Marco A. E. Marcus

Reversal of rocuronium-induced (1.2 mg/kg) profound neuromuscular block by sugammadex: a multicenter, dose-finding and safety study.

Background: Reversal of rocuronium-induced neuromuscular blockade can be accomplished by chemical encapsulation of rocuronium by sugammadex, a modified &ggr;-cyclodextrin derivative. This study investigated the efficacy and safety of sugammadex in reversing rocuronium-induced profound neuromuscular blockade at 5 min in American Society of Anesthesiologists physical status I and II patients. Methods: Forty-five American Society of Anesthesiologists physical status I and II patients (aged 18–64 yr) scheduled to undergo surgical procedures (anticipated anesthesia duration ≥ 90 min) were randomly assigned to a phase II, multicenter, assessor-blinded, placebo-controlled, parallel, dose-finding study. Anesthesia was induced and maintained with propofol and an opioid. Profound neuromuscular blockade was induced with 1.2 mg/kg rocuronium bromide. Sugammadex (2.0, 4.0, 8.0, 12.0, or 16.0 mg/kg) or placebo (0.9% saline) was then administered 5 min after the administration of rocuronium. Neuromuscular function was monitored by acceleromyography, using train-of-four nerve stimulation. Recovery time was the time from the start of administration of sugammadex or placebo, to recovery of the train-of-four ratio to 0.9. Safety assessments were performed on the day of the operation and during the postoperative and follow-up period. Results: A total of 43 patients received either sugammadex or placebo. Increasing doses of sugammadex reduced the mean recovery time from 122 min (spontaneous recovery) to less than 2 min in a dose-dependent manner. Signs of recurrence of blockade were not observed. No serious adverse events related to sugammadex were reported. Two adverse events possibly related to sugammadex were reported in two patients (diarrhea and light anesthesia); however, both patients recovered without sequelae. Conclusions: Sugammadex rapidly and effectively reversed profound rocuronium-induced neuromuscular blockade in humans and was well tolerated.

A comparison of three videolaryngoscopes: the Macintosh laryngoscope blade reduces, but does not replace, routine stylet use for intubation in morbidly obese patients

BACKGROUND: Many manufacturers are producing videolaryngoscopes (VLSs) with differing specifications, user interfaces, and geometry. It is clinically relevant to know the relative performance of the blades. Visualization of the glottis and intubation are often problematic in (extremely) obese patients, and the new video technology may offer better functionality and performance. Although many tracheal intubations with direct laryngoscopy are performed with an unstyletted endotracheal tube, it is recommended to use a stylet for intubation using videolaryngoscopy. In this study, we compared 3 VLSs in morbidly obese patients undergoing intubation for elective surgery and tested whether it is feasible to intubate the tracheas of morbidly obese patients without using a stylet. METHODS: One hundred fifty consecutive adult morbidly obese patients (body mass index >35 kg/m2) were randomly selected to receive one of 3 VLSs: GlideScope®, Storz® V-Mac™, and McGrath®. Direct laryngoscopy scored the best possible view of the glottis; subsequently, the respective VLS was used, and the patients trachea was intubated. Common preprocedural (e.g., Mallampati grade) and intraprocedural (Cormack-Lehane grade) metrics of intubation difficulty were measured, as well as the dependent variables of intubation time, number of attempts, and subjective difficulty. RESULTS: All 3 VLSs tested offered an equal or better view of the glottis compared with traditional direct laryngoscopy. The number of attempts necessary to intubate the trachea differed significantly among VLSs (average 2.6 ± 1.0 attempts for the GlideScope, 1.4 ± 0.7 for the Storz, and 2.9 ± 0.9 for the McGrath VLS). The average intubation times were 33 ± 18 s for the GlideScope, 17 ± 9 s for the Storz, and 41 ± 25 s for the McGrath VLS. CONCLUSIONS: In this study, the VLS with the Macintosh blade (Storz VLS) had a better overall satisfaction score, intubation time, number of intubation attempts, and necessity of extra adjuncts, compared with the 2 other tested devices.

Epidural analgesia with local anesthetics after abdominal surgery : Earlier motor recovery with 0.2% ropivacaine than 0.175% bupivacaine

UNLABELLED The aim of this prospective, randomized, double-blinded study was to compare pain relief, side effects, and ability to ambulate during epidural anesthesia with ropivacaine 0.2% plus sufentanil versus bupivacaine 0.175% plus sufentanil after major gastrointestinal surgery. Epidural catheters were inserted at T8-11, and 30 microg of sufentanil with 15 mL of ropivacaine 0.75% (Group 1, n = 42) or bupivacaine 0.5% (Group 2, n = 44) was injected. General anesthesia was induced, a continuous epidural infusion (5 mL/h) was then begun with 1 microg/mL sufentanil plus ropivacaine 0.2% (Group 1) or bupivacaine 0.175% (Group 2). Postoperatively, the infusion rate was adjusted to individual requirements. Patients were also able to receive additional 2-mL bolus doses every 20 min. Demographic data (except for gender and height), analgesia, drug dosage, and side-effects, including motor blockade (Bromage score), were similar in both groups, but mobilization recovered more quickly in Group 1. Gender, age, ASA physical status, duration of surgery, and intraoperative blood loss had no effect on mobilization. We conclude that epidural analgesia is effective and safe with both regimens. There is not necessarily a correlation between the Bromage score and the desired outcome of mobilization. The ability to walk postoperatively is hastened if ropivacaine is used instead of bupivacaine. IMPLICATIONS Regarding pain relief and side effects, epidural analgesia with ropivacaine 0.2% and sufentanil 1 microg/mL yields pain scores and pain intensity comparable to those for the well evaluated combination of bupivacaine 0.175% and sufentanil 1 microg/mL. However, earlier recovery of the ability to walk unassisted in patients receiving the combination of ropivacaine and sufentanil may result in their earlier rehabilitation.

Hemodynamic changes during induction of anesthesia with eltanolone and propofol in dogs

The purpose of this study was to examine global and regional hemodynamic changes during induction of anesthesia with eltanolone, a new short-acting steroid hypnotic, as compared to propofol, in chronically instrumented dogs. The effects on cardiac performance were assessed in six animals. Renal and hepatic blood flows were examined in a separate study including five animals. Two doses of each drug were investigated: eltanolone 2.5 and 5 mg/kg and propofol 7.5 and 15 mg/kg. Left atrial filling pressures and cardiac output were not affected by either drug. Maximum rate of increase of left ventricular pressure decreased both with eltanolone (-28% and -40% from awake control for the 2.5 and 5 mg/kg doses, respectively) and with propofol (-19% and -30% from awake controls with 7.5 and 15 mg/kg, respectively). In contrast to propofol, eltanolone preserved arterial blood pressure. Propofol lowered systemic vascular resistance (-21% and -39% with the low and high dose, respectively), and only slightly decreased left ventricular wall thickening fraction (-16% and -21%). Eltanolone did not affect systemic vascular resistance but reduced the wall-thickening fraction dose-dependently (-28% and -61%). Propofol, but not eltanolone, induced moderate coronary vasodilation. Hepatic arterial blood flow velocity decreased dose-dependently (-21% and -64%) during eltanolone anesthesia whereas, in contrast, it increased after propofol (+59% and +64%). Renal and portal venous blood flows remained essentially unaltered from awake conditions. Our data demonstrate that both propofol and eltanolone have cardiodepressant properties but differ with regard to their effects on peripheral vascular tone. Systemic arterial vasodilation, as caused by propofol, may prove more favorable to overall cardiac performance. Liver blood flow was also better preserved with propofol when compared to eltanolone. (Anesth Analg 1995;81:125-31)

The Effects of Oral Transmucosal Fentanyl Citrate Premedication on Preoperative Behavioral Responses and Gastric Volume and Acidity in Children

The authors compared the safety, efficacy, and effects on gastric volume and pH of oral transmucosal fentanyl citrate (OTFC) premedication and of placebo lollipop and no premedication in 55 children undergoing elective operations. The patients were randomly assigned to receive no premedication (group A, N = 18); OTFC containing 15–20 μg/kg of fentanyl citrate (group B, N = 18); or a placebo lollipop (group C, N = 19). Activity (sedation) and anxiety scores, vital signs (including systolic and diastolic arterial blood pressures, heart and respiratory rates), and pulse oximetry determined oxygen saturation were measured before and at 10-min intervals after premedication until the patients were taken to the operating room. Gastric contents were aspirated via an orogastric tube and analyzed for volume and pH after induction of anesthesia. Quality of induction and recovery were evaluated using scoring schedules; recovery times were measured and side effects recorded. OTFC was readily accepted and provided levels of sedation and anxiolysis significantly greater after 10 min than after no premedication or the placebo lollipop. Arterial blood pressures, heart rate, and oxygen saturations were not different among the three groups. In patients given OTFC, respiratory rates were significantly lower after 10 min than they were in patients having no premedication. When compared to patients having no premedication, patients having OTFC had slightly increased gastric volumes (14.6 ± 10 vs 7.6 ± 5.3 mL, mean ± SD). Patients having a placebo lollipop had similar gastric volumes (15.6 ± 13.5 mL) as those having OTFC. The three groups had similar gastric pHs (1.69 ± 0.31, 1.92 ± 0.53 and 1.72 ± 0.28, mean ± SD, groups A, B, and C, respectively). Induction and recovery evaluations and recovery times were also similar in the three groups. OTFC was associated with a 50% incidence of mild, nondisturbing, preoperative facial pruritus and a higher overall incidence of postoperative nausea (44%) than was premedication with the placebo lollipop (16%) or no premedication (0%). The results demonstrate that OTFC is readily accepted, safe, and more effective than no premedication or premedication with a placebo lollipop, and does not affect gastric pH but does increase gastric volume.

Prevalence and predictors of chronic pain after labor and delivery.

Purpose of review Labor pain is a complex phenomenon with sensory, emotional, and perceptive components and can be regarded as one of the most serious kinds of pain. Different strategies to approach acute labor pain have been developed. Chronic pain after labor and delivery has not been studied so extensively. In this review recent findings about chronic pain after labor and delivery will be discussed. Recent findings Prevalence rates of chronic pain after cesarean section are between 6 and 18% and after vaginal delivery they are between 4 and 10%. Predictors for chronic pain after cesarean section and delivery are previous chronic pain, general anesthesia and higher postdelivery pain. As labor pain is rated as one of the most serious kinds of acute pain one could make a prediction about chronic pain after labor and delivery. We speculate that effective treatment of this pain with epidural analgesia could prevent the development of chronic pain. Summary Treatment of acute pain during labor and delivery is necessary to prevent chronic pain. Future studies should focus on the long-term effects of different analgesic regimens on the development of chronic pain after labor and delivery.

Remifentanil for fetal immobilization and maternal sedation during fetoscopic surgery: a randomized, double-blind comparison with diazepam.

Obstetric endoscopy procedures are routinely performed at our institution to treat selected complications of monochorionic twin gestation. We perform these procedures under combined spinal epidural anesthesia plus maternal sedation. In the absence of general anesthesia, fetal immobilization is not achieved. We hypothesized that remifentanil would induce adequate maternal sedation and provide fetal immobilization, which is equal or superior to that induced by diazepam. Fifty-four second trimester pregnant women were included in this randomized, double-blind trial. After combined spinal epidural anesthesia, maternal sedation was initiated using either incremental doses of diazepam or a continuous infusion of remifentanil. Maternal sedation, hemodynamics, side effects, and fetal hemodynamics and immobilization were evaluated before, during, and for 60 min after surgery. Remifentanil produced adequate maternal sedation with mild but clinically irrelevant respiratory depression (respiratory rate 13 ± 4 breaths/min and Pco2 38.6 ± 4 mm Hg at 40 min of surgery), whereas diazepam resulted in a more pronounced maternal sedation but no respiratory depression (respiratory rate 18 ± 3 breaths/min and Pco2 32.7 ± 3 mm Hg at 40 min of surgery). Compared with diazepam, fetal immobilization with remifentanil occurred faster and was more pronounced, resulting in improved surgical conditions; the number of gross body and limb movements was 12 ± 4 (diazepam) versus 2 ± 1 (remifentanil) at 40 min of surgery. Because of this, the mean (range) duration of surgery was significantly shorter in the remifentanil-treated patients, 60 (54–71) min versus 80 (60–90) min in the diazepam group. We conclude that remifentanil produces improved fetal immobilization with good maternal sedation and only minimal effects on maternal respiration.

Fetal Plasma Concentrations after Intraamniotic Sufentanil in Chronically Instrumented Pregnant Sheep

Background Rapid progress is being made in fetal surgery. Because the fetus is capable of pain perception after the 26th week of gestation, adequate postoperative fetal pain management is essential. The preferred approach would provide fetal analgesia without affecting the mother. Intraamniotically administered sufentanil may be an interesting option if it achieves therapeutic plasma concentrations (PCs) in the fetus but not the mother. Methods After approval of the study, 25 or 50 &mgr;g sufentanil was administered intraamniotically in 10 chronically instrumented pregnant ewes. Maternal and fetal vital signs, arterial blood gases, and uterine blood flow were recorded over 120 min. Sufentanil PCs were determined before and 1, 3, 5, 10, 15, 30, 45, 60, 90, and 120 min after injection. Statistical analysis was performed using one- or two-way analysis of variance followed by Dunnett or Tukey test, as appropriate (P < 0.05; data presented as median [95% confidence interval]). Results After 25 &mgr;g sufentanil, fetal PC stabilized at 134 ± 89 pg/ml (after 10 min), and maternal PCs stabilized at 44 ± 11 pg/ml (after 15 min). After 50 &mgr;g sufentanil, fetal PCs stabilized at 134 ± 35 pg/ml (after 15 min), and maternal PCs reached 80 ± 25 pg/ml (at 30 min). Injection of 25 &mgr;g sufentanil intraamniotically did not affect maternal or fetal hemodynamics, uterine blood flow, or arterial blood gases. Fetal heart rate increased after administration of 50 &mgr;g sufentanil (maximum change at 10 min: +16 ± 12%). Conclusion The sheep fetus absorbs sufentanil after intraamniotic instillation. Significantly greater PCs were obtained in the fetal lamb as compared with the ewe. This suggests that investigation of intraamniotic opioids for fetal analgesia might be worthwhile.

Hydroxyethyl starch versus lactated Ringer's solution in the chronic maternal-fetal sheep preparation: a pharmacodynamic and pharmacokinetic study.

Administration of fluids intravenously prior to spinal and epidural analgesia in obstetrics is required to prevent maternal hypotension and fetal hypoxia.A colloid solution, such as hydroxyethyl starch (HES), might be preferable considering the capacity to stay intravascularly for a longer period. In this study the placental transfer of HES and the hemodynamic effects after infusion were investigated using a chronic maternal-fetal sheep preparation. Either 500 mL HES 10% or 750 mL lactated Ringers solution (RL) was infused intravenously into the ewe over 30 min. Fetal and maternal blood were assayed for HES, blood gases, and acid-base status before and at regular intervals after infusion. Maternal and fetal cardiovascular variables were recorded continuously for 90 min. After HES infusion, maternal HES levels peaked at 30 min ranging from 6.9 mg/mL to 12.1 mg/mL and declined at 24 h to levels between 0.3 mg/mL and 2.8 mg/mL. Mean fetal HES concentrations remained below 0.3 mg/mL. Infusion of HES decreased hemoglobin (Hb) and plasma viscosity (PV) in the mother. Infusion of RL decreased Hb, but did not change PV. Infusion of HES significantly increased uterine blood flow (UBF), cardiac output (CO), total oxygen-delivery capacity, and uterine artery oxygen delivery. In contrast, infusion of RL did not significantly change these variables. Infusion of HES increases UBF, CO, and uterine and total oxygen-carrying capacity in the pregnant ewe. No significant transplacental transfer of HES was shown. (Anesth Analg 1995;80:949-54)

Sublingual piroxicam for postoperative analgesia: preoperative versus postoperative administration: a randomized, double-blind study.

Nonsteroidal antiinflammatory drugs have been used to obtain preemptive analgesia. We investigated, in this randomized, double-blind study, whether sublingual (s.l.) piroxicam given before was more effective than that given after surgery. Fifty-two patients scheduled for laparoscopic bilateral inguinal hernia repair under general anesthesia were enrolled. Group PRE (25 patients) received 40 mg of piroxicam s.l. 2 h before surgery and a placebo 10 min after surgery. Group POST (27 patients) were treated with a placebo 2 h before surgery and received 40 mg of piroxicam s.l. 10 min after surgery. After an initial dose of 100 mg tramadol IV, patient-controlled analgesia with tramadol was started and recorded. Visual analog scores were assessed in the recovery and at 6, 20, and 30 h postoperatively. Significantly lower visual analog scores were found in group PRE at 6 and 20 h. Significantly smaller cumulative tramadol consumption was observed after 30 h in group PRE. In summary, our findings suggest that preoperative s.l. piroxicam is more effective than the postoperative administration. Because of the low pain scores in both groups, the clinical relevance of these findings is not clear from this study.