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.
anaesthetic mechanisms; anaesthetic targets; anaesthetics; ion channels; receptors
General anaesthetics act in an agent-specific manner on synaptic transmission in the central nervous system by enhancing inhibitory transmission and reducing excitatory transmission. The synaptic mechanisms of general anaesthetics involve both presynaptic effects on transmitter release and postsynaptic effects on receptor function. The halogenated volatile anaesthetics inhibit neuronal voltage-gated Na+ channels at clinical concentrations. Reductions in neurotransmitter release by volatile anaesthetics involve inhibition of presynaptic action potentials as a result of Na+ channel blockade. Although voltage-gated ion channels have been assumed to be insensitive to general anaesthetics, it is now evident that clinical concentrations of volatile anaesthetics inhibit Na+ channels in isolated rat nerve terminals and neurons, as well as heterologously expressed mammalian Na+ channel α subunits. Voltage-gated Na+ channels have emerged as promising targets for some of the effects of the inhaled anaesthetics. Knowledge of the synaptic mechanisms of general anaesthetics is essential for optimization of anaesthetic techniques for advanced surgical procedures and for the development of improved anaesthetics.
anaesthetics volatile; anaesthetics volatile, halogenated hydrocarbons; nerve, neurotransmitters; pharmacology, anaesthetic action; pharmacology, neurotransmission
Removal of genital warts by thermocautery was performed in 108 patients (57 men and 51 women) under topical anaesthesia with a local anaesthetic cream, lidocaine and prilocaine (EMLA). Most men had warts in the preputial cavity, most women had warts situated on the mucous membranes of the vulva, and warts at multiple sites were common. About 1 ml of cream per lesion was applied to the warts for 20 to 105 minutes before the operation. Plastic film (Glad, Union Carbide) was applied over the cream when natural occlusion, such as under the prepuce or on the introitus, was not present. Local pallor was seen in 30% of the patients, redness in 53%, and oedema in 15%, but did not cause any discomfort and were clinically insignificant. Analgesia was sufficient in 96% of the men and in 40% of the women. Additional local infiltration was given to 60% of the women, but was not as painful as injections generally are in the genital area. The analgesic efficacy on women may be further improved by optimising the application time on the genital mucosa.
Anaesthesia of structures innervated by the mandibular nerve is necessary to provide adequate pain control when performing dental and localised surgical procedures. To date, numerous techniques have been described and, although many of these methods are not used routinely, there are some situations where their application may be indicated. Patient factors as well as anatomical variability of the mandibular nerve and associated structures dictate that no one technique can be universally applied with a 100% success rate. This fact has led to a proliferation of alternative techniques that have appeared in the literature. This selective review of the literature provides a brief description of the different techniques available to the clinician as well as the underlying anatomy which is fundamental to successfully anaesthetising the mandibular nerve.
Anaesthetic pre-registration house officer posts have been available since 1997. With the change to postgraduate medical training introduced in 2005, these posts have become vital building blocks for Foundation Programmes.
We debate the skills that new Foundation Programme doctors in such posts should be taught, particularly whether administration of an anaesthetic holds an important place. The opinion of college tutors prior to the institution of the foundation programme is included. These were obtained from a postal questionnaire.
We maintain that teaching how to administer an anaesthetic remains an important learning objective and something that should be actively pursued.
Background: All anaesthetists have to handle life threatening crises with little or no warning. However, some cognitive strategies and work practices that are appropriate for speed and efficiency under normal circumstances may become maladaptive in a crisis. It was judged in a previous study that the use of a structured "core" algorithm (based on the mnemonic COVER ABCD–A SWIFT CHECK) would diagnose and correct the problem in 60% of cases and provide a functional diagnosis in virtually all of the remaining 40%. It was recommended that specific sub-algorithms be developed for managing the problems underlying the remaining 40% of crises and assembled in an easy-to-use manual. Sub-algorithms were therefore developed for these problems so that they could be checked for applicability and validity against the first 4000 anaesthesia incidents reported to the Australian Incident Monitoring Study (AIMS).
Methods: The need for 24 specific sub-algorithms was identified. Teams of practising anaesthetists were assembled and sets of incidents relevant to each sub-algorithm were identified from the first 4000 reported to AIMS. Based largely on successful strategies identified in these reports, a set of 24 specific sub-algorithms was developed for trial against the 4000 AIMS reports and assembled into an easy-to-use manual. A process was developed for applying each component of the core algorithm COVER at one of four levels (scan-check-alert/ready-emergency) according to the degree of perceived urgency, and incorporated into the manual. The manual was disseminated at a World Congress and feedback was obtained.
Results: Each of the 24 specific crisis management sub-algorithms was tested against the relevant incidents among the first 4000 reported to AIMS and compared with the actual management by the anaesthetist at the time. It was judged that, if the core algorithm had been correctly applied, the appropriate sub-algorithm would have been resolved better and/or faster in one in eight of all incidents, and would have been unlikely to have caused harm to any patient. The descriptions of the validation of each of the 24 sub-algorithms constitute the remaining 24 papers in this set. Feedback from five meetings each attended by 60–100 anaesthetists was then collated and is included.
Conclusion: The 24 sub-algorithms developed form the basis for developing a rational evidence-based approach to crisis management during anaesthesia. The COVER component has been found to be satisfactory in real life resuscitation situations and the sub-algorithms have been used successfully for several years. It would now be desirable for carefully designed simulator based studies, using naive trainees at the start of their training, to systematically examine the merits and demerits of various aspects of the sub-algorithms. It would seem prudent that these sub-algorithms be regarded, for the moment, as decision aids to support and back up clinicians' natural responses to a crisis when all is not progressing as expected.
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.
Preclinical imaging; Anaesthesia; Physiological monitoring
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.
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.
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.
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.
Bispectral index; closed loop anaesthesia; high altitude; propofol
We report the anaesthetic management of a 48-year-old male patient with Deafness, Onycho-Osteodystrophy and mental Retardation syndrome, epilepsy and cerebral palsy who had two dental procedures under anaesthetic care. For the first short examination sedoanalgesia was employed and the second, longer, procedure was performed under general anaesthesia. His airway management was moderately difficult and the postoperative period was complicated by partial seizures involving the upper extremity and a short period of decreased oxygen saturation. The potential anaesthetic implications of Deafness, Onycho-Osteodystrophy and mental Retardation syndrome are highlighted.
BACKGROUND—Treatment of retinopathy of prematurity (ROP) in the UK is subject to considerable regional variation in terms of anaesthetic support. Change in practice at St Mary's neonatal medical unit from topical to general anaesthesia and, subsequently, to sedation/analgesia allowed comparison of the impact of these three modalities on infants' early postoperative course in a consecutive, non-randomised, observational study.
METHODS—The study population consisted of 30 babies undergoing treatment of threshold ROP. Twelve were treated using topical anaesthesia alone (group A), six using general anaesthesia (group B), and 12 using sedation/analgesia combined with elective intubation and artificial ventilation (group C). Daily measurements of infant health were recorded starting 4 days preoperatively and continuing for 7 days postoperatively to facilitate the formulation of a cardiorespiratory stability index as follows: (0) improvement from baseline, (1) no change from baseline, (2) mild instability, (3) marked instability, and (4) life threatening event.
RESULTS—Within the first 48 hours postoperatively in group A 5/12 showed mild instability and 4/12 showed marked instability (including three babies suffering life threatening events requiring emergency resuscitation). In group B within the first 48 hours postoperatively 1/6 showed mild and 1/6 showed marked instability, and in group C 5/12 babies showed mild instability alone. There was a significant difference for cardiorespiratory stability scores between the three groups overall for the 7 days postoperatively (repeated measures ANOVA, p = 0.018).
CONCLUSIONS—Premature infants undergoing cryotherapy for ROP who were treated using topical anaesthesia alone had more severe and protracted cardiorespiratory complications.
A newborn requires constant vigilance, rapid recognition of the events and swift intervention during anaesthesia. The anaesthetic considerations in neonatal surgical emergencies are based on the physiological immaturity of various body systems, poor tolerance of the anaesthetic drugs, associated congenital disorders and considerations regarding the use of high concentration of oxygen. The main goal is for titration of anaesthetics to desired effects, while carefully monitoring of the cardiorespiratory status. The use of regional anaesthesia has shown to be safe and effective. Advancements in neonatology have resulted in the improvement of the survival of the premature and critically ill newborn babies. Most of the disorders previously considered as neonatal surgical emergencies in the past no longer require immediate surgery due to new technology and new methods of treating sick neonates. This article describes the common neonatal surgical emergencies and focuses on factors that affect the anaesthetic management of patients with these disorders.
Anaesthesia; emergency surgeries; neonate
The biological central pattern generator (CPG) integrates open and closed loop control to produce over-ground walking. The goal of this study was to develop a physiologically based algorithm capable of mimicking the biological system to control multiple joints in the lower extremities for producing over-ground walking. The algorithm used state-based models of the step cycle each of which produced different stimulation patterns. Two configurations were implemented to restore over-ground walking in five adult anaesthetized cats using intramuscular stimulation (IMS) of the main hip, knee and ankle flexor and extensor muscles in the hind limbs. An open loop controller relied only on intrinsic timing while a hybrid-CPG controller added sensory feedback from force plates (representing limb loading), and accelerometers and gyroscopes (representing limb position). Stimulation applied to hind limb muscles caused extension or flexion in the hips, knees and ankles. A total of 113 walking trials were obtained across all experiments. Of these, 74 were successful in which the cats traversed 75% of the 3.5 m over-ground walkway. In these trials, the average peak step length decreased from 24.9 ± 8.4 to 21.8 ± 7.5 (normalized units) and the median number of steps per trial increased from 7 (Q1=6, Q3 = 9) to 9 (8, 11) with the hybrid-CPG controller. Moreover, these trials, the hybrid-CPG controller produced more successful steps (step length ≤ 20 cm; ground reaction force ≥ 12.5% body weight) than the open loop controller: 372 of 544 steps (68%) versus 65 of 134 steps (49%), respectively. This supports our previous preliminary findings, and affirms that physiologically based hybrid-CPG approaches produce more successful stepping than open loop controllers. The algorithm provides the foundation for a neural prosthetic controller and a framework to implement more detailed control of locomotion in the future.
The occupational exposure of hospital staff to inhaled anaesthetics was investigated using a personal sampling device that provides a measure of the average concentrations breathed by a person over a period of time, as distinct from the spot sampling in the general environment. The anaesthetist's average exposure to nitrous oxide and halothane during complete operating sessions was twice that expected from simple dilution of the escaping gases by the operating room ventilation. The sampling technique was also used to evaluate the effect of (1) redirection of the waste gas outflow; (2) active scavenging connected to the piped vacuum system. Short-period studies under controlled conditions in the operating theatres and anaesthesia induction rooms showed that the anaesthetist's exposure could be reduced two- or fourfold by redirecting the outflow and another four- to sixfold by active scavenging. Exposures during complete operating sessions were reduced two- to seven-fold by scavenging.
In this article we present the surgical activity of the Burns Service in the University Hospital Centre in Tirana. Not only burn patients but also patients with trauma and soft tissue losses are hospitalized in a burns centre, as well as patients needing plastic surgery coming from similar specialities. In 2006, 1127 patients were subjected to surgery in our service. The techniques of anaesthesia used are general anaesthesia (endotracheal tube, laryngeal mask airway, intravenous) and regional anaesthesia. An anaesthesiologist acting in the role of physician manager can add significant value to the overall operating room process by improving efficiency in resource utilization and simultaneously quality of care. We have found that giving priority to burns, including burns sequelae and other hospitalized burn patients, if possible in day surgery, can optimize the bed occupancy rate.
SPREAD; BURN; NON-BURN; PATHOLOGIES; ANAESTHETIC; SUPPORT; MANAGEMENT; DATA
There is high incidence of venous thromboembolism, comprising of deep vein thrombosis and pulmonary embolism, in hospitalized patients. The need for systemic thromboprophylaxis is essential, especially in patients with inherited or acquired patient-specific risk factors or in patients undergoing surgeries associated with high incidence of postoperative deep vein thrombosis and pulmonary embolism. These patients, on prophylactic or therapeutic doses of anticoagulants, may present for surgery. General or regional anaesthesia may be considered depending on the type and urgency of surgery and degree of anticoagulation as judged by investigations. The dilemma regarding the type of anaesthesia can be solved if the anaesthesiologist is aware of the pharmacokinetics of drugs affecting haemostasis. The anaesthesiologist must keep abreast with the latest developments of methods and drugs used in the prevention and management of venous thromboembolism and their implications in the conduct of anaesthesia.
Anaesthetic considerations; deep vein thrombosis; pulmonary embolism; thromboprophylaxis; venous thromboembolism
Multiple sclerosis (MS) is a rare autoimmune demyelinating disorder of the central nervous system clinically manifesting as periodic attacks of varied neurologic symptoms, eventually progressing to fixed neurologic deficits and disability. The treatment is symptomatic and directed towards prevention of future progression of the disease involving multiple agents. We present here a case report of a patient with MS who underwent an orthopaedic procedure under general anaesthesia (G.A.) uneventfully. Anaesthetic implications include assessment of neurological deficits with documentation pre- and postoperatively, awareness towards side-effects, potential drug interactions of medications, selection of suitable techniques/anaesthetic agents, neuromuscular monitoring-guided titration of non-depolarizing blocking agents with lowest necessary dose and avoidance of hyperthermia along with temperature, haemodynamic and respiratory monitoring. Lower concentrations of local anaesthetic (LA) should be used for regional blocks keeping in mind the susceptibility of demyelinated neurons, towards LA neurotoxicity. To the best of our knowledge, this is the first report of anaesthetic management of MS in India.
Anaesthetic; demyelination; multiple sclerosis
The molecular mechanisms of general anaesthetics have remained largely obscure since their introduction into clinical practice just over 150 years ago. This review describes the actions of general anaesthetics on mammalian neurotransmitter-gated ion channels. As a result of research during the last several decades, ligand-gated ion channels have emerged as promising molecular targets for the central nervous system effects of general anaesthetics. The last 10 years have witnessed an explosion of studies of anaesthetic modulation of recombinant ligand-gated ion channels, including recent studies which utilize chimeric and mutated receptors to identify regions of ligand-gated ion channels important for the actions of general anaesthetics. Exciting future directions include structural biology and gene-targeting approaches to further the understanding of general anaesthetic molecular mechanisms.
General anaesthesia; ligand-gated ion channels; GABA; glutamine; acetylcholine; glycine; serotonin; electrophysiology
Although most general anaesthesia procedures are performed without any complications, volatile agents may have adverse effects on various living systems. This study aims to compare the antioxidant effects of isoflurane and N-acetylcysteine (NAC) on liver function.
Forty-one patients in the ASA I-II risk groups, who were scheduled to undergo gynaecologic laparoscopy, were randomly divided into two groups: The placebo (group P, n=21) and the NAC group (group N, n=20). In both groups, anaesthesia was maintained with 1–2% isoflurane in 50% Oxygen–50% N2O at 6 l/min, also administered by inhalation. Venous blood samples were obtained before anaesthesia induction, and then in the postoperative 1st hour and at the 24th hour. The samples were centrifuged and serum levels of glutathione S-transferase (GST), malondialdehyde (MDA), aspartate amino transferase (AST), alanine amino transferase (ALT), lactate dehydrogenase (LDH), gamma glutamyltranspeptidase (GGT), prothrombin time (PT), activated partial thromboplastin time (aPTT) and international normalised ratio were determined.
GST levels were significantly higher in group N than in group P in the postoperative 1st hour. Postoperative values of GST in the two groups were higher when compared to preoperative values (P<0.05). When postoperative levels were compared with preoperative levels, the postoperative MDA levels of group N were significantly higher (P<0.05). Levels of AST, ALT, GGT and LDH in both groups revealed significant decreases at the postoperative 1st hour and postoperative 24th hour compared to preoperative values (P<0.05, P<0.001). PT values were significantly higher in both groups in the postoperative 1st hour and 24th hour (P<0.05, P<0.001), although there were no differences in aPTT levels.
Our results showed that liver functions were well preserved with administration of NAC during anaesthesia with isoflurane. Isoflurane with NAC has lesser effect on liver function tests compared to isoflurane alone.
Isoflurane; liver function tests; N-acetylcysteine
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.
ketamine; anaesthetics; intraocular surgery; resuscitation; children
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.
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.
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.
Propofol; Isoflurane anaesthesia; spine surgery
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.
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.
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.
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.
Data were analyzed with comprehensive Meta-analysis Version 2.2.044.
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%).
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.
Meta-analysis; post-operative cognitive dysfunction; regional anaesthesia
We aimed to investigate the effects on post-operative pain of local anaesthetic administration via a catheter placed into the operation site in patients who were undergoing upper and lower extremity paediatric orthopaedic surgery.
In this randomised, double-blind and placebo study, 40 ASA I–II patients aged between 1 and 12 years were randomly allocated into two groups: study group (Group S: 0.2 ml/kg, 0.5% bupivacaine, n = 20) and control group (Group C: 0.2 ml/kg, serum physiologic, n = 20). Before the fascia was closed by the surgical team, the solution previously prepared by the chief nurse was injected into the subfascial soft tissue with the syringe as the “injected dose” of serum physiologic or bupivacaine. After the closure, 0.2 ml/kg (1 mg/kg) bupivacaine or saline was instillated as the “first instillated dose” into the surgical area via the catheter. Pain scores were recorded at 0, 1, 2, 4, 8, 12, 24 and 48 h post-operatively. Patients were administered 0.75 mg/kg meperidine intramuscularly post-operatively to equalise the pain scores.
No statistically significant difference was found between Group S and Group C in terms of demographic and other data and pain scores in the post-anaesthesia care unit, while a statistically significant decrease was found at 2, 4, 8, 12, 24 and 48 h in Group S and at 1, 2 and 4 h in Group C based on pain scores in the post-anaesthesia care unit (P < 0.05). A statistically significant decreasing pain score was found at 4, 8, 12, 24 and 48 h in Group S (P < 0.05).
The local anaesthetic administered via a catheter implanted in the surgical field may provide long-term and efficient post-operative analgesia.
Post-operative pain; Paediatric; Local anaesthetic
This study compared the odds ratio (OR) of surgical site infection (SSI) within 30 days after operation with general anaesthesia (GA) or neuraxial anaesthesia (NA) in Taiwanese women undergoing Caesarean delivery (CD).
An epidemiologic design was used. The study population was based on the records of all deliveries in hospitals or obstetric clinics between January 2002 and December 2006 in Taiwan. Anonymized claim data from the Taiwan National Health Insurance Research Database (NHIRD) were analysed. Women who received CD were identified from the NHIRD by Diagnosis-Related Group codes. The mode of anaesthesia was defined by order codes. Multivariate logistic regression was used to estimate the OR and associated 95% confidence interval (CI) of post-CD SSIs for GA when compared with NA. The outcome was whether a woman had been diagnosed as having an SSI during the hospitalization or was re-hospitalized within 30 days after CD for the treatment of SSIs using five or 81 International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes.
Among the 303 834 Taiwanese women who underwent CD during the 5 yr observation period, the 30 day post-CD SSI rate was 0.3% or 0.9% based on five or 81 ICD-9-CM codes. The multivariate-adjusted OR of having post-CD SSIs in the GA group was 3.73 (95% CI, 3.07–4.53) compared with the NA group (P<0.001) using five ICD-9-CM codes for the definition of SSI.
GA for CD was associated with a higher risk of SSI when compared with neuraxial anaesthesia.
anaesthesia; Caesarean section; general anaesthesia; neuraxial anaesthesia; surgical site infection
Anaesthetic care during thoracic surgical procedures in children combines components of the knowledge bases of paediatric anaesthesia with those of thoracic anaesthesia. This article highlights the principles of anaesthesia during thoracoscopic surgery in children including preoperative evaluation, anaesthetic induction techniques, maintenance anaesthesia and options for postoperative analgesia. In addition, given the need to provide optimal surgical visualization during the procedure, one lung ventilation may be required. Techniques to provide one lung ventilation in the paediatric patient and the principles of anaesthesia care during one lung ventilation are discussed.
Thoracoscopy; anaesthesia; paeditaric