Intubation time required for tracheal intubation with low-dose rocuronium in children with and without atropine

Purpose

The purpose of this study was to determine the intubation time needed to facilitate tracheal intubation (Time_EI) with a low dose of rocuronium (0.3 mg/kg) during propofol induction, and to determine whether this time was reduced by the administration of atropine.

Methods

Forty-six children, aged 3–10 years, were randomly assigned to receive either saline (control group) or atropine 10 μg/kg (atropine group). Anesthesia was induced with alfentanil 10 μg/kg, propofol 2.5 mg/kg, and rocuronium 0.3 mg/kg. Each Time_EI at which tracheal intubation was attempted was predetermined according to the up-and-down method. The values of Time_EI that provided excellent intubation conditions in 50 and 95 % of patients were defined as Time_EI50 and Time_EI95, respectively.

Results

Time_EI50 ± SD was 160 ± 26.2 and 150 ± 13.7 s in the control and atropine groups, respectively. Using isotonic regression, Time_EI95 in the control and atropine groups was 199 s (95 % CI 198.8–200.7 s) and 171 s (95 % CI 171.3–172.1 s), respectively. Time_EI95 was significantly higher in the control group than in the atropine group (P < 0.001). HR was significantly higher in the atropine group than in the control group during the study period.

Conclusions

This study demonstrated that the Time_EI95 of a low dose of rocuronium (0.3 mg/kg) required for excellent tracheal intubation was 199 s during i.v. anesthesia induction using propofol and alfentanil in children. Also, i.v. atropine (10 μg/kg) before anesthesia induction was able to reduce Time_EI95 by 28 s.     

Effect of nitrous oxide inhalation on pain after propofol and rocuronium injection

Purpose

This prospective, double-blind, placebo-controlled study was designed to determine the efficacy of nitrous oxide (N₂O) in alleviating the pain that followed sequential injection of propofol and rocuronium.

Methods

A total of 205 adult patients (age, 18–68 years) received one of the following combinations: NaCl and 100 % O₂ (group C); 0.5 mg/kg lidocaine and 100 % O₂ (group L); NaCl and a mixture of 67 % N₂O/O₂ (group N); or 0.5 mg/kg lidocaine and a mixture of 67 % N₂O/O₂ (group LN). Vein occlusion was released after 1 min, and 5 ml propofol was injected over 10 s. Pain was evaluated on a visually enlarged, laminated, numeric rating (0–10) scale. The remainder of the induction dose of propofol (with a 3-ml bolus of normal saline and 0.6 mg/kg rocuronium) was then injected. The response to the rocuronium injection was assessed with a four-point scale (0–3).

Results

The incidence and severity of pain from the propofol injection in groups L, N, and LN were significantly lower than those in group C (P < 0.001). Frequency and intensity of the withdrawal response were significantly less in groups N and LN than in groups C and L (no response, P < 0.001; severe response, P < 0.001).

Conclusions

Pretreatment with inhaled N₂O can reduce the pain associated with propofol and rocuronium injection. Moreover, N₂O (with or without lidocaine) is more effective than lidocaine alone in reducing rocuronium-related withdrawal reactions associated with sequential injection of propofol and rocuronium.     

The interaction of antiemetic dose of droperidol with propofol on QT interval during anesthetic induction

Purpose

We investigated the effect of low-dose droperidol on heart rate-corrected QT (QTc) interval and interaction with propofol.

Methods

Seventy-two patients undergoing upper limb surgery were included in this study. Patients were randomly allocated to one of three groups: group S (n = 24), which received 1 ml saline; group D1 (n = 24), which received 1.25 mg droperidol; or group D2 (n = 24), which received 2.5 mg droperidol. One minute later, fentanyl (3 μg/kg) was administered. Two minutes after fentanyl administration, anesthesia was induced using propofol (1.5 mg/kg) and vecronium. Tracheal intubation was performed 3 min after the administration of propofol. Heart rate, mean arterial pressure, bispectral index, and QTc interval were recorded at the following time points: immediately before the droperidol injection (baseline); 3 min after the saline or droperidol injection; 3 min after the propofol injection; and 2 min after tracheal intubation.

Results

Compared to baseline, the QTc interval in group S and group D1 was significantly shorter after propofol injection, but recovered after tracheal intubation. In group D2, the QTc interval was significantly prolonged after droperidol injection, but recovered after propofol injection, and was significantly prolonged after tracheal intubation.

Conclusions

We found that saline or 1.25 mg droperidol did not prolong QTc interval, whereas 2.5 mg droperidol prolonged the QTc interval significantly, and that propofol injection counteracted the prolongation of the QTc interval induced by 2.5 mg droperidol.     

Ketamine, but not priming, improves intubating conditions during a propofol–rocuronium induction

Purpose

Both ketamine and priming may shorten the onset time of rocuronium. This study investigates the effects of ketamine and priming as components of a propofol induction on intubating conditions and onset of neuromuscular block.

Methods

This prospective randomized double-blind study was performed in 120 American Society of Anesthesiologists (ASA) I–II patients who were assigned to one of four groups of 30 patients each: control, priming, ketamine, and ketamine-priming. Ketamine 0.5 mg ? kg^?1 or saline was given before priming and induction. Rocuronium 0.06 mg ? kg^?1 or saline was injected 2 min before propofol 2.5 mg ? kg^?1. This was followed by rocuronium 0.6 mg ? kg^?1 or by rocuronium 0.54 mg ? kg^?1 if priming was given. Intubation was performed one minute later. Intubating conditions were graded as excellent, good, or poor. Heart rate, noninvasive blood pressure, and train-of-four (TOF) response were monitored.

Results

Intubating conditions were graded excellent in 20% of the control group, 30% of the priming group, 47% of the ketamine group, and 57% of the ketamine-priming group. Analysis using forward stepwise regression indicated that ketamine improved intubating conditions (P = 0.001) but priming did not (P = 0.35). Time to reach a TOF count of zero was shortened by ketamine (P = 0.001) but not by priming (P = 0.94): 216 ± 20 s in the control group, 212 ± 27 s in the priming group, 162 ± 18 s in the ketamine group, and 168 ± 22 s in the ketamine-priming group.

Conclusion

A low-dose ketamine used with a propofol–rocuronium induction improved intubating conditions and shortened onset time. Priming did not influence intubating conditions or onset time.     

A prospective, randomized, double-blind study to compare the efficacy of lidocaine + metoclopramide and lidocaine + ketamine combinations in preventing pain on propofol injection

Purpose

Propofol injection is known to cause distressing pain, and various methods have been used to decrease this pain. We investigated the efficacy of the lidocaine + metoclopramide and lidocaine + ketamine combinations on modulating propofol injection pain.

Methods

Ninety ASA I/II patients aged 20–60 years were randomly assigned to three groups to receive lidocaine 20 mg (group L), lidocaine 20 mg + metoclopramide 10 mg (group LM), or lidocaine 20 mg + ketamine 5 mg (group LK), respectively, with venous occlusion for 1 min using a forearm tourniquet. Propofol 0.5 mg/kg was subsequently administered into a dorsal hand vein, and pain was assessed during its injection using a verbal rating score. The results were analyzed statistically with analysis of variance, the chi-square test, and the Wilcoxon rank sum test, where appropriate. The significance level was set at p < 0.05.

Results

The incidence of pain was rated to be significantly less in patients in groups LM (40 %) and LK (6.7 %) than in those in group L (83.3 %) (p = 0.001 and p < 0.001, respectively). The pain score [median (range)] was also significantly less in patients in groups LM [0 (0–3)] and LK [0 (0–2)] than in those in group L [2 (0–3)] (p = 0.001 for both groups).

Conclusion

The lidocaine–ketamine combination is most effective for decreasing the pain on propofol injection.     

The effect of rocuronium, sugammadex, and their combination on cardiac muscle and diaphragmatic skeletal muscle cells

Purpose

Rocuronium has been associated with muscle weakness when administered in prolonged infusions. The effect of sugammadex and rocuronium together on muscle is unknown. In this study, we examined the effects of rocuronium and sugammadex, and the complex formed by these agents, on cardiac and diaphragmatic muscle cells.

Methods

Forty-two Sprague–Dawley male rats were divided into six groups. Group I received only rocuronium at a dose of 1 mg/kg and groups II and III received sugammadex alone at doses of 16 and 96 mg/kg, respectively. Groups IV and V received 1 mg/kg rocuronium plus 16 mg/kg sugammadex and 1 mg/kg rocuronium plus 96 mg/kg sugammadex, respectively. Group six was the control group and received only 0.9 % NaCl without any drug.

Results

Histopathological examination demonstrated that rocuronium and high doses of sugammadex accumulated in both cardiac and diaphragm muscle tissues. We also observed intense edema and degeneration in diaphragmatic and myocardial cells when the rocuronium-sugammadex complex was used. Rocuronium and sugammadex remain in the circulation for a long time and they may cause skeletal muscle myopathy, vacuolization, pyknotic nuclear clumps, and hypertrophy, and weaken the muscle fibers.

Conclusion

Rocuronium, sugammadex, and rocuronium–sugammadex complexes cause histopathological changes and immunoreactivity to calcineurin in muscle cells.     

Comparison of effects of propofol and ketamine–propofol mixture (ketofol) on laryngeal mask airway insertion conditions and hemodynamics in elderly patients: a randomized, prospective, double-blind trial

Purpose

The objective of this study was to compare the effects of ketamine–propofol mixture (ketofol) and propofol on ProSeal laryngeal mask airway (PLMA) insertion conditions and hemodynamics in elderly patients.

Methods

Eighty elderly patients, American Society of Anesthesiologists (ASA) physical status I and II, were randomly divided into two groups to receive either propofol 0.15 ml/kg (n = 40), or ketofol (using a 1:1 single-syringe mixture of 5 mg/ml ketamine and 5 mg/ml propofol) (n = 40) before induction of anesthesia. Sixty seconds after induction, the PLMA was inserted. Heart rate and arterial blood pressure (systolic [S] BP) were recorded prior to the induction of anesthesia, immediately following induction, immediately after PLMA insertion, and 5 and 10 min after PLMA insertion. PLMA insertion conditions were scored according to mouth opening, swallowing, coughing, head and body motion, laryngospasm, and ease of PLMA insertion by the same experienced anesthesiologist, who did not know which agents were used.

Results

There were no differences in PLMA insertion conditions between the groups. The number of patients in need of ephedrine (P = 0.043) and the total dose of ephedrine (P = 0.022) were significantly lower, and apnea duration (P < 0.001) was significantly higher in the ketofol group compared with the propofol group. SBP was significantly higher in the ketofol group than in the propofol group immediately after PLMA insertion and 5 min after PLMA insertion.

Conclusions

The same PLMA insertion conditions were found with ketofol and propofol. The number of patients in need of ephedrine and the total ephedrine dose were lower and apnea duration was increased in the ketofol group.     

The LMA CTrach™ in morbidly obese and lean patients undergoing gynecological procedures: a comparative study

Purpose

The tracheas of obese patients may be more difficult to intubate than those of normal-weight patients. The aim of this study was to compare the airway management quality in morbidly obese and lean patients with use of the LMA CTrach.

Methods

After Ethics Committee approval, 60 adult patients (30 morbidly obese patients with body mass index >40 kg/m² and 30 lean patients with body mass index <30 kg/m²) scheduled to undergo gynecological surgery were enrolled in this prospective study. The induction of anesthesia was standardized using propofol, fentanyl, and rocuronium. Ventilation and intubation success rates, time taken to achieve successful ventilation, and intubation through the CTrach and airway complications were recorded.

Results

The CTrach was successfully inserted and adequate ventilation through the CTrach was achieved in 59 patients (98%). Only 1 patient in the lean group was not able to ventilate through the CTrach. We were successful in endotracheal intubation, either under vision or blind, in 56 patients (93%). We were able to view the larynx in 51 patients (85%). Total intubation time was significantly longer in morbidly obese patients, 69 (311) s, than in lean patients, 33 (107) s [median (range)] (P < 0.001).

Conclusions

We concluded that the time to intubate the trachea in obese patients was significantly longer than in lean patients when the LMA CTrach was used.     

Dexmedetomidine impairs success of patient-controlled sedation in alcoholics during ERCP: a randomized, double-blind, placebo-controlled study

Background

There is a lack of studies about procedural sedation of alcoholics. Dexmedetomidine is recommended for procedural sedation and reported effective for alcohol withdrawal. We evaluated the suitability of dexmedetomidine for sedation of alcoholics during endoscopic retrograde cholangiopancreatography (ERCP).

Methods

Fifty patients with chronic alcoholism scheduled for elective ERCP were randomized 1:1 to receive dexmedetomidine (Dex group) (loading dose 1 μg kg^?1 over 10 min, followed by constant intravenous infusion 0.7 μg kg^?1 h^?1) or saline placebo (P group). Patient-controlled sedation with propofol–alfentanil was used by patients as a rescue method. Sedation was considered as successful if no intervention of an anesthesiologist was needed. Consumption of sedatives was registered, and sedation levels and vital signs were monitored.

Results

Dexmedetomidine alone was insufficient in all patients. The mean ± SD consumption of propofol was 159 ± 72 mg in the P group, and 116 ± 61 mg in the Dex group (p = 0.028). Sedation was successful in 19 of 25 (76 %) patients in the Dex group and in all patients in the P group (p = 0.022). The incidence of sedation adverse events did not differ between the groups. Dexmedetomidine was associated with delayed recovery.

Conclusions

Patient-controlled sedation with propofol and alfentanil but not dexmedetomidine can be recommended for sedation of alcoholics during ERCP.     

Smoking increases the requirement for rocuronium

Purpose

To compare the potency of rocuronium in non-smokers and smokers during general anaesthesia.

Methods

In a randomized, open clinical study, 40 patients, 17–62 yr of age, were anaesthetized with propofol, alfentanil and nitrous oxide in oxygen. After obtaining individual dose-response curves for rocuronium, bolus doses of rocuronium were given to maintain neuromuscular block at 90–99% for 60 min. Evoked adductor pollicis electromyography (EMG) was used to monitor neuromuscular block.

Results

The ED₉₅ values (± SEM) for rocuronium were 460.5 ± 28.9 and 471.5 ± 22.1 μg·kg^?1 for nonsmokers and smokers, respectively (P:NS). However, doses of rocuronium to maintain 90–99% neuromuscular block (± SEM) were 620.1 ± 46.7 and 747.4 ± 56.0 μg·kg^?1·hr^?1 for non-smokers and smokers, respectively (P = 0.0504).

Conclusion

The results may indicate increased metabolism of rocuronium in smokers rather than increased requirement of rocuronium at the receptor site.     

Excellent intubating conditions with remifentanil–propofol and either low-dose rocuronium or succinylcholine

Purpose

The shortest time to tracheal intubation, the best intubating conditions, and the shortest duration of muscle paralysis are achieved with succinylcholine. During a lidocaine–remifentanil–propofol induction of anesthesia, we compared intubating conditions 90 s after administering low-dose rocuronium (0.3 mg · kg^?1) with intubating conditions 60 s after administering succinylcholine 1.5 mg · kg^?1.

Methods

The randomized double-blind study included 184 healthy adult patients scheduled for elective surgery. Anesthesia was induced in all patients with lidocaine 1.5 mg · kg^?1, remifentanil 2 μg · kg^?1, and propofol 2 mg · kg^?1 administered over 30 s. In one group, rocuronium 0.3 mg · kg^?1 was administered before the induction sequence, and in the other group, succinylcholine 1.5 mg · kg^?1 was administered after the induction sequence. Laryngoscopy was attempted 90 s after rocuronium administration and 60 s after succinylcholine administration. Intubating conditions were assessed as excellent, good, or poor on the basis of ease of laryngoscopy, position of the vocal cords, and reaction to insertion of the tracheal tube and cuff inflation.

Results

There were 92 patients per group. In the rocuronium group, intubating conditions were excellent in 83 patients (90%), good in 8 (9%), and poor in 1 (1%), not significantly different from the intubating conditions in the succinylcholine group, which were excellent in 88 patients (96%), good in 3 (3%), and poor in 1 (1%) (P = 0.3).

Conclusion

During a lidocaine–remifentanil–propofol induction of anesthesia, rocuronium 0.3 mg · kg^?1 administered before the induction sequence provides intubating conditions comparable to those achieved with succinylcholine 1.5 mg · kg^?1 administered after the induction sequence.     

A rapid precurarization technique using rocuronium

Purpose

To evaluate a rapid and time-saving precurarization technique using rocuronium to prevent succinylcholine-induced myalgia.

Method

In a prospective, double blind randomized study, 42 ASA 1–2 patients were assigned to one of three pretreatment groups: 0.01 ml · kg^?1 normal saline, 0.1 mg · kg^?1 atracurium, and 0.1 mg · kg^?1 rocuronium. Anaesthesia commenced with 1.5 μg · kg^?1 fentanyl and 0.5 mg · kg^?1 lidocaine at time zero. Pretreatment was administered 60 sec later, followed by 2.5 mg · kg^?1 propofol. At 90 sec, 1.5 mg · kg^?1 succinylcholine was injected and 30 sec later, the trachea was intubated and the ease of intubation was graded. The patient was observed for the presence and severity of fasciculations. Myalgias were recorded on postoperative days 1, 2 and 7.

Results

The incidence of fasciculations in the rocuronium group (21.4%) was lower (P < 0.001) than atracurium (78.5%) or placebo (92.8%) groups. On postoperative day 1, the incidence of postoperative myalgia in the rocuronium group (14.2%) was less than the placebo group (78.2%;P < 0.002) and atracurium group (85.7%;P < 0.001). The incidence of myalgia in the rocuronium group (7.1%) was lower than in the placebo group (78.5%;P < 0.001) but not different from the atracurium group (42.8%;P = 0.077) on postoperative day 2. On postoperative day 7, there was no difference among the three groups. Fasciculations were related to post-operative myalgia. There was no difference in intubating conditions among the three groups.

Conclusion

Rocuronium pretreatment given just before induction of anaesthesia with propofol reduces fasciculations and succinylcholine-induced myalgia.     

Comparison between intranasal dexmedetomidine and intranasal ketamine as premedication for procedural sedation in children undergoing MRI: a double-blind,randomized, placebo-controlled trial

Introduction

Providing anesthesia to children undergoing MRI is challenging. Adequate premedication, administered noninvasively, would make the process smoother. In this study, we compare the efficacy of intranasal dexmedetomidine (DXM) with the intranasal administration of ketamine for procedural sedation in children undergoing MRI.

Methods

We studied 150 children, between 1 and 10 years of age, divided randomly into three groups (DXM, K, and S). For blinding, every child received the intranasal drugs twice; syringe S1, 60 min before, and syringe S2, 30 min before intravenous (IV) cannulation. For children in group DXM, S1 contained DXM (1 μg/kg) and S2 was plain saline. Children in group K received saline in S1 and ketamine (5 mg/kg) in S2 whereas children in group S received saline in both S1 and S2. The child’s response to drug administration, ease of IV cannulation, the satisfaction of the anesthesiologist and child’s parents with the premedication, and the total propofol dose required for the satisfactory conduct of the procedure were compared. We also compared the time to awakening and discharge of the child as well as the occurrence of any side effects with these drugs.

Results

Both DXM and ketamine were equally effective as premedication in these patients. Most of the children accepted the intranasal drugs with minimal discomfort; 90.4 % of the anesthesiologists in the DXM group and 82.7 % in the ketamine group were satisfied with the conditions for IV cannulation whereas only 21.3 % were satisfied in the saline group. The total dose of propofol used was less in the study groups. Furthermore, children in group DXM and group K had earlier awakening and discharge than those in group S.

Conclusion

DXM and ketamine were equally effective, by the intranasal route, as premedication in children undergoing MRI.     

Comparison of the effects of intranasal midazolam versus different doses of intranasal ketamine on reducing preoperative pediatric anxiety: a prospective randomized clinical trial

Purpose

To compare the effects of intranasal midazolam versus different doses of intranasal ketamine on reducing preoperative pediatric anxiety.

Methods

The participants of this double-blinded clinical trial study consisted of 120 children aged between 2 and 8 years. They were chosen for elective surgery and randomly assigned to four equal groups. For reducing preoperative anxiety, in the first group midazolam 0.2 mg/kg, in the second group (K1) ketamine 0.5 mg/kg, in the third group (K2) ketamine 3 mg/kg, and in the fourth group normal saline 1 drop/5 kg were administered intranasally. After 15 min, severity of anxiety was assessed with the modified Yale preoperative anxiety score (m-Yale PAS), and level of sedation was evaluated by the Ramsay Sedation Scale before intravenous catheterization. All data were transferred to SPSS-10 software and analyzed statistically with ANOVA, Kruskal–Wallis, and Mann–Whitney tests. A p value < 0.05 was considered meaningful.

Results

The mean of m-Yale PAS in midazolam group was significantly lower than the other three groups (p < 0.05). Regarding this score, there was no significant statistical difference between K2 and normal saline groups (p = 0.944), but the differences between K1 and K2 (p = 0.034) and also between K1 and normal saline (p = 0.049) groups were significant statistically. The Ramsay Sedation Scale in the midazolam group was significantly higher than the other three groups (p < 0.05). By this scale, there was no significant statistical difference between (K2) and normal saline groups (p = 0.940). The differences between (K1) and normal saline (p = 0.045) and also between (K1) and (K2) groups (p = 0.009) were significant statistically.

Conclusion

Intranasal midazolam was more effective than low- or high-dose intranasal ketamine in reducing preoperative pediatric anxiety. The lower dose of ketamine reduced preoperative anxiety more than a higher dose of ketamine, which may be clinically insignificant.     

Comparison of neuromuscular effects, efficacy and safety of rocuronium and atracurium in ambulatory anaesthesia

Purpose

To compare the neuromuscular effects, efficacy, and safety of equi-effective doses of rocuronium and atracurium in ambulatory female patients undergoing surgery.

Methods

Forty-one patients undergoing laparoscopic gynaecological surgery were randomized to receive 2 × ED₉₀ rocuronium (0.6 mg·kg^?1; n = 20) or atracurium (0.5 mg·kg^?1; n = 21) during intravenous propofol/alfentanil anaesthesia with N₂O/O₂ ventilation. Neuromuscular block was measured with a mechanomyogram eliciting a train-of-four (TOF) response at the wrist. Intubation conditions 60 sec after administration of muscle relaxant and immediate cardiovascular disturbances or adverse events during the hospital stay were noted by blinded observers.

Results

Compared with atracurium, rocuronium was associated with a shorter onset time (59.0 ± 22.2vs 98.6 ± 41.4 sec;P < 0.001) and clinical duration of action (33.3 ± 7.1vs 44.7 ± 7.2 min;P < 0.001), but longer spontaneous recovery index (9.6 ± 2.41vs 6.9 ± 1.89 min;P = 0.023) and a similar time to spontaneous recovery to TOF 70%; 53 ± 6.31vs 59.2 ± 7.59 min;P =0.139). Tracheal intubation was accomplished in < 90 sec in all patients receiving rocuronium but in only 14 of 21 patients receiving atracurium. The incidence of adverse events and the cardiovascular profiles for the two drugs were similar, although one patient receiving atracurium experienced transient flushing of the head and neck.

Conclusion

Rocuronium has minimal side effects, provides conditions more suitable for rapid tracheal intubation, and is associated with a shorter clinical duration than atracurium. Once begun, the spontaneous recovery profile of rocuronium is slightly slower than that of atracurium.     

Efficacy of endotracheal lidocaine administration with continuous infusion of remifentanil for attenuating tube-induced coughing during emergence from total intravenous anesthesia

Purpose

Although attenuation of tube-induced coughing is necessary in specific types of surgery, the best method for such attenuation is still unclear. We studied the combined intervention of endotracheal lidocaine and intravenous remifentanil compared to intravenous remifentanil alone with respect to coughing during emergence from anesthesia.

Methods

We examined 60 ASA 1–2 patients (age, 20–69 years) undergoing tympanoplasty under general anesthesia. Anesthesia was induced with propofol, remifentanil, and rocuronium. The trachea was intubated using a laryngotracheal instillation of topical anaesthetic (LITA) tracheal tube. Anesthesia was maintained with propofol and remifentanil (0.1–0.3 μg/kg/min). Propofol was discontinued and remifentanil (0.1 μg/kg/min) was continued at the end of the operation. Patients were randomly allocated to the lidocaine (n = 30) and control groups (n = 30). We administered 3 ml 4 % lidocaine via the LITA tube to patients in lidocaine group at the end of the operation. The trachea was extubated when the patient regained consciousness and followed orders. Coughing was evaluated using a 4-point scale by an observer who examined the video records at extubation.

Results

Fewer patients in lidocaine group (8 of 30) than in control group (18 of 30, p < 0.01) coughed. Fewer patients in lidocaine group (2 of 30) than in control group (12 of 30, p < 0.01) had moderate or severe cough (scale 2 or 3).

Conclusions

This study is consistent with the finding that endotracheal lidocaine administration and continuous infusion of remifentanil before extubation is useful to prevent coughing on emergence from anesthesia.     

Local warming at injection site helps alleviate pain after rocuronium administration

Purpose

Various strategies have been proposed to reduce discomfort of pain after rocuronium injection. These studies have shown pretreatment of drugs such as fentanyl and lidocaine to be effective. In a prospective randomized study, we evaluated whether pretreatment with local warming at injection site using an air-warming device could effectively alleviate pain induced by rocuronium.

Methods

Ninety patients undergoing spinal surgeries were randomly divided into two groups: group C (control) and group T (treatment). Patients in group T were subjected to warming at 40°C for 1 min prior to injecting 1 ml (10 mg) of rocuronium at the site of venous access. Patients were then assessed for any discomfort and to quantify their discomfort on a 5-point scale.

Results

Age, sex, and weight were comparable between the two groups. Pain on rocuronium administration was reported by 88.9% patient in group C versus 66.7% in group T (p < 0.05). Severe pain was significantly less in group T (35.6% vs. 8.9%).

Conclusion

Application of warmth over the vascular access prior to rocuronium administration effectively reduces injection-related pain.     

Intubationsbedingungen und Verlauf der neuromuskulären Blockade nach Rocuronium bei endoskopischen Operationen in der HNO-Heilkunde

Rocuronium is a new nondepolarizing muscle relaxant for which a fast onset has been described. The goal of this study was to examine whether the characteristics of rocuronium could make it an appropriate relaxant for the anaesthetic management of operations of intermediate duration such as endoscopic upper airway surgery. These operations, which require the anaesthesiologist and surgeon to ”share” the patient’s airway, require good muscle relaxation for endotracheal intubation and placement of endoscopic instruments. In addition, the time course of neuromuscular blockade and its relation to the quality of intubating conditions were analysed. Methods: The study was approved by the local ethics committee; 30 patients (ASA status 1–3) scheduled for elective endoscopic upper airway surgery were included after written informed consent. Exclusion criteria were suspected difficult intubating conditions, neuromuscular disease, or antibiotic therapy with aminoglycosides during the last 24?h. Anaesthesia was induced by propofol 2?mg/kg and alfentanil 1?mg after volume loading with 500?ml Ringer’s lactate and preoxygenation, and was maintained by propofol infusion 5–8?mg/kg/h and repetitive alfentanil injections according to clinical needs. Endotracheal intubation was performed by a senior anaesthesiologist 90?s after injection of rocuronium 0.6?mg/kg (2×ED₉₅). Intubating conditions were graded 1 to 4 (1=excellent, 2=good, 3=sufficient, 4=inadequate). Acceleromyography was used for neuromuscular monitoring by means of the TOF-guard (Organon Teknika/Biometer). The adduction movement of the thumb was measured by an acceleration transducer while stimulating the ulnar nerve at the wrist via surface electrodes in a supramaximal train-of-four (TOF) mode (2?Hz every 15?s). Twitch height and TOF ratio were documented during the course of neuromuscular blockade. Data are presented as mean±standard deviation. Results: Patients were aged 37 to 64 years (mean 54±7). Intubating conditions were excellent in 17 cases and good in 7. In 2 cases intubating conditions were graded sufficient, as patients could be easily intubated but showed clear diaphragmatic movements at intubation. In 4 patients intubating conditions could not be judged, as a laryngoscopic view of the glottic structures was impossible for anatomic reasons. Neuromuscular block at intubation was 78±22%, onset time 152±62?s, clinical duration 30±8?min, and recovery index 11±4?min. The TOF ratio required 51±14?min to return to 0.7. Conclusions: Good to excellent intubating conditions can be expected 90?s after injection of rocuronium 0.6?mg/kg. Diaphragmatic reactions cannot be excluded. Complete relaxation of the adductor pollicis muscle is not necessary for endotracheal intubation. Intubation at a certain time interval, for example, 90?s after injection of rocuronium 0.6?mg/kg, can be recommended. Onset and recovery characteristics of rocuronium make it an appropriate relaxant for the anaesthetic management of operations of intermediate duration such as endoscopic upper airway surgery. Care should be given, however, to detect inadequate recovery of neuromuscular transmission, as there are considerable interindividual differences in recovery.     

Recurarization after sugammadex reversal in an obese patient

Purpose

We report a case that involved immediate postoperative respiratory failure necessitating tracheal intubation, which was possibly related to recurarization after sugammadex reversal.

Clinical findings

A 54-yr-old woman weighing 115-kg was scheduled for laparoscopic repair of abdominal dehiscence under general anesthesia. Muscle relaxation was induced and maintained with rocuronium (170 mg iv total dose). At the end of the 170-min procedure, two twitches were visualized after supramaximal train-of-four (TOF) stimulation at the adductor pollicis muscle, and the patient’s central core temperature was 35.6°C. Sugammadex 200 mg iv (1.74 mg·kg^?1) was administered. With the patient fully awake, a TOF ratio 0.9 was obtained five minutes later. The tracheal tube was then removed, and the patient was transferred to the postanesthesia care unit. Ten minutes later, the patient presented respiratory failure necessitating tracheal intubation and sedation with propofol. One TOF response only was visualized at the adductor pollicis muscle. Another dose of sugammadex 200 mg iv was administered. Forty-five minutes later, the patient was fully awake and her trachea was extubated after repeated measures of the TOF ratio (≥ 0.9) at the adductor pollicis muscle. The patient fully recovered without sequelae, further complication, or prolonged hospital stay.

Conclusion

Shortly after tracheal extubation, an obese patient experienced respiratory failure necessitating tracheal intubation and an additional dose of sugammadex. This occurred despite initial reversal of neuromuscular blockade with an appropriate dose of sugammadex 2 mg·kg^?1 iv given at two responses to TOF stimulation.     

Ketaminrazemat bei „Fast-track“-Anästhesie

Introduction

In this study the impact of 25 mg of ketamine racemate given just before surgery on recovery times and postoperative analgesic needs in patients undergoing vaginal hysterectomy and receiving propofol-remifentanil anaesthesia was investigated.

Methods

With ethics committee approval 70 female patients aged 25–65 years were enrolled. All patients received a total intravenous anaesthesia with remifentanil and propofol with the propofol infusion being controlled to a Narcotrend index of 40. Patients in the ketamine group (n=35) received additionally a bolus dose of 25 mg ketamine racemate intravenously 3 min before skin incision. In addition to monitoring haemodynamics and circulation parameters, recovery times, postoperative pain and opioid needs were also recorded. Patients were also questioned on their satisfaction with the pain therapy.

Results

All 70 patients completed the study and the groups were similar with respect to demographic data. The haemodynamics of the patients were stable in both groups and the postoperative pain measured over a 24-h period as well as the opioid needs were also comparable. However, recovery times were significantly prolonged in the ketamine group, e.g. the times to extubation were 8.3±4.0 min with ketamine compared to 6.1±2.1 min in the control group (p<0.01). Undesired side effects were overall rare but occurred to the same extent in both groups.

Conclusions

This study demonstrated that 25 mg ketamine racemate given just before surgery significantly prolongs recovery times without reducing post-operative analgesic needs when applied to patients undergoing vaginal hysterectomy and receiving propofol-remifentanil anaesthesia. A bolus dose of 25 mg ketamine racemate cannot therefore be recommended for preemptive analgesia under these conditions.