Tuesday, September 30, 2008

Tuesday September 30, 2008

Q: Why its not a good idea to give "amp. of bicarb" via same line from where LR (Lactate Ringer) is infusing?

A: Reason, its not a good idea to mix "bicarb" with LR (Lactated Ringer) as LR contains calcium which will bind bicarbonate and will make the whole management ineffective.

Related previous pearls: LR and NS

Monday, September 29, 2008

Monday September 29, 2008
Bedside trick - suspecting tracheal aspiration !!

One quick method of suspecting tracheal aspiration or atleast ruling out tracheal aspiration is checking glucose concentration by regular bedside glucose meters. A glucose concentration of more than 20 mg/dl of bloodless tracheal aspirate doesn't confirm but atleast enhance the suspicion of tracheal aspiration.

Though literature is full of conflicting data for this method but still it is a very quick, effective and easy way of suspecting or ruling out tracheal aspiration.

Related previous pearls:
Is post pyloric feeding absolute?
Non-radiological tests to confirm naso-gastric tube placement

References: click to get abstracts / articles

1. Clinical implications of the glucose test strip method for early detection of pulmonary aspiration in nasogastric tube- fed patients - Taehan Kanho Hakhoe Chi. 2004 Dec;34(7):1215-23

2. Comparison of blue dye visualization and glucose oxidase test strip methods for detecting pulmonary aspiration of enteral feedings in intubated adults - Chest, Vol 103, 117-121

3. Glucose content of tracheal aspirates: Implications for the detection of tube feeding aspiration. Crit Care Med 1994; 22:1557-1562

4. Glucose Content of Tracheal Aspirates - Letter to the Editor - Critical Care Medicine: Volume 23(8) August 1995 pp 1451-1452

Sunday, September 28, 2008

Sunday September 28, 2008
CURB-65 Score

Lim and colleagues have designed a score called CURB-65 to rate mortality in community acquired pneumonia (CAP) - based on information available at initial hospital assessment. Give one point each for following values

C = Confusion
U = Urea (BUN) if more than 20 mg/dl (7 mmol/l)
R = Respiratory rate if more than / = 30/min,
B = BP if SBP less than 90 or DBP less than/= 60,
65 = If age more than / = 65 years

With score 0 expected mortality is 0.7%,
With score 1 expected mortality is 3.2%,
With score 2 expected mortality is 13%,
With score 3 expected mortality is 17%,
With score 4 expected mortality is 41.5% and
With score 5 expected mortality is 57%

Reference: click to get abstract

1.Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study - W S Lim, M M van der Eerden, R Laing, W G Boersma, N Karalus, G I Town, S A Lewis and J T Macfarlane - Thorax 2003;58:377-382

Saturday, September 27, 2008

Saturday September 27, 2008
An important score card to remember !


Category = Points
Age more than 75 yrs = 3
Age 65-74 yrs = 2
DM or HTN or Angina = 1
SBP less than 100 mm hg = 3
HR more than 100 bpm = 2
Killip II-IV = 2
Weight less than 67 kg (150 lbs) = 1
Anterior STE or LBBB = 1
Time to treatment more than 4hrs = 1
Total points (0-14)


Risk Score = 30 day mortality
0 = 0.8
1 = 1.6
2 = 2.2
3 = 4.4
4 = 7.3
5 = 12
6 = 16
7 = 23
8 = 27
more than 8 = 36

Friday, September 26, 2008

Friday September 26, 2008
KILLIP Classification

The Killip classification (designed about 40 years ago) is a system used in individuals with an acute myocardial infarction (heart attack), in order to risk stratify them. Individuals with a low Killip class are less likely to die within the first 30 days after their myocardial infarction than individuals with a high Killip class.

Patients were ranked by Killip class in the following way:

Killip class I includes individuals with no clinical signs of heart failure
Killip class II includes individuals with rales or crackles in the lungs an S3 gallop, and elevated jugular venous pressure.
Killip class III describes individuals with frank acute pulmonary edema.
Killip class IV describes individuals in cardiogenic shock or hypotension (measured as SBP lower than 90 mmHg), and evidence of peripheral vasoconstriction (oliguria, cyanosisor sweating).

Mortality rate based on Killip classification

Killip class I: 81/250 patients; 32% (27 to 38%). Mortality rate was found to be at 6%.
Killip class II: 96/250 patients; 38% (32 to 44%). Mortality rate was found to be at 17%.
Killip class III: 26/250 patients; 10% (6.6 to 14%). Mortality rate was found to be at 38%.
Killip class IV: 47/250 patients; 19% (14 to 24%). Mortality rate was found to be at 81%.

Killip T, Kimball JT. Treatment of myocardial infarction in a coronary care unit: a two year experience of 250 patients. Am J Cardiol 1967; 20: 457-464.

Thursday, September 25, 2008

Thursday September 25, 2008

Q: Does Phenytoin (Dilantin) get cleared by hemodialysis or hemoperfusion?

A; No (clinically insignificant removal)

Clinical significance:

1. In Phenytoin toxicity/overdose, Hemodialysis or hemoperfusion are ineffective for enhancing elimination.

2. Hemodialysis patients do not require extra dosing post dialysis though require frequent monitoring due to lower albumin level.

Wednesday, September 24, 2008

Wednesday September 24, 2008
Is there any change in criteria for identifying exudative pleural effusion

Heffner and Steven Sahn did the study to determine multilevel likelihood ratios for pleural fluid tests that are commonly used to discriminate between exudative and transudative pleural effusions. Studies were identified by searching MEDLINE and related bibliographies. Data were obtained for 1,448 patients from seven primary investigators led to modified Light criteria. These incorporate the test combination of the value of LDH of pleural fluid to serum ratio, PF/serum protein ratio, PF/serum LDH ratio, LDH of pleural fluid alone. If any of these being positive that indicates exudative effusion.

Pleural fluid Test/ Metaanalysis cut Points
Pleural fluid protein = more than 2.9 g/dl
PF/serum protein ratio = more than .5
Pleural fluid LDH = more than 0.45 upper limit of normal
PF/serum LDH ratio = more than 0.6
Pleural fluid cholesterol = more than 45 mg/dl

Conclusion: Multilevel likelihood ratios combined with a clinician’s estimation of the pretest probability of an exudative effusion improve the diagnostic accuracy of discriminating between exudative and transudative pleural effusions. Likelihood ratios avoid the use of confusing terms, such as “pseudoexudates,” that derive from the use of single cutoff points for pleural fluid tests.

Reference: click to get abstract

Heffner JE, Sahn SA, Brown LK.
Multilevel Likelihood Ratios for Identifying Exudative Pleural Effusions. CHEST 2002; 121:1916–1920