Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialThe advantages of the lateral decubitus position after spinal anesthesia with hyperbaric tetracaine.
We investigated the effects of lateral decubitus positioning after spinal anesthesia with hyperbaric tetracaine on the spread of sensory blockade and hemodynamic variables. One hundred ASA physical status I or II patients scheduled for elective surgery to the lower limb received spinal anesthesia at a rate of approximately 0.1 mL/s using 0.5% tetracaine in 7.5% glucose with 0.125% phenylephrine in the lateral decubitus position with the operated side dependent. They were randomly divided into three groups: patients in Group I were placed supine immediately after spinal injection; those in Group II remained in the lateral position for 10 min before being turned supine; those in Group III were kept in the lateral position for 20 min then turned supine. Neural block was assessed by cold, pinprick, and touch sensation, and a modified Bromage scale. Hemodynamic variables included blood pressure, heart rate, and the use of ephedrine for the treatment of hypotension. The median (10th, 90th percentiles) peak dermatomal level to pinprick on the dependent side in Group III was T8 (T11, T5), which was significantly lower than that in Groups I and II, which extended to T4 (T9, T3) and T5 (T10, T2), respectively (P < 0.05). The difference in the maximal cephalad spread of sensory blockade between both sides in Group III was only one dermatome but was statistically significant (P < 0.05); in contrast, there was no significant difference in the maximal sensory level between both sides in Groups I and II. The use of ephedrine for the treatment of hypotension was significantly less frequent in Group III than the other groups. We conclude that keeping a patient in the lateral decubitus position for 20 min after hyperbaric tetracaine spinal anesthesia maintains preferential anesthetic distribution to the dependent side. Despite small differences between the two sides, the restricted spread of blockade and less hemodynamic variability may be clinically advantageous. ⋯ The effects of posture on the spread of hyperbaric spinal anesthesia have not been adequately investigated. The results of the present study suggest an advantage of prolonged lateral decubitus positioning after intrathecal hyperbaric tetracaine.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialDexamethasone decreases the incidence of shivering after cardiac surgery: a randomized, double-blind, placebo-controlled study.
Shivering after cardiac surgery is common, and may be a result of intraoperative hypothermia. Another possible etiology is fever and chills secondary to activation of the inflammatory response and release of cytokines by cardiopulmonary bypass. Dexamethasone decreases the gradient between core and skin temperature and modifies the inflammatory response. The goal of this study was to determine whether dexamethasone can reduce the incidence of shivering. Two hundred thirty-six patients scheduled for elective coronary and/or valvular surgery were randomly assigned to receive either dexamethasone 0.6 mg/kg or placebo after the induction of anesthesia. All patients received standard monitoring and anesthetic management. After arrival in the intensive care unit (ICU), nurses unaware of the treatment groups recorded visible shivering, as well as skin and pulmonary artery temperatures. Analysis of shivering rates was performed by using chi2 tests and logistic regression analysis. Compared with placebo, dexamethasone decreased the incidence of shivering (33.0% vs 13.1%; P = 0.001). It was an independent predictor of reduced incidence of shivering and was also associated with a higher skin temperature on ICU admission and a lower central temperature in the early postoperative period. ⋯ Dexamethasone is effective in decreasing the incidence of shivering. The effectiveness of dexamethasone is independent of temperature and duration of cardiopulmonary bypass. Shivering after cardiac surgery may be part of the febrile response that occurs after release of cytokines during cardiopulmonary bypass.
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Previous studies of gastric contents in children presenting for surgery specifically excluded those with gastrointestinal disorders. Because these children often need sedation or anesthesia for procedures such as upper endoscopy, it is important to determine the gastric fluid volume and pH in this group to better characterize their risk of aspiration. We therefore analyzed the gastric fluid volume and pH of children with a variety of gastrointestinal symptoms presenting for upper endoscopy. After obtaining institutional review board approval, the stomach contents of 248 children (aged 2 mo to 18 yr) presenting for upper endoscopy were prospectively measured under direct endoscopic vision. Children were fasted for both solids and liquids for at least 6 h (<6 mo) or 8 h (>6 mo). Gastric fluid pH was measured using pH paper. Children received either deep sedation or general anesthesia and were grouped according to their presenting diagnosis. Results were analyzed by using analysis of variance, Kruskal-Wallis, and correlation (P value < 0.05). The mean gastric fluid volume was 0.35 +/- 0.45 mL/kg (range 0-3.14 mL/kg), and the mean gastric fluid pH was 1.37 +/- 1.6 (range 1-7). Of the children, 33% had gastric fluid volumes >0.4 mL/kg, 87% had gastric fluid pH <2.5, and 30% had gastric fluid volume >0.4 mL/kg and pH <2.5. Children with the presenting complaint of abdominal pain had the largest gastric fluid volumes. These data are not appreciably different from historical controls (healthy children fasted for an equivalent period of time who did not have gastrointestinal symptoms). ⋯ When fasted for at least 6-8 h, children with a history of gastrointestinal symptoms presenting for upper endoscopy did not have gastric contents with increased volume and acidity compared with previously published groups of children without gastric symptoms who were fasted the same length of time. These results do not support the argument that children with gastrointestinal symptoms pose an increased anesthetic risk for aspiration.
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Anesthesia and analgesia · Oct 1998
Comment Letter Case ReportsRelief of chronic refractory hiccups with glossopharyngeal nerve block.
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Anesthesia and analgesia · Oct 1998
Randomized Controlled Trial Clinical TrialThe effect of magnesium sulphate on hemodynamics and its efficacy in attenuating the response to endotracheal intubation in patients with coronary artery disease.
Laryngoscopy and endotracheal intubation may produce adverse hemodynamic effects. Magnesium has direct vasodilating properties on coronary arteries and inhibits catecholamine release, thus attenuating the hemodynamic effects during endotracheal intubation. We studied 36 patients with coronary artery disease (CAD) scheduled for elective coronary artery bypass grafting to evaluate the hemodynamic effects of magnesium and its efficacy in attenuating the response to endotracheal intubation. Patients received either 0.1 mL/kg (50%) magnesium sulfate (50 mg/kg) (Group A, n = 19) or isotonic sodium chloride solution (Group B, n = 17) before the induction of anesthesia and 0.05 mL/kg of isotonic sodium chloride solution (Group A) or lidocaine 2% (1 mg/kg) (Group B) before intubation. The hemodynamic variables were recorded before induction, after the trial drug, after induction, and after endotracheal intubation. Automatic ST segment analysis was performed throughout the study period. Magnesium sulfate administration was associated with increased cardiac index (P < 0.01), a minimal increase in heart rate, and a significant decrease in mean arterial pressure (MAP) and systemic vascular resistance (SVR) (P < 0.001). None of the patients in the magnesium group had significant ST depression compared with three patients in the control group. The magnesium group patients had a significantly lesser increase in MAP (P < 0.05) and SVR (P < 0.01) compared with the control group patients who received lidocaine before endotracheal intubation. Thus, magnesium is an useful adjuvant to attenuate endotracheal intubation response in patients with CAD. ⋯ Endotracheal intubation produces adverse hemodynamic effects, which may be more detrimental in patients with coronary artery disease than in healthy patients. The present study shows that magnesium administered before endotracheal intubation can attenuate this response better than lidocaine.