaying signs of delirium and psychosis. Which anti-psychotic would be of use?

Answer: Quetiapine

Quetiapine and clozapine are recommended for the treatment of Parkinson's disease related psychosis because of their low extrapyramidal side effects. Clozapine is known for some heavy side effects alike agranulocytosis, therefore quetiapine would be considered as a better choice. 

Reference:

Shotbolt P, Samuel M, David A (November 2010). "Quetiapine in the treatment of psychosis in Parkinson’s disease". Therapeutic Advances in Neurological Disorders 3 (6): 339–350

Q: 45 year old male now recovering in ICU ansd s/p tracheostomy POD # 10. Patient is liberated from ventilator and now put on Passy-Muir valve. Which one precaution should be taken?

Answer: Passy-Muir valve should be removed during aerosol treatments. Otherwise, humidity can be used while the valve is in place and oxygen can be given with the valve is in place.

HbA1C in ICU

Introduction:

HbA1c is widely used as a marker of glycaemic control and has been proposed and used, but not yet officially accepted, as a diagnostic marker for diabetes. We have tested its usefulness for diagnosing diabetes in the intensive care setting.

Methods

All patients with negative history for DM and hyperglycaemia in ICU were called for measurement of fasting glucose and OGTT within 1 month after discharge.

Results

There were 618 patients in the cohort:  293 patients had hyperglycaemia during the ICU stay and no information about DM in the history. Cut-off of 6% had 97% sensitivity and 93% specificity for pre-diabetes, 7% cut-off had 95% sensitivity and 98% specificity for DM.

Conclusions

HbA1c can be used for diagnosing diabetes and pre-diabetes in patients with critical care hyperglycaemia with high sensitivity and specificity. 

Reference:

I Gornik, A Vujaklija-Brajković and V Gašparović - Validation of HbA1c as a diagnostic marker for diabetes in the critically ill -Critical Care 2010, 14(Suppl 1):P581

Q: What are the few indicators that Pulmonary Artery Catheter (Swan-Ganz catheter) tip is in appropriate West Zone III of lung?

Answer:

• PAWP < PADP by 1-5 mmHg
• PAWP alters < than 50% of increase in PEEP
• PAWP increases by < 50% of changes in alveolar pressure (Pplat)
• O2 saturation in wedged position greater than unwedged position 
• CXR: below level of Left Atrium

Q: At physiologic level what PTT and PT actually determine?

Answer:

PTT - is the characteristics of the velocity of passage of the intrinsic coagulation pathway

PT –  is the characteristics of the velocity of passage of the extrinsic coagulation pathway.