Comparison between local anaesthesia with remifentanil and total intravenous anaesthesia for operative hysteroscopic procedures in day surgery.

BACKGROUND: This study aimed at comparing total i.v. anaesthesia (TIVA) with monitored anaesthesia care (MAC) during day-surgery operative hysteroscopy regarding: operation time, time to mobilization and discharge, and patient satisfaction. METHODS: Ninety-one healthy women were randomized to MAC with paracervical local anaesthesia and remifentanil or to TIVA with propofol and remifentanil. Time from arrival to leaving the operating theatre, time from arrival in the recovery room to mobilization and discharge readiness, and patient satisfaction with MAC and TIVA were observed. RESULTS: Time from arrival to leaving the operating theatre showed no significant difference between groups (P=0.6). The time to mobilization {MAC: 53 min [inter-quartile range (IQR) 40-83], TIVA: 69 min (IQR 52-96) (P=0.017)} and the total time from arrival to discharge readiness [MAC: 118 min (IQR 95-139), TIVA: 138 (IQR 120-158) (P=0.0009)] were significantly reduced for patients in the MAC group. More patients in the MAC group 45 (91.8%) than in the TIVA group 24 (64.9%) responded positively to the question: would you like to receive the same kind of anaesthesia for a similar procedure in the future? (P=0.003). CONCLUSIONS: Paracervical local anaesthesia combined with remifentanil is suitable for operative hysteroscopy in day surgery.

Is day surgery safe? A Danish multicentre study of morbidity after 57,709 day surgery procedures.

BACKGROUND: Day surgery is expanding in several countries, and it is important to collect information about quality. The aim of this study was to assess morbidity and unanticipated hospital visits 0-30 days post-operatively in a large cohort. METHODS: We prospectively recorded data from 57,709 day surgery procedures performed in eight day surgery centres over a 3-year period. We cross-checked with the National Patient Registry to identify complications 0-30 days post-operatively, and registrations from The Danish Register of Cause of Death were requested. We retrieved the records of 1174 patients to assign a relation between secondary contact and day surgery. RESULTS: The overall rate of return hospital visits was 1.21% [95% confidence interval (CI): 1.12-1.30%] caused by a wide range of diagnoses. No deaths were definitely related to day surgery. The return hospital visits were due to haemorrhage/haematoma 0.50% (95% CI: 0.44-0.56%), infection 0.44% (95% CI: 0.38-0 49%) and thromboembolic events 0.03%. Major morbidity was rare. The surgical procedures with the highest rate of complication were tonsillectomies 11.4%, surgically induced abortions 3.13% and inguinal hernia repairs 1.23%. CONCLUSION: This large-scale Danish national study confirmed that day surgery is associated with a very low rate of return hospital visits. Despite the rapid expansion of day surgery, safety has been maintained, major morbidity being very rare, and no deaths being definitely related to day surgery.

Monitoring of neuromuscular transmission.

Considerable advances have been achieved in developing new techniques and equipment for the assessment of neuromuscular transmission during anaesthesia. This paper is a review of the methods currently used in research as well as in daily clinical practice. The principles of nerve stimulation and the evoked muscular response, the function of the nerve stimulator, features of the stimulation electrodes, possible stimulation sites, and the various stimulation patterns with their responses are described. The methods for measurement of neuromuscular function with mechanomyography, electromyography and acceleromyography are reviewed, and commercially available equipment for each purpose is described. The clinical evaluation of the responses to nerve stimulation, and which stimulation patterns to prefer during onset, maintenance and recovery of neuromuscular block are dealt with, as well as possible errors to be encountered. Arguments are given for routine use of neuromuscular monitoring in the clinical setting, and situations where monitoring of neuromuscular function are of particular importance are noted.

[Information, satisfaction and anxiety in connection with anesthesia. A questionnaire study]. / Information, tilfredshed og angst ved anaestesi. En spørgeskemaundersøgelse.

The purpose of the study was to assess the level of information, anxiety and satisfaction with treatment and care among patients undergoing general anaesthesia. A questionnaire was answered by 406 patients. Seventeen criteria comprising various aspects of the total course of anaesthesia were defined to characterise a "satisfactory anaesthetic experience". After the preoperative visit 65% of the nervous patients were less nervous. Only 47% were informed of possible postanaesthetic side effects. Although 86% were "satisfied" with the treatment and care, only 36% met the criteria of satisfaction. The main problems were anxiety (especially fear of not waking up again), nausea and pain after waking up. We conclude that patients are not told enough about anaesthesia and side effects. Many patients, particularly the younger patients and the female patients, are afraid of anaesthesia.

Return hospital visits and morbidity within 60 days after day surgery: a retrospective study of 18,736 day surgical procedures.

BACKGROUND: As day surgery includes more extensive procedures focus should be put on late outcome. The frequency of day surgery-related return visits and the associated morbidity were examined to identify suitable indicators of quality. METHODS: From two centres, 16,048 patients underwent 18,736 day surgery operations including 4,829 surgical abortions. Patients were retrospectively analysed for contacts to Danish hospitals within 60 post-operative days and the associated morbidity and mortality. Data were obtained from the Danish National Patient Registry and the National Causes of Death Registry. Patient records were studied to validate contacts as being definite, likely, possible or not related. RESULTS: Altogether 113 patients (not including the surgical abortions) were readmitted to hospitals with 117 complications definitely or likely related to day surgery. The most common complications were haematomas or haemorrhage (0.40%) and infections (0.29%). Morbidity after the two most common procedures, hernia repair and knee arthroscopy, was observed in 1:39 patients and 1:220 patients, respectively. More serious complications included four patients with septic arthritis of the knee and six patients with venous thromboembolism. After surgical abortion, pelvic inflammation and bleeding were observed in 3.1% and 2.2%, respectively, with centre differences. Altogether no myocardial infarctions, central nervous system deficits, pneumonias or deaths were recorded that could definitely or likely be related to day surgery. CONCLUSION: Day surgery in Denmark is a safe practice. Readmission rates, haematomas and wound infections are likely future indicators of outcome quality after day surgery.

Intubation conditions after rocuronium or succinylcholine for rapid sequence induction with alfentanil and propofol in the emergency patient.

BACKGROUND AND OBJECTIVE: Previous studies mainly conducted on elective patients recommend doses of 0.9-1.2 mg kg[-1] rocuronium to obtain comparable intubation conditions with succinylcholine 1.0 mg kg[-1] after 60 s during a rapid-sequence induction. We decided to compare the overall intubating conditions of standard doses of rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] during a strict rapid-sequence induction regimen including propofol and alfentanil. METHODS: Male and female patients (ASA I-III) older than 17 yr scheduled for emergency abdominal or gynaecological surgery and with increased risk of pulmonary aspiration of gastric content were randomized to a rapid-sequence induction with succinylcholine 1.0 mg kg[-1] or rocuronium 0.6 mg kg[-1]. Patients with a predicted difficult airway were excluded. A senior anaesthesiologist 'blinded' for the randomization performed the intubation 60 s after injection of the neuromuscular blocker. Intubating conditions were evaluated according to an established guideline. Tracheal intubation not completed within 30 s was recorded as failed. RESULTS: 222 patients were randomized. Three patients had their operation cancelled and 10 did not fulfil the inclusion criteria. Clinically acceptable intubation conditions were present in 93.5% and 96.1% of patients in the succinylcholine group (n=107) and the rocuronium group (n=102), respectively (P=0.59). CONCLUSIONS: During a rapid-sequence induction with alfentanil and propofol, both rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] provide clinically acceptable intubation conditions in 60 s in patients scheduled for emergency surgery. Under the conditions of this rapid-sequence induction regimen rocuronium may be a substitute for succinylcholine.

Monitoring of neuromuscular transmission by electromyography during anaesthesia. A comparison with mechanomyography in cat and man.

In this study the applicability of the electromyographical method for monitoring neuromuscular transmission during anaesthesia has been investigated. The purpose was to determine the stability and temperature dependence of the EMG and to evaluate and compare EMG area, amplitude and duration during a non-depolarizing neuromuscular block in the tibialis anterior muscle preparation of the cat. Further, in clinical studies the purpose was to investigate differential hand muscle sensitivity to non-depolarizing neuromuscular blocking agents based on the EMG and the standard adductor pollicis mechanomyogram, and to establish the agreement between the electromyographical and the mechanomyographical methods and their relationship to clinical parameters of residual neuromuscular block. For this purpose a new monitoring equipment was developed for simultaneous recording of the evoked mechanomyogram and the surface compound EMG area, amplitude and duration. In the animal studies the EMG was found to be stable with changes less than 10% during 3 hours of stimulation and with a high degree of reproducibility. In contrast, the mechanomyogram proved unstable over time with changes of 35-50% (positive staircase) within minutes after onset of stimulation followed by a slower decline of the response to 70-75% of control. An inverse relationship was found between temperature and both the mechanomyogram and the EMG, the EMG area and duration being more affected (5-7% per degrees C) than EMG amplitude (2-3% per degrees C). During onset and recovery from non-depolarizing neuromuscular block, EMG area and amplitude of the first major negative deflection and of the total compound response both reflected neuromuscular transmission equally. The EMG duration was found to be unsuitable as a predictor of neuromuscular block. In the clinical studies of the hand muscles (adductor pollicis, hypothenar and first dorsal interosseous muscles) small but clinically insignificant differences in EMG-based sensitivity to pancuronium were observed. There was no difference between EMG area and amplitude in the estimated effective doses of pancuronium and roctronium producing 50% and 90% block, respectively (ED50 and ED90), but EMG-based sensitivity of the adductor pollicis muscle was less than when based on mechanomyography. Comparative analysis of first dorsal interosseous EMG and adductor pollicis mechanomyogram during non-depolarizing neuromuscular block was based on the concept of bias (mean difference between the results by the two methods) and limits of agreement (an estimation of how much results obtained with one method are likely to differ from the results of the other method) and evaluated during TOF nerve stimulation. The two methods agreed within acceptable limits during neuromuscular block with estimated bias being less than 2% during onset. A variable bias of 3-7% was observed during recovery, with EMG overestimating block at 25% recovery and underestimating block at 75% and 90% recovery. Limits of agreement were more narrow during onset (+/- 7-8%) than during recovery (+/- 12-17%), EMG area and amplitude equally reflected the degree of neuromascular block. First dorsal interosseous EMG TOF ratio recovered more slowly than TOF ratio of the adductor pollicis mechanomyogram during early recovery. The relationship between the two methods was described as being log-linear, and during late recovery bias between the TOF ratios of the two methods was zero. However, due to the range of deviations between the EMG and the mechanomyogram, EMG TOF ratios down to 0.55 or up to 0.90 in some patients were found to be compatible with adequate recovery of a mechanomyographical TOF ratio of 0.75. Differences between electromyographical and mechanomyographical TOF ratios in their relation to 5 s sustained headlift were only revealed when the TOF ratio was below 0.50-0.60. More patients were then able to perform the test if the TOF ratio was measured from the EMG.(ABSTRACT T

Differential effect of pancuronium at the adductor pollicis, the first dorsal interosseous and the hypothenar muscles. An electromyographic and mechanomyographic dose-response study.

Cumulative dose-response curves were constructed from evoked compound electromyographic (EMG) recordings in man to compare the sensitivity to pancuronium of the adductor pollicis, the hypothenar and the first dorsal interosseous muscles. Also, the EMG and mechanomyography-based sensitivity of the adductor pollicis muscle were compared. The EMG and the mechanomyogram were evaluated in random sequence in each of 21 adult thiopental, fentanyl and diazepam anesthetized patients. The EMG-based ED50 were 36-38 micrograms.kg-1 with no differences between muscles. The EMG-based ED90 of the adductor pollicis and the hypothenar muscles were 62-65 micrograms.kg-1 compared to the 60 micrograms.kg-1 of the first dorsal interosseous muscle (P < 0.05). ED50 (34 micrograms.kg-1), and ED90 (56 micrograms.kg-1) obtained from the adductor pollicis mechanomyogram were significantly lower than those based on the EMG (P < 0.05). It is concluded that differences in sensitivity to pancuronium exist between the three muscles when evaluated from the EMG, and that the apparent sensitivity of a given muscle to a muscle relaxant may depend upon whether the response is evaluated using EMG or mechanomyography.

Precurarization--a hazard to the patient?

Four case histories are presented illustrating the unpleasant and serious reactions that may follow precurarization with small doses of non-depolarizing muscle relaxants. The importance of preoperative information, the necessity of relating the dose of the precurarizing drug to the weight of the patient and the possibility of hypersensitivity to this drug are emphasized.

Adverse reactions and interactions of the neuromuscular blocking drugs.

The adverse reactions seen following administration of neuromuscular blocking agents are mainly cardiovascular. Due to the lack of specificity for the nicotinic receptor at the neuromuscular junction, these agents may interact with receptors in autonomic ganglia and muscarinic receptors in the heart. Furthermore, muscle relaxants may have histamine-releasing properties. The cardiovascular effects vary with potency and specificity of the drug, depending mainly on the chemical structure. Pancuronium, fazadinium and especially gallamonium block cardiac muscarinic receptors, and tachycardia may be seen. Atracurium, metocurine and in particular d-tubocurarine have histamine-releasing properties and may cause flushing, hypotension and tachycardia. Vecuronium has no effect on the cardiovascular system. The effect of succinylcholine on heart rate differs between children, where bradycardia is seen, and adults in whom tachycardia may follow. However, bradycardia may occur in adults following a single dose. Succinylcholine increases plasma potassium, especially in patients with nerve damage, and arrhythmias may be observed. The neuromuscular adverse effects of succinylcholine, such as fasciculations and increased gastric and intraocular pressure, may be prevented by precurarisation. Many drugs interact with neuromuscular blocking agents and there is often a potentiation of the neuromuscular effect. This is of clinical importance in the case of antibiotics, inhalational anaesthetics, lithium and cyclosporin. Difficulty in reversing the block may occur with calcium channel blockers and polymyxin. However, some drugs, such as phenytoin, carbamazepine and lithium, may cause resistance to neuromuscular blocking agents. Furthermore, clinically important interactions exist between individual neuromuscular blocking drugs. Precurarisation with a non-depolarising drug prolongs the onset of succinylcholine, and conversely a prolonged effect of non-depolarising drugs is seen following succinylcholine. The effect of succinylcholine is markedly prolonged if the drug is administered during recovery from pancuronium blockade or following neostigmine for reversal. Succinylcholine is hydrolysed by plasma cholinesterase, and drugs which decrease the activity of this enzyme may produce a prolonged block, i.e. contraceptive pills, cyclophosphamide, echothiopate and organophosphate.