Propofol anaesthesia reduces early post-operative emesis after paediatric strabismus surgery

Propofol anaesthesia may reduce postoperative emesis. The purpose of this study was to compare the incidence of emesis after propofol anaesthesia with and without nitrous oxide, compared with thiopentone and halothane anaesthesia, in hospital and up to 24 hr postoperatively, in outpatient paediatric patients after strabismus surgery. Seventy-five ASA class I or II, unpremedicated patients, aged 2–12 yr were randomly assigned to one of three groups: Thiopentone, 6.0 mg · kg^{? 1} iv induction followed by halothane and N₂O/O₂ for maintenance (T/H); propofol for induction, followed by propofol and oxygen for maintenance (P/O₂); and propofol for iv induction, followed by propofol infusion and N₂O/O₂ for maintenance (P/N₂O). All received vecuronium, controlled ventilation, and acetaminophen pr. Morphine was given as needed for postoperative analgesia. There were no differences in age, weight, number of eye muscles operated upon, duration of anaesthesia or surgery. The P/N₂O group (255 ± 80 μg· kg^{? 1}· min^{? 1}) received less propofol than the P/O₂ group (344 ± 60 μg · kg^{? 1}· min^{? 1}) (P ≤ 0.0001) and had shorter extubation (P < 0.001) and recovery (P < 0.01) times. Emesis in the hospital, in both the P/N₂O (4.0%) and P/O₂ group (4.0%) was less than in the T/H group (32%) (P < 0.01). Antiemetics were required in four patients in the T/H group (16.0%). Overall emesis after surgery was not different among the groups: T/H (48%), P/O₂ (28%) and P/N₂O (42%). The use of propofol anaesthesia with and without N₂O decreased only early emesis. This supports the concept of a short-acting, specific antiemetic effect of propofol.     

Intrapleural analgesia in a child with a mediastinal tumour

A case is presented of an eight-year-old child with a mediastinal tumour, who had developed acute renal failure following the institution of steroid therapy. Intrapleural analgesia was successfully used for the insertion of a peritoneal dialysis catheter so that the considerable risks of general anaesthesia were avoided. Subsequent dialysis allowed chemotherapy to commence and, as a result of the shrinkage in tumour size, general anaesthesia was administered safely two days later. The purpose of this report is to highlight the use of intrapleural analgesia in children as an alternative to general anaesthesia, when the latter is contraindicated. The mechanism of action of intra-pleural analgesia and the risks of anaesthesia in the presence of a mediastinal tumour are discussed.     

Monitoring during paediatric cardiac anaesthesia

Monitoring of paediatric anaesthesia has become increasingly more complex in recent years and this is particulary true of cardiac anaesthesia. The purpose of this review is to give a comprehensive update of published material related to both routine and specialized cardiac monitoring. Routine monitoring can be particularly affected by the alterations of cardiac rhythm, blood flow, cardiac output and oxygenation which result from the congenital heart abnormalities themselves, the type of surgery undertaken and the effects of cardiopulmonary bypass. The use of specialized monitoring is becoming more widespread, particularly in the areas of cerebral function, mixed venous oxygenation, cardiac output measurement and coagulation. In the last five years, with the development of smaller probes, a great deal has been published on transoesophageal echocardiography. The use of the current monitors of cerebral function still remains controversial despite the need for a monitor of adequate brain perfusion, reflecting the need for a great deal of further research in this area. This review will concentrate on particular areas which have seen the most profound changes and on monitoring that may form the standards of tomorrow. Finally, amongst all the technology, it should not be forgotten that the most important clinical monitor is the bedside clinical monitoring of the physicians themselves. Depuis quelques années, le monitorage de l’anesthésie pédiatrique devient déplus en plus complexe et tout particulièrement en anesthésie cardiaque. L’objectif de ce travail consiste à passer en revue la littérature actuelle qui traite du monitorage usuel et spécialisé. Le monitorage usuel peut être influencé par les modifications de la fréquence cardiaque, du courant sanguin, du débit cardiaque et de l’oxygénation provoqués par les anomalies cardiaques congénitales, du type de chirurgie et des retentissements de la circulation extracorporelle. L’utilisation du monitorage spécialisé est de plus en plus répandu et concerne particulièrement la circulation cérébrale, l’oxygénation du sang veineux mêlé, la mesure du débit cardiaque et la coagulation. Au cours des cinq dernières années, le développement de sondes plus petites a généré de nombreuses publications sur l’échocardiographie transoesophagienne. L’utilisation des moniteurs actuels de la fonction cérébrale demeure sujet à controverse bien qu ’un moniteur de perfusion cérébrale adéquat demeure toujours aussi essentiel, confirmant ainsi le besoin de recherches supplémentaires sur ce sujet. Ce survol se portera spécialement sur les champs d’activités qui ont connu les changements les plus profonds et sur le monitorage qui établira les standards du futur. Finalement, au milieu de cette technologie, il ne faut jamais oublier que le moniteur clinique le plus important se trouve au chevet du malade en la personne du médecin.     

Cerebral arteriovenous malformations in children

The treatment of cerebral arteriovenous malformations (AVM) or vascular anomalies are challenging neurosurgical procedures for an anaesthetist. Large AVMs are uncommon in children. Only 18% of AVMs become symptomatic before the age of 15 yr. This series reviews the experience at this institution during the period of 1982 to 1992. The symptoms at the time of presentation are varied and include haemorrhage (50%), seizures and hydrocephalus (36%) or congestive cardiac failure (18%). Symptoms of congestive heart failure predominate in the new-born whilst neurological symptoms, such as stroke, seizures or hydrocephalus occur more commonly in infants and older children. Approximately one third of AVMs in childhood present acutely. Radiological investigations, e.g., CT scan, MRI and cerebral angiography are essential to identify the precise location of the lesion. Therapeutic intervention in the acute presentation may involve craniotomy for evacuation of haematoma and treatment of increased intracranial pressure (ICP). Control of seizures and congestive heart failure may take priority and allow time to plan the elective procedures of embolization and surgical excision of the AVM. Operative intervention is hazardous and peroperative complications can be expected in more than 50% of patients. The morbidity and mortality associated with cerebral AVM are high, especially in infants who present in the neonatal period with congestive cardiac failure. The overall mortality in this series was 20%. Children presenting with intracranial arteriovenous malformations require a multidisciplinary approach. The successful management of anaesthesia either for embolization or surgical resection necessitates an understanding of the disciplines of paediatric and neuroanaesthesia. Special care and specific attention to detail may contribute to reduce the high morbidity and mortality encountered in these compromised children.     

Mivacurium-induced neuromuscular blockade during sevoflurane and halothane anaesthesia in children

The neuromuscular blocking effects of mivacurium during sevoflurane or halothane anaesthesia was studied in 38 paediatric patients aged 1–12 yr. All received premedication with midazolam, 0.5 mg · kg⁻¹ po and an inhalational induction with up to 3 MAC of either agent in 70% N₂O and O₂. The ulnar nerve was stimulated at the wrist by a train-of-four stimulus every ten seconds and the force of adduction of the thumb recorded with a Myotrace force transducer. Anaesthesia was maintained with a one MAC end-tidal equivalent of either volatile agent for five minutes before patients received mivacurium (0.2 mg · kg⁻¹) iv. The onset of maximal blockade occurred in 2.4 ± 1.26 (mean ± SD) min with halothane and 1.8 ± 0.54 min with sevoflurane (NS). Four patients failed to achieve 100% block (3 halothane, 1 sevoflurane). The times from injection to 5, 75, and 95% recovery during sevoflurane (9.8 ± 2.6, 19.5 ± 4.4, and 24.2 ± 4.8 min) were greater than during halothane anaesthesia (7.2 ± 2.2, 15.0 ± 4.0, 19.2 ± 4.9 min, respectively (P < 0.005). All patients demonstrated complete spontaneous recovery of neuromuscular function (T₁ > 95%, T₄/T₁ > 75%) during the surgery which lasted 24–63 min. All patients showed clinical signs of full recovery of neuromuscular blockade (i.e., headlift, gag, or cough). Pharmacological reversal was not required. It is concluded that following a single intubating dose of mivacurium, the time to maximum relaxation was not different during halothane and sevoflurane anaesthesia; recovery times to 5, 75 and 95% twitch height were longer during sevoflurane anaesthesia and neuromuscular reversal was not necessary. L’activité neurobloquante du mivacurium pendant l’anesthésie au sévoflurane ou à l’halothane fait l’objet de cette étude réalisée chez 38 enfants de 1 à 12 ans. Tous ont été prémédiqués au midazolam 0,5 mg · kg⁻¹ et l’anesthésie est induite avec un agent volatil jusqu’à MAC 3 de l’un des agents dans du N₂O à 70%. Le nerf cubital était stimulé au poignet au train de quatre aux dix seconds et la force de l’adduction du pouce mesurée avec un transducteur de force Myotrace. L’anesthésie était entretenue avec l’équivalent MAC I d’un des deux agents volatils pendant cinq minutes avant l’administration de mivacurium (0,2 mg · kg⁻¹). Le début du bloc maximum est survenu dans 2,4 ± 1,26 (moyenne ± SD) min avec l’halothane et 1,8 ± 0,54 min avec le sévoflurane (NS). Quatre patients n’ont pas été bloqués à 100% (trois avec l’halothane, un avec le sévoflurane). L’intervalle séparant l’injection à 5; 75, et 95% de la récupération pendant l’anesthésie au sévoflurane (9,8 ± 2,6, 19,5 ± 4,4 et 24,2 ± 4,8 min) a été plus long que pendant l’anesthésie à l’halothane (7,2 ± 2,2, 15,0 ± 4,0, 19,2 ± 4,9 min, respectivement (P < 0,005). An moniteur, chez tous les patients, la fonction neuromusculaire a récupéré spontanément (T₁ > 95%, T₄/T₁ > 75%) au cours de la chirurgie qui a duré de 24–63 min. Tous les patients montraient aussi les signes cliniques d’une récupération complète (par ex., levée de la tête, réflexe pharyngé ou toux). Aucun antagoniste pharmacologique n’a été requis. Il est conclu que le délai jusqu’à la relaxation maximum après une seule dose d’intubation de mivacurium ne diffère pas entre l’anesthésie à l’halothane et l’anesthésie au sévoflurane; les délais de retour à 5, 75 et 95% de la hauteur du twitch sont plus longs pendant l’anesthésie au sévoflurane et il n’est pas nécessaire d’antagoniser le bloc neuromusculaire.

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Supported in part by a grant from Abbott Laboratories, Chicago, Illinois.     

Oral ondansetron decreases vomiting after tonsillectomy in children

Vomiting is a common, unpleasant aftermath of tonsillectomy in children. Intraoperative intravenous ondansetron (OND) reduces vomiting after this operation. Our doubleblind, placebocontrolled, randomized investigation studied the effect of the oral form of OND on vomiting after outpatient tonsillectomy in children. We studied 233 healthy children age 2–14 yr undergoing elective tonsillectomy. Subjects were given placebo (PLAC) or OND 0.1 mg · kg^?1 rounded off to the nearest 2 mg one hr before surgery. Anaesthesia was induced with either propofol or halothane/N₂O. Vecuronium 0.1 mg · kg^?1 was administered at the discretion of the anaesthetist. Anaesthesia was maintained with halothane/N₂O, 50 μg · kg^?1 midazolam iv and 1–1.5 mg · kg^?1 codeine im. At the end of surgery, residual neuromuscular blockade was reversed with neostigmine and atropine. All episodes of inhospital emesis were recorded by nursing staff. Rescue antiemetics in the hospital were 1 mg · kg^?1 dimenhydrinate ivfor vomiting × 2 and 50 μg · kg^?1 droperidol iv for vomiting × 4. Parents kept a diary of emesis after discharge. Postoperative pain was treated with morphine, codeine and/or acetaminophen. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. Oral OND (n = 109) reduced postoperative emesis from 54% to 39%, P < 0.05. This effect was most dramatic inhospital, where 10% of the OND-patients and 30% of the PLAC-group vomited, P < 0.05. The OND-subjects required fewer rescue antiemetics, 7% vs 17%, P < 0.05. In conclusion, oral ondansetron decreased the incidence of vomiting after outpatient tonsillectomy in children.     

Anaesthetic management of a child with Bartter’s syndrome

We report the anaesthetic management of an eight-year-old asthmatic boy with Bartter’s syndrome who had bilateral orchidopexy with caudal epidural analgesia. Bartter’s syndrome is a rare congenital disorder characterized by hypokalaemic hypochloraemic metabolic alkalosis, hyperaldosteronism, hyperreninaemia and hyperplasia of the juxtaglomerular apparatus of the kidneys. Characteristically, although these patients are normotensive they may be hypovolaemic. They may have unstable baroreceptor responses and show marked resistance to vasopressors. Hence, fluid, acid-base and electrolyte imbalances along with haemodynamic instability pose particular problems in their anaesthetic management. Previous case reports have described the management of these patients with general anaesthesia, our patient had his orchidopexy with caudal epidural analgesia using plain bupivacaine 0.5%. The patient was haemodynamically stable throughout surgery and was comfortable with caudal analgesia as the sole anaesthetic. Hypovalaemia, acid-base status and electrolyte imbalance were treated before instituting caudal epidural analgesia. We present this case report which describes the anaesthetic considerations in the light of the pathophysiology of Bartter’s syndrome.     

“Do You Have a Healthy Smile?”

This article examines whether cosmetic interventions by dentists and plastic surgeons are medically indicated and, hence, qualify as medical interventions proper. Cosmetic interventions (and the business strategies used to market them) are often frowned upon by dentists and physicians. However, if those interventions do not qualify as medical interventions proper, they should not be evaluated using medical-ethical norms. On the other hand, if they are to be considered medical practice proper, the medical-ethical principles of nonmaleficence, beneficence, justice and others hold true for cosmetic interventions as much as they do for other medical and dental interventions. It is concluded that most cosmetic interventions do not qualify as medical interventions proper because they do not restore or maintain the patient's health (defined as the patient's integrity) by any objective standards. Rather, cosmetic interventions are intended to enhance a person's physical appearance; more specifically, they intend to fulfill the client's subjective perception of an enhanced appearance. This revised version was published online in July 2006 with corrections to the Cover Date.     

Developing rational protocols for paediatric psychopharmacological prescribing.

The number of child psychiatrists, paediatricians and general practitioners prescribing psychotropic medication for children in the UK is increasing. Medication is being used not just to treat children of normal intelligence with hyperkinetic disorder or depression, but also to modify behavioural problems in children with developmental disorders and severe learning difficulties. Literature reviews highlight the lack of robust randomized controlled drug trials on which to base clinical practice and the authors have found no appropriate existing protocols to help develop a systematized approach. Against such a background the authors have developed a comprehensive set of protocols covering prescribing details for individual drugs, and also addressing issues such as informed consent, long-term monitoring and school liaison. All children referred to the authors' clinics go through a standardized decision-making process. This article describes both the protocols themselves and the philosophies that guided their development. The authors describe how such a system benefits the children, their families, general practitioners and schools, whilst also facilitating audit and research.