Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1997
Randomized Controlled Trial Clinical TrialIntrathecal sufentanil, fentanyl, or placebo added to bupivacaine for cesarean section.
We compared the effects of intrathecal sufentanil 2.5 and 5 microg, fentanyl 10 microg, and placebo when administered together with hyperbaric bupivacaine 0.5% 12.5 mg for cesarean section. The study was performed in a randomized, double-blind fashion in 80 (20 per group) healthy, full-term parturients presenting for elective cesarean section. Postoperative pain was assessed using the visual analog scale (VAS). Duration of complete analgesia was defined as the time from the intrathecal injection to VAS score > 0. Duration of effective analgesia was defined as the time to VAS score > or = 4. No patient experienced intraoperative pain. Complete analgesia was prolonged in all groups receiving opioids. Effective analgesia was prolonged and the 0- to 6-h intravenous opioid requirements were lower in the groups receiving sufentanil compared with those receiving fentanyl and placebo. The need for intraoperative antiemetic medication was greater in the placebo group. Pruritus was a frequent and dose-related side effect in the groups receiving sufentanil. There were no differences in umbilical cord blood gases or neonatal Apgar scores and neurological and adaptive capacity scores among the groups. In conclusion, the addition of sufentanil or fentanyl improved the quality of subarachnoid block compared with placebo. The duration of action was longer for sufentanil than fentanyl. ⋯ Small doses of fentanyl or sufentanil (synthetic opioids) added to bupivacaine (local anesthetic) for spinal anesthesia for cesarean section reduce the need for intraoperative antiemetic medication and increase the duration of analgesia in the early postoperative period compared with placebo.
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Anesthesia and analgesia · Dec 1997
Randomized Controlled Trial Clinical TrialOptimal dose of nicardipine for maintenance of hemodynamic stability after tracheal intubation and skin incision.
To determine the optimal dose of nicardipine (N) for maintenance of hemodynamic stability during the postinduction period, we designed a randomized, double-blind, placebo-controlled, dose-ranging study using four different doses of N administered after a standardized anesthetic induction sequence. A total of 106 patients were assigned to one of the following treatment groups: saline (control), N 0.5 mg (N0.5), N 1 mg (N1), N 2 mg (N2), and N 4 mg (N4). The study medication was administered intravenously (I.V.) in 2.5 mL of saline over 30 s 2 min before laryngoscopy. Mean arterial pressure (MAP) and heart rate (HR) were recorded at 1-min intervals for 15 min after tracheal intubation and for 5 min after skin incision. After intubation, the peak MAP values differed from the preinduction baseline MAP values by 21% +/- 20%, 9% +/- 12%, 1% +/- 13%, -10% +/- 12%, and -15% +/- 13% (mean +/- SD) in the control, N0.5, N1, N2, and N4 groups, respectively. However, the percent change in the pre- to postintubation MAP values (37% to 47%) was similar in all five groups. The highest postintubation HR values were recorded in the N4 group (P < 0.05 versus the other groups). However, the increases in MAP values after skin incision were the least in the N4 group. In conclusion, N1 I.V., administered 2 min before laryngoscopy provides optimal control of arterial blood pressure during the postinduction period. ⋯ Acute increases in blood pressure during anesthesia are undesirable in patients with preexisting cardiovascular diseases. This double-blind study found that the calcium-channel blocker, nicardipine, 1 mg intravenously 2 min before tracheal intubation maintained hemodynamic stability during the intraoperative period.
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Anesthesia and analgesia · Dec 1997
Randomized Controlled Trial Clinical TrialThe choice of anesthetic maintenance technique influences the antiinflammatory cytokine response to abdominal surgery.
Outcome in some diseases is determined by the relationship between pro- and antiinflammatory cytokines. Surgery may also provoke a cytokine response, which has both pro- and antiinflammatory components. The aim of this study was to ascertain whether anesthetic technique can modify the balance of cytokines associated with abdominal surgery. Twenty patients scheduled to undergo elective abdominal hysterectomy were randomly allocated to receive maintenance of anesthesia with isoflurane (IH group) or propofol (IV group). Venous blood samples for measurement of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-1 receptor antagonist (IL-1ra) were taken before the induction of anesthesia and at set intervals until 24 h postoperatively. TNF-alpha levels remained low throughout the study; however, all patients showed a significant postoperative increase in IL-6, IL-10, and IL-1ra (P < 0.05). Levels of the proinflammatory cytokine IL-6 were similar in both groups, whereas the antiinflammatory cytokine IL-10 was higher in the IV group at 4 h postoperatively (P < 0.02). The difference between groups in terms of IL-1ra production just failed to reach significance (P < 0.06). We conclude that the cytokine response to abdominal surgery has both pro- and antiinflammatory components and that the choice of anesthetic may modify the balance of these cytokines. ⋯ This study demonstrates that in addition to the widely reported proinflammatory cytokine response, elective abdominal surgery provokes an antiinflammatory response, which may be enhanced by total intravenous anesthesia. The ability of anesthetics to modify the cytokine response to surgery may have therapeutic potential.
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Anesthesia and analgesia · Dec 1997
The effects of sevoflurane on cerebral hemodynamics during propofol anesthesia.
We investigated the cerebral hemodynamic effects of 0.5 and 1.5 minimum alveolar anesthetic concentration (MAC) sevoflurane during propofol anesthesia in 10 patients undergoing supratentorial tumor resection. All patients received a standardized anesthetic, and their lungs were ventilated with a mixture of air and oxygen to produce mild hypocapnia. Anesthesia was then maintained with a propofol infusion. Muscle relaxation was obtained by infusion of atracurium. A transcranial Doppler probe was used to measure red cell flow velocity in the right middle cerebral artery (Vmca). A right-sided jugular bulb catheter was inserted for sampling of jugular bulb blood. After a 30-min period of stabilization and before the start of surgery, baseline arterial and jugular bulb blood samples were drawn to define the arterial-venous oxygen content difference (AVDO2). Mean arterial pressure and Vmca were recorded. Sevoflurane (0.5 and 1.5 MAC) in oxygen/air was then administered, and all measurements were repeated. Administration of sevoflurane at 0.5 MAC did not change Vmca or AVDO2. Sevoflurane (1.5 MAC) did not change Vmca. There was an approximately 25% reduction in AVDO2 (P < 0.05). This suggests that during propofol anesthesia, although 1.5 MAC sevoflurane does not increase red blood cell velocity, there is a relative increase in flow with respect to metabolism. Administration of large-dose sevoflurane may be associated with a degree of luxury perfusion. ⋯ We investigated the cerebral hemodynamic effects of sevoflurane in patients undergoing neurosurgery. Small-dose sevoflurane (1%) did not change brain blood flow or oxygen consumption. Large-dose sevoflurane (3%) did not change flow velocity but reduced brain oxygen consumption by 25%. Sevoflurane may provide a degree of luxury perfusion.