Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialPropofol-nitrous oxide anesthesia enhances the heart rate response to intravenous isoproterenol infusion.
Heart rate (HR) response to IV atropine is attenuated during propofol-nitrous oxide (N(2)O) anesthesia. We studied the effects of propofol-N(2)O anesthesia on isoproterenol-induced HR changes. The control group (n = 15) received no propofol and no N(2)O. Patients in the propofol-N(2)O group (n = 21) received IV propofol 2.5 mg/kg over 1 min followed by a continuous infusion of propofol 10 mg x kg(-1) x h(-1). After tracheal intubation, anesthesia was maintained with propofol 5 mg. kg(-1) x h(-1) and 67% N(2)O in oxygen. All patients in both groups received IV isoproterenol at incremental infusion rates (2.5, 5, 7.5, 10, 12.5, 15, and 17.5 ng x kg(-1) x min(-1) for 2 min at each dose) until HR increased more than 20 bpm from baseline values. At the end of each infusion period, hemodynamic data were collected. The HR response to isoproterenol 7.5 ng. kg(-1) x min(-1) was increased more in the propofol group than in the control group (20 +/- 5 versus 14 +/- 4 bpm; P < 0.05). During the isoproterenol infusion at 10 ng. kg(-1) x min(-1), HR increased by more than 20 bpm in all patients in the propofol group but in only 31% of patients in the control group (P < 0.0001). These results suggest that continuous isoproterenol infusion might be useful when a large dose of atropine is ineffective in restoring normal HR during propofol-N(2)O anesthesia. ⋯ We demonstrated that the heart rate response to IV isoproterenol infusion is enhanced during propofol-nitrous oxide anesthesia. This suggests that continuous isoproterenol infusion may be useful when a large dose of atropine is ineffective for restoration of normal heart rate in patients receiving propofol-nitrous oxide anesthesia.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Clinical TrialSupplemental oxygen does not reduce the incidence of postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.
Supplemental 80% oxygen administration halves the incidence of postoperative nausea and vomiting (PONV) in inpatients. Whether it prevents PONV after ambulatory surgery is unknown. We tested the efficacy of supplemental 80% oxygen in decreasing the incidence of PONV after ambulatory gynecologic laparoscopy. One hundred patients were given a standardized sevoflurane anesthetic. They were randomly assigned to two groups: routine oxygen administration with 30% oxygen, balance nitrogen (Group A); and supplemental oxygen with 80% oxygen, balance nitrogen (Group B). Oxygen was administered during surgery and up to 1 h after surgery. The incidence of nausea and vomiting and the need for rescue antiemetics did not differ between the groups in the postanesthesia care unit, in the Phase II unit, or during the 24-h follow-up. The overall incidence of nausea and vomiting during the first postoperative 24 h was 62% in Group A and 55% in Group B (P = 0.486). There were no differences in the recovery profiles and patient satisfaction between the groups. In this study, supplemental oxygen did not prevent PONV in patients undergoing ambulatory gynecologic laparoscopy. ⋯ Supplemental 80% oxygen administration during surgery and until 1 h after surgery compared with 30% oxygen administration did not prevent postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.
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Anesthesia and analgesia · Jan 2003
Clinical TrialEchocardiographic monitoring during induction of general anesthesia with a miniaturized esophageal probe.
Standard transesophageal echocardiography (TEE) does not allow cardiac monitoring during the induction of anesthesia because standard probes would limit the oropharyngeal space and impair mask ventilation and tracheal intubation. We hypothesized that a prototype, miniaturized TEE probe could be safely introduced transnasally in awake patients and that mask ventilation and orotracheal intubation could be performed while continuously monitoring left ventricular (LV) function during the induction of anesthesia. Forty-five patients were studied prospectively. The transnasal TEE probe was introduced through one of the nares and advanced until a transverse plane image of the LV at the level of the papillary muscles was seen. Anesthesia was induced, and the patients were ventilated with a mask that had previously been threaded over the TEE probe via a central perforation. Probe insertion was successful in 12 patients under local anesthesia alone and in an additional 31 patients with a combination of local anesthesia and mild sedation. In two cases, probe placement was unsuccessful. Overall, hemodynamic variables did not change significantly during insertion. No case of significant mucosal bleeding was seen. In one patient, regurgitation of gastric contents occurred without affecting the perioperative outcome. The two-dimensional echocardiogram image quality of the LV during the induction of anesthesia was good or acceptable in 95% of patients. We conclude that transnasal TEE can effectively be used for cardiac monitoring during the induction of general anesthesia. ⋯ This study demonstrates that it is feasible and generally safe to introduce a miniaturized transesophageal echocardiography probe transnasally in awake cardiac risk patients to monitor cardiac performance during the induction of general anesthesia.
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Anesthesia and analgesia · Jan 2003
Oral tramadol for the treatment of pain of 7-30 days' duration in children.
This open-label, multicenter trial was designed to determine the safety profile and analgesic efficacy of tramadol for the treatment of painful conditions lasting 7-30 days in 7-16-yr-old children. We found that tramadol 1-2 mg/kg per os every 4-6 h (maximal dose = 8 mg x kg(-1). d(-1), not to exceed 400 mg/d) is a safe and effective analgesic in this patient population.