Prone Positioning

Objective:

The survival benefit of prone positioning during mechanical ventilation for acute respiratory distress syndrome has been a matter of debate. Recent multicenter randomized controlled trials have shown a significant reduction of 28-day and 90-day mortality associated with prone positioning during mechanical ventilation for severe acute respiratory distress syndrome. We performed an up-to-date meta-analysis on this topic and elucidated the effect of prone positioning on overall mortality and associated complications.

Data Sources:

PubMed, EMBASE, BioMed Central, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and conference proceedings through May 2013.

Study Selection:

Randomized controlled trial comparing overall mortality of prone-versus-supine positioning in patients with acute respiratory distress syndrome.

Data Extraction:

Data were extracted for populations, interventions, outcomes, and risk of bias. The prespecified primary endpoint was overall mortality, using the longest available follow-up in each study. The odds ratio with 95% CI was the effect measure.

Data Synthesis:

This analysis included 11 randomized controlled trial, 2,246 total adult patients, and 1,142 patients ventilated in the prone position. Prone positioning during ventilation significantly reduced overall mortality in the random-effect model (odds ratio, 0.77; 95% CI, 0.59–0.99; p = 0.039; I2 = 33.7%), and the effects were marked in the subgroup in which the duration of prone positioning was more than 10 hr/session, compared with the subgroup with a short-term duration of prone positioning (odds ratio, 0.62; 9% CI, 0.48–0.79; p = 0.039; pinteraction = 0.015). Prone positioning was significantly associated with pressure ulcers (odds ratio, 1.49; 95% CI, 1.18–1.89; p = 0.001; I2 = 0.0%) and major airway problems (odds ratio, 1.55; 95% CI, 1.10–2.17; p = 0.012; I2 = 32.7%).

Conclusions:

Ventilation in the prone position significantly reduced overall mortality in patients with severe acute respiratory distress syndrome. Sufficient duration of prone positioning was significantly associated with a reduction in overall mortality. Prone ventilation was also significantly associated with pressure ulcers and major airway problems.

Reference:

Lee, Joo Myng MD, MPH; Bae, Won MD; Lee, Yeon Joo MD; Cho, Young-Jae MD, MPH - The Efficacy and Safety of Prone Positional Ventilation in Acute Respiratory Distress Syndrome: Updated Study-Level Meta-Analysis of 11 Randomized Controlled Trials - Critical Care Medicine: May 2014 - Volume 42 - Issue 5 - p 1252-1262

Q: 42 year old female with recent refractory hypoxemia has been salvaged with adjuvant treatment of inhaled Nitric Oxide (iNO). Patient is now improved and require discontinuation of iNO?

Answer:  Sudden discontinuation of iNO after prolonged use may cause rebound acute hypoxemia and acute pulmonary hypertension. iNO should be wean gradually. One recommended strategy is to reduce the dose by 10ppm every 2 hours till it reaches to dose of 10ppm, and then reduce the dose by 2.5ppm over several hours with close monitoring.

Q: At what level of WBC, Platelet and Hematocrit count,  pseudohyperkalemia is expected

Answer: Pseudohyperkalemia is usually a laboratory artifact rather than a real biological abnormality.

Beside common causes of pseudohyperkalemia like hemolysis, excessive tourniquet time or a delay in the processing of the blood specimen, it can also occur in specimens from patients with abnormally high numbers of

• platelets (>500,000/mm³),
• leukocytes (> 70 000/mm³), or
• erythrocytes (hematocrit > 55%)

Q: 37 year old female with previous history of 3 pulmonary embolisms, on warfarin - admitted to ICU with new onset seizure activity. CT scan of head in ER reported negative. Phenytoin has been started in ER. What is major concern?

Answer: Decrease effect of Warfarin

A note on Digoxin-Amiodarone interaction

Amiodarone may decrease the clearance of digoxin, causing prolonged digoxin activity. Also, there may be a synergistic effect on the sinus node. Digoxin level should always be obtained prior to initiation of amiodarone therapy. Usually, it requires to decrease the dose of digoxin by 25-50% and close monitoring of digoxin levels. In addition, electrolytes should also be closely monitored. Patients with hypothyroidism needs extra attention.

Q: Temperature around stored oxygen tanks in hospital / ICU should not exceed to what degree

Answer:  125 F (52 C)

When the oxygen tank is not in use valves should be kept close and oxygen tanks should be stored below 125°F (52 C).

Q: 37 year old female is in ICU for suspected DVT. There is concern for HIT (Heparin induced Thrombocytopenia). Patient is clinically stable. Patient is therapeutic  Decision is made to stop Heparin and start Argatroban. How long should you wait before initiating Argatroban?

Answer:  About 3 hours

For Enoxaparin it is recommended to wait about 8 hours. All relevant labs should be checked before starting Argatroban.

Q: 47 year old male just arrived from OR and now have accelerated hypertension, A.fib with RVR, Hyperthermia and muscle rigidity. There is a high suspicion of Neuroleptic malignant syndrome (NMS). Decision was made to use IV Dantrolene (Dantrium). Which drug should be avoided in treatment of A.fib. with RVR?

Answer: Calcium Channel Blocker (Cardizem or Verapamil)

Concomitant use of calcium channel blockers like Cardizem or Verapamil with intravenous treatment with dantrolene may lead to severe cardiovascular collapse, arrhythmias, myocardial depressions, and hyperkalemia.

Bonus Pearl: Dantrium is incompatible with D5W or normal saline! And is given by direct injection.

Pleural effusion via ultrasound

Link: http://youtu.be/X1E7OgOLzw0

Echocardiographic diagnosis of Aortic Dissection

Link: https://www.youtube.com/watch?feature=player_embedded&v=mrbT4Sd1nS4

Q: In Acute Aortic Dissection, why it is imperative to not only decrease the blood pressure but also the heart rate??

Answer:   In aortic dissection and aortic aneurysm, propagation of aortic dissection depends not only on the absolute blood pressure, but also on the velocity of left ventricular contraction. Target heart rate between 55 and 65 per minute is recommended.

Reference:  Varon, J.; Marik, P.E. The diagnosis and management of hypertensive crises. Chest 2000, 118, 214-227.

Q: Why Vasotec (Enalapril) never got popular as an intravenous anti-hypertensive in ICUs?

Answer:   Vasotec (Enalapril) can be use as an anti-hypertensive in doses from 0.625 – 5 mg IV q6 hours.

Though initial BP reduction occurs in 15 minutes but full response may not occur for up to 4-6 hours after  first dose and in many instances may lead to cumulative effect of various doses, causing massive drop in BP.

Q: What is the advantage of Fosinopril (Monopril) over other ACE-Inhibitors?

Answer:  Fosinopril is the only phosphinate-containing ACE inhibitor.

Clinical significance: In contrast to other ACE inhibitors, fosinopril is eliminated from the body via both renal and hepatic pathways, which make it a safer choice in  patients with impaired kidney function.

Q: 56 year old male with established history of Paroxysmal Atrial fibrillation - on home medications of Digoxin and warfarin is admitted to ICU with A.fib.-RVR (Rapid Ventricular Response). Patient didn't respond to Esmolol or Cardizem IV drips, but to IV bolus and maintenance drip of Amiodarone. What should be a caution?

Answer:  Monitor Digoxin level closely.

Amiodarone will increase the level or effect of digoxin by cationic drug competition for renal tubular clearance, which may cause life-threatening interaction.

Q: Which PO drug is approved for DVT prophylaxis after knee or hip surgery ?

Answer:  Rivaroxaban (Xarelto)

Dose is 10 mg daily with or without food 6 to 10 hours after surgery. Treatment duration should be for 12 days after knee surgery and 35 days after hip surgery.

Q: Which commonly used diuretic in ICU may effect cosyntropin test?

Answer:  Spironolactone

Patients taking spironolactone or drugs which contain estrogen may exhibit abnormally high basal plasma cortisol levels. Also, women should ideally undergo testing during the first week of their menstrual cycle as aldosterone (and possibly cortisol) may be falsely elevated in the luteal cycle secondary to progesterone inhibition.

Q: Why corticosteroids are added with Praziquantel in treatment of Neurocysticercosis?

Answer:  Praziquantel can evoke an inflammatory response in CNS. Corticosteroids helps in decreasing inflammation. But to note, when corticosteroids are given in combination with praziquantel, it decreases the action of praziquantel by enhancing its first pass metabolism. It is recommended to add cimetidine in the regimen.  Co-administration of cimetidine raises serum praziquantel levels.

References:

1. White, Jr., A. Clinton (2009). "New developments in the management of neurocysticercosis". The Journal of Infectious Diseases 199 (9): 1261–2.

2. Dimitrios K. Matthaiou, Georgios Panos, Eleni S. Adamidi,Matthew E. Falagas “Albendazole versus Praziquantel in the Treatment of Neurocysticercosis: A Meta-analysis of Comparative Trials” PLoS Negl Trop Dis. 2008 March; 2(3): e194

3. Dachman WD1, Adubofour KO, Bikin DS, Johnson CH, Mullin PD, Winograd M. - Cimetidine-induced rise in praziquantel levels in a patient with neurocysticercosis being treated with anticonvulsants. - J Infect Dis. 1994 Mar;169(3):689-91

Q: What is the characteristic finding in CSF in Guillain–Barré syndrome (GBS)?

Answer: Albumino-cytological dissociation

In Guillain–Barré syndrome, cerebrospinal fluid (CSF) shows characteristic finding of albumino-cytological dissociation. In contrast to infectious causes, there is an elevated protein level (100–1000 mg/dl), without pleocytosis. An increased white blood cell count may indicate an alternative diagnosis, probably an infection.

Q: Which benzodiazepine is more prone to have paradoxical effects than any other benzodiazepines?

Answer: Lorazepam

Paradoxical effects of benzodiazepines like increased hostility, aggression, angry outbursts, and psychomotor agitation are seen more commonly with lorazepam than any other benzodiazepines.

Reference:

Sorel L, Mechler L, Harmant J (1981). "Comparative trial of intravenous lorazepam and clonazepam im status epilepticus". Clinical Therapeutics 4 (4): 326–336

Q: What could be the one bedside trick to get pass small bore feeding tube post-pyloric, once its placement is confirmed in stomach?

Answer: Once small bore feeding tube (DHT) is confirmed in stomach but continue to present challenge to go beyond pylorus - insufflate about 300cc of air into stomach to help open pylorus. Once DHT is placed post-pyloric, air can be deflated via NGT or be observed if no clinical compromise.

Understanding IABP waveform

     Link:  http://www.youtube.com/watch?feature=player_embedded&v=Ff-1YXaUBO0

Q: How to define submassive PE?

Answer: Acute PE without systemic hypotension (systolic blood pressure ≥90 mm Hg) but with either RV dysfunction or myocardial necrosis.

1. RV dysfunction means the presence of at least 1 of the following:

• RV dilation (apical 4-chamber RV diameter divided by LV diameter >0.9) or RV systolic dysfunction on echocardiography
• RV dilation (4-chamber RV diameter divided by LV diameter >0.9) on CT
• Elevation of BNP (>90 pg/mL)
• Elevation of N-terminal pro-BNP (>500 pg/mL); or
• Electrocardiographic changes (new complete or incomplete right bundle-branch block, anteroseptal ST elevation or depression, or anteroseptal T-wave inversion)

2. Myocardial necrosis is defined as either of the following:

• Elevation of troponin I (>0.4 ng/mL) or
• Elevation of troponin T (>0.1 ng/mL)

Reference:

Management of Massive and Submassive Pulmonary Embolism, Iliofemoral Deep Vein Thrombosis, and Chronic Thromboembolic Pulmonary Hypertension - A Scientific Statement From the American Heart Association - Circulation. 2011; 123: 1788-1830

Pulmonary Embolism in Pregnancy

Investigation of suspected pulmonary embolism in pregnant patient is similar to that in non-pregnant patients, beginning with duplex ultrasound. False-positive results may occur because of venous occlusion by the enlarged uterus. Ventilation-perfusion scanning and CT angiogram can be carried out with a low risk for fetal radiation exposure.

Unfractionated heparin and low molecular-weight heparin are safe and effective in pregnancy.

Warfarin is usually avoided because of the risk for embryopathy with first-trimester use and central nervous system abnormalities and bleeding risk with second- and third-trimester use.

Thrombolysis has been used successfully during pregnancy and the postpartum period but should be limited to life-threatening situations.

Mechanical Ventilation in Pregnancy

The indications for intubation of a pregnant patient are no different than the non-pregnant patient.

The guiding principle of ventilating the pregnant patient is ensuring adequate oxygen delivery. The goal is a PaO2 of >90 mmHg.

Positive end-expiratory pressure (PEEP) should be applied to keep the FiO2 <60%, but the patient should be kept in the left lateral decubitus position to minimize the effect of PEEP on venous return.

Permissive hypercapnia, a strategy used in acute lung injury, may lead to fetal distress. If higher PaCO2 levels are being sustained in the pregnant patient, then continuous fetal monitoring is required.

Sedation with propofol and opioid drugs are safe, though the fetus may need to be intubated on delivery as these drugs cross the placenta.

Benzodiazepines should be avoided as they have been shown to increase the incidence of cleft palate.

Higher than normal peak and plateau airway pressures can be expected on the ventilator: compression of the diaphragm by the gravid uterus will increase respiratory system elastance.

Fetal viability can be maintained while a patient is on mechanical ventilation, even during maternal brain death. Delivery or termination of pregnancy does not seem to improve the respiratory status of the mother, and therefore is not recommended.

Cardiopulmonary Arrest in Pregnancy

Cardiac arrest occurs only about one in every 30,000 late pregnancies, but survival from such an event is exceptional.

Because of the increased risk of regurgitation and pulmonary aspiration of gastric contents in late pregnancy, cricoid pressure should be applied until the airway has been protected by a cuffed tracheal tube.

Ventilation is made more difficult by the increased oxygen requirements and reduced chest compliance in pregnancy. The reduced compliance is due to rib flaring and splinting of the diaphragm by the abdominal contents. Observing the rise and fall of the chest in pregnant patients is also more difficult.

A pregnant patient requiring chest compressions should have a Cardiff Wedge or other device achieving approximately a 30° tilt placed under her back. This allows the patient to have adequate support of the torso for cardiopulmonary resuscitation (CPR) but also minimizes compression of the inferior vena cava (IVC). A backboard with rolled up towels or pillows under one side can substitute.

The pregnant patient can safely undergo direct current cardioversion, both synchronized and unsynchronized. Drugs such as lidocaine, procainamide, adenosine, and quinidine can be safely used in the gravidpatient. Amiodarone is contraindicated secondary to the possible effects on fetal thyroid development.

It is possible for an emergent cesarean section to be performed during CPR.

                                  Cardiff Wedge

                                     

Q: What is the “T-A-DA" approach in the management of Delirium?

Answer: T-A-DA stands for tolerate, anticipate, don't agitate

T-A-DA is an effective management technique for people with delirium. As name suggests,

• all unnecessary IVs, catheters, NG tubes or attachments are discontinued
• Allow  greater mobility
• Patient behavior is tolerated (as long as it does not put the patient or other people in danger)
• Patient is provided close supervision for safety
• Patient behavior is anticipated (care givers teaching)
• Patient is treated to reduce agitation

Flaherty, J.; Little, M. (2011). "Matching the Environment to Patients with Delirium: Lessons Learned from the Delirium Room, a Restraint-Free Environment for Older Hospitalized Adults with Delirium". Journal of the American Geriatrics Society 59: 295–300

One emotional talk for ICU caregivers

Link: http://youtu.be/bvm6_6vtGa4

Q: Is Amiodarone dialyzable?

Answer: No

Neither amiodarone nor N-desethylamiodarone (DEA) is dialyzable. N-desethylamiodarone (DEA) is the major active metabolite of amiodarone.

Related: 

Handbook Dialysis of Drugs 2013 http://renalpharmacyconsultants.com/assets/2013dodbooklet.pdf