Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2005
Randomized Controlled Trial Clinical TrialProphylactic intravenous ondansetron and dolasetron in intrathecal morphine-induced pruritus: a randomized, double-blinded, placebo-controlled study.
Pruritus is the most common side effect of intrathecal morphine for postoperative pain relief. Activation of central 5-hydroxytryptamine subtype 3 (5-HT3) receptors is one of its possible mechanisms. The role of 5-HT3 antagonists in the prevention of pruritus has not been clearly established. ⋯ The incidence and severity of pruritus was significantly less frequent in the ondansetron and dolasetron groups compared with placebo (34%, 20%, and 66% respectively, P < 0.01). Patients who received 5-HT3 antagonist reported significantly less total severity of pruritus compared with placebo during the first 8 h and the severe pruritus was observed only in patients within P group (P group: 4 of 35; 11%, O or D group: 0 of 35; 0%, P < 0.05). We conclude that the prophylactic use of ondansetron and dolasetron helps to reduce the incidence and severity of intrathecal morphine-induced pruritus.
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One of the most common methods for providing postoperative analgesia is via patient-controlled analgesia (PCA). Although the typical approach is to administer opioids via a programmable infusion pump, other drugs and other modes of administration are available. This article reviews the history and practice of many aspects of PCA and provides extensive guidelines for the practice of PCA-administered opioids. In addition, potential adverse effects and recommendations for their monitoring and treatment are reviewed.
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Anesthesia and analgesia · Nov 2005
Nitric oxide is not a mediator of inflammation-induced resistance to atracurium.
Resistance to atracurium as a result of increased drug binding to alpha1-acid glycoprotein is associated with increased inducible nitric oxide synthase activity and increased nitric oxide levels in plasma. We investigated if the inhibition of inducible nitric oxide synthase and suppression of nitric oxide can reverse the resistance to atracurium. As a model of alpha1-acid glycoprotein and nitric oxide increase, 84 male Sprague-Dawley rats received an IV injection of either 60 mg/kg Corynebacterium parvum (CP) or saline (control). ⋯ In the CP groups, N-Iminolysine suppressed nitric oxide levels in a dose-dependent manner. Resistance to atracurium persisted. alpha1-acid glycoprotein serum levels remained increased in all CP groups with no differences in acetylcholine receptor expression. Our results suggest that the mechanism leading to increased expression of alpha1-acid glycoprotein and consecutive increased protein binding of atracurium is not mediated by inducible nitric oxide synthase induction and nitric oxide expression.
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Anesthesia and analgesia · Nov 2005
Postoperative nausea and vomiting are strongly influenced by postoperative opioid use in a dose-related manner.
We prospectively examined the incidence of postoperative nausea and vomiting (PONV) in a group of 193 elderly surgical inpatients receiving no postoperative antiemetic prophylaxis. Risk factors for PONV and detailed data on postoperative opioid use were recorded. The overall postoperative vomiting (POV) rate was 23.8%, whereas postoperative nausea (PON) was 51.3%. ⋯ There was a strong logarithmic dose-response relationship between postoperative opioid dose and POV (r2= 0.98, P < 0.01), as well as PON (r2= 0.98, P = 0.01). Use of patient-controlled analgesia or epidural analgesia was a marker for large-dose opioid use (P < 0.001) and was associated with POV in the 24-h postoperative period of 41% and 31% respectively, compared with 11% for other patients (P < 0.001). Future studies defining risk factors for POV should treat postoperative opioid use as a continuous variable, rather than treat it as a dichotomous variable.