Retrospective analysis of risk factors and predictors of intraoperative complications in neuraxial blocks at Faculdade de Medicina de Botucatu-UNESP.

BACKGROUND AND OBJECTIVES: Cardiovascular changes associated with neuraxial blocks are a cause of concern due to their frequency and because some of them can be considered physiological effects triggered by the sympathetic nervous system blockade. The objective of this study was to evaluate intraoperative cardiovascular complications and predictive factors associated with neuraxial blocks in patients ≥ 18 years of age undergoing non-obstetric procedures over an 18-year period in a tertiary university hospital--HCFMB-UNESP. METHODS: A retrospective analysis of the following complications was undertaken: hypertension, hypotension, sinus bradycardia, and sinus tachycardia. These complications were correlated with anesthetic technique, physical status (ASA), age, gender, and preoperative co-morbidities. The Tukey test for comparisons among proportions and logistic regression was used for statistical analysis. RESULTS: 32,554 patients underwent neuraxial blocks. Intraoperative complications mentioned included hypotension (n=4,109), sinus bradycardia (n=1,107), sinus tachycardia (n=601), and hypertension (n=466). Hypotension was seen more often in patients undergoing continuous subarachnoid anesthesia (29.4%, OR=2.39), ≥ 61 years of age, and female (OR=1.27). CONCLUSIONS: Intraoperative hypotension and bradycardia were the complications observed more often. Hypotension was related to anesthetic technique (CSA), increased age, and female. Tachycardia and hypertension may not have been directly related to neuraxial blocks.

[The use of dexmedetomidine in neurosurgery.]. / Uso de dexmedetomidina em neurocirurgia.

BACKGROUND AND OBJECTIVES: The use of alpha2-adrenergic agonists is increasingly more frequent in Anesthesiology, as adjuvant or the sole anesthetic drug. Currently, dexmedetomidine is gaining popularity due to its greater selectivity for the alpha2-adrenergic receptors and its pharmacokinetic profile. The aim of this review was to analyze the use of dexmedetomidine in neurosurgery. CONTENTS: Besides considerations and review of the literature regarding the use of dexmedetomidine, specifically in neurosurgical procedures, its effects on the different organ systems are described. CONCLUSIONS: 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.

The early systemic and gastrointestinal oxygenation effects of hemorrhagic shock resuscitation with hypertonic saline and hypertonic saline 6% dextran-70: a comparative study in dogs.

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.

Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery.

STUDY OBJECTIVES: To evaluate the effects of intraoperative skin-surface warming with and without 1 hour of preoperative warming, in preventing intraoperative hypothermia, and postoperative hypothermia, and shivering, and in offering good conditions to early tracheal extubation. DESIGN: Prospective, randomized, blind study. SETTING: Teaching hospital. PATIENTS: 30 ASA physical status I and II female patients scheduled for elective abdominal surgery. INTERVENTIONS: Patients received standard general anesthesia. In 10 patients, no special precautions were taken to avoid hypothermia. Ten patients were submitted to preoperative and intraoperative active warming. Ten patients were only warmed intraoperatively. MEASUREMENTS AND MAIN RESULTS: Temperatures were recorded at 15-minute intervals. The patients who were warmed preoperatively and intraoperatively had core temperatures significantly more elevated than the other patients during the first two hours of anesthesia. All patients warmed intraoperatively were normothermic only at the end of the surgery. The majority of the patients warmed preoperatively and intraoperatively or intraoperatively only were extubated early, and none had shivering. In contrast, five unwarmed patients shivered. CONCLUSIONS: One hour of preoperative warning combined with intraoperative skin-surface warming, not simply intraoperative warming alone, avoided hypothermia caused by general anesthesia during the first two hours of surgery. Both methods prevented postoperative hypothermia and shivering and offered good conditions for early tracheal extubation.