Wednesday October 22, 2008


Q: What is half life of Xigris - Recombinant Protein C (Activated) ?


A; Xigris has a short half-life, indicating rapid inactivation of Xigris after stopping infusion and more than 70% get eliminate within 30 minutes.

General recommendations are

• Discontinue Xigris 2 hours prior to performing an invasive procedure and may restart immediately after uncomplicated, less invasive procedures
• Initiation of Xigris can be considered 12 hours after major invasive procedures or surgery
• Prophylactic heparin/LMWH may be continued while patient is on xigris
  

Note:

• Xigris may variably prolong the APTT. Therefore, the APTT cannot be reliably used to assess the status of the coagulopathy during Xigris infusion.
• Xigris has minimal effect on the PT

Tuesday October 21, 2008

Q: What percentage of patients may develop complications secondary to brachial artery cannulation?

Answer: upto 42%

It was established almost 40 years ago by Mortensen 1 that brachial artery cannulation is not an ideal location. The lack of collateral circulation about the elbow may predispose to forearm and hand ischemic complications.

Case report & review: Compartment Syndrome of the Forearm and Hand After Brachial Artery Cannulation (pdf) - Anesth Analg 1995; 81: 1092-4



Reference:

1. Mortensen JD. Clinical sequelae from arterial needle puncture, cannulation, and incision. Circulation 1967;35:1118-23.

Monday October 20, 2008
Dexmedetomidine (precedex) Infusion as Adjunctive Therapy for Acute Alcohol Withdrawal

Emerging literature is very promising for Dexmedetomidine (precedex) Infusion as an adjunctive therapy to benzodiazepines in acute alcohol withdrawal.

Review of literature shows that dexmedetomidine was shown to be beneficial in alcohol withdrawal delirium first in rats about 10 years ago ! 4 but later many case series in humans have shown a rapid response to alcohol withdrawal delirium after the standard treatment. 1, 2, 3, 5 Dexmedetomidine is a selective alpha-2 adrenergic agonist that possesses a high ratio of specificity for the alpha-2 versus the alpha-1 receptor.

The biggest advantage of Dexmedetomidine over benzodiazepines in acute alcohol withdrawal therapy, is that it doesn't suppress respiratory drive and carries simultaneuos properties of analgesia, sedation and anxiolysis.

Related article: The Role of Dexmedetomidine (Precedex) in the Sedation of Critically Ill Patients (ref: P&T, Vol. 30 No. 3 • March 2005 , 158-161)



References: click to get abstract / article

1. Dexmedetomidine as an adjuvant in the treatment of alcohol withdrawal delirium: a case report - General Hospital Psychiatry , Volume 28 , Issue 4 , Pages 362 - 363
2. Dexmedetomidine in the Treatment of Withdrawal Syndromes in Cardiothoracic Surgery Patients - Journal of Intensive Care Medicine, Vol. 20, No. 2, 118-123 (2005)
3. Dexmedetomidine for peri-operative sedation and analgesia in alcohol addiction - Correspondence - Anaesthesia. 61(3):299-300, March 2006.
4. . Dexmedetomidine, diazepam, and propranolol in the treatment of ethanol withdrawal symptoms in the rat - Alcohol Clin Exp Res.1997 Aug;21(5):804-8
5. Dexmedetomidine Infusion as Adjunctive Therapy to Benzodiazepines for Acute Alcohol Withdrawal - Published Online, 9 September 2008, Tha annals of Pharmacotherapy.

Sunday October 19, 2008


Q: What difference does it make in giving 1 ampule of calcium gluconate and 1 ampule of calcium chloride to patient?

Answer: Calcium chloride contains 3 times more elemental calcium in camparison to same dose of calcium gluconate. 1 gram of Calcium gluconate contains 4.65 mEq of elemental Calcium but 1 gram of Calcium chloride contains 13.6 mEq of elemental Calcium.

Saturday October 18, 2008

Scenario: 37 year old otherwise healthy male brought to ER with acute upper airway obstruction after developing severe angioedema secondary to seafood. In view of compromised airway, emergent intubation was performed. Despite securing airway, patient oxygen saturation remained low and required significant support of PEEP and FiO2 on mechanical ventilator. Patient's JVP is noticed to be elevated with bilateral crackles on lung auscultation. CXR showed pulmonary edema. Your probable diagnosis....



Answer: Postobstructive pulmonary edema (POPE)

POPE is the sudden onset of pulmonary edema following upper airway obstruction. There are two recognized types of POPE.

Type 1 POPE: follows a sudden, severe episode of upper airway obstruction such as postextubation laryngospasm, epiglottitis, croup, and choking.

Type II POPE: develops after surgical relief of chronic upper airway obstruction like tonsillectomy and removal of upper airway tumors.



References:

Guffin TN, Har-el G, Sanders A, Lucente FE, Nash M. Acute postobstructive pulmonary edema. Otolaryngol Head Neck Surg 1995;112:235-7.

Lang SA, Duncan PG, Shephard DA, Ha HC. Pulmonary oedema associated with airway obstruction. Can J Anaesth 1990;37:210-8.

Oswalt CE, Gates GA, Holmstrom FM. Pulmonary edema as a complication of acute airway obstruction. Rev Surg 1977;34:364-7.

Galvis AG. Pulmonary edema complicating relief of upper airway obstruction. Am J Emerg Med 1987; 5:294-7.

Scarbrough FE, Wittenberg JM, Smith BR, Adcock DK. Pulmonary edema following postoperative laryngospasm: case reports and review of the literature. Anesth Prog 1997;44:110-6.

Dicpinigaitis PV, Mehta DC. Postobstructive pulmonary edema induced by endotracheal tube occlusion. Intensive Care Med 1995;21:1048-50.

Friday October 17, 2008

Scenario: You have a 88 year old male admitted with COPD exacerbation. Patient's code status is Do Not Resuscitate (DNR) but chemical intervention is granted. Patient went into Atrial fibrillation & Rapid Ventricular Rate (RVR), with heart rate 150-170. Blood pressure is marginal and you want to avoid calcium channel blockers or beta-blockers. Electrolytes drawn 4 hours ago were reported normal. You decide to manage patient with ibutilide. Which other drug you may consider to use prior to or concomittently with Ibutalide.



Answer: Intravenous Magnesium

Ibutilide (Corvert) is indicated for the chemical conversion of atrial fibrillation. It prolongs action potential duration in myocytes and increases both atrial and ventricular refractoriness. Dose is .01 mg/kg (Up to 1mg total) IV over 10 minutes. About 2% of patients may convert into polymorphic ventricular tachycardia (torsade de pointes) and therefore Ibutilide should not be used in patients receiving concomitant drugs which prolong the QT interval. If time and clinical situation permits, some clinicians preload patients with intravenous magnesium (2-4 grams) prior to infusing ibutilide as a preventative measure for torsade de pointes (TdP).

Interestingly, one study also showed that prophylactic magnesium improve the antiarrhythmic efficacy of ibutilide as demonstrated by an increase in the rate of successful chemical conversion and reduction in the need for direct current cardioversion.


References: Click to get article

1. Intravenous Magnesium Sulfate Enhances the Ability of Intravenous Ibutilide to Successfully Convert Atrial Fibrillation or Flutter - Pacing and Clinical Electrophysiology, Volume 30, Number 11, November 2007 , pp. 1331-1335(5)

2. Cost Effectiveness of Ibutilide With Prophylactic Magnesium in the Treatment of Atrial Fibrillation - PharmacoEconomics, Volume (Year): 22 (2004)Issue: 13, Pages: 877-883

Thursday October 16, 2008
Why ultrasound guided central line placement


Study: Real-time ultrasonographic guidance is compared to the traditional landmark technique for the insertion of internal jugular vein catheters in an emergency department (ED) setting. This was a prospective, randomized, clinical study. 130 patients were enrolled.

Outcome measures: Successful insertion of an internal jugular vein catheter, number of attempts, access times, and complications.


Results

• Cannulation of the internal jugular vein was successful in 61 of 65 patients (93.9%) using ultrasonography and in 51 of 65 patients (78.5%) using the landmark technique, a significant difference of 15.4%
• Fifty of 61 (82.0%) of the successful ultrasonographically guided catheters were inserted on the first attempt compared with 36 of 51 (70.6%) of the successful landmark catheters.
• Mean access times to venipuncture and successful insertion were 138 and 281 seconds by ultrasonographic guidance and 132 and 271 seconds by the landmark technique.
• There was a 10.8% complication rate, with 11 complications (16.9%) in the landmark group and 3 (4.6%) in the ultrasonographic group, a difference of 12.3%

Conclusion: Ultrasonographically guided internal jugular vein catheterization in the ED setting was associated with a higher successful insertion rate and a lower complications rate.




Reference: click to get article

Ultrasonographic Guidance for Internal Jugular Vein Cannulation: An Educational Imperative, A Desirable Practice Alternative , Alfredo Sabbaj, Jerris R. Hedges, Annals of Emergency Medicine, November 2006 (Vol. 48, Issue 5, Pages 548-550)