Q: 32 year old male presented to ED after new year Friday night party with chest pain and hypertension. He admits using Cocaine. Initial labs showed hypokalemia of 2.9 mEq/L. What would be your concern?


Answer: Clenbuterol

Clenbuterol is an adulterant frequently found in cocaine and heroin. Clenbuterol tends to cause  a tetrad of 

• tachycardia 
• hyperglycemia 
• palpitations, and 
• hypokalemia

Also, it may cause  nausea, hypo or hypertension, thyrotoxicosis, chest pain, venous hyperoxia but with lactic acidosis, central symptoms of agitation and anxiety. 

Treatment is supportive.


 Reference: 

 Centers for Disease Control and Prevention (CDC). Atypical reactions associated with heroin use--five states, January-April 2005. MMWR Morb Mortal Wkly Rep 2005; 54:793.

Q; All of the following are indications of starting hemodialysis (HD) in patients with Chronic Kidney Disease: (CKD) :

A) Pericarditis 
B) Pleuritis
C) Wrist or foot drop
D) Seizures
E) All of the above


Answer: E

Fluid overload, acidosis, hyperkalemia and other electrolyte disturbances are well known indications of emergent HD. But some of the manifestations of CKD and/or uremia are under-appreciated where relatively urgent intervention is needed like pericarditis or pleuritis, encephalopathy manifesting as confusion, asterixis, myoclonus, wrist or foot drop, or, even seizures. Also uncontrolled uremic bleeding diathesis may require HD sooner than later.


Reference: 

 Hemodialysis Adequacy 2006 Work Group. Clinical practice guidelines for hemodialysis adequacy, update 2006. Am J Kidney Dis 2006; 48 Suppl 1:S2.

Q; How order for analgesia should be written, differently in dying patient over non-dying patients?

Answer:  As well known, narcotics are the mainstay of analgesia in end of life (dying) patients. But as dying patients may be frail to ask for medicine, instead of writing PRN (as needed), it should be written as either “offer, may refuse” or “as scheduled for symptoms”.

Q: How Guanylate cyclase (sGC)stimulant (Riociguat) (trade name = Adempas) works for thromboembolic Pulmonary hypertension? 


Answer: It has a dual mode of action.

1. Increases the sensitivity of sGC to endogenous nitric oxide (NO)
2. Directly stimulate the receptor to mimic the action of NO

It should be used with extreme caution in patients who are already on nitrates and phosphodiesterase inhibitors.


References: 

1. Rubin LJ, Galiè N, Grimminger F, et al. Riociguat for the treatment of pulmonary arterial hypertension: a long-term extension study (PATENT-2). - Eur Respir J 2015; 45:1303. 

2. Ghofrani HA, Galiè N, Grimminger F, et al. Riociguat for the treatment of pulmonary arterial hypertension. N Engl J Med 2013; 369:330.

Q: With recent advances in laboratory technology, which one precaution should be taken while interpreting the labs in diabetic ketoacidosis (DKA)?

Answer:  The sodium is traditionally corrected by 1.6 mEq/L for every 100 mg/dL increase in serum glucose, above 100 mg/dL. Some experts prefer adjustment of 2.4 mEq/L. But with recent advances in technology, many labs now report actual sodium. Correcting reported actual sodium with increased glucose level may give a wrong result of plasma osmolality and may lead to erroneous IVF replacement in DKA. It should be checked with local hospital labs personnel.

Q: How to calculate the Plasma Exchange volume for plasmapheresis?


Answer:

Usually, one plasma volume exchange is performed per procedure, which is expected to remove most of the target substance. There are two ways to calculate

1. Rule of thumb: In a regular adult person (70 kg) just use 3 liters of replacement fluid.

2. Use the formula 
    Estimated plasma volume (in liters) = 0.07 x weight (kg) x (1 - hematocrit) 

 To recap, plasmapheresis is a universal term used for removal of plasma from the blood using either centrifugation or filtration. In general population, it is used to collect plasma (plasma donation). Therapeutic plasma exchange means removal of patient plasma and replacement with another fluid (donor plasma, colloid, crystalloid). 


Reference:

Kaplan AA. A simple and accurate method for prescribing plasma exchange. ASAIO Trans 1990; 36:M597.

Q: Continuous infusion and bolus intravenous loop diuretic overall carries same efficacy in heart failure (CHF) patients. Beside, less chances of ototoxicity, what other advantage continuous infusion of loop diuretic may have over IV bolus in CHF patients? 


Answer: It helps in maintaining sodium level

Continuous intravenous infusion maintains an effective rate of drug excretion, and  inhibits sodium chloride reabsorption in the loop of Henle. IV bolus doses of loop diuretics, as expected are associated with higher and then lower rate of drug excretion, causing unreliable maintenance of sodium chloride hemostasis.


References: 

 1. Rudy DW, Voelker JR, Greene PK, et al. Ann Intern Med 1991; 115:360. 

2.  Brater DC, Day B, Burdette A, et al. Kidney Int 1984; 26:183

Q: Should angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blockers (ARBs) be hold to prevent Contrast Induced Nephropathy (CIN)? (Select one)

A) Yes
B) No
C) Not Clear


Answer: C

There is no convincing evidence present in literature to support the idea of withholding ACE inhibitors and/or ARBs to prevent CIN. Most of the time, it is done reflexly. Actually, they have been suggested as rather helpful,  by blocking renin-angio II vasoconstriction. 

It should be done only on case to case basis - and should not be held in mild renal insufficiency.


References:

1. Rim MY, Ro H, Kang WC, et al. The effect of renin-angiotensin-aldosterone system blockade on contrast-induced acute kidney injury: a propensity-matched study. Am J Kidney Dis 2012; 60:576. 

2. Rosenstock JL, Bruno R, Kim JK, et al. The effect of withdrawal of ACE inhibitors or angiotensin receptor blockers prior to coronary angiography on the incidence of contrast-induced nephropathy. Int Urol Nephrol 2008; 40:749.

Q: In last few years cough strength has been advocated as one of the weaning parameter. How cough strength can be objectively measured?


Answer: After inserting a spirometer into the ventilator circuit, and then patient instructed to cough, the peak expiratory flow (PEF) is measured. If PEF less than 60 L/min, chances of extubation failure is high. 



References:

1. Smina M, Salam A, Khamiees M, et al. Cough peak flows and extubation outcomes. Chest 2003; 124:262.

2. Salam A, Tilluckdharry L, Amoateng-Adjepong Y, Manthous CA. Neurologic status, cough, secretions and extubation outcomes. Intensive Care Med 2004; 30:1334.

Q: Due to its laminar flow, Heliox is more effective (Select one) 

 A) in the small airways 
 B) in the large airways


Answer: B

Heliox, though has a similar viscosity to air but a significantly lower density. In the small airways, resistance is proportional to gas viscosity so Heliox has lesser impact. Moreover, in smaller airways flow is laminar anyway. 

In the large airways, Heliox's low density produces a higher laminar flow in comparison to turbulent flow of air. Laminar flow generates less resistance. Also, in the large airways where flow is turbulent, resistance is proportional to density, so heliox has a significant clinical impact.

(often missed in ICU is ophthalmic care!) 

 Protocolized eye care prevents corneal complications in ventilated patients in a medical intensive care unit

Background: Eye care is an essential component in the management of critically ill patients. Standardized eye care can prevent corneal complications in ventilated patients.

Objective: This study was designed to compare old and new practices of corneal care for reduction in corneal complications in ventilated patients.

Methods: This study was done in three phases each of six month duration. Phase 1 was the ongoing practice of eye care in the unit. Before the start of phase 2, a new protocol was made for eye care. Corneal complications were observed in terms of haziness, dryness, and ulceration. All nursing staffs were educated and made compliant with the new protocol. In phase 2, a follow-up audit was done to check the effectiveness and compliance to protocol. In phase 3, a follow-up audit was started 3 months after phase 2.

Results: In phase 1, total ventilated patients were 40 with 240 ventilator days. The corneal dryness rate was 40 per 1000 ventilator days while the haziness and ulceration rate was 16 per 1000 ventilator days each. In the second phase 2, total ventilated patients were 53 making 561 ventilator days. The rate of corneal haziness and dryness was 3.52 and 1.78 per 1000 ventilator days, respectively, with no case of corneal ulceration. In phase 3, the number of ventilated patients was 91 with 1114 ventilator days. The corneal dryness rate was 2.69 while the haziness and ulceration rate was 1.79 each.

Conclusion: Protocolized eye care can reduce the risk of corneal complications in ventilated patients.


Reference: 

Mohammad Feroz Azfar, Muhammad Faisal Khan, and Abdulaziz H. Alzeer - Protocolized eye care prevents corneal complications in ventilated patients in a medical intensive care unit - Saudi J Anaesth. 2013 Jan-Mar; 7(1): 33–36.

(One interesting study to be aware of in relation to Pulmonary Artery Catheter's hemodynamic monitoring) 

Diastolic Pulmonary Vascular Pressure Gradient: A Predictor of Prognosis in “Out-of-Proportion” Pulmonary Hypertension (1)

Background: Left-sided heart disease (LHD) is the most common cause of pulmonary hypertension (PH). In patients with LHD, elevated left atrial pressure causes a passive increase in pulmonary vascular pressure by hydrostatic transmission. In some patients, an active component caused by pulmonary arterial vasoconstriction and/or vascular remodeling superimposed on left-sided pressure elevation is observed. This “reactive” or “out-of-proportion” PH, defined as PH due to LHD with a transpulmonary gradient (TPG) > 12 mm Hg, confers a worse prognosis. However, TPG is sensitive to changes in cardiac output and left atrial pressure. Therefore, we tested the prognostic value of diastolic pulmonary vascular pressure gradient (DPG) (ie, the difference between invasive diastolic pulmonary artery pressure and mean pulmonary capillary wedge pressure) to better prognosticate death in “out-of-proportion” PH.

Methods: A large database of consecutive cases was analyzed. One thousand ninety-four of 2,351 complete data sets were from patients with PH due to LHD. For proof of concept, available lung histologies were reviewed.

Results: In patients with postcapillary PH and a TPG > 12 mm Hg, a worse median survival (78 months) was associated with a DPG ≥ 7 mm Hg compared with a DPG < 7 mm Hg (101 months, P = .010). Elevated DPG was associated with more advanced pulmonary vascular remodeling.

Conclusions: DPG identifies patients with “out-of-proportion” PH who have significant pulmonary vascular disease and increased mortality. We propose a diagnostic algorithm, using pulmonary capillary wedge pressure, TPG, and DPG in sequence to diagnose pulmonary vascular disease superimposed on left-sided pressure elevation.



References and further reading:

1. Christian Gerges; Mario Gerges, MD; Marie B. Lang; Yuhui Zhang, MD; Johannes Jakowitsch, PhD; Peter Probst, MD; Gerald Maurer, MD; Irene M. Lang, MD - Diastolic Pulmonary Vascular Pressure Gradient: A Predictor of Prognosis in “Out-of-Proportion” Pulmonary Hypertension  Chest. 2013;143(3):758-766. doi:10.1378/chest.12-1653 

2. Pulmonary hypertension in sepsis: Measurement by the pulmonary arterial Diastolic-pulmonary wedge pressure gradient and the influence of passive and active factors. Chest 1978; 73:583-91 

3. Significance of the pulmonary artery diastolic-pulmonary wedge pressure gradient in sepsis. Crit Care Med 1982; 10:658-61 

4. Pulmonary artery diastolic and wedge pressure relationships in critically and injured patients. Arch Surg 1988; 123:933-6 

5. Increased Pulmonary Venous Resistance Contributes to Increased Pulmonary Artery Diastolic-Pulmonary Wedge Pressure Gradient in Acute Respiratory Distress Syndrome - Anesthesiology: Volume 102(3) March 2005 pp 574-580

Q: The goal of optimum PEEP is to?

A) avoid derecruitment
B) optimize best oxygenation at lowest FiO2
C) best balance between acceptable hypoxemia and permissive hypercapnia
D) minimize Dead space to zero
E) get best compliance  


Answer: A (1)

Optimum PEEP continue to remain a concept of debate among critical care practitioners. To make things complicate optimum PEEP is a not a static component, rather is a constantly changing physiological model depending on the relationship between lung volume, respiratory mechanics, dead space, cardiac output, compliance, shunt and oxygenation. But at the end the primary goal is to avoid de-recruitment. This is a misconception that optimum PEEP is to obtain best oxygenation at lowest FiO2, or playing subjectively with acceptable hypoxemia or permissive hypercapnia. It is impossible to decrease dead space to zero. Arguably, closet choice is the E,  where the best compliance is obtained but compliance can be deceiving depending on number of recruited and decruited alveoli (2) (3).


 References: 

1.  Caironi P, Cressoni M, Chiumello D, Ranieri M, Quintel M, Russo SG, et al. Lung opening and closing during ventilation of acute respiratory distress syndrome. Am J Respir Crit Care Med. 2009;181:578–86.

2. Suter PM, Fairley HB, Isenberg MD. Effect of tidal volume and positive end-expiratory pressure on compliance during mechanical ventilation. Chest. 1978;73:158–62. 

3. Jonson B, Richard JC, Straus C, Mancebo J, Lemaire F, Brochard L. Pressure-volume curves and compliance in acute lung injury: Evidence of recruitment above the lower inflection point. Am J Respir Crit Care Med. 1999;159:1172–8. 

Q: What is Carnett's sign?

Answer: Carnett's sign is an easy to do bedside exam in 5 seconds. It may provide significant clinical clues. This maneuver is performed in patients with acute abdominal pain to differentiate between intraabdominal pathology (like appendicitis) or abdominal wall pathology (like rectus sheath hematoma or hernia).

During the exam, the patient is asked to lift the head and shoulders from the supine position or to raise both legs with straight knees - to tense the abdominal muscles. If pain increase in intensity, the abdominal wall is the likely source of pain and if the abdominal pain decreases, an intra-abdominal pathology of the pain is likely


Reference: 

Gray DW, Dixon JM, Seabrook G, Collin J (July 1988). "Is abdominal wall tenderness a useful sign in the diagnosis of non-specific abdominal pain?". Ann R Coll Surg Engl. 70 (4): 233–4

Q: During weaning of Ventilator, how much is load of work due to endotracheal tube (ETT)?


Answer: About 10% 

There is a continuous debate about applying ETT compensation during weaning. Most ventilators are equipped to provide Automatic Tube Compensation (ATC), but physicians advocating against ATC argues that increased work load  by ETT is equivalent to upper airways obstruction immediately following extubation, so ATC is not required. But literature continue to see arguments from both side.


References: 

1. Strauss C, Louis B, Isabey D, Lemaire F, Harf A, Brochard L. Contribution of the endotracheal tube and the upper airway to breathing workload. Am J Respir Crit Cared Med 1998;157(1):23-30. 


2. Branson RD. Endotracheal tubes and imposed work of breathing: what should we do about it, if anything? Critical Care 2003;7(5):347–348. 

3. Figueroa-Casas JB, Montoya R, Arzabala A, Connery SM. Comparison between automatic tube compensation and continuous positive airway pressure during spontaneous breathing trials (SBTs). Respir Care 2010;55(5):549-554. 

Q: Autonomic dysfunction induced hypotension is common in ICU and may become challenging in weaning vasopressors. All of the following can be used as treatment or as an adjuvant treatment in orthostatic hypotension?

A)  Fludrocortisone 
B)  Midodrine
C)  Recombinant erythropoietin 
D)  Nonsteroidal antiinflammatory drugs (NSAID)
E) All of the above


Answer: E

Like most MCQs, answer to above question is E (all of the above)!!!

 Objective of above question to bring in light, the help of recombinant erythropoietin in patients with chronic anemia to counter autonomic hypotension. Also, Nonsteroidal antiinflammatory drugs (NSAID) may be of help too in combination with other agents.

There is a long list of medicines which have been tried either solo or in combinations with various success in autonomic dysfunction induced hypotension including midodrine, pyridostigmine, caffeine, synthetic vasopressin analogue desmopressin (dDAVP), Yohimbine, octreotide, dihydroergotamine, droxidopa, atomexitine and others.

Q: Acute respiratory distress syndrome (ARDS) is diagnostic

A) If P/F ratio less than 200
B) If Pulmonary Wedge Pressure less than 18
C) if bilateral infiltrates present with negative sputum culture
D) is diagnosis of exclusion
E) if improvement in P/F ratio by prone positioning



Answer:  D

Though seems very basic but it is of utmost importance to understand that ARDS is a diagnosis of exclusion. This is the basis of new Berlin definition of ARDS. All other causes of hypoxemia need to be ruled out, with objective evaluation including floatation of  Pulmonary Artery Catheter (swan), echocardiography, bronchoscopy, and/or lung biopsy. 

Q: All of the following can be a clinical sign or symptom of Acute Aortic Dissection except?

A) Stroke 
B) Horner syndrome 
C) Hoarseness 
D) Complete heart block
E) Low D-Dimer


Answer: E

Objective of above question is to emphasize the unusual presentations of acute aortic dissection which can be devastating if missed or read wrong. It is important to understand that presentation of stroke with negative c/o chest pain and negative CT scan may lead to infusion of thrombolytic which would be catastrophic in acute aortic dissection. Propagation of the dissection proximal into the carotid arteries or even diminished carotid blood flow may present acute aortic dissection as stroke. Expanding aneurysm may cause horner syndrome due to compression  on the superior cervical sympathetic ganglion, and hoarseness due to compression of the left recurrent laryngeal nerve. 

Low D-Dimer actually rules out Aortic dissection.

Olanzapine and smoking

Q: Olanzapine (trade = Zyprexa) is a commonly used drug in ICU for various reasons including delirium and psychosis. In which subset of patients, it may not work or require higher dose?


Answer: Olanzapine after oral dose is removed by the hepatic first-pass effect. Patients who are smoker have increase activity of CYP1A2, and may significantly increase the hepatic first-pass clearance of Olanzapine.

Q: All of the following increase the Rapid Shallow Breathing Index (RSBI) except?

A) size of endotracheal tube (ETT) 
B) male gender
C) sepsis
D) supine position
E) suctioning


Answer: B

 It is an usual clinical practice to insert lower sized diameter ETT in females - and both these factors may falsely give high RSBI, independent of the weaning outcome. Another common bedside mistake is to measure RSBI right after suctioning, which may also falsely increase RSBI.


References: 

1.  Epstein SK, Ciubotaru RL. Influence of gender and endotracheal tube size on preextubation breathing pattern. Am J Respir Crit Care Med 1996; 154:1647. 

2. Seymour CW, Cross BJ, Cooke CR, et al. Physiologic impact of closed-system endotracheal suctioning in spontaneously breathing patients receiving mechanical ventilation. Respir Care 2009; 54:367.

Q: Which one unique feature distinguish filarial lymphangitis from other causes of lymphangitis?

Answer:  Filarial lymphangitis occurs in a retrograde progression, means it spread away from the lymph nodes, where parasite resides. As parasites die they causes retrograde lymphangitis. Acute episode is followed by its complications as thickening of skin and subcutaneous tissue and superimposed bacterial infection. Organisms responsible  are wuchereria bancrofti, B. malayi, and B. timori.

It may be of interest for intensivists that adult worms can seen by bedside ultrasound of the inguinal, crural, and axillary lymph nodes and possibly adjacent vessels!


 References: 

1.  Pani SP, Yuvaraj J, Vanamail P, et al. Episodic adenolymphangitis and lymphoedema in patients with bancroftian filariasis. Trans R Soc Trop Med Hyg 1995; 89:72. 

2.  Dreyer G, Noroes J, Figueredo-Silva J. New insights into the natural history and pathology of bancroftian filariasis: implications for clinical management and filariasis control programmes. Trans R Soc Trop Med Hyg. 2000; 94(6): 594-6. 

3. Dreyer G, Noroes J, Figueredo-Silva J, Piessens WF. Pathogenesis of lymphatic disease in bancroftian filariasis: a clinical perspective. Parasitol Today. 2000; 16(12): 544-8. 

4.  Fox LM, Furness BW, Haser JK, Brissau JM, Louis-Charles J, Wilson SF, Addiss DG, Lammie PJ, Beach MJ. Ultrasonographic examination of Haitian children with lymphatic filariasis: a longitudinal assessment in the context of antifilarial drug treatment. Am J Trop Med Hyg. 2005; 72(5): 642-8.

Q: The right common carotid artery has been used for cannulation for VA ECMO (Extracorporeal membrane oxygenation) in patients with severe peripheral arterial disease. What is the highest risk involved with this approach? 


 Answer: 5 to 10 percent risk of a clinically significant watershed cerebral infarction. In situations where femoral access is not viable, experts recommend the subclavian approach. But again, clinical situation precedes any decision.


 Reference: 

Navia JL, Atik FA, Beyer EA, Ruda Vega P. Extracorporeal membrane oxygenation with right axillary artery perfusion. Ann Thorac Surg 2005; 79:2163.

Q: What is "rebound pain" effect of morphine in Hemodialysis patients? 

 Answer: Morphine and its metabolites get removed with dialysis and may cause “rebound” pain effect. 

Patient with renal insufficiency but not on dialysis should receive morphine with caution. Morphine gets metabolized in the liver to morphine-3-glucuronide, morphine-6-glucuronide and normorphine, which are excreted via kidneys. About 10% of Morphine remain unchanged. Though parent compound gets excreted fine in renal insufficiency, excretion of metabolites get compromised in renal insufficiency.

The worrisome metabolite of morphine is morphine-6-glucuronide, also known as M6G. It is extremely potent (more than its parent compound), crosses the blood-brain barrier and may cause life-threatening respiratory depression as well as hallucinations. Though it is removable via dialysis (which takes away analgesic effect and causes rebound pain effect), it takes a long time to diffuse out of CNS and continue to have CNS depression effect. Moreover, on the other hand, morphine-3-glucuronide (M3G) causes behavioral excitation. 

In conclusion, Morphine in patients with renal insufficiency can cause very unpredictable effects.


Reference: 

 Dean M. Opioids in renal failure and dialysis patients. J Pain Symptom Manage. 2004;28:497-504.

Q: Though clinical judgement prevails, but why it is recommended to continue  intravenous infusion of diltiazem after bolus for control of atrial fibrillation with Rapid Ventricular Response (RVR) rate?


Answer: It is recommended to continue intravenous infusion of diltiazem after bolus for control of atrial fibrillation with Rapid Ventricular Response (RVR) rate because control of the ventricular rate gets lost in about 90 minutes after bolus dose.

Q: Increased Plateau Pressure (Pplat) on ventilator represents (Select one)

A) static compliance of lung parenchyma
B) static compliance of lung parenchyma and chest wall
C) static compliance of lung parenchyma, chest wall, and abdomen
D) an increase in airway resistance 
E) pressure recorded during a pause at end-expiration


Answer:  C

 The objective of above MCQ is to emphasize the point that increased Plateau Pressure (Pplat) on ventilator represents static compliance of lung parenchyma, chest wall, and abdomen. Effect of abdominal distension on ventilator mechanics is very under-appreciated.

 Choice D is wrong as an increase in resistance of the airways due to various reasons including obstruction of the endotracheal tube is measured by Peak Pressure (Ppeak).

 Choice E is wrong as Plateau Pressure (Pplat) on ventilator represents recorded pressure during a pause at end-inspiration. 


References: 

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

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

3. Tobin MJ. Advances in mechanical ventilation. N Engl J Med 2001; 344:1986.

Q: In Full Pulmonary embolism (PE) severity index (PESI), which gender is assigned 10 points? (select one) 

 A) Male 
B) Female 


 Answer: Male

Against common concept that females are more prone to get more severe pulmonary embolism, male gender is found to have a higher risk of more severe PE. Full PESI has 11 identified points, which was later simplified to 6 points.

References: 

1. Aujesky D, Obrosky DS, Stone RA, et al. Derivation and validation of a prognostic model for pulmonary embolism. Am J Respir Crit Care Med 2005; 172:1041. 

2. Jiménez D, Aujesky D, Moores L, et al. Simplification of the pulmonary embolism severity index for prognostication in patients with acute symptomatic pulmonary embolism. Arch Intern Med 2010; 170:1383.

Q: All of the following predicts probable failure of non-invasive positive pressure ventilation (NIPPV) in patients with acute exacerbation of  COPD except?

A) Glasgow Coma Score less than 8
B) APACHE II score more than or equal to 29
C) Respiratory rate more than or equal to 30 
D) PH less than 7.25
E) No improvement in ABG after 2 hours on NIPPV


Answer: A

Glasgow Coma Score less than 11 predicts probable failure of trial of standard two hours of NIPPV in patients with acute exacerbation of COPD. All other choices are applicable too. Also, if patient PH does not show any improvement or remain less than 7.25 after 2 hours trial of NIPPV, predicts probable intubation.


References: 

1. Confalonieri M, Garuti G, Cattaruzza MS, et al. A chart of failure risk for noninvasive ventilation in patients with COPD exacerbation. Eur Respir J 2005; 25:348. 

2. Stefan MS, Shieh MS, Pekow PS, et al. Trends in mechanical ventilation among patients hospitalized with acute exacerbations of COPD in the United States, 2001 to 2011. Chest 2015; 147:959. 

3. Phua J, Kong K, Lee KH, et al. Noninvasive ventilation in hypercapnic acute respiratory failure due to chronic obstructive pulmonary disease vs. other conditions: effectiveness and predictors of failure. Intensive Care Med 2005; 31:533. 

4. Carratù P, Bonfitto P, Dragonieri S, et al. Early and late failure of noninvasive ventilation in chronic obstructive pulmonary disease with acute exacerbation. Eur J Clin Invest 2005; 35:404.

Q: pRBC can be freezed and can be preserved for how many years?

Answer: pRBC which is frozen at -80ºC in 40% glycerol can be preserved for 10 years. It is found to be of extreme value for patients who have very rare type of blood group or if IgA negative donor cannot be found for patients with IgA deficiency. Only drawback of frozen pRBC is time needed to thaw and wash the product.


References: 

 1. Lecak J, Scott K, Young C, et al. Evaluation of red blood cells stored at -80 degrees C in excess of 10 years. Transfusion 2004; 44:1306. 

2. Fabricant L, Kiraly L, Wiles C, et al. Cryopreserved deglycerolized blood is safe and achieves superior tissue oxygenation compared with refrigerated red blood cells: a prospective randomized pilot study. J Trauma Acute Care Surg 2013; 74:371.

Q: All of the followings can be used in the healing of pressure ulcers in long-term patients except?

A) Negative pressure wound therapy 
B) Hyperbaric oxygen therapy (HBOT) 
C) Ultrasound therapy
D) Electrical stimulation
E) Topical nitrogen


Answer: E

Pressure ulcer is one potential catastrophe in ICU which can be prevented with proper care and designated protocol. Various adjunctive therapies have been used to heal pressure ulcer besides standard dressing, debridement and use of transparent films. 

Negative pressure wound therapy (woundVac) enhances wound healing by increasing blood flow and formation of granulation tissue. HBOT  is used with less frequency. Ultrasound, electrical stimulation, application of growth factors, topical oxygen (not topical nitrogen - Choice E), pulsed radiofrequency energy therapy and electromagnetic therapy have also been proposed.