Sunday November 22, 2009
Acute organophosphate toxicity !

Normally, acetylcholinesterase catalyzes the degradation of the neurotransmitter acetylcholine in the synapse (yellow panel below). Organophosphate pesticides phosphorylate acetylcholine, thereby reducing the ability of the enzyme to break down the neurotransmitter (red panel below). This produces an accumulation of acetylcholine in the central and peripheral nervous systems, resulting in an acute cholinergic syndrome via continuous neurotransmission - called M-U-D-D-L-E-S:

• miosis,
• urination,
• diarrhea,
• diaphoresis,
• lacrimation,
• excitation of the central nervous system, and
• salivation

Saturday November 21, 2009
Lets have some music in CCU !

Background: Most percutaneous coronary interventions are performed through the femoral artery. In order to stop bleeding and achieve homeostasis, a C-clamp is used after percutaneous coronary interventions. However, the experience is painful for patients and they inevitably suffer discomfort. Pain may lead to stress responses and may affect the physical and mental health of patients. One potential beneficial practice is having the patient listen to relaxing music, which might have the effect of reducing situational discomfort and pain.

Methods: A randomized controlled study was conducted during the period September 2004 to March 2005. Forty-three people (20 experimental and 23 control) were recruited from the intensive care units of two acute care hospitals in Hong Kong. Physiological and psychological variables were collected at baseline and at 15, 30 and 45 minutes.


Results:

• In the music group, there were statistically significant reductions (P = 0·001) in heart rate, respiratory rate, and oxygen saturation than the control participants at 45 minutes.
  
• In the music group, statistically significant reductions (P = 0·001) in systolic blood pressure, heart rate, respiratory rate and oxygen saturation were found at the four time points, but not in the control group.
  
• No statistically significant differences were found at baseline comparison of the two groups, but statistically significant differences in pain scores were found at 45 minutes for participants in the music group compared with the control group (P = 0·003).
  
• Participants in the control group showed statistically significant increases in pain at 45 minutes compared with baseline (P less than 0·001).
  

Conclusions: The benefits of preventing physiological reactions to pain were demonstrated. Music is a simple, safe and effective method of reducing potentially harmful physiological and psychological responses arising from pain.



Effects of music on patients undergoing a C-clamp procedure after percutaneous coronary interventions: Journal of Advanced Nursing: Volume 53 Issue 6, Pages 669 - 679 - Published Online: 8 Mar 2006

Friday November 20, 2009
CASCADE: Aspirin alone as effective as aspirin plus clopidogrel in preventing vein graft disease post-CABG


Aspirin alone is as effective as aspirin and clopidogrel in preventing vein graft disease after CABG, results of the CASCADE trial demonstrated, suggesting that the use of dual antiplatelet therapy is not supported in this population.

CASCADE researchers randomly assigned 113 patients undergoing primary multivessel CABG with at least two saphenous vein grafts to either 162 mg aspirin daily and 75 mg clopidogrel daily (n=56) or 162 mg aspirin daily and placebo (n=57). Primary outcome was vein graft intimal hyperplasia, with intimal area measured by IVUS. The study was powered for 20% clinically-relevant reduction with clopidogrel.

At one year, patency did not differ between the groups; overall patency was 95.2% in the treatment group and 95.5% in the placebo group (P=1.00).

Freedom from individual major adverse cardiac events – stroke, death and MI – and a composite of all three was similar in both groups (P=.76), as was major and minor bleeding (P=.02).


Source:

Kulik A. Presented at: American Heart Association Scientific Sessions 2009; Nov. 14-18, 2009; Orlando, Fla - http://www.theheart.org/article/1024575.do

Thursday November 19, 2009

Q: Serum alkalinization with intravenous sodium bicarbonate has been the mainstay of therapy in (CA) cyclic antidepressants (amitriptyline, desipramine, imipramine, nortriptyline, doxepin, clomipramine, and protriptyline) overdose. What is the cutoff limit of QRS complex for use of intravenous sodium bicarbonate therapy?

Answer: A QRS of 100 milliseconds or greater is generally use as the cut off for intravenous sodium bicarbonate. Beside alkalinization, sodium loading may be the most important factor in the reversal of the symptoms of cyclic antidepressant toxicity. IV normal saline are indicated for CA-induced hypotension.

Wednesday November 18, 2009


Q: Which patient is more hypoxemic?

Patient A: PaO2 85 mm Hg, SaO2 95%, Hb 7 gm%
Patient B: PaO2 55 mm Hg, SaO2 85%, Hb 15 gm%


Answer:

Calculate arterial oxygen content (CaO2) (SaO2 x Hb x 1.34) assuming PaO2 is constant

Patient A
CaO2 = .95 x 7 x 1.34 = 8.9 ml O2/dl

Patient B
CaO2 = .85 x 15 x 1.34 = 17.1 ml O2/dl

Patient A, with the higher PaO2, is more hypoxemic.


Full formula: Ca02 = (Hgb)(1.34)(Sa02) + (0.0031)(Pa02)

Tuesday November 17, 2009

Q: What is the biggest danger while evaluating CXR with subcutaneous emphysema?

Answer: Missing underlying pneumothorax

The air may interdigitate with the muscle bundles to produce a characteristic linear streaky pattern, especially in the pectoralis muscles over the chest. When the streaky linear densities become widespread over the anterior and posterior chest walls, subcutaneous emphysema can obscure underlying pleural white line of a pneumothorax.

Monday November 16, 2009

Q: What is the salvage treatment for severe pruritis in cirrhotic patient if all coventional and non-conventional treatment fails?

Answer: Plasmapheresis



References:

1. Plasmapheresis in the treatment of cholestasis-induced pruritus Ugeskr Laeger. 2006 Feb 20;168(8):779-81.

2. Role of plasmapheresis in the treatment of severe pruritus in pregnant patients with primary biliary cirrhosis: case reports - Can J Gastroenterol. 2008 May;22(5):505-7.

3. Plasmapheresis for the treatment of intrahepatic cholestasis of pregnancy refractory to medical treatment - American Journal of Obstetrics and Gynecology, Volume 192, Issue 6, Pages 2088-2089