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
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.
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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 TrialThe addition of a tramadol infusion to morphine patient-controlled analgesia after abdominal surgery: a double-blinded, placebo-controlled randomized trial.
In this double-blinded, randomized controlled trial, we tested whether the addition of tramadol to morphine for patient-controlled analgesia (PCA) resulted in improved analgesia efficacy and smaller morphine requirements compared with morphine PCA alone after abdominal surgery in adults. Sixty-nine patients were randomly allocated into two groups, each receiving morphine 1 mg/mL via PCA after surgery. The tramadol group received an intraoperative initial loading dose of tramadol (1 mg/kg) and a postoperative infusion of tramadol at 0.2 mg. kg(-1). h(-1). The control group received an intraoperative equivalent volume of normal saline and a postoperative saline infusion. Postoperatively, tramadol was associated with improved subjective analgesic efficacy (P = 0.031) and there was significantly less PCA morphine use in the tramadol group (P = 0.023). No differences between the groups were found with regard to nausea, antiemetic use, sedation, or quality of recovery (all P > 0.05). We conclude that a tramadol infusion combined with PCA morphine improves analgesia and reduces morphine requirements after abdominal surgery compared with morphine PCA alone. ⋯ In this study, we determined whether adding a second pain-killing drug, tramadol, could improve pain relief after major surgery in patients receiving morphine patient-controlled analgesia. We found that patients receiving tramadol had significantly better opinions of their pain relief and used significantly less morphine with no increase in side effects.
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Anesthesia and analgesia · Dec 2002
Risk assessment of hemorrhagic complications associated with nonsteroidal antiinflammatory medications in ambulatory pain clinic patients undergoing epidural steroid injection.
We prospectively studied 1035 individuals undergoing 1214 epidural steroid injections to determine the risk of hemorrhagic complications. A history of bruising or bleeding was present in 176 (15%) patients. A platelet count was assessed in 77 patients before the epidural steroid injection; none was less than 100 x 10(9)/L. Nonsteroidal antiinflammatory drugs (NSAIDs) were reported by 383 (32%) patients, including 34 patients on multiple medications. Aspirin was the most common NSAID and was noted by 158 patients, including 104 patients on 325 mg or less per day. There were no spinal hematomas (major hemorrhagic complications). Blood was noted during needle or catheter placement in 63 (5.2%) patients (minor hemorrhagic complications). NSAIDs did not increase the frequency of minor hemorrhagic complications. However, increased age, needle gauge, needle approach, needle insertion at multiple interspaces, number of needle passes, volume of injectant, and accidental dural puncture were all significant risk factors for minor hemorrhagic complications. There were 42 patients with new neurologic symptoms or worsening of preexisting complaints that persisted more than 24 h after injection; median duration of the symptoms was 3 days (range, 1-20 days). Our results confirm those of previous studies performed in obstetric and surgical populations that document the safety of neuraxial techniques in patients receiving NSAIDs. We conclude that epidural steroid injection is safe in patients receiving aspirin-like antiplatelet medications. Minor worsening of neurologic function may occur after epidural steroid injection and must be differentiated from etiologies requiring intervention. ⋯ Previous studies performed in obstetric and surgical populations have demonstrated that antiplatelet therapy does not increase the risk of spinal hematoma associated with spinal or epidural anesthesia and analgesia. We confirm the safety of epidural steroid injection in patients receiving aspirin-like medications.