Measurement of salivary cortisol concentration in the assessment of adrenal function in critically ill subjects: a surrogate marker of the circulating free cortisol.

METHODS: Baseline and cosyntropin-stimulated serum (total and free) and salivary cortisol concentrations were measured, in the early afternoon, in 51 critically ill patients and healthy subjects. Patients were stratified according to their serum albumin at the time of testing: those whose serum albumin levels were 2.5 gm/dl or less vs. others whose levels were greater than 2.5 gm/dl. RESULTS: Baseline and cosyntropin-stimulated serum free cortisol levels were similar in the two groups of critically ill patients and were severalfold higher (P < 0.001) than those of healthy subjects. Similarly, baseline and cosyntropin-stimulated salivary cortisol concentrations were equally elevated in the two critically ill patient groups and were severalfold higher (P < 0.001) than those of healthy subjects. Salivary cortisol concentrations correlated well with the measured serum free cortisol levels. CONCLUSIONS: Salivary cortisol measurements are simple to obtain, easy to measure in most laboratories, and provide an indirect yet reliable and practical assessment of the serum free cortisol concentrations during critical illnesses. The concentrations of the two measures of unbound cortisol determined in two different body fluids correlated very well, regardless of the serum protein concentrations. Measurements of salivary cortisol can serve as a surrogate marker for the free cortisol in the circulation.

The impact of penicillin resistance on short-term mortality in hospitalized adults with pneumococcal pneumonia: a systematic review and meta-analysis.

BACKGROUND: The clinical impact of penicillin resistance on the outcome of pneumococcal pneumonia has remained controversial. We performed a meta-analysis of prospective cohort studies to examine the association between penicillin resistance and short-term all-cause mortality for pneumococcal pneumonia. METHODS: We retrieved studies published in any language by a comprehensive search of the Medline, Current Contents, and Embase databases for all appropriate articles published up to January 2005. We also manually reviewed bibliographies of retrieved articles, recent national treatment guidelines, and review articles. We included prospective cohort studies that involved adult subjects, and we examined the association between penicillin resistance and short-term mortality for pneumococcal pneumonia. Two reviewers independently extracted data on crude and adjusted risk estimates of all-cause mortality for pneumococcal infections with different levels of penicillin resistance and assessed the methodological quality of selected studies. We also contacted authors to obtain additional information. We performed meta-analyses using a random-effect model. RESULTS: Of 1152 articles identified in the search, 10 studies that involved 3430 patients (most of whom were hospitalized) were included. The mortality rate was 19.4% in the penicillin-nonsusceptible Streptococcus pneumoniae group and 15.7% in the penicillin-susceptible S. pneumoniae group. The combined relative risks of all-cause mortality for the penicillin-nonsusceptible, -intermediate, and -resistant S. pneumoniae groups, compared with the penicillin-susceptible S. pneumoniae group, were 1.31 (95% confidence interval [CI], 1.08-1.59), 1.34 (95% CI, 1.13-1.60), and 1.29 (95% CI, 1.01-1.66), respectively. The combined adjusted relative risks of mortality for penicillin-nonsusceptible versus penicillin-susceptible S. pneumoniae group was 1.29 (95% CI, 1.04-1.59) for the 6 studies that adjusted for age, comorbidities, and severity of illness. There was minimal between-study heterogeneity in these analyses. CONCLUSION: Penicillin resistance is associated with a higher mortality rate than is penicillin susceptibility in hospitalized patients with pneumococcal pneumonia. Additional efforts are needed to understand the mechanisms of this association.