Paediatric anaesthesia: past, present and future

Twenty years ago, much of paediatric anaesthesia was delivered by anaesthetists with an enormous experience accumulated during training and practice that involved a prodigious number of hours of direct clinical care. This experience was vital as monitoring was rudimentary and much of it involved subjective assessment of the patient's condition; the feel of the bag by the ‘educated hand’, the quality of the heart and breath sounds through the precordial stethoscope and the pulse volume felt through the continuously palpated pulse. Most consultant anaesthetists were happy to manage small infants. The National Confidential Enquiry into Peri-Operative Deaths (NCEPOD) of 1989 [1], the Children's National Service Framework [2], changes in doctor's hours of work and technological advances have ensured that the situation changed completely and irrevocably in the last decade. The challenge, for the next 10 years, is to ensure that children requiring surgery and investigations receive safe, high quality, family friendly anaesthesia and that those who deliver it have rewarding and manageable working lives. In 1989 in the UK, 86% of consultant anaesthetists treated infants less than 6 months of age. Most of these consultants were well trained and had a continuing involvement in the anaesthesia of infants and children, but some only occasionally encountered children, usually for emergency surgery out of hours, and some of this care was of unacceptably poor quality. The NCEPOD report of that year identified unnecessary anaesthesia-related mortality and morbidity in children less than 10 years old and suggested ‘Surgeons and anaesthetists should not undertake occasional paediatric practice. The outcome of surgery and anaesthesia in children is related to the experience of the clinicians involved.” A lively debate ensued and has continued over the last decade, over what constitutes occasional paediatric practice. In an article in 1992, Lunn, one of the authors of the report, suggested that it was necessary to anaesthetise 300 children less than 10 years old, 50 less than 3 years old and 12 less than 6 months old per year to maintain expertise [3]. These figures were never intended to be an official limit, nor were they adopted by any organisation but, in the prevailing defensive culture, they became the unofficial guide to the term ‘occasional’. The effect of this was not only to limit occasional practice; it also resulted in a large number of individuals who were experienced in the anaesthesia of children, particularly infants, dropping this part of their work. In 1999, only 42% of consultants anaesthetised infants less than 6 months old [4]. The consequent reorganisation of service provision for paediatric anaesthesia has been far reaching. There has been a reduction in anaesthesia-related mortality and morbidity but also discontent amongst those whose work patterns have been disrupted. The Royal College of Anaesthetist bulletin ‘Guidance on the provision of paediatric anaesthetic services’ provides a summary and a sensible perspective on the issue, reaching a good balance between ideal and achievable [5]. There have been some major changes in the drugs and techniques of paediatric anaesthesia over the last decade. The most notable of these and, probably, the major contributor to the reductions in mortality and morbidity, has been the universal adoption of comprehensive monitoring. From the NCEPOD reports of 1989 and 1999 the use of pulse oximetry increased from 64% to 100%, CO2 monitoring from 17% to 95%, and non-invasive blood pressure from 46% to 73%. Furthermore, in 1989 only 17% of children had oxygen saturation monitoring in recovery; it is likely that a current survey would reveal that all children were appropriately monitored both during and after anaesthesia. An area that has changed fundamentally is the approach to pain relief. The driving factors for this have been the realisation that even newly born infants fully experience pain, together with technical advances that have allowed the safe application of advanced analgesic techniques such as central conduction blocks and microprocessor controlled infusions. These advances have been facilitated by the development of specialist paediatric acute pain control teams, which have provided the organisational structure required to oversee and safely monitor the techniques. Many uncomfortable procedures in children used to be performed using a combination of sedation and restraint. There has been a major cultural change away from the use of any restraint and this, together with the increased safety of anaesthesia, has resulted in a large increase in the demand for general anaesthesia for minor procedures such as lumbar puncture and endoscopy. Much of this work may be performed in locations remote from the operating theatre and the safe management of this extra workload represents a considerable challenge for the future. The most notable change in drug administration has been the decline in the use of halothane, which used to be the pre-eminent inhalational agent, to the point where its use in most centres is confined to anaesthesia for complex airway cases such as microlaryngoscopy in infants. The introduction of sevoflurane has provided an equally satisfactory agent for gaseous induction with fewer concerns over myocardial irritability and hepatic toxicity. Furthermore, the adoption of circle systems with carbon dioxide absorption has ameliorated the potential cost increases associated with the use of the more recently introduced agents. It is likely that, as anaesthetists will have been increasingly trained in the posthalothane era, halothane's use will eventually be confined to areas, such as the developing world, where low cost is a dominant factor. The use of succinylcholine has also declined to the point in which it is largely confined to emergency airway management, such as in rapid sequence intubation or the management of post extubation laryngeal spasm. The widespread use of the laryngeal mask airway for airway management in the spontaneously breathing child has largely removed the need for a short-acting relaxant to provide good conditions for tracheal intubation. When a short period of airway reflex suppression is necessary, such as in some of the techniques employed for ENT surgical procedures, succinylcholine is increasingly avoided by the use of mivacurium, propofol or ultra-short acting narcotics. Paediatric anaesthetists have taken a lead role in some important improvements to peri-operative and intensive care; a good example of this is training in paediatric resuscitation. Courses in this subject started in Europe in 1992, they are now widely available and since their inception there has been a considerable improvement in knowledge about the management of the acutely ill child. In the UK, there has been a 16% reduction in trauma mortality in children in the last decade primarily due to improved hospital care [6]. Peri-operative fluid therapy has been strongly influenced by an increased awareness that postoperative hyponatraemia is a more common and dangerous problem than previously appreciated. Fluid management has consequently evolved away from the use of dextrose containing fluids toward balanced salt solutions. This trend has been augmented by the frequent use of bedside blood glucose measurement, which reveals that hypoglycaemia is a rare finding rather than a universal occurrence. The advances in paediatric anaesthesia over the last 10 years have ensured that safety has improved considerably and, although it would be foolish to be complacent on this issue, the focus over the next 10 years will shift towards the quality of the experience for the child. A large proportion of surgery is now conducted as day care and this trend will continue as far as possible. Peri-operative anxiety and postoperative pain relief, and nausea and vomiting are clearly areas where improvements are still possible. It has become widely accepted that parents should be present during their child's anaesthetic induction, it is going to be just as important to get children and their parents involved in helping us understand what will make their experience of hospital care as pleasant as possible. A number of changes over the next 10 years will be driven by the reduction in hours of work and training which are occurring all over the world, partly due to changes in working culture, with increased emphasis on leisure time, and partly due to legislative initiatives such as the European Working Time Directive. The reduction in the duration of training and experience that results from these changes is accompanied by increased demands for quality from the patients and their parents. At first sight these two requirements seem to be incompatible but the apparent conflict can and should be resolved by a combination of properly structured training programmes and the pertinent use of technological support. In a similar way that the ‘educated hand’ has been supplemented by measurement of pressure volume loops and respiratory volumes, clinical experience can be enhanced by supportive technology. An example of this is the use of ultrasound guidance in invasive procedures. A large amount of experience is required to reliably and safely place central venous access in small children using landmark techniques but, used properly, an ultrasound probe can help to improve the accuracy of placement in many circumstances. Similar considerations apply to peripheral nerve blocks and other invasive techniques. Another example of this principle is the use of point of care testing, which is particularly relevant in paediatric practice due to the rapid rates of change in many parameters. It is already possible to perform most haematological and biochemical tests at the bedside but the use of these is not yet universal. Decision-making in the transfusion of blood products is a good illustration of this application. Reduction in availability and concerns over the infection transmission will require that they should only be administered when absolutely necessary. Readily available bedside measurement of haemoglobin levels and coagulation parameters will help to inform their use. One way of predicting developments in paediatric anaesthesia is by looking at developments in adult anaesthesia over the preceding period as techniques and agents tend to be introduced in adults and passed on to paediatric practice when they are established. The most obvious example of this type at the moment is Total Intravenous Anaesthesia (TIVA) and Target Controlled Infusions (TCI). These are both fully established techniques in adult anaesthesia but only used occasionally in children. It is clear that this is an area of potential development; once a paediatric pharmacokinetic algorithm for propofol has been elucidated and fully validated this is likely to become a far more commonly used technique. Its full acceptance in children, however, will probably also require a reliable ‘depth of anaesthesia’ monitor. Drug developments over the next decade will continue to be blighted by the reluctance of the pharmaceutical industry to fully test new drugs in children. It is probable that the only way of ensuring that children are given equal priority to adults in this area is to have enforcing legislation. The most welcome additions to the paediatric anaesthetic pharmacopoeia would be an odourless inhalational induction agent, a safe, predictable and effective oral sedative, and an efficacious intravenous non-opiate analgesic. The last of these is the only one likely to be available in the next decade. The requirement for sedation or short duration anaesthesia is, as mentioned earlier, growing rapidly. It is increasingly required for any uncomfortable procedure or anything where immobility is required. This demand is unlikely to be met in the near future by the development of a perfect sedative agent or combination of agents. The probable way forward in the short term is through organisational changes to the way such care is delivered; such as the development of dedicated units employing anaesthetist supervised nurse-led sedation teams. In the area of pain control, there is still scope for continued refinement of current techniques and practices. It is probable that there will be increased adoption of local anaesthetic agents with more favourable safety profiles and longer-acting local anaesthetic agents, such as lyposomal preparations, are likely to be introduced. The biggest developments in the practice of paediatric pain control, however, are expected to be in the field of chronic pain management, which is still in the early stages of evolution, as is our understanding of the long-term neurobehavioural consequences of pain and its treatment in infancy [7]. Finally, in keeping with the remit of the journal, the focus of this article has been on practice in the UK and developed world. By far the biggest contribution paediatric anaesthetists can make to global child health in the next 10 years, however, is by supporting initiatives intended to provide safe peri-operative care to children in the developing world.