[New aspects of rapid sequence induction including treatment of pulmonary aspiration]

Pulmonary aspiration of solid components leads to displacement of the tracheobronchial tree, the aspiration of acidic gastric juices to chemical pneumonitis (Mendelson's syndrome) and the aspiration of oropharyngeal secretions or gastrointestinal pathogens to aspiration pneumonia. Principally, pulmonary aspiration can occur at any stage of anesthesia. In the clinical routine the aim must therefore be to identify those patients who have an increased risk of aspiration. When this is successful, measures can be taken to reduce the risk; these can be regional anaesthesia or the performance of general anaesthesia as rapid sequence induction (RSI). If severe pulmonary aspiration occurs despite all preventive measures, mostly during induction of anaesthesia, extensive experience and rapid action are necessary. This can only be achieved if the induction to RSI is performed by three persons with supervision of the trainee anaesthetist by a consultant anaesthetist.

Attenuation of a rocuronium-induced neuromuscular block in patients receiving prednisolone

BACKGROUND

This study tested the influence of continuous medication (more than 4 weeks) with prednisolone on a rocuronium-induced neuromuscular block.

METHODS

The time course of a rocuronium-induced neuromuscular blockade (0.3 mg/kg) was investigated in 40 patients with chronic inflammatory bowel disease undergoing elective abdominal surgery. The primary end point was the time from the start of injection of rocuronium until recovery of the TOF ratio to 0.9. Twenty patients received continuous medication with prednisolone (group A), and 20 were without glucocorticoid medication (group B). Additionally, another 20 patients without inflammatory bowel disease and without glucocorticoid medication served as control (group C).

RESULTS

The onset time was prolonged in group A [253 (51.2) s] compared with group B [187 (61.3) s]. Twitch height at the onset of the block was higher in group A [16.5 (0-61)%] than that in group B [5.0 (0-33)%]. The duration to 25% twitch height was shorter in group A [12.6 (0-20.7) min] compared with group B [16.7 (0-25.3) min] and group C [16.9 (0-29.3) min]. The recovery to a train-of-four ratio of 0.9 was reduced in group A [25.7 (23-34.3) min] compared with group B [34.7 (32.7-44.2) min] and group C [36.5 (31.7-42.3) min].

CONCLUSIONS

Prednisolone treatment in patients with inflammatory bowel disease is associated with a delayed onset and a shorter duration of action of rocuronium. The presence of an inflammatory bowel disease did not influence the neuromuscular block.

Are women more sensitive to a pre-curarization dose of rocuronium than men?

BACKGROUND

There is increasing evidence that there are gender-related differences in the pharmacodynamics of neuromuscular blocking drugs. However, it is not known whether gender influences the pharmacodynamics of a pre-curarizing dose.

METHODS

In the first part, we measured the neuromuscular blockade after administration of rocuronium 0.03 mg/kg (10% of ED(95)) after induction of anaesthesia in 20 patients (10 female and 10 male patients) by electromyography. In the second part, 40 female and 40 male patients were observed for signs and symptoms of muscle weakness 2.5 min after injection of rocuronium 0.03 mg/kg before loss of consciousness. Succinylcholine-associated post-operative myalgia (POM) was also assessed.

RESULTS

Median twitch heights were comparable between the two groups: 95.5 (range: 85-97; female) vs. 96.0 (range: 85-99; male), (NS). Train-of-four ratios were 97.5 (range: 64-100; female) vs. 99.0 (range: 52-100; male) (NS). Signs and symptoms of muscle weakness were observed in 64 (80%) patients, but there were no gender-related differences. The incidence and severity of POM did not differ significantly between the study groups.

CONCLUSIONS

Pre-curarization with rocuronium 0.03 mg/kg affected men and women equally. Nor was the incidence and the severity of muscle weakness affected by gender.

Influence of a continuous prednisolone medication on the time course of neuromuscular block of atracurium in patients with chronic inflammatory bowel disease

BACKGROUND

Corticosteroids interact with neuromuscular blocking agents. However, experimental data are contradictory: enhancement and attenuation of the neuromuscular block has been observed. This study tested the influence of long-term medication with prednisolone on atracurium-induced neuromuscular block.

METHODS

Sixty patients with chronic inflammatory bowel disease undergoing elective abdominal surgery were investigated. Thirty patients received a long-term medication with prednisolone (Group A) and 30 were without corticoid medication (Group B). Additionally, another 30 patients without inflammatory bowel disease and without corticoid medication served as control (Group C). The following parameters of an atracurium-induced neuromuscular block (0.25 mg kg(-1)) were measured: onset time, maximum block, recovery to 25% first twitch height, recovery index (time from 25% until 75% recovery of first twitch), duration to recovery to a train-of-four (TOF) rate of 0.7 and 0.9.

RESULTS

The groups did not differ with regard to onset time, maximum block, and recovery index. The duration to 25% twitch height was significantly lower in Group A [18.1 (0-30.7) min] compared with Group B [23.5 (0-36.7) min; P<0.05]. Duration to a TOF rate of 0.7 and 0.9, respectively, were significantly reduced in Group A [36.1 (7.9) and 40.9 (9.0 min)] compared with Group B [47.9 (7.6) and 53.4 (9.2) min; P<0.001].

CONCLUSIONS

Long-term medication with prednisolone resulted in a shorter duration of an atracurium-induced neuromuscular block in patients with Crohn's disease or ulcerative colitis. The presence of the inflammatory bowel disease did not influence the time course of the neuromuscular block.

Intraartikuläre Bupivacaingabe bei Hüftgelenkarthroskopie

The effect of intra-articular bupivacaine on postoperative pain following arthroscopy has been intensively studied for the knee joint but no data are currently available for the hip joint. The aim of the present prospective, randomized and double-blind study was to evaluate a possible effect of intra-articular bupivacaine on postoperative pain intensity following hip arthroscopy. A total of 26 patients were included: 13 received 20 ml of 0.25% bupivacaine through the trocar at the end of surgery and 13 patients received 20 ml of 0.9% NaCl as placebo. Postoperative pain intensity was assessed using a visual analogue scale (VAS) at 0.5 h, 4 h, 8 h, 12 h, 16 h and 20 h, at rest and during movement of the joint and on the basis of additional piritramide requirements. Furthermore, a mean VAS was calculated as the arithmetic mean of all VAS scores assessed over the whole study period. In the bupivacaine group, a significantly lower mean VAS was recorded at rest (17.5 vs 27.5, p=0.05) and during movement of the hip joint (23 vs. 46, p=0.001). The additional piritramide consumption tended to be higher in the placebo group. In conclusion, intra-articular bupivacaine following arthroscopic hip surgery reduces pain in the postoperative period mainly during movement and thus may possibly allow earlier mobilization.

Effect of propofol on seizure-like phenomena and electroencephalographic activity in children with epilepsy vs children with learning difficulties

There is an ongoing debate as to whether propofol exhibits pro- or anticonvulsant effects, and whether it should be used in patients with epilepsy. We prospectively assessed the occurrence of seizure-like phenomena and the effects of intravenous propofol on the electroencephalogram (EEG) in 25 children with epilepsy (mean (SD) age: 101 (49) months) and 25 children with learning difficulties (mean (SD) age: 52 (40) months) undergoing elective sedation for MRI studies of the brain. No child demonstrated seizure-like phenomena of epileptic origin during and after propofol sedation. Immediately after stopping propofol, characteristic EEG changes in the epilepsy group consisted of increased beta wave activity (23/25 children), and suppression of pre-existing theta rhythms (11/16 children). In addition, 16 of 18 children with epilepsy and documented EEG seizure activity demonstrated suppression of spike-wave patterns after propofol sedation. In all 25 children with learning difficulties an increase in beta wave activity was seen. Suppression of theta rhythms occurred in 11 of 12 children at the end of the MRI study. In no child of either group was a primary occurrence or an increase in spike-wave patterns seen following propofol administration. The occurrence of beta wave activity (children with learning difficulties and epilepsy group) and suppression of spike-wave patterns (epilepsy group) were transient, and disappeared after 4 h. This study demonstrates characteristic, time-dependent EEG patterns induced by propofol in children with epilepsy and learning difficulties. Our data support the concept of propofol being a sedative-hypnotic agent with anticonvulsant properties as shown by depression of spike-wave patterns in children with epilepsy and by the absence of seizure-like phenomena of epileptic origin.

Does preoperatively administered parecoxib prevent succinylcholine-associated myalgia? A randomized, placebo-controlled trial

BACKGROUND AND OBJECTIVE

Data from several studies implicate that pre-treatment with non-selective cyclooxygenase inhibitors such as aspirin or diclofenac may decrease the incidence of postoperative succinycholine-related myalgia. We tested the influence of a preoperatively administered selective cyclooxygenase 2 inhibitor, parecoxib, on postoperative myalgia.

METHODS

After Ethics Committee approval, 68 patients were randomized into two groups (n = 34 each). Group 1 received parecoxib 40 mg intravenously 3 min before induction of anaesthesia, and Group 2 received saline (in a double-blinded manner). Incidence and severity of myalgia was evaluated systematically with a standardized questionnaire 24, 48 and 72 h after anaesthesia. We also the assessed the number of patients who felt limited in their activity due to myalgia.

RESULTS

Seven patients in the parecoxib-treated group complained of myalgia compared with 11 in the control group (not significant). No significant difference in the severity of myalgia or in the limitation of patients activity was found between the groups.

CONCLUSION

Intravenous parecoxib 40 mg, when administered before induction of anaesthesia, did not reduce incidence and severity of postoperative myalgia and did not improve activity in those who suffered from myalgia.

Einfluss des Geschlechts auf die Intubationsbedingungen nach Rocuronium

PURPOSE

There is increasing evidence for gender differences in the pharmacokinetics and pharmacodynamics of anaesthetic drugs and neuromuscular blocking agents, e.g. rocuronium (Roc). Females require 30% less Roc than males to achieve the same degree of neuromuscular block and onset times are shorter. However, whether this leads to an improvement of the intubation conditions in females is unclear.

METHODS

After approval of the ethics committee 60 female and 60 male patients were each randomised into 2 groups to receive 0.6 mg/kg body weight Roc or 1.0 mg/kg succinylcholine (Sux; control group). Induction: thiopentone (5 mg/kg), fentanyl (3 microg/kg) then Roc (Roc groups) or Sux (Sux groups) and tracheal intubation after 60 s. Time to intubation, glottic exposure and intubating conditions were assessed.

RESULTS

Men were significantly larger and heavier (p<0.001) than women, but the body mass index was comparable (ns). Number of attempts, time to intubation, and Cormack grades were comparable (ns). However, the rate of clinically acceptable intubation conditions was significantly higher in the female compared to the male Roc group: 80% vs 47%, p<0.05. The incidence of clinically acceptable intubation conditions in the female Roc and Sux groups were similar (80%).

CONCLUSION

The intubation conditions after Roc were significantly better in women than in men. The differences were Roc-related and did not occur in the control groups.

Women report more pain on injection of a precurarization dose of rocuronium: a randomized, prospective, placebo-controlled trial

BACKGROUND

The purpose of this study was to investigate whether gender influences the perception of pain on injection of rocuronium.

METHODS

In this prospective, placebo-controlled trial 120 patients were randomized into four groups to receive rocuronium 0.03 mg kg(-1) (40 female and 40 male patients) or saline (20 female and 20 male patients). The incidence and severity of the injection pain after administration of the study drug was compared between female and male patients using a numerical rating scale (0-10). Signs of local irritation, i.e. erythema and thrombophlebitis, were assessed up to 48 h after surgery.

RESULTS

In 26 (32.5%) of the 80 patients receiving rocuronium, pain on injection was observed. This occurred significantly more frequently in the female compared with male patients: 18 (45%) vs. eight (20%), respectively (P = 0.032). The severity was more pronounced in the women than in the men (P = 0.020). The incidence of the rocuronium-associated pain was significantly increased compared with the Saline groups (P < 0.001). After surgery no patient complained of any residual pain and no local signs were observed in any patient during the study period.

CONCLUSIONS

Women experienced more pain on injection of rocuronium than men, moreover this is an additional evidence for gender-related differences in pain perception. When rocuronium is used as a precurarization agent, an analgesic pretreatment (e.g. opioids) should be considered, especially for female patients.

[Precurarization of succinylcholine with cisatracurium: the influence of the precurarization interval]

PURPOSE

To determine the influence of two different pretreatment intervals, i.e. 3 and 6 min, on the efficacy of 0.01 mg/kg cisatracurium in preventing succinylcholine-induced fasciculations and myalgia.

METHODS

A total of 60 adult patients were randomized and received either 0.01 mg/kg cisatracurium (0.2*ED(95)) i.v. (Cis 3 group: pretreatment interval 3 min, Cis 6 group: pretreatment interval 6 min) or normal saline i.v. (placebo group) prior to injection of succinylcholine. The incidence and severity of fasciculations and myalgia and side-effects of precurarization were assessed.

RESULTS

The incidence of muscle fasciculations was only reduced in the Cis 6 group (45%) compared with the Placebo group (85%), p<0.05. Cisatracurium was associated with a higher incidence of paralytic symptoms in both pretreatment groups (Cis 3: 75%, Cis 6: 80%) compared with the Placebo group (30%), p<0.05.

CONCLUSION

Cisatracurium is only effective in preventing succinylcholine-induced fasciculations when a longer pretreatment interval, i.e. 6 min instead of 3 min, is chosen. Precurarization led to signs of paralysis in both pretreatment groups in the majority (75-80%) of patients without reducing the incidence or severity of postoperative myalgia.

[Neuromuscular blockade with cisatracurium in infants andchildren. Its course under sevoflurane anesthesia]

OBJECTIVE

To compare the onset, duration and maximum effect of 0.1 mg/kg cisatracurium during balanced anesthesia with sevoflurane and remifentanil between infants and children.

METHODS

We measured the time course of the neuromuscular blockade in 15 infants and 15 children by electromyography. Anesthesia was induced with propofol/remifentanil and maintained with sevoflurane (constant 2% endtidal) and remifentanil according to the patients individual requirements. After injection of 0.1 mg/kg cisatracurium we measured the following parameters: onset time: time between the beginning of injection of cisatracurium and maximum T1 depression, clinical duration: time between injection of the drug and recovery of T1 to 25%, recovery index: time between recovery of T1 from 25% to 75%. TOFR 0.9: time between injection of cisatracurium and recovery of the train-of-four ratio to 90%. In addition, we determined the maximum neuromuscular blockade Tmax after 0.1 mg/kg cistracurium.

RESULTS

Both groups differed significantly with regard to onset time and clinical duration. In the infants, the onset time was shorter (74 s vs. 198 s) and the clinical duration longer (55 min vs. 41 min) compared to the older children. The TOFR 0.9 was 73 min (range 56-86 min) in the group of the infants and 59 min (range 43-72 min) in the group of the older children (p < 0.001). Tmax was 100% (range 97-100%) in the infants and 98% (range 92-100%) in the children (p < 0.01). However, the recovery index was comparable in both groups (21 vs. 16 min).

CONCLUSIONS

Infants are substantially more sensitive to cisatracurium than children, which can be demonstrated in a significantly shorter onset time, a prolonged clinical duration and a delayed neuromuscular recovery. As there exist large interindividual differences, we recommend the use of neuromuscular monitoring in the routine practice of pediatric anesthesia.

Use of reversal agents in day care procedures (with special reference to postoperative nausea and vomiting)

There is some confusion about the contribution of reversal of residual paralysis to the occurrence of postoperative nausea and vomiting. The aim of this review is to discuss whether antagonism of residual paralysis is a cause of postoperative nausea and vomiting, and to assess the risk of residual paralysis if the reversal is omitted. Data from a meta-analysis published before 1998 were considered, along with trials published after that date to assess the influence of reversal of residual paralysis on postoperative nausea and vomiting, and the likelihood of harm when antagonism was omitted. Moreover, an overview of pathophysiological consequences, incidence and clinical consequences of residual paralysis is given and the actual criteria of the adequacy of neuromuscular recovery presented. When emetic outcomes are combined across all trials and all different neostigmine doses, there is no beneficial effect from omitting neostigmine on postoperative nausea and vomiting, but there is some evidence of a dose-responsiveness with neostigmine; higher doses may have emetic properties. However, omitting reversal introduces a non-negligent risk of residual paralysis. An improved understanding of the pathological consequences of residual paralysis (i.e. impaired laryngeal and pharyngeal muscle function, alterations in hypoxic ventilatory control, reduced margin of safety) led to establishment of more rigorous criteria for defining adequacy of neuromuscular recovery. A train-of-four ratio of > or = 0.9 is now accepted as the index of adequate recovery of neuromuscular function. Applying this new definition, residual paralysis becomes a frequent adverse side-effect. Neuromuscular recovery should therefore be routinely monitored in ambulatory patients and residual paralysis prevented by reversing neuromuscular block.

Spontaneous movements, local reactions and pain on injection of rocuronium. A comparison between female and male patients

BACKGROUND

We investigated the incidence of withdrawal, local reactions and pain on injection of rocuronium in 120 adult ASA I-II patients undergoing general anaesthesia (group A: 60 male patients, group B: 60 female patients).

METHODS

After induction of anaesthesia with propofol and remifentanil, rocuronium 0.6 mg kg(-1) was injected in a separate intravenous cannula on the opposite arm. The patient's response to the injection of rocuronium was graded using a four-point scale. The appearance of local signs (i.e. erythema, venous sequelae) on the arm where rocuronium had been injected was recorded at the end of the injection as well as 1 h and 24 h after recovery from anaesthesia. Moreover, patients were asked 24 h after recovery from anaesthesia whether they had recall of pain or movements in this arm during induction of anaesthesia.

RESULTS

In 26 of the 120 patients (22%) included, withdrawal reactions after injection of rocuronium were observed. Of these 26 patients, 16 (13%) had severe movements. The overall incidence of withdrawal reactions after rocuronium as well as the incidence of severe reactions was significantly higher in female patients compared to male patients (overall incidence: 18 females (30%) vs. 8 males (13%), P<0.05; severe reaction: 13 females (22%) vs. 3 males (5%), P<0.05). No local reactions were observed and no patient remembered any pain or movements during induction of anaesthesia.

CONCLUSION

The incidence and the degree of withdrawal reactions in response to the injection of rocuronium were significantly higher in women than in men. This was not associated with adverse clinical consequences for the patient's outcome.

[Time course of neuromuscular blockade after rocuronium. A comparison between women and men]

BACKGROUND

We studied 40 patients (20 female and 20 male) undergoing elective surgery under general anaesthesia to evaluate the effect of gender on the pharmacodynamics of rocuronium.

METHODS

Using electromyography (EMG) we determined the maximal neuromuscular block and time course of action of 0.45 mg/kg rocuronium (1.5 x ED95).

RESULTS

Age and body mass index were comparable between females and males (38 (+/- 8) vs. 37 (+/- 10) years and 24.2 (+/- 2.9) vs. 25.2 (+/- 1.7) kg/m2. However, significant differences in weight and height were found between females and males (65.7 +/- 9.3 kg vs. 77.5 +/- 5.5 kg; p < 0.01 and 178 +/- 6.8 cm vs. 164 +/- 6.7 cm; p < 0.01). Onset time was shorter in females (168 +/- 65 s vs. 211 +/- 56 s; p < 0.05). Maximal neuromuscular blockade after 0.45 mg/kg rocuronium was 94 (+/- 3) % in females and 89 (+/- 6) % in males; p < 0.01. Clinical duration was increased in females (23 +/- 5 min vs. 17 +/- 5 min; p < 0.05), while the recovery index was comparable between both groups (9 +/- 4 min in females and 9 +/- 3 min in males; n.s.).

CONCLUSION

Compared to men neuromuscular blockade after 0.45 mg/kg rocuronium was more pronounced in women. The onset time was shortened and the clinical duration increased in female patients.

[General anesthesia or spinal anesthesia for hip prosthesis replacement? Studies of acceptance of both procedures by patients]

Patients undergoing total hip replacement are given general anaesthesia or spinal anaesthesia. The aim of this study was to investigate the experiences of patients before, during and after general anaesthesia (68 patients) or spinal anaesthesia (77 patients). Our investigation revealed that with regard to complications (nausea and vomiting, headache and back pains), no differences between the two methods occurred. Between 25 and 30% of the patients in both groups had these complications, although there were differences between both groups regarding their concomitant diseases and medication. Patients with spinal anaesthesia had a three times higher incidence of cardiac concomitant diseases and received corresponding drugs more frequently. We found that the time of postoperative analgesia after spinal anaesthesia (210 minutes) was significantly longer than after general anaesthesia (90 minutes). The majority of the patients in both groups (approximately 90%) were satisfied with the chosen method of anaesthesia and with the postoperative pain therapy. These findings make it possible to conclude that with the exception of differences in the postoperative analgesia time, there are no differences between general anaesthesia and spinal anaesthesia regarding complications and satisfaction of the patients with both methods of anaesthesia.