Q: Why "Nitro" drip is always supplied in glass bottle with special tubing?

Answer: Nitroglycerin binds to soft plastics bags and tubings which commonly contains polyvinylchloride (PVC). According to pharmacy literature, about 80% of the drug can be lost by this adsorption. Nitroglycerin should be given in glass and stiff polyethylene tubing. This could very well be the cause if patient requires high dose for effective clinical response*, though nitrate tolerance is another major reason if causes for adsorption is eliminated.


* Some central venous catheters may be made out from  PVC.

Q: Which 2 factors may increase the risk of Vasoplegia after CABG (Coronary Artery Bypass Graft)?

Answer:

1. On-pump CABG, and

2. Hypothermia during surgery

References:

1. Sun X, Zhang L, Hill PC, et al. (October 2008). "Is incidence of postoperative vasoplegic syndrome different between off-pump and on-pump coronary artery bypass grafting surgery?". Eur J Cardiothorac Surg 34 (4): 820-5. 

2.  Xu J, Long C, Qi R, Xie L, Shi S, Zhang Y (January 2002). "[Study of mechanism of vasoplegic syndrome for open heart surgery]". Zhonghua Yi Xue Za Zhi (in Chinese) 82 (2): 127–30.

Methylene blue to treat vasoplegia due to a severe protamine reaction: a case report.

Protamine sulfate is used during coronary artery bypass graft surgery to reverse the anticoagulating effects of heparin. Vasoplegic syndrome is a state of endothelial dysregulation that produces profound vasodilatation that is refractory to vasopressors. This syndrome leads to systemic hypoperfusion and may progress to death. Up to 27% of patients after cardiac bypass may experience vasoplegia. Symptoms of vasoplegia may also be present in many different clinical settings. This case report describes a 57-year-old woman who after cardiac bypass experienced a severe protamine reaction with profound hypotension, which was unresponsive to volume resuscitation and vasopressor therapy. A dramatic increase in blood pressure resulted almost immediately after administration of methylene blue. This patient had no prior risk factors for a protamine reaction other than her current cardiac surgery. A review of the pathophysiologic characteristics associated with vasoplegia and the pharmacodynamics of methylene blue will potentially enable anesthesia providers to utilize this lifesaving drug when needed.

Reference:

Lutjen DL, Arndt KL - Methylene blue to treat vasoplegia due to a severe protamine reaction: a case report.- AANA J. 2012 Jun;80(3):170-3.

Intracranial clot retrieval

If video does not play, here is the link: http://youtu.be/7gn96se6j00

Q: For how many days air travel should be avoided after resolution of pneumothorax?

Answer:

Air travel should be avoided for up to 7 days after complete resolution of a pneumothorax. Some guidelines even prefer to wait for 2 weeks. A followup CXR should be obtained prior to travel to confirm resolution of pneumothorax.

Reference: 

1. MacDuff A, Arnold A, Harvey J, BTS Pleural Disease Guideline Group (December 2010). "Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010". Thorax 65 (8): ii18–ii31

2. Practice Guideline, Orlando Regional Medical Center. Air travel following traumatic pneumothorax. October 2009.

Atelectasis as a cause of postoperative fever: where is the clinical evidence?

BACKGROUND: Atelectasis is considered to be the most common cause of early postoperative fever (EPF) but the existing evidence is contradictory. We sought to determine if atelectasis is associated with EPF by analyzing the relevant published evidence.

  METHODS: We performed a systematic search in PubMed and Scopus databases to identify studies examining the association between atelectasis and EPF.

  RESULTS: A total of eight studies, including 998 cardiac, abdominal, and maxillofacial surgery patients, were eligible for analysis. Only two studies specifically examined our question, and six additional articles reported sufficient data to be included. Only one study reported a significant association between postoperative atelectasis and fever, whereas the remaining studies indicated no such association. The performance of EPF as a diagnostic test for atelectasis was also assessed, and EPF performed poorly (pooled diagnostic OR, 1.40; 95% CI, 0.92-2.12). The significant heterogeneity among the studies precluded a formal metaanalysis.

CONCLUSION: The available evidence regarding the association of atelectasis and fever is scarce. We found no clinical evidence supporting the concept that atelectasis is associated with EPF. More so, there is no clear evidence that atelectasis causes fever at all. Large studies are needed to precisely evaluate the contribution of atelectasis in EPF.


  Reference: 

Mavros MN, Velmahos GC, Falagas ME.- Atelectasis as a cause of postoperative fever: where is the clinical evidence? Chest. 2011 Aug;140(2):418-24. Epub 2011 Apr 28.

Using the Bougie for Endotracheal Intubation

lf video does not play or appear, here is the link

http://youtu.be/qcDXZgV3m8I

Q; What is Foster Kennedy syndrome?

Answer:

Foster Kennedy syndrome  is a group of findings associated with tumors of the frontal lobe. It causes optic atrophy in the ipsilateral eye but disc edema in the contralateral eye. Also, it cause central scotoma in the ipsilateral eye and anosmia ipsilaterally.

Usually intracranial mass and increase ICP causes optic nerve and olfactory nerve compression.

It may cause other frontal lobe symptoms too like memory loss, emotional lability etc.

A short note on Lidocaine therapeutic profile 

When the lidocaine dose is increased from 1 mg/kg to 1.5 mg/kg, the risk of CNS toxicity increases from 10% to 80%. 

Usually, seizures generally do not occur with lidocaine levels of less than 10 mcg/mL but other CNS effects may occur like lightheadedness, dizziness, visual disturbance, headache, numbness, impaired concentration, dysarthria, tinnitus, muscular twitching etc

Q: Hematology service ordered IV Iron for an anemic patient who is Jehovah witness by faith. Nurse asked you about test dose?

Answer:

As studies indicates that allergic reactions may still occur in patients who have not reacted to a test dose, a test dose is no longer recommended.

Every caution should be exercised with every dose of intravenous iron that is given, even if previous administrations have been shown no signs of reaction.


Reference:

Press release from The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) on 28/06/2013 - New recommendations to manage risk of allergic reactions with intravenous iron-containing medicines.

Q: Do you need ABG (arterial blood gas) in DKA (Diabetic Ketoacidosis)?

Answer: An Interesting study recently published from UK concluded that:

"A venous blood sample, analysed on a blood gas machine, is sufficiently reliable to assess pH, bicarbonate and potassium concentrations in critically ill patients, suggesting that venous sampling alone is appropriate in the management of diabetic ketoacidosis."

Reference:

Herrington WG, Nye HJ, Hammersley MS, Watkinson PJ. Are arterial and venous samples clinically equivalent for the estimation of pH, serum bicarbonate and potassium concentration in critically ill patients?. Diabet Med. Jan 2012;29(1):32-5.

Olanzapine and Hyperglycemia

Olanzapine (Zyprexa) is frequently used in ICU for delirium. One of the side effects to be aware of is hyperglycemia. Olanzapine may induce hyperglycemia by altering insulin secretion from the pancreatic beta-cell through blockade of the muscarinic M3 receptor. It has been reported to induce DKA (Ketoacidosis).

If Olanzapine-induced hyperglycemia is suspected, it should be withdrawn or switched to some other medicines without worsening the psychiatric condition of patient.

Further reading

1. Weston-Green, Katrina; Huang, Xu-Feng; Lian, Jiamei; Deng, Chao (2012). "Effects of olanzapine on muscarinic M3 receptor binding density in the brain relates to weight gain, plasma insulin and metabolic hormone levels". European Neuropsychopharmacology 22 (5): 364–73.

2. Lindenmayer JP, Patel R. Olazapine-induced ketoacidosis with diabetes mellitus (letter) Am J Psychiatry. 1999;156:1471.

3. Roefaro J, Mukherjee SM. Olanzapine-lnduced hyperglycemic nonketonic coma. Ann Pharmacother.2001;35:300–2.

4. Seaberg HL, McLendon BM, Doraiswamy PM. Olanzapine-Associated Severe Hyperglycemia, Ketonuria, and Acidosis: Case Report and Review of Literature. Pharmacotherapy. 2001;21:1448–54

5. Ober SK, Hudak R, Rusterholtz Hyperglycemia and olanzapine. Am J Psychiatry. 1999;156:970.

6. Goldstein LE, Sporn J, Brown S, Kim H, Finkelstein J, Gaffey GK, et al. New-onset diabetes mellitus and diabetes ketoacidosis associated with olanzapine treatment. Psychosomatics. 1999;40:438–4

Q: How early psychosis can hit with steroid therapy?

Answer: As early as 4 days

Psychiatric symptoms may develop as soon as after 4 days of corticosteroid therapy, although they can occur anytime in therapy or even after treatment ends. High corticosteroid dose is the primary risk factor for psychosis.

Primary treatment is tapering off steroid along with various antipsychotic drugs if needed.

Further reading:

1. Warrington TP, Bostwick JM. Psychiatric adverse effect of corticosteroids. Mayo Clin Proc. 2006;81(10):1361-1367

2. Sirois F. Steroid psychosis: a review. Gen Hosp Psychiatry. 2003;25:27-33.

3.  Hall RC, Popkin MK, Stickney SK, et al. Presentation of the steroid induced psychosis. J Nerv Ment Dis. 1979;167:229-236

Q: Assume if you don't have luxury of time - and - you have to send patient for CT scan with IV contrast, who has listed allergy to IV contrast. What would be your recommendation?

Answer:

200mg Hydrocortisone IV 4 hours (or as soon as possible) before injection. Also, 50mg Benadryl (Diphenhydramine) IV/PO before (or as soon as possible) 1 hour of the injection.

If time permits, ideal would be to give 50mg Prednisone PO 13, 7 and 1 hour before the injection. And, 50mg Benadryl (Diphenhydramine) IV/PO before 1 hour of the injection.

Q: In which allergy Protamine should be given with caution?

Answer: Protamine was originally isolated from the sperm of salmon and other species of fish but is now produced primarily through recombinant biotechnology. The patients who are considered to be most at risk for a reaction to protamine are those with

• An allergy to fish
• Prior protamine exposure
• Vasectomy

Note: There is a distinct genetic difference between shellfish and vertebrate fish, so, an allergy to shellfish does not predispose one to an adverse protamine reaction.




Further reading:

1. Collins and A O'Donnell - Perfusion 2008 23: 369 Does an allergy to fish pre-empt an adverse protamine reaction? A case report and a literature review

2. Watson RA, Ansbacher R, Barry M, Deshon GE Jr, Agee RE - Allergic reaction to protamine: a late complication of elective vasectomy? - Urology. 1983 Nov;22(5):493-5.

Q: Which one disease process in ICU may give prolong ACT (Activated Clotting Time) ?

Answer:  Lupus anticoagulant (LA)

In patients with Lupus anticoagulant, other tests should be considered. ACT becomes unreliable in patients with LA.

In some patients the presence of a lupus anticoagulant has been shown to interfere with and prolong the ACT but in other cases the ACT may be relatively unaffected.

Q: What is Ecarin clotting time (ECT)?

Answer:  Clinically not in much use but "Ecarin Clottting Time" is the most precise way to measure/monitor the activity of Direct Thrombin Inhibitors (DTIs). Though most of the literature is available with experience to hirudin, but is likely to be useful to other DTIs, in particular to new oral direct thrombin inhibitors.

Ecarin, the primary reagent in this assay, is derived from the venom of the saw-scaled viper, Echis carinatus.

This is an important test to be aware of in ICU as both Activated Clotting Time (ACT) and PTT have no particular linear correlation between the plasma DTIs levels and their activities particularly at higher level.

Refer to lab. for reference therapeutic level for a particular DTI.

References:

1. Di Nisio M, Middeldorp S, Büller H (2005). "Direct thrombin inhibitors.". N Engl J Med 353 (10): 1028–40

2.  Use of Ecarin Clotting Time (ECT) with Lepirudin Therapy in Heparin-Induced Thrombocytopenia and Cardiopulmonary Bypass. JECT 33:117–125.

3.  Lange U, Nowak G, Bucha E. Ecarin chromogenic assay—a new method for quantitative determination of direct thrombin inhibitors like hirudin. Pathophysiol Haemost Thromb. 2003 Jul-2004 Aug;33(4):184-91.

4. Pathophysiol. Haemost. Thromb. 33 (4): 173–83.

Q: How to distinguish between traumatic bloody ascitic tap and non-traumatic bloody ascitic fluid?


Answer:

Bloody ascitic fluid from a traumatic tap will be heterogeneously bloody, and tend to clot. Nontraumatic bloody fluid is usually homogeneously red and does not clot because the blood has already been lysed after clotting within sac.

A minimum of 10,000 red blood cells/µL is required for ascitic fluid to appear pink, and more than 20,000 red blood cells/µL to produce distinctly blood-tinged fluid.

Q: Give few under recognized reasons of Intra-abdominal compartment syndrome in ICU?

Answer:

• Massive volume resuscitation
• Retroperitoneal hematoma
• Diffuse peritonitis
• Acute pancreatitis causing retroperitoneal inflammatory edema
• Ileus and bowel obstruction
• Any massive Intraabdominal mass
• Abdominal packing
• Tense closure of the abdomen
• Ascites

Q: Why Etomidate should not be pushed fast ?


Answer:  Very rapid push of etomidate may cause trismus.

Trismus is the reduced opening of the jaws caused by spasm of the muscles of mouth. Etomidate must be pushed slowly. If trismus is encountered, it may become necessary  to use paralytics.

On significance of Post Intubation hypotension (PIH)

See this interesting poster presentation

Introduction

Arterial hypotension is known to follow emergency intubation but the significance of this event is poorly described. We aimed to measure the incidence of post-intubation hypotension (PIH) following emergency intubation and determine its association with in-hospital mortality.

Methods

A retrospective cohort study of endotracheal intubations performed in a large, urban emergency department over a 1-year period. Patients were included if they were >17 years old and had systolic blood pressure (SBP) >90 mmHg for 30 consecutive minutes prior to intubation. Patients were analyzed in two groups: those with PIH defined by SBP <90 mmHg within 60 minutes of intubation, and those with no PIH. The primary outcome was hospital mortality.

Results

Emergency intubation was performed on 465 patients, of which 336 met inclusion criteria and were analyzed. The median patient age was 49 years, 59% of patients presented with nontraumatic illness and 92% underwent induction with etomidate. PIH occurred in 76/336 (23%) of patients. The median time to first PIH was 11 minutes (IQR 2 to 27). Intubation for acute respiratory failure was the only independent predictor of PIH (OR = 2.1, 95% CI = 1.1 to 4.0). Patients with PIH had significantly higher in-hospital mortality (33% vs. 21%; 95% CI for 12% difference = 1 to 23%) and longer mean ICU length of stay (9.7 vs. 5.9 days, P < 0.01) and hospital length of stay (17.0 vs. 11.4 days, P < 0.01). Multivariate logistic regression analysis confirmed PIH as an independent predictor of hospital mortality (OR = 1.9, 95% CI = 1.1 to 3.6).

Conclusions

PIH occurs in nearly one-quarter of normotensive patients undergoing emergency intubation. Intubation for acute respiratory failure is an independent predictor of PIH. PIH is associated with a significantly higher in-hospital mortality and longer ICU and hospital lengths of stay.

Reference:

Frequency and significance of post-intubation hypotension during emergency airway management - Critical Care 2011, 15(Suppl 1):P154 

Q: What is the indication of hemodialysis in acute ethanol poisoning solely depending on blood level?

Answer:   Ethanol blood level  >400 mg%

Hemodialysis should be considered in patients if the blood concentration is dangerously high, >400 mg%. Or if clinical condition remains unstable with metabolic acidosis, severe CNS depression, life threatening respiratory failure or hypotension refractory to pressors.

Q: Which common conditions encountered in ICU may give falsely normal or higher level of Pre-albumin?

Answer:

1. Alcoholics may have elevated levels of prealbumin after binge drinking. In acute alcohol intoxication, a leakage of proteins from damaged hepatic cells may cause a rise in the prealbumin level.  It takes about a week, when levels return to baseline.

2. Prednisone therapy may cause falsely higher prealbumin levels.

3. Patients on chronic progestational agents may have falsely higher prealbumin level.

Reference:

1.  Staley MJ, Naidoo D, Pridmore SA. Concentrations of transthyretin (prealbumin) and retinol-binding protein in alcoholics during alcohol withdrawal [Letter]. Clin Chem. 1984;30:1887.

2. Oppenheimer JH, Werner SC. Effect of prednisone on thyroxine-binding proteins. J Clin Endocrinol Metab. 1966;26:715–21.

Q: Which lab tests may help in distinguish between Cardiogenic pulmonary edema and TRALI (Transfusion related acute lung injury) ?

Answer:

Brain natriuretic peptide (BNP) may be useful in distinguishing the cardiogenic pulmonary edema present in circulatory overload from the noncardiogenic pulmonary edema which is usually presents in TRALI.

Other laboratory findings may include unexpected haemoconcentration and a sudden fall in serum albumin. As in other causes of acute alveolar capillary leak, the pulmonary exudate in TRALI has a high albumin content. Also, Peripheral blood neutropenia has been reported but neutrophilia is more common.

Reference:

1. Skeate RC, Eastlund T. Distinguishing between transfusion related acute lung injury and transfusion associated circulatory overload. Curr Opin Hematol. Nov 2007;14(6):682-7

2. The pathology of transfusion-related acute lung injury. Am J Clin Pathol 1999; 112: 216–21