Herpes simplex virus in the respiratory tract of critical care patients: a prospective study.

BACKGROUND: Herpes simplex virus (HSV) is occasionally detected in the lower respiratory tract of patients in intensive care, but its clinical importance in such situations remains unclear. We did a prospective cohort study to define the prevalence, origin, risk factors, and clinical relevance of HSV in the respiratory tract of patients undergoing critical care. METHODS: We tested 764 patients admitted to intensive care for the presence of HSV in the respiratory tract, and assessed statistical relations between this virus and clinical variables. FINDINGS: HSV was detected by oropharyngeal swab in the upper respiratory tract of 169 (22%) of 764 patients, within 10 days of admission for 150 (89%) of these individuals. The virus was isolated in 58 (16%) of 361 patients whose lower respiratory tract was sampled. The presence of HSV in the throat was a risk factor for development of HSV infections in the lower respiratory tract (p<0.001). HSV was isolated most frequently in patients with severe disease. HSV in the throat was associated with acute respiratory distress syndrome (p<0.001) and with increased length of stay in intensive care (p<0.001). INTERPRETATION: Our data suggest that HSV reactivation or infection of the upper respiratory tract is frequent among patients in intensive care, and is a risk factor for development of lower respiratory tract infection with this virus, possibly by means of aspiration.

Meningoencephalitis caused by Streptococcus pneumoniae: a diagnostic and therapeutic challenge. Diagnosis with diffusion-weighted MRI leading to treatment with corticosteroids.

Streptococcus pneumoniae is a common cause of bacterial meningitis but only rarely causes other infections such as brain abscess, encephalitis, encephalomyelitis or meningoencephalitis. We report on three adult patients with meningoencephalitis caused by S. pneumoniae. In all three, CT and MRI revealed widespread brain lesions, suggesting extensive parenchymal injury. Diffusion-weighted MRI showed lesions with restricted diffusion, reflecting local areas of ischaemia with cytotoxic oedema secondary to an immunologically mediated necrotising vasculitis and thrombosis. High levels of markers of neuronal, glial and myelin damage were found in the cerebrospinal fluid. According to the literature, brain parenchyma lesions in adults with pneumococcal meningoencephalitis are often associated with death or severe neurological deficit. Our patients were treated with pulse doses of glucocorticoids: this resulted in dramatic clinical improvement and an excellent final neurological recovery.

Strategies for selecting antibiotics in intensive care units.

Crowding of severely ill patients in intensive care units has led worldwide to important increases in nosocomial (ICU-related) infections. Moreover, the nature of these hospital-acquired infections is shifting towards Gram-positive microorganisms, yeast and Gram-negative rods, possessing important resistance genes (e.g. extended spectrum beta-lactamases and inducible Enterobacteriaceae). Ceftazidime and aztreonam are loosing their activity against the Gram-negative microorganisms. The fourth generation cephalosporins have an intrinsic high activity against the inducible Enterobacteriaceae. On our Hematology and Intensive Care units, the introduction of cefepime for nosocomial infections led to a remarkable drop in the number of Enterobacter isolates combined with important decreases in Enterobacter resistance towards several antibiotics.

Unusual D-lactic acid acidosis from propylene glycol metabolism in overdose.

OBJECTIVE: To report a case of D-lactic acid acidosis owing to massive oral ingestion of propylene glycol. CASE REPORT: A 72-year old man with known congestive failure was admitted to the ICU with encephalopathy. Twelve hours prior to admission he had erroneously ingested a large amount of propylene glycol (PG). The laboratory revealed high anion gap (anion gap = 27 meq/l) acidosis (arterial pH = 7.16) and an increased osmolal gap. Toxicological analysis revealed a low serum propylene glycol level. Biochemical analysis indicated that very high amounts of D-lactic acid (up to 110 mmol/l), but not of the usual type of L-lactic acid, were responsible for the metabolic acidosis. Hemodialysis was initiated and associated with a decline of both the acidosis and D-lactic acid levels. The patient regained conciousness. CONCLUSION: Ingestion of massive doses of propylene glycol, previously not reported as a cause of D-lactic acidosis, should be added to the differential diagnosis of this rare condition.