Anesthesia and analgesia
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Anesthesia and analgesia · Nov 1999
Randomized Controlled Trial Comparative Study Clinical TrialTwo doses of intrathecal sufentanil (2.5 and 5 microg) combined with bupivacaine and epinephrine for labor analgesia.
In this study, we evaluated the effect of two doses of intrathecal sufentanil combined with bupivacaine and epinephrine on the incidence of pruritus and on the duration and quality of analgesia. One hundred five parturients were enrolled in this randomized, double-blinded, placebo-controlled study. They received either intrathecal 1.25 mg bupivacaine and 25 microg epinephrine (control group); 1.25 mg bupivacaine, 25 microg epinephrine, and 2.5 microg sufentanil (2.5-microg group); or 1.25 mg bupivacaine, 25 microg epinephrine, and 5 microg (5-microg group). Pain relief was assessed 10 min after injection, and pruritus was recorded at 30 min by a blinded observer. The study ended when the parturients requested further analgesia. There were no demographic differences among groups. Ninety of 103 parturients achieved complete pain relief with the initial dose, 11 patients in the control group (P < 0.004, control versus both sufentanil groups), and 2 patients in the 2.5-microg group needed a supplemental epidural bupivacaine. Pruritus was absent in the control group (P < 0.0001, control versus both sufentanil groups), whereas it was present in 36% of the 2.5-microg group and in 66% of the 5-microg group (P = 0.015, 2.5-microg versus 5-microg group). The mean duration of analgesia was similar in patients receiving sufentanil (2.5-microg group: 133 +/- 55 min; 5-microg group: 142 +/- 52 min) but was significantly higher than the control group (56 +/- 32 min). Reducing the sufentanil dose from 5 microg to 2.5 microg when combined with bupivacaine and epinephrine, decreases the incidence of pruritus without impeding the quality or duration of analgesia. ⋯ We evaluated two different doses of intrathecal sufentanil combined with bupivacaine and epinephrine for labor analgesia. Sufentanil 2.5 microg offered an advantage over sufentanil 5 microg because, while providing the same quality and duration of analgesia, it was associated with a reduced incidence of pruritus.
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Anesthesia and analgesia · Nov 1999
Randomized Controlled Trial Comparative Study Clinical TrialComparison of 9 mg of intrathecal plain and hyperbaric bupivacaine both with fentanyl for cesarean delivery.
We randomized 76 parturients to a double-blinded trial to receive spinal anesthesia with either hyperbaric or plain bupivacaine 9 mg with fentanyl 20 microg for elective cesarean delivery. A combined spinal-epidural technique was used. The onset and duration of anesthesia (absence of pinprick sensation), analgesia (absence of sharp sensation to pinprick), and absence of cold sensation and motor block were measured until recovery from the motor block. No major differences were seen in onset or duration of anesthesia between the groups. Motor block, however, vanished faster when hyperbaric bupivacaine was used (P < 0.05). The level of anesthesia (no pinprick sensation) required for painless operation was at dermatome T5. At this time, the absence of cold sensation ranged from dermatome T1 to C3. The median time for the anesthesia to reach dermatome T5 was 10 min. Cervical spread of pinprick anesthesia was noted in six patients, and five needed supplementary analgesics during surgery (not significant between the groups). Maternal satisfaction was good. Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution. ⋯ Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution.
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Anesthesia and analgesia · Nov 1999
Randomized Controlled Trial Clinical TrialAttempting to maintain normoglycemia during cardiopulmonary bypass with insulin may initiate postoperative hypoglycemia.
We attempted to develop an insulin administration protocol that maintains normoglycemia in patients undergoing cardiac surgery and to study the effects of intraoperative blood glucose management on serum levels of creatine phosphokinase isoenzyme BB (CK-BB) and S-100 protein. Twenty nondiabetic patients were randomly allocated to receive either "tight control" of blood glucose with a standardized IV insulin infusion intraoperatively (Group TC) or "no control" of blood glucose intraoperatively (Group NC). Perioperative serum levels of glucose, CK-BB, and S-100 protein were determined in all patients. Group TC patients received 90.0 +/- 49.2 units of insulin, whereas Group NC patients received none. Despite insulin, both Group TC (P = 0.00026) and Group NC (P = 0.00003) experienced similar significant increases in blood glucose levels during hypothermic cardiopulmonary bypass. However, mean blood glucose level upon intensive care unit arrival was significantly decreased in Group TC, compared with Group NC (84.7 +/- 41.0 mg/dL, range 32-137 mg/dL vs 201.4 +/- 67.5 mg/dL, range 82-277 mg/dL, respectively; P = 0.0002). Forty percent of Group TC patients required treatment for postoperative hypoglycemia (blood glucose level <60 mg/dL). Substantial interindividual variability existed in regard to insulin resistance. The investigation was terminated after we realized that normoglycemia was unattainable with the study protocol and that postoperative hypoglycemia was unpredictable. All patients in both groups experienced similar significant increases in postoperative serum levels of CK-BB and S-100 protein. These results indicate that "tight control" of intraoperative blood glucose in nondiabetic patients undergoing cardiac surgery was unattainable with the study protocol and may initiate postoperative hypoglycemia. ⋯ The appropriate intraoperative management of hyperglycemia and whether it adversely affects neurologic outcome in patients after cardiac surgery remains controversial. This investigation reveals that attempting to maintain normoglycemia in this setting with insulin may initiate postoperative hypoglycemia.
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Anesthesia and analgesia · Nov 1999
Randomized Controlled Trial Clinical TrialThe effect of midazolam premedication on mental and psychomotor recovery in geriatric patients undergoing brief surgical procedures.
To assess the effect of IV midazolam premedication on recovery of cognitive function, 90 geriatric patients (aged 65-81 yr) undergoing brief transurethral procedures were enrolled into this prospective, placebo-controlled, double-blinded study. In all cases, a standard general anesthetic was administered. Thirty minutes before operating room transfer, patients in Group 0.5 mg, Group 2 mg, and Group S received 0.5 mg of midazolam, 2 mg of midazolam, or an equal volume of saline, respectively. Before study-drug administration (baseline), at 15 min thereafter, as well as on arrival in the postanesthesia care unit (PACU), and at 60 min and 120 min, postoperatively, we administered a digit-symbol substitution test, a mini-mental test, a shape-sorter test, and a patient-generated 100-mm visual analog score (0 = minimal and 100 = maximal) for anxiety, sleepiness, and coordination. A 4-point scale was used to assess the degree of patient sedation at 7, 15, and 30 min after study-drug administration. Using a modified Aldrete scoring system, PACU discharge was determined by the PACU staff. Patient anxiety, sleepiness, and coordination scores at baseline and at 15 min after study-drug administration were similar. When compared with saline, midazolam was associated with a significantly (P < 0.05) higher incidence of "deep" sedation. In Group 2 mg, the incidence of a low preoperative Spo2 (<94%) was significantly (P < 0.05) higher when compared with Group S. Emergence, extubation, and orientation times, as well as time to follow commands were unaffected by midazolam premedication. Postoperatively, the digit-symbol substitution test, mini-mental test, and shape-sorter test were similar among the groups. However, time to PACU discharge was significantly (P = 0.03) longer in the two midazolam treatment groups (41 +/-25 min, 60 +/- 32 min, 53 +/- 39 min for Groups S, 0.5 mg, and 2 mg, respectively). Finally, patient satisfaction was unaffected by the randomization schedule. ⋯ IV premedicant midazolam 0.5 mg or 2 mg does not adversely affect mental and psychomotor recovery in geriatric patients undergoing brief surgical procedures. However, midazolam administration significantly prolonged postanesthesia care unit discharge time. Finally, during the preoperative period, midazolam increases the incidence of a Spo2 <94% in a dose-dependent manner.
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Anesthesia and analgesia · Nov 1999
Randomized Controlled Trial Clinical TrialThe use of a remifentanil infusion for hemodynamic control during intracranial surgery.
Remifentanil is an extremely rapid and short-acting opioid analgesic which is effective in controlling acute stress responses during surgery. During neurosurgical anesthesia, laryngoscopy and intubation, application of the head holder, scalp incision, and the craniectomy can produce significant increases in mean arterial pressure (MAP). In this dose-response study, we evaluated the efficacy of a remifentanil infusion in maintaining hemodynamic stability during intracranial surgery under desflurane anesthesia. Forty-five patients were assigned randomly to one of the three remifentanil infusion groups. All patients received a standardized anesthetic induction consisting of midazolam, 2 mg IV, lidocaine 0.75 mg/kg IV, propofol 1.0 mg/kg IV, and remifentanil 0.5 microg/kg IV. Immediately after induction of anesthesia, a remifentanil infusion was started at 0.0625 microg x kg(-1) x min(-1) (Group 1), 0.125 microg x kg(-1) x min(-1) (Group 2), or 0.250 microg x kg (-1) x min(-1)(Group 3) according to a double-blinded study protocol. Maintenance of anesthesia consisted of desflurane 3% (end-tidal) in air/oxygen. If the MAP exceeded 80 mm Hg, a supplemental bolus of remifentanil, 0.5 microg/kg IV was administered, and when the MAP decreased below 65 mm Hg, the remifentanil infusion was discontinued temporarily. "Rescue" cardiovascular medications consisted of nitroprusside (100 microg IV) or phenylephrine (100 microg IV). Heart rate, systolic, diastolic, and MAP values, were recorded every minute for 20 min after each specific stimulus. The overall quality of the intraoperative hemodynamic control was evaluated by the attending anesthesiologist on a scale from 1 = poor to 5 = excellent. The overall quality of the hemodynamic control was superior in Group 2 compared with Group 1 (P < 0.05). Although the total dose of remifentanil administered during the study period did not differ among the three groups, Group 1 required significantly more supplemental boluses of remifentanil (66%-80%) than Groups 2 (13%-33%) and 3 (70% 13%), and the remifentanil infusion was discontinued more often in Group 3 (80%-93%) than in Groups 1 (0%-13%) and 2 (21%-40%). In conclusion, the recommended remifentanil infusion rate for controlling acute autonomic responses during neurosurgical anesthesia is 0.125 microg x kg(-1) x min(-1) when administered during a desflurane-based anesthetic. ⋯ Compared with remifentanil 0.0625 microg x kg(-1) x min(-1) and 0.250 microg x kg(-1) x min(-1), a remifentanil infusion rate of 0.125 microg x kg(-1) x min(-1) provided more stable hemodynamic conditions during intracranial surgery under desflurane anesthesia.