Clinical evaluation of hyponatremia and hypovolemia in critically ill adult neurologic patients: contribution of the use of cumulative balance of sodium.

PURPOSE: Knowledge of the cumulative balance of sodium (CBS) is important for the diagnosis of salt disorders and water homeostasis and has the potential to predict hypovolemic status in acute neurological patients. However, an extensive application of the use of CBS is still lacking in the intensive care setting, where salt and water homeostasis represents a priority. METHODS: Records of consecutive series of acute neurological patients admitted to a neurointensive care unit over a 6-month period were retrospectively reviewed. CBS was calculated at the admission to the Emergency Department. Discrimination between cerebral salt-wasting syndrome (CSWS) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was performed on the basis of the classical criteria. Additionally, we used the findings of a negative CBS exceeding 2 mEq/kg for the diagnosis of CSWS. Two independent clinicians who were blinded to the CBS results performed diagnosis of the causes of hyponatremia and estimated the daily volemic status of the patients on the basis of clinical parameters. Logistic regression analysis was used to determine the independent prognostic factors of hypovolemia. RESULTS: Thirty-five patients were studied for a total of 418 days. Four patients (11.4%) fitted the criteria of CSWS and three patients (8.5%) had SIADH. The unavailability of the CBS led to a wrong diagnosis in three of the eight hyponatremic patients (37.5%). The risk of developing hypovolemia in patients with negative CBS was 7.1 times higher (CI 3.86-13.06; p < 0.001). Multivariate analysis revealed that negative cumulative fluid balance, negative CBS >2 mEq/kg, and CVP ≤5 cmH2O were independent prognostic factors for hypovolemia. CONCLUSIONS: CBS is likely to be a useful parameter in the diagnosis of CSWS and a surrogate parameter for estimating hypovolemia in acute neurological patients.

What is hiding behind bubbles of air? An unusual Streptococcus pyogenes meningitis.

Streptococcus pyogenes is a rare but aggressive cause of meningitis, which often evolves in a poor outcome with fatal consequences. Although lumbar puncture and CT scan of the brain are the gold standard of diagnosis of cerebral infections, they can have some limitations. We report and describe the clinical history and neuroimaging of a 36-year-old woman admitted to the emergency department of our hospital three days after the onset of earache and otorrhoea. When the patient developed an emergent refractory status epilepticus, the CT scan of the brain showed an unusual pneumocephalus. However, the MRI study of the brain revealed a pachymeningitis with partial thrombosis of the right transverse sinus and subdural empyema due to a S. pyogenes otitis media. Prompt diagnosis and the specific findings of the MRI allowed rapid correct treatment and thus led to a good outcome for the patient.