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The implementation of imaging technologies has dramatically increased the efficiency of preclinical studies, enabling a powerful, non-invasive and clinically translatable way for monitoring disease progression in real time and testing new therapies. The ability to image live animals is one of the most important advantages of these technologies. However, this also represents an important challenge as, in contrast to human studies, imaging of animals generally requires anaesthesia to restrain the animals and their gross motion. Anaesthetic agents have a profound effect on the physiology of the animal and may thereby confound the image data acquired. It is therefore necessary to select the appropriate anaesthetic regime and to implement suitable systems for monitoring anaesthetised animals during image acquisition. In addition, repeated anaesthesia required for longitudinal studies, the exposure of ionising radiations and the use of contrast agents and/or imaging biomarkers may also have consequences on the physiology of the animal and its response to anaesthesia, which need to be considered while monitoring the animals during imaging studies. We will review the anaesthesia protocols and monitoring systems commonly used during imaging of laboratory rodents. A variety of imaging modalities are used for imaging rodents, including magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computed tomography, high frequency ultrasound and optical imaging techniques such as bioluminescence and fluorescence imaging. While all these modalities are implemented for non-invasive in vivo imaging, there are certain differences in terms of animal handling and preparation, how the monitoring systems are implemented and, importantly, how the imaging procedures themselves can affect mammalian physiology. The most important and critical adverse effects of anaesthetic agents are depression of respiration, cardiovascular system disruption and thermoregulation. When anaesthetising rodents, one must carefully consider if these adverse effects occur at the therapeutic dose required for anaesthesia, if they are likely to affect the image acquisitions and, importantly, if they compromise the well-being of the animals. We will review how these challenges can be successfully addressed through an appropriate understanding of anaesthetic protocols and the implementation of adequate physiological monitoring systems.

Background:

Closed loop anaesthesia delivery systems (CLADSs) are a recent advancement in accurate titration of anaesthetic drugs. They have been shown to be superior in maintaining adequate depth of anaesthesia with few fluctuations as compared with target-controlled infusion or manual titration of drug delivery.

Methods:

Twenty patients scheduled to undergo general abdominal or orthopaedic procedures under general anaesthesia at Leh (3505 m above sea level) were recruited as subjects. Anaesthesia was delivered by a patented closed loop system that uses the Bispectral Index (BIS™) as a feedback parameter to titrate the rate of propofol infusion. All vital parameters, drug infusion rate and the BIS™ values were continuously recorded and stored online by the system. The data generated was analysed for the adequacy of anaesthetic depth, haemodynamic stability and post-operative recovery parameters.

Results:

The CLADS was able to maintain a BIS™ within ±10 of the target of 50 for 85.0±7.8% of the time. Haemodynamics were appropriately maintained (heart rate and mean arterial blood pressure were within 25% of baseline values for 91.2±2.2% and 94.1±3% of the total anaesthesia time, respectively). Subjects were awake within a median of 3 min from cessation of drug infusion and achieved fitness to recovery room discharge within a median of 15 min. There were no adverse events or report of awareness under anaesthesia.

Conclusions:

The study demonstrates the safety of our CLADS at high altitude. It seeks to extend the use of our system in challenging anaesthesia environments. The system performance was also adequate and no adverse events were recorded.

Summary

A great deal of concern has recently arisen regarding the safety of anaesthesia in infants and children. There is mounting and convincing preclinical evidence in rodents and non-human primates that anaesthetics in common clinical use are neurotoxic to the developing brain in vitro and cause long-term neurobehavioural abnormalities in vivo. An estimated 6 million children (including 1.5 million infants) undergo surgery and anaesthesia each year in the USA alone, so the clinical relevance of anaesthetic neurotoxicity is an urgent matter of public health. Clinical studies that have been conducted on the long-term neurodevelopmental effects of anaesthetic agents in infants and children are retrospective analyses of existing data. Two large-scale clinical studies are currently underway to further address this issue. The PANDA study is a large-scale, multisite, ambi-directional sibling-matched cohort study in the USA. The aim of this study is to examine the neurodevelopmental effects of exposure to general anaesthesia during inguinal hernia surgery before 36 months of age. Another large-scale study is the GAS study, which will compare the neurodevelopmental outcome between two anaesthetic techniques, general sevoflurane anaesthesia and regional anaesthesia, in infants undergoing inguinal hernia repair. These study results should contribute significant information related to anaesthetic neurotoxicity in children.

Aims: Children with treatable, vision impairing conditions may not have access to surgical care when they live in regions where anaesthesia is unavailable. The use of ketamine anaesthesia in a developing region was studied to determine its safety and effectiveness.

Methods: This is a consecutive series of 679 children who had a variety of paediatric eye disorders necessitating a short general anaesthesia. Ketamine was administered intravenously by a paediatrician with training in paediatric resuscitation procedures. Both intraocular and extraocular procedures were performed. The location of treatment was the Tilganga Eye Hospital in Kathmandu, Nepal, a developing region of the world. The study took place over a 5 year period.

Results: All procedures were performed without any anaesthetic complications. No child required unanticipated resuscitation or laryngeal intubation. Postoperative dysphoria occurred occasionally and was difficult to measure quantitatively. This side effect of ketamine resolved by the first postoperative day.

Conclusion: Ketamine is an effective agent for both intraocular and extraocular surgery in the paediatric age group. None of the children in this series needed resuscitation or intubations, and the ophthalmic surgery was carried out safely. Ketamine can be used safely in any ophthalmic procedure of short duration by a person having some training in anaesthetic resuscitation procedures. Because of its simplicity and safety, ketamine may be useful in a simple ophthalmic setup in the developing word.

We set out to determine if arthroscopic knee surgery was acceptable to patients and their surgeon when carried out using a local anaesthetic infiltration technique. Patients awaiting arthroscopy were randomly allocated to have either a local or a general anaesthetic. The same surgeon (NPT) carried out all the procedures. The demographic profile was similar in the two groups, as were the diagnosis and the surgical procedures. The only difference between the two groups was that those performed under local anaesthesia did not have a limb tourniquet inflated. The time spent in the theatre suite was similar in each group. This did not include the recovery time in the general anaesthetic group. The duration of the operation was longer in the local anaesthetic group (P = 0.05). A simple 0 to 10 scoring system indicated that patients preferred a local anaesthetic but the surgeon preferred to have the patient asleep (P > 0.05). Those having a local anaesthetic required less physiotherapy (P = 0.025) and more of them returned to work and sport earlier (P = 0.05). We attributed this to not having sustained pressure-induced tissue damage to the thigh muscle as they did not have a tourniquet inflated. We had a 4% failure rate in the local anaesthetic group. Arthroscopic surgery is already a well-established day case procedure and our findings have a financial implication (a saving of 25 pounds per case) as well as identifying a safer technique in the medically unfit. Unfortunately, this technique is not suitable for the investigation and treatment of all knee problems. There are certain constraints, viz the very anxious patient, acute problems, children, larger arthroscopic procedures and the inability to perform an examination under anaesthetic but, overall, it is a useful and effective way of performing a common surgical procedure.

Background:

Often conventional Inhalational agents are used for maintenance of anaesthesia in spine surgery. This study was undertaken to compare propofol with isoflurane anaesthesia with regard to haemodynamic stability, early emergence, postoperative nausea and vomiting (PONV) and early assessment of neurological functions.

Patients & Methods:

Eighty ASA grade I &II adult patients were randomly allocated into two groups. Patients in study group received inj propofol for induction as well as for maintenance along with N2O+O2 and the control group patients received inj thiopentone for induction and N2O+O2+isoflurane for maintenance. BIS monitoring was used for titrating the anaesthetic dose adjustments in all patients. All patients received fentanyl boluses for intraoperative analgesia and atracurium as muscle relaxant. Statistical data containing haemodynamic parameters, PONV, emergence time, dose of drug consumed & quality of surgical field were recorded and compared using student t' test and Chi square test.

Results:

The haemodynamic stability was coparable in both the groups. The quality of surgical field were better in study group. Though there was no significant difference in the recovery profile (8.3% Vs 9.02%) between both the groups, the postoperative nausea and vomiting was less in propofol group than isoflurane group (25%Vs60%). The anaesthesia cost was nearly double for propofol than isoflurane anaesthesia.

Conclusion:

Haemodynamic stability was comparable in both the groups. There was no significant difference in the recovery time between intravenous and inhalational group. Patients in propofol group were clear headed at awakening and were better oriented to place than inhalational group.

OBJECTIVE--To determine the influence of general or regional anaesthesia on long term mental function in elderly patients. DESIGN--Prospective study of patients randomly allocated to receive general or regional anaesthesia. SETTING--The patients' homes and a large teaching hospital in Cardiff. SUBJECTS--146 Patients aged 60 and over scheduled for elective hip or knee replacement. MAIN OUTCOME MEASURES--Scores achieved in tests of cognitive function and functional competence. RESULTS--72 Patients were allocated to receive general anaesthesia and 74 regional anaesthesia. Anaesthetic technique did not influence the duration of the operation, time to mobilisation postoperatively, requirements for analgesia after the operation, or duration of stay in hospital. Three months after the operation there was an improvement in the score for the recognition component (76 ms, 95% confidence interval 9 to 144) and the response component (82 ms, 5 to 158) of the choice reaction time in the group receiving general anaesthesia compared with the group receiving regional anaesthesia. This was the only significant difference between the two groups in the assessments of cognitive and functional competence. Eleven patients receiving regional anaesthesia and 12 receiving general anaesthesia reported that their memory and concentration were worse than before the operation, but this was not confirmed by testing. CONCLUSION--Cognitive and functional competence in elderly patients was not detectably impaired after either general or regional anaesthesia when attention was paid to the known perioperative influences on mental function.

Context:

The contribution of anaesthesia itself to post-operative cognitive dysfunction (POCD) or the potential protective effect of one specific type of anaesthesia on the occurrence of POCD is unclear.

Aims:

This is a meta-analysis evaluating the effects of the anaesthetic technique (regional vs. general anaesthesia) on POCD of patients undergoing non-cardiac surgery.

Settings and Design:

Meta-analysis performed in a University affiliated hospital.

Methods:

A search for randomized controlled trials (RCT) comparing regional anaesthesia to general anaesthesia for surgery was done in PUBMED, MEDLINE, EMBASE, EBM Reviews-Cochrane Central Register of Controlled Trials, PsychINFO and Current Contents/all editions in 2009.

Statistical Analysis:

Data were analyzed with comprehensive Meta-analysis Version 2.2.044.

Results:

Twenty-six RCTs including 2365 patients: 1169 for regional anaesthesia and 1196 for general anaesthesia were retained. The standardized difference in means for the tests included in the 26 RCTs was -0.08 (95% confidence interval: –0.17–0.01; P value 0.094; I-squared = 0.00%). The assessor was blinded to the anaesthetic technique for 12 of the RCTs including only 798 patients: 393 for regional anaesthesia and 405 for general anaesthesia. The standardized difference in means for these 12 studies is 0.05 (–0.10–0.20; P=0.51; I-squared = 0.00%).

Conclusions:

The present meta-analysis does not support the concerns that a single exposure to general anaesthesia in an adult would significantly contribute to permanent POCD after non-cardiac surgery.

P Garnerin, quality manager and F Clergue, department head and professor

J-F Sicard, anaesthetist and F Bonnet, department head and professor

Background—Reporting systems in anaesthesia have generally focused on critical events (including death) to trigger investigations of latent and active errors. The decrease in the rate of these critical events calls for a broader definition of significant anaesthetic events, such as hypotension and bradycardia, to monitor anaesthetic care. The association between merely undesirable events and critical events has not been established and needs to be investigated by voluntary reporting systems.

Objectives—To establish whether undesirable anaesthetic events are correlated with critical events in anaesthetic voluntary reporting systems.

Methods—As part of a quality improvement project, a systematic reporting system was implemented for monitoring 32 events during elective surgery in our hospital in 1996. The events were classified according to severity (critical/undesirable) and nature (process/outcome) and control charts and logistic regression were used to analyse the data.

Results—During a period of 30 months 22% of the 6439 procedures were associated with anaesthetic events, 15% of which were critical and 31% process related. A strong association was found between critical outcome events and critical process events (OR 11.5 (95% confidence interval (CI) 4.4 to 27.8)), undesirable outcome events (OR 4.8 (95% CI 2.0 to 11.8)), and undesirable process events (OR 4.8 (95% CI 1.3 to 13.4)). For other classes of events, risk factors were related to the course of anaesthesia (duration, occurrence of other events) and included factors determined during the pre-anaesthetic visit (risk of haemorrhage, difficult intubation or allergic reaction).

Conclusion—Undesirable events are associated with more severe events and with pre-anaesthetic risk factors. The way in which information on significant events can be used is discussed, including better use of preoperative information, reduction in the collection of redundant information, and more structured reporting.

(Quality in Health Care 2000;9:203–209)

Key Words: reporting system; correlation analysis; quality assessment; adverse events; anaesthesia

General anaesthesia is administered each day to thousands of patients worldwide. Although more than 160 years have passed since the first successful public demonstration of anaesthesia, a detailed understanding of the anaesthetic mechanism of action of these drugs is still lacking. An important early observation was the Meyer-Overton correlation, which associated the potency of an anaesthetic with its lipid solubility. This work focuses attention on the lipid membrane as a likely location for anaesthetic action. With the advent of cellular electrophysiology and molecular biology techniques, tools to dissect the components of the lipid membrane have led, in recent years, to the widespread acceptance of proteins, namely receptors and ion channels, as more likely targets for the anaesthetic effect. Yet these accumulated data have not produced a comprehensive explanation for how these drugs produce CNS depression. In this review, we follow the story of anaesthesia mechanisms research from its historical roots to the intensely neurophysiologic inquiries regarding it today. We will also describe recent findings that identify specific neuroanatomical locations mediating the actions of some anaesthetic agents.

Aims

Pharmacological-challenge magnetic resonance imaging (phMRI) is powerful new tool enabling researchers to map the central effects of neuroactive drugs in vivo. To employ this technique pre-clinically, head movements and the stress of restraint are usually reduced by maintaining animals under general anaesthesia. However, interactions between the drug of interest and the anaesthetic employed may potentially confound data interpretation. NMDA receptor (NMDAR) antagonists used widely to mimic schizophrenia have recently been shown to interact with the anaesthetic halothane. It may be the case that neural and cerebrovascular responses to NMDAR antagonists are dependent on the types of anaesthetic used.

Methodology

We compared the phMRI response to NMDAR antagonist ketamine in rats maintained under α-chloralose to those under isoflurane anaesthesia. A randomized placebo/vehicle controlled design was used in each of the anaesthetic groups.

Results

Changes in the anaesthetic agent resulted in two very different profiles of activity. In the case of α-chloralose, positive activations in cortical and sub-cortical structures reflected a response which was similar to patterns seen in healthy human volunteers and metabolic maps of conscious rats. However, the use of isoflurane completely reversed such effects, causing widespread deactivations in the cortex and hippocampus.

Conclusion

This study provides initial evidence for a drug-anesthetic interaction between ketamine and isoflurane that is very different from responses to α-chloralose-ketamine.

Summary

Awareness is the postoperative recall of sensory perception during general anaesthesia. The incidence is quoted at 1-2 per every 1000 patients. This rare but serious adverse event can be extremely distressing for both the patient as well as the anaesthesiologist. Awareness during anaesthesia may occur despite apparently sound anaesthetic management and is usually not associated with pain. However, a few cases may experience excruciating pain and have long term neuropsychiatric sequelae like post-traumatic stress disorder. This adverse event can also have serious medicolegal implications. This article addresses the various contributory factors that may predispose to intra-operative awareness. Preventive measures in the preinduction period as well as intraoperatively are discussed, including the use of depth of anaesthesia monitors. Remedial steps to be taken when such an event occurs are also discussed.

A prospective study of 104 cases has been carried out to compare the use of local and general anaesthesia for the elective repair of groin hernias. There were no apparent disadvantages in using a local anaesthetic procedure. Patients having local anaesthetic herniorrhaphy required postoperative analgesics and antiemetics significantly less often and also returned home sooner (3.2 days) than patients having a general anaesthetic (4.1 days). These findings argue strongly in favour of local anaesthesia as a suitable alternative to general anaesthesia for repair of groin hernias.

Aim:

Peri-operative pain relief in children can be provided by conventional general anaesthesia or by regional nerve blocks. The present study was carried out to evaluate and compare the effectiveness of penile block for penile surgery with the standard technique of general anaesthesia (GA) of short duration of less than two hours, and also to evaluate the postoperative pain relief obtained by penile block.

Materials and Methods:

The study was carried out in the department of Anaesthesiology and Intensive care of our hospital, on 60 children in the age group of 1-10 years, belonging to American Society of Anesthesiologists (ASA) grades I and II, and divided randomly into two groups: Group B and group G, comprising of 30 patients each. Group B children received a penile block whereas group G children underwent a standard general anaesthetic procedure. Baseline, intra-operative and post-operative heart rate (HR), electrocardiogram (ECG), non-invasive blood pressure (NIBP) (systolic and diastolic) and pulse oximeter oxygen saturation (SpO2) were recorded at regular intervals. The duration of post-operative pain relief, time to rescue analgesia and time to first feed were also evaluated and recorded. Statistical analysis was carried out using statistical package for social sciences (SPSS) 11 version for windows and employing analysis of variance (ANOVA), unpaired student t test, Chi-square test and Mann Whitney U test for various parameters. Value of P<0.05 was considered as significant and P<0.0001 as highly significant.

Results:

The demographic characteristics were comparable in both the groups. Heart rate, systolic blood pressure, diastolic blood pressure and pulse oximetry showed remarkable differences at various time intervals during intra-operative and post-operative period, which were statistically significant on comparison (P<0.05 and P<0.0001). Post-operative pain relief, time to first rescue analgesia and time to first feed also showed statistically significant differences.

Conclusions:

Penile block is very effective when used along with light sedation for distal penile surgeries of less than 2 hours duration as compared to standard GA as reflected by more stable haemodynamics in peri-operative period, excellent pain relief extending up to 6-8 hrs postoperatively and absence of any significant complications or side effects.

Paediatric cardiac anaesthesia involves anaesthetizing very small children with complex congenital heart disease for major surgical procedures. The unique nature of this patient population requires considerable expertise and in-depth knowledge of the altered physiology. There have been several developments in the last decade in this subspecialty that has contributed to better care and improved outcome in this vulnerable group of patients. The purpose of this review is to present some of the recent advances in the anesthetic management of these children from preoperative evaluation to postoperative care. This article reviews the role of magnetic resonance imaging and contrast-enhanced magnetic resonance angiography in preoperative evaluation, the use of ultrasound to secure vascular access, the use of cuffed endotracheal tubes, the optimal haematocrit and the role of blood products, including the use of recombinant factor VIIa. It also deals with the advances in technology that have led to improved monitoring, the newer developments in cardiopulmonary bypass, the use of centrifugal pumps and extracorporeal membrane oxygenation and the role of DHCA. The role of new drugs, especially the α-2 agonists in paediatric cardiac anesthetic practice, fast tracking and effective postoperative pain management have also been reviewed.

Between 1980 and 1992, 116 patients had either a simple mastectomy (32) or intra-abdominal procedures (84) under local anaesthesia (0.5-1% lignocaine with 1:200 000 adrenaline). A wide variety of general surgical procedures were feasible using only supplementary intravenous sedation (54%). Complications were uncommon and related to surgical procedure (three incorrect diagnoses, three procedures impossible) rather than the anaesthetic technique. There were no anaesthetic toxicity or postoperative problems. Local anaesthesia is extremely safe and facilitates larger surgical procedures than is generally appreciated.

Parkinson's disease (PD), one of the most common disabling neurological diseases, affects about 1% of the population over 60 years of age. It is a degenerative disease of the central nervous system caused by the loss of dopaminergic fibers in basal ganglia of the brain. PD is an important cause of perioperative morbidity and with an increasingly elderly population, it is being encountered with greater frequency in surgical patients. Particular anaesthetic problems in PD include old age, antiparkinsonian drug interaction with anaesthetic drugs and various alterations in the respiratory, cardiovascular, autonomic, and neurological systems. This brief review focuses on the preoperative, intraoperative, and postoperative anesthetic management of PD and gives a brief account of intraoperative exacerbation of PDs and anesthetic management of stereotactic pallidotomy.

General anaesthesia was administered on 284 occasions to 200 patients with sickle-cell disease at one hospital during July 1958 to June 1978. No intraoperative but six postoperative deaths occurred. The management of anaesthesia may have contributed to two of the postoperative deaths. Clinically uneventful anaesthesia did not appear to provoke severe sickling crises or to be responsible for mortality, but a contribution to postoperative morbidity could not be excluded. A simple, careful anaesthetic technique and selective but not routine blood transfusion appears to be associated with minimal anaesthetic morbidity and mortality in patients with sickle-cell disease.

Background:

To review the anaesthetic management and outcome for emergency laparotomy for paediatric intestinal obstruction in the University of Nigeria Teaching Hospital, Enugu, Nigeria.

Methods:

The anaesthetic charts and folders of pediatric patients that had emergency laparotomy for intestinal obstruction in the general operating theatre of the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria, from October 2007 – September 2008 were reviewed. The records were examined for anaesthetic technique, patient primary diagnosis, intra-operative events, blood and fluid therapy and patient outcome. Patients above thirteen years were excluded.

Results:

Forty-four out of 285 (15.7%) paediatric patients underwent emergency laparotomy for intestinal obstruction in the general operating theatre. There were 29 males and 15 females. The average age of the patients was 3.75 years. There were a total of 1674 anesthetics in the general operating theatre during the study. The leading causes of intestinal obstruction in this study were typhoid peritonitis (14 or 31.8%), intussusceptions (14 or 31.8%) and congenital anomalies (11 or 25%). Six patients (13%) had a preoperative packed cell volume of less than 30%, while ten patients received intra-operative blood transfusion (21.7%). There was one anesthetic death to give a case mortality rate of 2.2%.

Conclusion:

The mortality rate in this study shows the importance and relevance of trained providers of anaesthesia managing paediatric patients in the developing world. Early presentation of patients allowed time for resuscitation and fewer complications before surgery.

Four hundred and sixty-nine anaesthetics were given to 27 children between the ages of 18 months and 5 years so that they could receive radiotherapy. When ketamine was used as the sole anaesthetic agent, the induction of anaesthesia was frequently stressful and traumatic, with problems and difficulties being encountered during 24% of anaesthetics. A change to an entirely gaseous method of inducing and maintaining anaesthesia resulted in a much more acceptable service being offered to the children and the incidence of complications fell to only 4%. The problems of monitoring children whilst they receive radiotherapy under general anaesthesia are discussed, the merits of different methods are reviewed and the use of the capnograph is commended.

The duration of impairment of mental functioning after anaesthesia was studied in 55 patients undergoing hernia repair who were divided into three groups in which the method of induction of anaesthesia (intravenous or inhalational) and ventilation (spontaneous or controlled) was varied. Performance in a five minute serial reaction time test and subjective estimates of coordination were assessed four times a day for two complete postoperative days and were compared with those in a control group of orthopaedic patients in hospital. After considerable impairment initially, reaction times in all groups gradually returned towards control values, but in patients breathing spontaneously during anaesthesia impairment recurred during the second postoperative day. These results suggest that such patients should be advised not to undertake hazardous tasks such as driving a car for at least 48 hours after a general anaesthetic. Discrepancies between subjective and objective assessments of impairment also suggest that patients should not rely on their own assessments of fitness to drive.

Background

Four nursing mothers consented to anaesthesia for urgent surgery only on condition that their ability to breast feed would not be impaired.

Methods

Following induction of general anaesthesia with propofol and remifentanil, 65-69% xenon supplemented with remifentanil was used as an inhalational anaesthetic for maintenance.

Results

After finishing surgery the women could be extubated between 2:52 and 7:22 minutes. The women were fully alert just minutes after extubation and spent about 45 minutes in the recovery room before discharge to a regular ward. They resumed regular breast feeding some time later. The propofol concentration in the blood was measured after 0, 30, 90, and 300 minutes and in the milk after 90 and 300 minutes. Just 90 minutes after extubation, the concentration of propofol in the milk was limited (> 3 mg/l) so that pharmacological effects on the babies were excluded after oral intake. Also, no traces of xenon gas were found in the maternal milk at any time. After propofol induction and maintenance of anaesthesia with xenon in combination with a water-soluble short-acting drug like remifentanil, the concentration of propofol in maternal milk is low (> 3 mg/l 90 min after anesthesia) and harmless after oral intake.

Conclusions

These results, as well as the rapid elimination and absence of metabolism of xenon, are of great interest to nursing mothers. General anaesthesia with propofol for induction only, combined with remifentanil and xenon for maintenance, has not yet been described in breast feeding mothers.

Summary

Propofol and isoflurane have well proven roles as intravenous and inhalational anaesthetics respectively in neurosurgery. We conducted this study to know the outcome using butorphanol as an intraoperative analgesic. Sixty craniotomy patients randomly divided into two groups of 30 each were included in this study. Group A patients were induced and maintained with propofol. Group B patients were induced with thiopentone and maintained with isoflurane. All patients were administered 30μg.kg−1 butorphanol intravenously 10 minutes before induction of anaesthesia, followed by slow injection of 30μg.kg−1 midazolam. All were assessed for sedation, respiratory insufficiency, postoperative nausea and vomiting (PONV) and other side effects in the recovery room. We found no difference in demographic parameters between the groups. The fall in HR was maintained in the post induction / intubation period and throughout the intraoperative period in Group A, unlike Group B patients in whom it rose significantly following intubation. Butorphanol was found to be a safe intraoperative analgesic in neurosurgical patients. In addition, it was associated with statistically better haemodynamics and earlier recovery when used with propofol as compared to thiopentone-isoflurane anaesthesia.

Summary

The Centers for Disease Control and Prevention (CDC) reported in 2003 that although the maternal mortality rate has decreased by 99% since 1900, there has been no further decrease in the last two decades1. A more recent report indicates a rate of 11.8 per 100,000 live births2, although anaesthesia-related maternal mortality and morbidity has considerably decreased over the last few decades. Despite the growing complexity of problems and increasing challenges such as pre-existing maternal disease, obesity, and the increasing age of pregnant mothers, anaesthesia related maternal mortality is extremely rare in the developed world. The current safety has been achieved through changes in training, service, technical advances and multidisciplinary approach to care. The rates of general anaesthesia for cesarean delivery have decreased and neuraxial anaesthetics have become the most commonly used techniques. Neuraxial techniques are largely safe and effective, but potential complications, though rare, can be severe.

Pollution of the atmosphere with halothane has been measured during general anaesthesia for outpatients undergoing dental extractions. The level of contamination was far in excess of that recorded in surgical operating theatres, and halothane was inhaled at similar concentrations by both the anaesthetist and the dental surgeon. The room air-changing system and a local fan had little effect on contamination. Scavenging devices on the exhalation valve of the anaesthetic circuit were only moderately effective in reducing the concentration of halothane in the atmosphere.