Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialThe effect of the addition of epinephrine on early systemic absorption of epidural ropivacaine in humans.
The addition of epinephrine to ropivacaine has not been recommended because ropivacaine has intrinsic vasoconstrictor properties. However, few pharmacokinetic data are available on the addition of epinephrine to epidural ropivacaine in humans. In this prospective, double-blinded study, we randomized patients having elective abdominal hysterectomy to receive epidural ropivacaine 1.5 mg/kg, diluted in 15 mL, either with (epinephrine group, n = 12) or without (plain group, n = 12) epinephrine 5 microg/mL and then measured arterial and venous plasma concentrations of ropivacaine at intervals up to 180 min. We found that arterial and venous plasma ropivacaine concentrations were smaller in the epinephrine group compared with the plain group in the first 60 min after the drug administration (P < 0.01). Mean (+/- SD) maximum total plasma ropivacaine concentration was smaller in the epinephrine group (arterial, 0.92 +/- 0.32 microg/mL; venous, 0.82 +/- 0.33 microg/mL) compared with the plain group (1.31 +/- 0.39 microg/mL and 1.31 +/- 0.50 microg/mL, respectively; P = 0.01). Time to maximum total plasma ropivacaine concentration was not significantly different between groups (mean +/- SD; arterial, 16 +/- 2 min; venous, 23 +/- 2 min in the epinephrine group versus 9 +/- 2 min and 12 +/- 3 min, respectively, in the plain group; P = 0.08). Arterial plasma ropivacaine concentrations were larger than venous concentrations during the first hour (P < 0.01); the arterio-venous difference decreased exponentially, and the rate and magnitude of this decrease was unaffected by epinephrine. We conclude that the addition of epinephrine 5 microg/mL to ropivacaine reduced the early systemic plasma concentrations of ropivacaine after epidural injection and may be useful for decreasing the risk of toxicity from systemic absorption of epidural ropivacaine. ⋯ The addition of epinephrine 5 microg/mL to epidural ropivacaine reduced the systemic arterial and venous plasma concentrations of ropivacaine in the first hour and the maximum plasma concentration of ropivacaine. Epinephrine may be a useful additive for reducing the risk of systemic toxicity when large doses of ropivacaine are given epidurally.
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Anesthesia and analgesia · Nov 2002
Physiological and psychological influences on postoperative fatigue.
Fatigue is common after major surgery and delays recovery. We studied the role of physiological and psychological factors in determining fatigue and physical well being after surgery in 102 patients undergoing primary hip arthroplasty. Self-administered questionnaires were used to measure the intensity of feelings of fatigue, vigor, depression, and subjective physical well being on the day before surgery, on the third and seventh postoperative days, and 1 and 6 mo after surgery. The physiological response to surgery was determined by sequential measurements of circulating norepinephrine, epinephrine, cortisol, interleukin-6, and C-reactive protein during the 7 days after surgery. The peak value of each variable was used for statistical analysis. Physical well being decreased significantly at 3 and 7 days but increased significantly at 1 and 6 mo. Fatigue decreased significantly at 1 and 6 mo. Multiple regression analysis showed that the main predictor of worse physical well being at 3 days was the size of the C-reactive protein response. Subsequently, the main predictor was the level of preoperative well being. The severity of fatigue and vigor after surgery were predicted mostly by the preoperative levels of the respective variable. We conclude that fatigue after hip arthroplasty was not predicted by physiological variables but was largely predicted by preoperative levels of fatigue. ⋯ Fatigue is common after major surgery and delays recovery. It is usually attributed to the physiological response to surgery. We studied patients undergoing hip arthroplasty and found that the severity of postoperative fatigue was not predicted by physiological changes. Instead, it was predicted by the preoperative level of fatigue.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialCaudal neostigmine, bupivacaine, and their combination for postoperative pain management after hypospadias surgery in children.
In a randomized, double-blinded study, we examined the analgesic efficacy of caudal neostigmine, bupivacaine, or a mixture of both drugs in 60 children. After the induction of general anesthesia, children were allocated randomly into three groups (n = 20) to receive a caudal injection of either 0.25% bupivacaine 1 mL/kg, with or without neostigmine 2 micro g/kg, or neostigmine 2 micro g/kg in normal saline 1 mL/kg. Intraoperatively, children receiving caudal bupivacaine or a bupivacaine/neostigmine mixture maintained hemodynamic stability, required less inhaled anesthetics, and had a shorter recovery time compared with the caudal neostigmine alone. Postoperatively, the caudal bupivacaine/neostigmine mixture resulted in superior analgesia compared with the other two groups. Recovery to first rescue analgesic times were (mean +/- SD) 22.8 +/- 2.9 h, 8.1 +/- 5.9 h, and 5.2 +/- 2.1 h in the bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.001). In addition, the bupivacaine and neostigmine groups received more doses of paracetamol than the bupivacaine/neostigmine group to maintain adequate analgesia in the first 24 postoperative h. Postoperative vomiting occurred in 25%, 10%, and 30% in the caudal bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.01). We conclude that caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. ⋯ Caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. Co-administration of the two drugs is associated with extended postoperative analgesia and reduced need for supplementary analgesics.
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Anesthesia and analgesia · Nov 2002
Case ReportsSupine hypertension during general anesthesia in a patient taking midodrine.
Midodrine, a drug used to treat symptomatic orthostatic hypotension, may cause or exacerbate supine hypertension. We describe a case of a patient taking midodrine who exhibited severe hypertension during general anesthesia. Possible preventive measures to avoid this complication are discussed.