M. Anees Khan

Efficacy of an expanded ventilator bundle for the reduction of ventilator-associated pneumonia in the medical intensive care unit

The ventilator bundle (VB) includes a group of clinical maneuvers (head-of-bed elevation, sedation vacation, deep vein thrombosis prophylaxis, and peptic ulcer disease prophylaxis) to improve outcomes in patients undergoing mechanical ventilation. We modified the standard VB in our medical intensive care unit to include a group of respiratory therapist-driven protocols and, postimplementation, observed a statistically significant (P = .0006) reduction in ventilator-associated pneumonia (VAP), from a median of 14.1 cases/10(3) ventilator-days (interquartile range [IQR] = 12.1 to 20.6) to 0 cases/10(3) ventilator-days (IQR = 0 to 1.1).

Cardiac troponin I levels and alveolar-arterial oxygen gradient in patients with community-acquired pneumonia.

BACKGROUNDnPatients with community-acquired pneumonia (CAP) appear to have cardiac stress as demonstrated by elevated B-type natriuretic peptide (BNP). We hypothesised that myocardial stress and decrease in oxygenation might also lead to elevations of cardiac troponin I (cTnI) levels in serum.nnnOBJECTIVEnThe aim of this study was to see if cTnI was associated with the alveolar-arterial oxygen gradient (DeltaA-a), a marker of severity in CAP.nnnMETHODSnRetrospective cohort study of 901 CAP patients with no evidence of acute coronary syndrome presenting to a large, tertiary-care, urban teaching hospital over a 3-year period.nnnRESULTSnA strong linear trend between log(10)cTnI and DeltaA-a was observed (r(2)=0.76) with a statistically significant Spearman correlation coefficient (r(s)=0.75; p<0.0001) between cTnI and DeltaA-a. A cTnI value of 0.5 ng/ml discriminated mild CAP from moderate-severe CAP with an OR=208 (95% CI: 50.5-408; p<0.0001).nnnCONCLUSIONSnThese data suggest that decreased blood O(2) levels as suggested by elevated DeltaA-a may lead to acute myocardial damage and that cTnI may be useful as a biomarker to stratify risk in subjects with CAP.

ALVEOLAR–ARTERIAL OXYGEN GRADIENT, PNEUMONIA SEVERITY INDEX AND OUTCOMES IN PATIENTS HOSPITALIZED WITH COMMUNITY ACQUIRED PNEUMONIA

1 The alveolar–arterial oxygen gradient (ΔA–a) provides a useful assessment of ventilation/perfusion (V/Q) abnormalities. The objectives of the present study were to: (i) examine the correlation between the ΔA–a and the pneumonia severity index (PSI); and (ii) determine whether these measures were comparable in predicting clinical outcomes. 2 The present study was conducted at a 750‐bed teaching hospital. It examined a retrospective cohort of 255 patients with community acquired pneumonia (CAP) over a 2 year period. Association between the CAP and ΔA–a was investigated by regression models and correlation, as well as two logistic models for subjects bifurcated by low‐risk/moderate‐to‐high risk. The decision levels (DL) for both PSI and ΔA–a were then compared as predictors of both length of stay (LOS) and survival. 3 The correlation between PSI and ΔA–a was strong (ρ = 0.76; P < 0.0001) and was best modelled by a curvilinear relationship. Both logistic models indicated a strong association (P < 0.001) between ΔA–a and PSI and yielded an optimal DL for the ΔA–a of < 89 mmHg. Inter‐test agreement of ΔA–a with PSI was 76.9% (κ = 0.60; 95% confidence interval 0.47–0.72; P < 0.0001). At < 89 mmHg, the odds ratios for LOS were similar to those at PSI = 90 in predicting LOS in the range 3–7 days, inclusive. There was no significant difference in the ability of ΔA–a and PSI to predict survival for either the low‐ or high‐risk group (P = 0.363 and P = 0.951, respectively). 4 The ΔA–a correlates well with PSI and performs comparably in predicting two major outcomes in subjects hospitalized with CAP.

Assessment of age-related isoniazid hepatotoxicity during treatment of latent tuberculosis infection

ABSTRACT Background:u2002Since the introduction of new recommendations for the treatment of latent tuberculosis infection (LTB1) disregarding age as a limitation, increasing numbers of older individuals are expected to undergo treatment with isoniazid for the prevention of tuberculosis, raising the potential for an increase in isoniazid hepatotoxicity. Objective:u2002To compare the frequency of hepatotoxicity requiring withdrawal of isoniazid therapy for LTB1 in patients under and over 35 years of age, managed according to current practice guidelines. Design:u2002A retrospective analysis of 300 patients who underwent isoniazid therapy for LTB1 according to a protocol based on the current practice guidelines. Setting:u2002Public health clinic of Passaic County, NJ. Main outcome measures:u2002The frequency of symptomatic isoniazid hepatitis in various age groups. Results:u2002Of 165 patients < 35 years of age, 3(2%) patients developed hepatitis (AST > 3 times the upper limit of normal). Of 135 patients ≥ 35 years of age, 4(3%) patients developed hepatitis. Statistical comparison between the two groups failed to show a significant difference (u2009p = 0.705). Conclusions:u2002No difference was detected in the frequency of isoniazid hepatotoxicity between patients < 35 and ≥ 35 years of age. Clinically monitored isoniazid therapy of LTB1 patients ≥ 35 years of age may not predispose subjects to an increased risk of hepatotoxicity. Limitations of this work include the small sample size and the retrospective nature of the study.

Pulmonary Tuberculosis In Children: Implications For Diagnosis

This study describes the epidemiologic surveillance necessary to detect pediatric pulmonary tuberculosis in the two populations most often affected by the disease, American-born children of minority race or ethnicity and foreign-born children. We reviewed the records of 34 cases of pediatric pulmonary tuberculosis in racial or ethnic minorities. Most children were asymptomatic and smear- and culture-negative. Contact tracing is essential, and, in the absence of bacteriologic confirmation, a positive tuberculin skin test and an abnormal chest roentgenogram are still the only clues to a clinical diagnosis