No abstract

The smaller volemic state from hypertonic (7.5%) saline (HS) solution administration in hemorrhagic shock can determine lesser systemic oxygen delivery and tissue oxygenation than conventional plasma expanders. In a model of hemorrhagic shock in dogs, we studied the systemic and gastrointestinal oxygenation effects of HS and hyperoncotic (6%) dextran-70 in combination with HS (HSD) solutions in comparison with lactated Ringer's (LR) and (6%) hydroxyethyl starch (HES) solutions. Forty-eight mongrel dogs were anesthetized, mechanically ventilated, and subjected to splenectomy. A gastric air tonometer was placed in the stomach for intramucosal gastric CO(2) (Pgco(2)) determination and for the calculation of intramucosal pH (pHi): The dogs were hemorrhaged (42% of blood volume) to hold mean arterial blood pressure at 40-50 mm Hg over 30 min and were then resuscitated with LR (n = 12) in a 3:1 relation to removed blood volume; HS (n = 12), 6 mL/kg; HSD (n = 12), 6 mL/kg; and HES (mean molecular weight, 200 kDa; degree of substitution, 0.5) (n = 12) in a 1:1 relation to the removed blood volume. Hemodynamic, systemic, and gastric oxygenation variables were measured at baseline, after 30 min of hemorrhage, and 5, 60, and 120 min after intravascular fluid resuscitation. After fluid resuscitation, HS showed significantly lower arterial pH and mixed venous Po(2) and higher systemic oxygen uptake index and systemic oxygenation extraction than LR and HES (P < 0.05), whereas HSD showed significantly lower arterial pH than LR and HES (P < 0.05). Only HS and HSD did not return arterial pH and pHi to control levels (P < 0.05). In conclusion, all solutions improved systemic and gastrointestinal oxygenation after hemorrhagic shock in dogs. However, the HS solution showed the worst response in comparison to LR and HES solutions in relation to systemic oxygenation, whereas HSD showed intermediate values. HS and HSD solutions did not return regional oxygenation to control values.

CONTEXT: Although 30 to 50% of hospitalized patients in a critical care unit are under sedation, there is sparse data on the impact of sedation on morbidity and case-fatality rates in Brazil. Sedation is associated with higher risks of infection and death rate among patients. However, it is difficult to assess the clinical impact of sedation. OBJECTIVE: To evaluate the impact of sedation on the incidence of nosocomial infection and all-cause deaths at a critical care unit. TYPE OF STUDY: Prospective study. SETTING: Tertiary-care teaching hospital. PARTICIPANTS: After the exclusion of patients hospitalized for less than 24 hours, 307 patients were assigned to two groups, considering their states of sedation. After confirmation of heterogeneity in relation to the Acute Physiology and Chronic Health Evaluation (APACHE II) prognostic system, 97 sedated and 97 non-sedated patients were matched in relation to this severity index. MAIN MEASUREMENTS: Impact of sedation on deep venous thrombosis, incidence of decubital eschars, presence of infection, mortality and length of hospital stay. RESULTS: There was no difference in the incidence of deep venous thrombosis between the sedated and non-sedated groups, while the frequency of decubital eschars was significantly higher among sedated patients (p = 0.03). Infection was detected in 45.4% of patients under sedation and 21.6% of patients not under sedation (p = 0.006). Mortality for patients that did not receive any kind of sedative was 20.6% and, for those that were sedated during hospitalization, the rate was 52.6% (p < 0.0001). The sedated patients had longer hospitalization (11 vs. 4 days) (p < 0.0001). CONCLUSION: We concluded that sedation is associated with higher infection risk and case-fatality rate, and longer hospital stay.

The pharmacokinetic and pharmacodynamic profile of dexmedetomidine favors its use in several neurosurgical procedures. Its use in craniotomy for the treatment of aneurysms and tumor removal is recent. Besides, its use in functional surgical interventions is promising.