Hyponatremia in neurological patients: cerebral salt wasting versus inappropriate antidiuretic hormone secretion.

OBJECTIVE: To assess whether hyponatremia in acute neurological patients is associated with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or with the cerebral salt-wasting syndrome (CSWS). DESIGN: Clinical, controlled, prospective study. SETTING: Department of intensive care of a tertiary care academic hospital. PATIENTS: Forty acute neurological patients with hyponatremia suggesting SIADH or CSWS (20) or with normonatremia (20). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Measurement of clinical and biological variables. Measurement of blood, plasma, and red blood cell volumes to discriminate SIADH and CSWS. Renal, adrenal and thyroid functions were normal in all patients. Average blood, plasma, and red blood cell volumes were 54, 37 and 17ml/kg in control patients and 54, 37 and 18ml/kg in hyponatremic patients, respectively. CONCLUSIONS: The adequate blood volumes in hyponatremic patients confirm the diagnosis of SIADH and do not support the concept of CSWS.

Albumin administration improves organ function in critically ill hypoalbuminemic patients: A prospective, randomized, controlled, pilot study.

OBJECTIVE: To test the hypothesis that administration of albumin to correct hypoalbuminemia might have beneficial effects on organ function in a mixed population of critically ill patients. DESIGN: : Prospective, controlled, randomized study. SETTING: Thirty-one-bed, mixed medicosurgical department of intensive care. PATIENTS: All adult patients with a serum albumin concentration < or =30 g/L were assessed for eligibility. Principal exclusion criteria were expected length of stay <72 hrs, life expectancy <3 months or a do-not-resuscitate order, albumin administration in the preceding 24 hrs, or evidence of fluid overload. INTERVENTIONS: The 100 patients were randomized to receive 300 mL of 20% albumin solution on the first day, then 200 mL/day provided their serum albumin concentration was <31 g/dL (albumin group), or to receive no albumin (control group). MEASUREMENTS AND MAIN RESULTS: The primary outcome was the effect of albumin administration on organ function as assessed by a delta Sequential Organ Failure Assessment score from day 1 to day 7 (or the day of intensive care discharge or death, whichever came first). The two groups of 50 patients were comparable at baseline for age, gender, albumin concentration, and Acute Physiology and Chronic Health Evaluation II score. Albumin concentration did not change over time in the control group but increased consistently in the albumin group (p < .001). Organ function improved more in the albumin than in the control group (p = .026), mainly due to a difference in respiratory, cardiovascular, and central nervous system components of the Sequential Organ Failure Assessment score. Diuretic use was identical in both groups, but mean fluid gain was almost three times higher in the control group (1679 +/- 1156 vs. 658 +/- 1101 mL, p = .04). Median daily calorie intake was higher in the albumin than in the control group (1122 [935-1158] vs. 760 [571-1077] kcal, p = .05). CONCLUSIONS: Albumin administration may improve organ function in hypoalbuminemic critically ill patients. It results in a less positive fluid balance and a better tolerance to enteral feeding.

Septic shock of early or late onset: does it matter?

STUDY OBJECTIVES: To determine possible differences in morbidity and mortality between early and late onset of septic shock in ICU patients. DESIGN: Systematic data collection. SETTING: Thirty-one-bed, mixed, medicosurgical ICU in a university hospital. PATIENTS: All 65 patients who acquired septic shock after admission to the ICU between February 1999 and April 2000. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Forty-one of the 65 patients presented with septic shock within 24 h of admission to the ICU (early septic shock [ESS]); the other 21 patients acquired septic shock > 24 h after ICU admission (late septic shock [LSS]). Eleven patients had a second episode (7 patients in the ESS group, and 4 patients in the LSS group), and 1 patient in the LSS group had a third episode of septic shock. Patients with ESS had higher APACHE (acute physiology and chronic health evaluation) II (mean +/- SD, 26 +/- 6 vs 20 +/- 6; p = 0.002) and sequential organ failure assessment (SOFA) scores (11 +/- 3 vs 7 +/- 3, p < 0.001) on ICU admission, and a higher blood lactate concentration at the onset of shock (median 3.70 mEq/L; interquartile range, 2.6 to 6.6 mEq/L; vs median, 2.50 mEq/L [interquartile range, 1.8 to 4.0 mEq/L], p = 0.03) than patients with LSS. However, the duration of septic shock (median, 42 h [interquartile range, 21 to 97 h] vs median, 93 h [interquartile range, 32 to 241 h], p = 0.058) and the length of ICU stay after the onset of septic shock (median, 75 h; [interquartile range, 38 to 203 h] vs median, 321 h [interquartile range, 96 to 438 h], p = 0.018), was shorter in patients with ESS than patients with LSS. The ICU mortality rate was 63% (26 patients) in the ESS group, and 88% (21 patients) in the LSS group (p = 0.071). At the onset of the first episode of shock, patients with ESS had higher SOFA scores (11 +/- 3 vs 9 +/- 3, p = 0.045), lower pH (7.24 +/- 0.15 vs 7.33 +/- 0.12, p = 0.01), and were treated with higher doses of dopamine (median, 20 microg/kg/min [interquartile range, 14 to 20 microg/kg/min] vs median, 12 microg/kg/min [interquartile range, 8 to 20 microg/kg/min], p = 0.028) than patients with LSS. CONCLUSIONS: Septic shock is more severe when of early onset, as reflected by more severe organ dysfunction, greater lactic acidosis, and higher vasopressor requirements, yet the outcome is better, as reflected by a shorter duration of the shock episode, shorter ICU stay, and slightly lower mortality rates. These differences may influence clinical trials of therapeutic agents for sepsis, and should be taken into account when analyzing the results.