Yifeng Ding

Propofol infusion during regional anesthesia: sedative, amnestic, and anxiolytic properties.

We examined the plasma concentrations and resultant clinical effects produced by four different propofol bolus infusion regimens in 98 healthy males undergoing elective urologic procedures under regional anesthesia. Patients were randomly assigned to one of four propofol dosage groups. In Groups 1-4, loading doses of propofol equal to 0.2, 0.4, 0.5, or 0.7 mg/kg intravenously, respectively, were followed by fixed-rate propofol infusions of 0.5, 1, 2, or 4 mg.kg-1.h-1, respectively, during the regional block procedure. Sedation (sleepiness) was assessed independently by the patient and a blinded observer using 100-mm visual analog scales. Intraoperative amnesia was assessed using picture recall. Sedation scores increased in a dose-dependent fashion (13 +/- 19, 21 +/- 19, 45 +/- 28, and 73 +/- 26 mm at 30 min in Groups 1-4, respectively). Within a given dosage group, sedation scores were stable during the maintenance infusion period. Mean plasma propofol concentrations increased with higher propofol infusion rates (0.16 +/- 0.3, 0.18 +/- 0.1, 0.47 +/- 0.2, and 1.1 +/- 0.8 microgram/mL at 30 min in Groups 1-4, respectively). However, significant variability was observed among individual patient sedation scores and plasma propofol concentrations. Anxiety scores decreased in all four propofol infusion groups during the maintenance period. Hemodynamic variables and hemoglobin oxygen saturation values were similar in all four treatment groups. Recovery from propofols central effects was rapid after discontinuation of the propofol infusion, and the incidence of side effects was low. Recall of intraoperative events was more commonly observed in the lower-dosage groups (86%, 96%, 58%, and 13% of patients in Groups 1-4, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of induction, maintenance, and recovery characteristics of sevoflurane-N2O and propofol-sevoflurane-N2O with propofol-isoflurane-N2O anesthesia.

&NA; Induction of, maintenance of, and recovery from sevoflurane anesthesia were compared with propofol and isoflurane anesthesia when administered with nitrous oxide to patients undergoing gynecologic surgery. Seventy‐five healthy (ASA I or II), consenting patients were randomly assigned to receive either (I) propofol for induction of anesthesia and isoflurane‐nitrous oxide for maintenance (control), (II) propofol for induction and sevoflurane‐nitrous oxide for maintenance, or (III) sevoflurane‐nitrous oxide for induction and maintenance of anesthesia. Inhaled induction of anesthesia with sevoflurane‐nitrous oxide was rapid (109 ± 25 s to loss of consciousness) and without any untoward hemodynamic changes or episodes of coughing and laryngospasm. Mean arterial blood pressure after induction of anesthesia with propofol (71 ± 11, 73 ± 12 mm Hg for groups I and II, respectively) was lower than when sevoflurane (80 ± 14 mm Hg) was used. The emergence time after discontinuation of isoflurane‐nitrous oxide (6.7 ± 2.2 min) was significantly longer than after propofolsevoflurane‐nitrous oxide or sevoflurane‐nitrous oxide alone (4.1 ± 2.2 and 4.0 ± 2.0 min for groups II and III, respectively). However, later recovery events did not differ between groups. Serum fluoride levels increased after administration of sevoflurane but not isoflurane. The levels of fluoride ions correlated with the degree of exposure to sevoflurane in MAC‐hours. In conclusion, induction of anesthesia with either propofol or sevoflurane‐nitrous oxide was rapid and without significant side effects. Emergence and early recovery after maintenance of anesthesia with sevoflurane‐nitrous oxide was significantly faster than that after an isoflurane‐nitrous oxide combination.

Use of mivacurium during laparoscopic surgery: effect of reversal drugs on postoperative recovery.

The authors studied the influence of mivacurium on the recovery profile following outpatient laparoscopic tubal ligation in 60 healthy nonpregnant women. After administration of midazolam 2 mg intravenously (IV) anesthesia was induced with fentanyl 2 mcg/kg and thiopental 4 mg/kg IV. When the patient became unresponsive (loss of eyelid reflex) either succinylcholine 1 mg/kg IV (Group 1) or mivacurium 0.2 mg/kg IV (Groups 2 and 3) was administered to facilitate tracheal intubation. Anesthesia was maintained with isoflurane (0.5%-2% inspired concentration) in combination with 67% N2 in oxygen. Muscle relaxation was maintained in all 3 groups with intermittent bolus doses of mivacurium 2-4 mg IV. In Group 3 residual neuromuscular block was reversed with a combination of neostigmine 2.5 mg and glycopyrrolate 0.5 mg IV at the end of the operation. In the postanesthesia care unit (PACU) patients in Group 3 had a significantly increased incidence of postoperative nausea and vomiting compared to Group 2. The use of succinylcholine (vs mivacurium) was also associated with more frequent postoperative nausea and vomiting. However these emetic sequelae did not delay postoperative recovery times. In addition a comparable number of patients in each treatment group required analgesic medication for postoperative pain. Although patients who received succinylcholine complained of significantly more neck pain during the 24 hour period after discharge nausea vomiting and shoulder pain were similar in all 3 groups during this period. The authors conclude that neostigmine and glycopyrrolate may contribute to the development of postoperative emesis when used for reversal of residual neuromuscular block. The use of mivacurium without reversal drugs was associated with a decreased incidence of nausea and vomiting in the PACU. (authors)

Post-herniorrhaphy pain in outpatients after preincision ilioinguinal-hypogastric nerve block during monitored anaesthesia care

The objective of this study was to evaluate the effect of an ilioinguinal-hypogastric nerve block (IHNB) with bupivacaine 0.25% on the postoperative analgesic requirement and recovery profile in outpatients undergoing inguinal herniorrhaphy with local anaesthetic infiltration. Thirty consenting healthy men undergoing elective unilateral inguinal herniorrhaphy procedures were randomly assigned to receive an IHNB with either saline or bupivacaine according to a double-blind, IRB-approved protocol. All patients received midazolam, 2 mg iv, and fentanyl 25 μg iv, prior to injection of 30 ml of either bupivacaine 0.25% or saline through the oblique muscle approximately 1.5 cm medial to the anterior superior iliac spine. Subsequently, the surgeon infiltrated the incision site with a lidocaine 1% solution. Sedation was maintained during the operation with a variable-rate propofol infusion, 25–140 μg · kg−1 · min−1. No significant differences were noted in the intraoperative doses of lidocaine, propofol and fentanyl in the two treatment groups. However, the pain visual analogue score at 30 min after entering the PACU was lower in the bupivacaine (versus saline) group (P < 0.05). Although the times to ambulation (86 ± 18 vs 99 ± 27 min) and being judged “fit for discharge” (112 ± 49 vs 126 ± 30 min) were similar in the two groups, the bupivacaine-treated (vs saline) patients required less oral analgesic medication after discharge (46% vs 85%). We concluded that the use of an ilioinguinal-hypogastric nerve block with bupivacaine 0.25% as an adjuvant during inguinal herniorrhaphy under monitored anaesthesia care decreased pain in the PACU and oral analgesic requirements after discharge from the day-surgery unit.RésuméCette étude vise à évaluer les répercussions du bloc ilioinguinal et hypogastrique (IIHB) à la bupivacaïne, 0,25% sur les besoins analgésiques et le profil de récupération postopératoires de patients opérés pour une herniorrhaphie inguinale sous infiltration locale d’anesthésique. Trente adultes consentants et bien portants soumis à une herniorrhaphie unilatérale programmée sont répartis au hasard pour recevoir un IIHB soit avec du soluté physiologique soit de la bupivacaine suivant un protocole approuvé par notre comité d’éthique. Tous les patients reçoivent du midazolam 2 mg iv et du fentanyl 25 μg iv avant l’injection de 30 ml de la bupivacaïne 0,25% ou du soluté physiologique à travers le muscle oblique à un point situé à 1,5 cm à l’intérieur de l’épine iliaque antéro-supérieure. Par la suite, le chirurgien infiltre la ligne d’incision avec de la lidocaïne 1%. La sédation est maintenue pendant l’intervention avec une perfusion adaptée de propofol de 25 à 140 μg kg−1 · min−1 On ne trouve pas de différence posologique peropératoire de lidocaïne, de propofol et de fentanyl entre les deux groupes. Cependant le score de l’échelle visuelles analogue (EVA) de la douleur à trente min après l’arrivée en salle de réveil est plus bas dans le groupe bupivacaïne (P < 0,05). Bien que le moment de l’aptitude à l’ambulation (86 ± 18 vs 99 ± 27 min) et l’autorisation de quitter l’hôpital (112 ± 49 vs 126 ± 30 min) soient les mêmes pour les deux groupes, le groupe bupivacaïne a moins besoin d’analgésiques oraux après le congé hospitalier (46% vs 85%). Nous concluons que l’utilisation de bloc ilioinguinal et hypo-gastrique à la bupivacaïne 0,25% comme adjuvant pendant la herniorrhaphie inguinale sous anesthésie monitorée diminue la douleur en salle de réveil et les besoins d’analgésiques oraux après le départ de l’unité de chirurgie ambulatoire.

Comparative effects of ketorolac, dezocine, and fentanyl as adjuvants during outpatient anesthesia.

The comparative effects of ketorolac, dezocine, and fentanyl were evaluated in 136 healthy female patients undergoing outpatient laparoscopic procedures according to a randomized, double-blind protocol. Patients received ketorolac (60 mg) or dezocine (6 mg) or fentanyl (100 micrograms, control group) before the start of the operation. A standardized general anesthetic technique consisting of midazolam (2 mg), fentanyl (50 micrograms), and propofol (2 mg/kg) for induction of anesthesia followed by propofol (120 micrograms.kg-1.min-1), vecuronium (1-2 mg), and 67% nitrous oxide in oxygen for maintenance of anesthesia, was used. In the postanesthesia care unit, 61% of patients in the fentanyl group received analgesic drugs for persistent pain, compared with 34% and 25% in the ketorolac and dezocine groups, respectively. Similarly, less postoperative fentanyl (mean +/- SD) was required in the ketorolac (22 +/- 33 micrograms) and dezocine (18 +/- 35 micrograms) groups, compared with the fentanyl (58 +/- 71 micrograms) group. However, 52% of the patients receiving dezocine required antinausea therapy in the postanesthesia care unit, compared with 20% and 18% in the fentanyl and ketorolac groups, respectively. Finally, recovery times were significantly shorter in the ketorolac (vs dezocine) group. Although both ketorolac and dezocine were effective alternatives to fentanyl when administered during outpatient laparoscopy, dezocine was associated with an increased incidence of postoperative nausea and a delayed discharge time compared with ketorolac.

Effects of ketorolac on postoperative analgesia and ventilatory function after laparoscopic cholecystectomy.

Ketorolac, a nonsteroidal anti-inflammatory drug, is alleged to produce postoperative analgesia without opioid-related side effects. Patients undergoing laparoscopic cholecystectomy were assigned randomly to receive either ketorolac or a placebo (saline) according to a double-blind protocol. Preoperative (baseline) pulmonary function was evaluated using a Respiradyne II monitor. Patients received midazolam, 2 mg, and 2 mL of either ketorolac, 60 mg (n = 311, or saline (n = 29), 20–40 min before surgery. Anesthesia consisted of thiopental, 4–5 mg/kg, and vecuronium, 0.1 mg/kg, for induction, and isoflurane, 0.5%–2.0%, with 67% nitrous oxide in oxygen for maintenance. A second 2-mL dose of the same study medication (ketorolac, 60 mg, or saline) was administered 4 h after the initial dose. Post-operatively, 66% of patients in the saline group complained of pain requiring treatment with fentanyl compared to 32% in the ketorolac group (P < 0.05). There were no significant differences between the two groups with respect to postoperative sedation, anxiety, pain, or nausea visual analog scores. Compared to the preoperative values, significant decreases in pulmonary function tests were noted in both groups at 4 h after the operation and the following morning (P < 0.01). In the ketorolac group, only values of forced expiratory volume at 1 s and forced expiratory flow at 25%–75% of the forced vital capacity at 4 h after the operation were significantly higher than those in the saline group (P < 0.05). Incidences of nausea (45% vs 52%) and vomiting (10% vs 10%) were similar in both groups. In conclusion, ketorolac decreased the postoperative requirement for opioid analgesic medication. However, the use of ketorolac failed to decrease postoperative emesis or ventilatory impairment after laparoscopic cholecystectomy.

Effect of topical eutectic mixture of local anesthetics on pain response and analgesic requirement during lithotripsy procedures.

We sought to determine whether topically applied eutectic mixture of local anesthetics (EMLA) would decrease analgesic requirement during extracorporeal shock wave lithotripsy (ESWL). Fifty-nine healthy out-patients undergoing elective ESWL using an unmodified Dornier HM-3 lithotriptor were randomly assigned to receive either a topical EMLA or placebo cream applied to the skin of the flank overlying the kidney 90 min prior to the ESWL procedure. Patients were given five test shocks at each of five different energy levels: 10, 12, 15, 18, and 20 kV. Patients evaluated the average pain at each stimulus level using a visual analog scale. Overall pain scores were significantly lower in EMLA-treated patients at 18 and 20 kV (P < 0.05). EMLA cream was significantly more effective at decreasing cutaneous pain in male than in female patients. However, during the lithotripsy procedure, EMLA cream had no significant effect on the intraoperative requirement for intravenous alfentanil, hemodynamic variables, recovery times, or postoperative side effects. Although the topical application of EMLA cream produced cutaneous analgesia, these data suggest that it failed to produce any opioid-sparing effect during the immersion lithotripsy procedure.

Total intravenous anesthesia: effects of opioid versus hypnotic supplementation on autonomic responses and recovery.

During radical prostatectomy procedures under total intravenous anesthesia, acute hemodynamic responses to retropubic dissection (30% ± 8% to 36% ± 12% [mean ± SD] increases in mean arterial pressure) were treated with supplemental doses of either an opioid analgesic (alfentanil) or a sedative-hypnotic (propofol) to return the mean arterial pressure to within 10% of the preincision value. Although both drugs were effective, control with propofol required 10.1 ± 2.5 min compared with 6.3 ± 2.6 min in the alfentanil group (mean ± SD; P < 0.01). Plasma stress hormone concentrations increased significantly in response to this surgical stimulus: epinephrine increased from 246% ± 169% to 283% ± 330%; norepinephrine increased from 44% ± 33% to 83% ± 104%; and antidiuretic hormone increased from 1300% ± 1591% to 1700% ± 1328%. Both alfentanil and propofol were equally effective in returning the catecholamine concentrations to their preincision levels. However, antidiuretic hormone levels remained above preincision values in both groups. Despite earlier awakening (3.4 ± 2.9 vs 9.1 ± 6.8 min; P < 0.05) in the alfentanil treatment group, there was no difference in time to spontaneous ventilation or tracheal extubation between the groups. In addition, 36% of the alfentanil-treated patients required antihypertensive therapy in the postanesthesia care unit compared with only 9% in the propofol group (P < 0.05). Postanesthesia care unit and hospital discharge times were similar in both treatment groups. We conclude that supplemental doses of alfentanil or propofol were equally effective in controlling acute hemodynamic and hormonal responses to surgical stimuli during total intravenous anesthesia.

Muscle pain after outpatient laparoscopy : influence of propofol versus thiopental and enflurane

The incidence and pattern of postoperative muscle pains was studied in 155 healthy women undergoing outpatient laparoscopic surgery who were assigned randomly to one of five treatment groups. Group 1 (control) received thiopental and succinylcholine, 1 mg/kg, followed by enflurane and nitrous oxide. Group 2 received d-tubocurarine, 3 mg, followed by succinylcholine, 1.5 mg/kg, but was otherwise similar to Group 1. Groups 3 and 4 were similar to Group 1, but received propofol instead of thiopental, and Group 4 also received a variable-rate propofol infusion instead of enflurane. Finally, Group 5 was similar to Group 3, but received atracurium instead of succinylcholine. Muscle fasciculations were often observed in Groups 1, 3, and 4, but were attenuated in Group 2 and absent in Group 5. Overall, postoperative shoulder pain occurred in 81%, 72%, and 29% of patients on the first, second, and third postoperative days, respectively. The incidence of this symptom did not differ among the five groups. Neck pain occurred less frequently than shoulder pain in each group, and also occurred less often in Group 5 than in Group 1. Muscle stiffness occurred less often than muscle pain, and also occurred less frequently in Group 5 than in Group 1. In conclusion, succinylcholine contributes to neck pain and muscle stiffness after laparoscopic procedures. Compared to thiopental and enflurane, the use of propofol for induction and/or maintenance of anesthesia failed to alter the incidence of postlaparoscopic muscle pain or stiffness.

Use of ketorolac and fentanyl during outpatient gynecologic surgery

In healthy outpatients undergoing minor gynecologic surgery, the analgesic efficacy of ketorolac was compared to fentanyl and to a combination of the two analgesics. One hundred and nine patients were randomly selected to receive fentanyl 50-100 micrograms, ketorolac 30-60 mg, or a combination of fentanyl 50-100 micrograms and ketorolac 30-60 mg, intravenously (IV). Anesthesia was induced with midazolam 2 mg IV and propofol 1 mg/kg, IV, and maintained with propofol, 50-160 micrograms.kg-1.min-1, IV, and nitrous oxide 67% in oxygen via a face mask. Intraoperative anesthetic conditions, recovery times, and postoperative pain and side effects were evaluated. In the ketorolac group, 75% of patients required supplemental fentanyl intraoperatively (mean dose +/- SD, 47 +/- 54 micrograms), compared to only 19% (13 +/- 30 micrograms) and 18% (6 +/- 15 micrograms) of patients in the fentanyl and combination groups, respectively. In the ketorolac group, 74% of patients moved in response to surgical stimulation compared to only 16% and 19% of patients in the fentanyl and combination groups, respectively. Although there were no significant differences in intraoperative mean arterial pressure, heart rate, and oxygen saturation of hemoglobin values among the three treatment groups, the ketorolac group manifested significantly more rapid respiratory rates throughout the procedure compared with the fentanyl and combination groups. Recovery times, postoperative side effects, and pain scores, as well as postoperative analgesic and antiemetic requirements, were similar in all three treatment groups. However, the ketorolac group reported significantly higher pain scores in the early postoperative period.(ABSTRACT TRUNCATED AT 250 WORDS)