Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2002
Duration of preoperative fast correlates with arterial blood pressure response to halothane in infants.
In this study, we sought to determine whether the duration of preoperative fasting affects the decrease in blood pressure observed in infants and children during halothane anesthesia. Two-hundred-fifty pediatric patients were divided into 5 age groups: term neonates (n = 50), 1-6 mo (n = 50), 6-24 mo (n = 50), 2-6 yr (n = 50), and 6-12 yr (n = 50). After anesthetic induction with halothane, end-tidal halothane was maintained at 2 minimum alveolar anesthetic concentration (MAC) for 10 min to allow myocardial uptake. Patients were grouped by duration of preoperative fast (0-4 h, 4-8 h, 8-12 h, and >12 h). Changes in heart rate and systolic (SAP) and mean (MAP) arterial blood pressure from preinduction to 2 MAC were compared among fasting groups within each age group. In the 1- to 6-mo age group, the changes in SAP and MAP were significantly greater in infants fasting 8-12 h than in those fasting 0-4 h (SAP, -51 mm Hg versus -31 mm Hg, respectively; MAP, -48 mm Hg versus -32 mm Hg; P < 0.05). No statistically significant differences were noted in the older age groups. The results of this study demonstrate that prolonged preoperative fasting is associated with a greater decrease in blood pressure in infants. This exacerbation of the already significant hemodynamic depression observed in infants during halothane anesthesia underscores the importance of adherence to published fasting guidelines. ⋯ We studied changes in blood pressure during halothane anesthesia in infants and children and found that blood pressure decreased to a greater extent in infants who fasted for longer than 8 h before surgery. This exacerbation of the already significant hemodynamic depression observed in infants during halothane anesthesia underscores the importance of adherence to published fasting guidelines.
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Anesthesia and analgesia · Dec 2002
Randomized Controlled Trial Clinical TrialProphylactic ondansetron reduces the incidence of intrathecal fentanyl-induced pruritus.
We investigated the effectiveness of prophylactic IV ondansetron in preventing intrathecal fentanyl-induced pruritus. One-hundred-fifty ASA status I-II patients undergoing spinal anesthesia with 7-10 mg of hyperbaric bupivacaine and 25 micro g of fentanyl were randomized to receive ondansetron 8 mg IV or normal saline IV before the commencement of spinal anesthesia. Evaluations were performed every 15 min in the first hour after the injection of study drugs and at 1, 2, 3, 4, 5, and 6 h after the administration of the study drug. Statistical analysis was performed by using chi(2) tests and Student's t-test, as appropriate. The incidence of pruritus was significantly more frequent in the placebo group compared with the ondansetron group (68% versus 39%) (P = 0.001). Time to pruritus was similar in both groups (placebo group, 55 +/- 32 min versus ondansetron group, 50 +/- 31 min). Duration of pruritus was also similar in both groups (placebo group, 98 +/- 60 min versus ondansetron group, 103 +/- 58 min). Ondansetron prophylaxis significantly reduced the incidence of intrathecal fentanyl-induced pruritus in patients undergoing surgery under bupivacaine spinal anesthesia. ⋯ Pruritus is a commonly reported side effect after intrathecal fentanyl administration during spinal anesthesia. This study was performed in a prospective, randomized, double-blinded, placebo-controlled manner to investigate the efficacy of prophylactic IV ondansetron in the prevention of pruritus after intrathecal fentanyl administration during spinal anesthesia. The incidence of pruritus was significantly more frequent in the placebo group compared with the ondansetron group (68% versus 39%) (P = 0.001).
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Anesthesia and analgesia · Dec 2002
Randomized Controlled Trial Clinical TrialGabapentin for the treatment of pain in guillain-barré syndrome: a double-blinded, placebo-controlled, crossover study.
Pain syndromes of Guillain-Barré are neuropathic as well as nociceptive in origin. We aimed to evaluate the therapeutic efficacy of gabapentin in relieving the bimodal nature of pain in Guillain-Barré syndrome in a randomized, double-blinded, placebo-controlled, crossover study in 18 patients admitted to the intensive care unit for ventilatory support. Patients were assigned to receive either gabapentin (15 mg. kg(-1). d(-1) in 3 divided doses) or matching placebo as initial medication for 7 days. After a 2-day washout period, those who previously received gabapentin received placebo, and those previously receiving placebo received gabapentin as in the initial phase. Fentanyl 2 micro g/kg was used as a rescue analgesic on patient demand or when the pain score was >5 on a numeric rating scale of 0-10. The numeric rating score, sedation score, consumption of fentanyl, and adverse effects were noted, and these observed variables were compared. The numeric pain score decreased from 7.22 +/- 0.83 to 2.33 +/- 1.67 on the second day after initiation of gabapentin therapy and remained low during the period of gabapentin therapy (2.06 +/- 0.63) (P < 0.001). There was a significant decrease in the need for fentanyl from Day 1 to Day 7 during the gabapentin therapy period (211.11 +/- 21.39 to 65.53 +/- 16.17 [ micro g]) in comparison to the placebo therapy period (319.44 +/- 25.08 to 316.67 +/- 24.25 [ micro g]) (P < 0.001). ⋯ Gabapentin, an antiepileptic drug, has been used effectively for different types of pain management. This study demonstrates that gabapentin has minimal side effects and is an alternative to opioids and nonsteroidal antiinflammatory drugs for management of the bimodal nature of pain of Guillain-Barré Syndrome patients.
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Anesthesia and analgesia · Dec 2002
Comparative StudyThe relationship between movement-evoked versus spontaneous pain and peak expiratory flow after abdominal hysterectomy.
The pathogenesis of postoperative lung dysfunction implies a role for movement-evoked pain (e.g., splinting/hypoventilation because of pain avoidance). However, interactions between evoked pain and respiratory physiology are poorly understood. Thus, we examined the relationship between evoked versus spontaneous pain and one index of pulmonary function. In 25 patients having undergone a hysterectomy, visual analog scale ratings (100 mm) for spontaneous pain (REST) and pain during sitting (SIT), forced expiration (BLOW), and coughing (COUGH) were measured together with peak expiratory flow (PEF) at eight time points during postoperative Days 1 and 2. Secondary outcome measures included oxygen saturation and oxygen requirements. Pain was significantly correlated with PEF for COUGH, SIT, BLOW, and REST at eight, seven, four, and two of the eight studied time points, respectively. Mean visual analog scale scores [SE] for COUGH (26.1 mm [1.7]) and SIT (21.5 mm [1.5]) were greater (P < 0.05) than REST (10.5 mm [0.8]), and COUGH was greater (P < 0.05) than BLOW (16.8 mm [1.3]). All pain measures diminished (P < 0.05), and PEF reductions improved (P < 0.05) across the study period. We hypothesize that the consistent negative correlation of COUGH-evoked pain with PEF is, in part, caused by avoidance of coughing, which ultimately limits deep inspiration, lung reexpansion, and clearance of secretions. ⋯ Movement-evoked pain may be an important contributor to postoperative complications, but its mechanisms are poorly understood. This study provides the first evidence that postoperative evoked pain correlates with lung function and highlights the need for future research on mechanisms and implications of this phenomenon.