Friday February 8, 2008
Dialysis and central catheter's diameter !

Internal diameter of each lumen of dialysis catheter is about twice the diameter of each lumen in a triple-lumen central venous catheter.

Clinical application: As per Hagen-Poiseuille equation, just 2 fold increase in radius increase flow by 16 fold.

Thursday February 7, 2008
Sodium Bicarbonate in contrast induced nephropathy (CIN) - a risk ?


Sodium Bicarbonate is increasingly being used to prevent contrast induced nephropathy which was based on a small study (1). The role of this prophylaxis is being questioned by a recent large retrospective study from Mayo (2).

Groups:

1. sodium bicarbonate,
2. N-acetylcysteine, and
3. the combination of sodium bicarbonate with N-acetylcysteine

Contrast nephropathy was defined as postexposure creatinine elevation of 25% or >0.5 mg/dl within 7 days of contrast exposure.

Total numbers:

• A total of 11,516 contrast exposures in 7977 patients had creatinine values available for review before and after contrast exposure.
• Sodium bicarbonate was used in 268 cases,
• N-acetylcysteine was used in 616 cases, and
• both agents were used in combination in 221 cases
  

Results:

• Use of sodium bicarbonate alone was associated with an increased risk of contrast nephropathy compared with no treatment
• N-acetylcysteine alone and in combination with sodium bicarbonate was not associated with any significant difference in the incidence of contrast nephropathy.
  
  

Conclusions: The use of intravenous sodium bicarbonate was associated with increased incidence of contrast nephropathy.

But also note, recent REMEDIAL trial, showed that the strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC in preventing CIN in patients at medium to high risk. (3)


Editors' note: So far, it appears except for adequate hydration, most of the therapies have no consistent track of advantage and results are variable.

References: click to get abstract/article

1. Prevention of contrast-induced nephropathy with sodium bicarbonate: A randomized controlled trial. JAMA 2004; 291:2328-2334.

2. Sodium bicarbonate is associated with an increased incidence of contrast nephropathy: A retrospective cohort study of 7977 patients at Mayo Clinic. Clin J Am Soc Nephrol 2008; 3:10-18.

3. Renal Insufficiency Following Contrast Media Administration Trial (REMEDIAL). A randomized comparison of 3 preventive strategies. Circulation 2007; DOI:10.1161/CIRCULATIONAHA.106.687152.

Wednesday February 6, 2008



Case: 52 year old male is back from cardiac angioplasty with abciximab (ReoPro) infusion. Pre-cath labs were normal. CBC was send per protocol after 4 hours of abciximab infusion and lab call with critical platelet level of 62. Abciximab was stopped and hematology consulted. Hematology advised to restart abciximab !!


Pseudothrombocytopenia

Pseudothrombocytopenia is a common phenomenon with patients on abciximab (ReoPro). It is a benign condition and is not a real thrombocytopenia as platelets actually clump in collecting tubes containg EDTA. It is an important diagnosis to make. Diagnosis can be made by reviewing peripheral blood film or drawing blood in citrated or heparinized tube. It is not clear why abciximab cause more EDTA-induced platelet clumping.* EDTA (Ethylenediaminetetraacetic acid) is a commonly used anticoagulant in sampling tubes for blood counts.



References: click to get abstract/article

1. Occurrence and clinical significance of pseudothrombocytopenia during abciximab therapy J Am Coll Cardiol. 2000 Jul;36(1):75-83.
2. Abciximab-Associated Pseudothrombocytopenia - Circulation. 2000;101:938
3. EDTA dependent pseudothrombocytopenia caused by antibodies against the cytoadhesive receptor of platelet gpIIB-IIIA - Journal of Clinical Pathology 1994;
47:625-6304. Pseudothrombocytopenia Volume 329:1467 Nov. 11, 1993

Tuesday February 5, 2008


Q: Can Wernicke's Encephalopathy be iatrogenic in ICU ?

A: Yes, it can be precipitate in any patient by glucose (like D-5, D-10 or D-50) administration who is thiamine deficient. It is not limited to alcoholics and can happen in any nutritionally deficient patient. It is always a good idea to add thiamine in glucose drip in patients who are at risk of Wernicke's Encephalopathy. Disorder was described 25 years ago by Carl Wernicke as a triad of

• acute mental confusion
• ataxia
• opthalmoplegia

Read a case of Wernicke's encephalopathy. in a non-alcoholic patient with MRI findings here (Ref.: The New England Journal of Medicine, Kaineg and Hudgins 352 (19): e18, May 12, 2005)

Also full review article Wernicke's encephalopathy at emedicine.com

Monday February 4, 2008
What to do in case of accidental esophageal intubation !

Editors' note: The following video is a practice or opinion of some intensivits but not proved or recommended by clinical trials.

Total video time: 1 minute 24 secs

Sunday February 3, 2008
Bimanual Laryngoscopy - BURP !!

One 'trick' to enhance successful intubation is using 'Bimanual Laryngoscopy'.
Its different from cricoid pressure as explained in video.

Its also called BURP: pressure backwards,upwards and to the right.





source:

Airwaycam.com

Saturday February 2, 2008
Arterial line colonization and infection

In this month of Critical Care Medicine 1, a study published from australia: Prospective study of peripheral arterial catheter infection and comparison with concurrently sited central venous catheters. It was prospective 24-month cohort study. 331 arterial catheters were observed for 1,082 catheter days, and 618 central venous catheters for 4,040 catheter days.

All catheters were inserted by trained personnel under aseptic conditions, and management was standardized.

Results:

• The incidence per 1,000 catheter days of catheter-related bloodstream infection was 0.92 for arterial catheters and 2.23 for central venous catheters.
• Arterial catheter colonization was not significantly different than that in central venous catheters.
• Femoral arterial catheters were colonized more often than radial arterial catheters
• Colonization was significantly higher when the catheter was inserted in the operating theater or emergency department compared with the ICU !

Conclusions: The incidence of catheter-related bloodstream infection from arterial catheters was low. However, both arterial catheter colonization and rates of catheter-related bloodstream infection were similar to those in concurrently sited and identically managed central venous catheters. By inference, the arterial catheter should be accorded the same degree of importance as the central venous catheter as a potential source of sepsis.

Reference: click to get abstract

Prospective study of peripheral arterial catheter infection and comparison with concurrently sited central venous catheters - Critical Care Medicine. 36(2):397-402, February 2008.

Friday February 1, 2008
Procedure video - IJ central line under ultrasound

Related previous video: Ultrasound windows for venous catheter placement