Severe pneumonia due to Legionella pneumophila: prognostic factors, impact of delayed appropriate antimicrobial therapy

OBJECTIVE

To compare the outcome of patients with severe Legionella pneumonia (LP) according to the presence or absence of prognostic factors currently reported in the literature and delays in initiating fluoroquinolones and macrolides.

DESIGN

Retrospective clinical investigation.

SETTING

Intensive care unit (ICU) of an university hospital.

PATIENTS

Forty-three consecutive cases with no previous treatment with a macrolide or a fluoroquinolone.

MEASUREMENTS AND MAIN RESULTS

The 14 (33%) patients who died of LP were compared with the 29 survivors. Thirty-eight patients (88%) received a fluoroquinolone in combination with a macrolide agent, two patients erythromycin alone and three ofloxacin alone. In univariate analysis, SAPS II more than 46 ( p=0.006) and intubation requirement ( p=0.012) were associated with a higher mortality whereas the administration of fluoroquinolones ( p=0.011) or erythromycin ( p=0.044) within 8 h of arrival on the ICU was associated with better survival. By logistic regression analysis, SAPS II score more than 46 [odds ratio (OR) 8.69; 95% confidence interval (CI) 1.15-66.7; p=0.036], duration of symptoms prior to ICU admission longer than 5 days (OR 7.46; 95% CI 1.17-47.6) were independent risk factors for death. Fluoroquinolone administration within 8 h of ICU arrival (OR 0.16; 95% CI 0.03-0.96; p=0.035) was associated with a reduced mortality.

CONCLUSIONS

SAPS II score higher than 46, duration of symptoms prior to ICU admission longer than 5 days and intubation were associated with increased mortality. Initiation of fluoroquinolone therapy within 8 h of ICU admission significantly reduced mortality.

Procalcitonin: a valuable indicator of infection in a medical ICU?

OBJECTIVE

To assess the use of procalcitonin (PCT) for the diagnosis of infection in a medical ICU.

DESIGN

Prospective, observational study.

PATIENTS

Seventy-seven infected patients and 24 patients with systemic inflammatory response syndrome (SIRS) due to other causes. Seventy-five patients could be classified into sepsis (n = 24), severe sepsis (n = 27) and septic shock (n = 24), and 20 SIRS patients remained free from infection during the study. Plasma PCT and C-reactive protein (CRP) levels were evaluated within 48 h of admission (day 0), at day 2 and day 4.

RESULTS

As compared with SIRS, PCT and CRP levels at day 0 were higher in infected patients, regardless of the severity of sepsis (25.2 +/- 54.2 ng/ml vs 4.8 +/- 8.7 ng/ml; 159 +/- 92 mg/l vs 71 +/- 58 mg/l, respectively). At cut-off values of 2 ng/ml (PCT) and 100 mg/l (CRP), sensitivity and specificity were 65% and 70% (PCT), 74% and 74% (CRP). PCT and CRP levels were significantly more elevated in septic shock (38.5 +/- 59.1 ng/ml and 173 +/- 98 mg/l) than in SIRS (3.8 +/- 6.9 ng/ml and 70 +/- 48 mg/l), sepsis (1.3 +/- 2.7 ng/ml and 98 +/- 76 mg/l) and severe sepsis (9.1 +/- 18. 2 ng/ml and 145 +/- 70 mg/l) (all p = 0.005). CRP, but not PCT, levels were more elevated in severe sepsis than in SIRS (p<0.0001). Higher PCT levels in the patients with four dysfunctional organs and higher PCT and CRP levels in nonsurvivors may only reflect the marked inflammatory response to septic shock.

CONCLUSION

In this study, PCT and CRP had poor sensitivity and specificity for the diagnosis of infection. PCT did not clearly discriminate SIRS from sepsis or severe sepsis.

Is the piglet a useful animal model of sudden infant death syndrome?

A prospective study of early death was conducted in a large population of piglets in order to investigate the causes of mortality and determine whether this species could be useful as an animal model of the sudden infant death syndrome (SIDS). 1,921 live-born piglets were closely monitored from birth to 2 months of age. The cause of death was analyzed in all the animals which died during this period. Complete histological, bacteriological and virological examinations of all sudden death animals were compared to identical examinations performed in age-matched control animals. 384 animals (20%) died during the study period and 8 sudden deaths were observed (0.4%). The principal causes of nonsudden death were overlaying (9.4%), hypotrophy (6%), infection (2%) and acute fetal suffering (1.4%). Bacterial infection was found in 6 of the sudden deaths. There was 1 case of suffocation and 1 unexplained sudden death. Compared to controls, there was a significantly greater prevalence of pathology (p < 0.01) and of positive tissue bacteriology (p < 0.05) in sudden death animals. The 6 sudden deaths due to bacterial infections were clearly different from the human syndrome. Suffocation is a known cause of sudden infant death. In the final analysis, only 1 animal (0.5/1000) had an outcome which could be assimilated with SIDS. It is concluded that although there probably exists a syndrome in the piglet equivalent to SIDS, its incidence is very low and major obstacles related to the high level of early mortality in this species hinder investigation.