Recovery after halothane anaesthesia induced with thiopental, propofol-alfentanil or halothane for day-case adenoidectomy in small children

Barbiturate Induction for the Prevention of Emergence Agitation after Pediatric Sevoflurane Anesthesia

OBJECTIVES

Emergence agitation (EA) is a common and troublesome problem in pediatric patients recovering from general anesthesia. The incidence of EA is reportedly higher after general anesthesia maintained with sevoflurane, a popular inhalational anesthetic agent for pediatric patients. We conducted this prospective, randomized, double-blind study to test the effect of an intravenous ultra-short-acting barbiturate, thiamylal, administered during induction of general anesthesia on the incidence and severity of EA in pediatric patients recovering from Sevoflurane anesthesia.

METHODS

Fifty-four pediatric patients (1 to 6 years of age) undergoing subumbilical surgeries were randomized into 2 groups. Patients received either intravenous thiamylal 5mg/kg (Group T) or inhalational Sevoflurane 5% (Group S) as an anesthetic induction agent. Following induction, general anesthesia was maintained with Sevoflurane and nitrous oxide (N2O) in both groups. To control the intra- and post-operative pain, caudal block or ilioinguinal/iliohypogastric block was performed. The incidence and severity of EA were evaluated by using the Modified Objective Pain Scale (MOPS: 0 to 6) at 15 and 30 min after arrival in the post-anesthesia care unit (PACU).

RESULTS

Fifteen minutes after arrival in the PACU, the incidence of EA in Group T (28%) was significantly lower than in Group S (64%; p = 0.023) and the MOPS in Group T (median 0, range 0 to 6) was significantly lower than in Group S (median 4, range 0 to 6; p = 0.005). The interval from discontinuation of Sevoflurane to emergence from anesthesia was not significantly different between the 2 groups.

CONCLUSIONS

Thiamylal induction reduced the incidence and severity of EA in pediatric patients immediately after Sevoflurane anesthesia.

Preoperative anxiety management, emergence delirium, and postoperative behavior

Preoperative anxiolysis is important for children scheduled for surgery. The nature of the anxiety depends on several factors, including age, temperament, past hospitalizations, and socioeconomic and ethnic backgrounds. A panoply of interventions effect anxiolysis, including parental presence, distraction, and premedication, although no single strategy is effective for all ages. Emergence delirium (ED) occurs after the use of sevoflurane and desflurane in preschool-aged children in the recovery room. Symptoms usually last approximately 15 minutes and resolve spontaneously. The Pediatric Anesthesia Emergence Delirium scale is used to diagnose ED and evaluate therapeutic interventions for ED such as propofol and opioids.

Intravenous versus inhalational anaesthesia for paediatric outpatient surgery

BACKGROUND

Ambulatory or outpatient anaesthesia is performed in patients who are discharged on the same day as their surgery. Perioperative complications such as postoperative nausea and vomiting (PONV), postoperative behavioural disturbances and cardiorespiratory complications should be minimized in ambulatory anaesthesia. The choice of anaesthetic agents and techniques can influence the occurrence of these complications and thus delay in discharge.

OBJECTIVES

The objective of this review was to evaluate the risk of complications (the risk of postoperative nausea and vomiting (PONV), admission or readmission to hospital, postoperative behavioural disturbances and perioperative respiratory and cardiovascular complications) and recovery times (time to discharge from recovery ward and time to discharge from hospital) comparing the use of intravenous to inhalational anaesthesia for paediatric outpatient surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 8); MEDLINE (1948 to 1 October 2013); EMBASE (1974 to 1 October 2013); Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) (1982 to 1 October 2013). We also handsearched relevant journals and searched the reference lists of the articles identified.

SELECTION CRITERIA

We included randomized controlled trials comparing paediatric outpatient surgery using intravenous versus inhalational anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data. When necessary, we requested additional information and clarification of published data from the authors of individual trials.

MAIN RESULTS

We included 16 trials that involved 900 children in this review. Half of all the studies did not describe the generation of randomized sequence and most studies did not describe adequate allocation sequence concealment. The included studies showed variability in the types and combinations of drugs and the duration of anaesthesia, limiting the meta-analysis and interpretation of the results.For the induction and maintenance of anaesthesia there was a significant difference favouring intravenous anaesthesia with propofol; the incidence of PONV was 32.6% for sevoflurane and 16.1% for propofol (odds ratio (OR) 2.96; 95% confidence interval (CI) 1.35 to 6.49, four studies, 176 children, low quality evidence). The risk of postoperative behavioural disturbances also favoured intravenous anaesthesiaas the incidence was 24.7% for sevoflurane and 11.5% for propofol (OR 2.67; 95% CI 1.14 to 6.23, four studies, 176 children, very low quality evidence). There were no differences between groups in the risk of intraoperative and postoperative respiratory and cardiovascular complications (OR 0.75; 95% CI 0.27 to 2.13, three studies,130 children, very low quality evidence) and there was no difference in the time to recovery from anaesthesia and discharge from hospital. These results should be interpreted with caution due to heterogeneity between studies in the type and duration of operations, types of reported complications and the high risk of bias in almost all studies. Two studies (105 participants) compared halothane to propofol and showed heterogeneity in duration of anaesthesia and in the type of ambulatory procedure. For the risk of PONV the results of the studies were conflicting, and for the risks of intraoperative and postoperative complications there were no significant differences between the groups.For the maintenance of anaesthesia there was a significant difference favouring anaesthesia with propofol, with or without nitrous oxide (N2O), when compared to thiopentone and halothane + N2O (OR 3.23; 95% CI 1.49 to 7.02, four studies, 176 children, low quality evidence; and OR 7.44; 95% CI 2.60 to 21.26, two studies, 87 children, low quality evidence), respectively. For the time to discharge from the recovery room, there were no significant differences between groups. The studies were performed with different ambulatory surgeries and a high risk of bias.Four studies (250 participants) compared the induction of anaesthesia by the inhalational or intravenous route, with inhalational anaesthesia for maintenance, and found no significant differences between groups in all outcomes (the risk of PONV, behavioural disturbances, respiratory and cardiovascular complications and time to discharge from recovery room). Meta-analysis was not done in this comparison because of significant clinical heterogeneity.Readmission to hospital was not reported in any of the included studies. No other adverse effects were reported.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine whether intravenous anaesthesia with propofol for induction and maintenance of anaesthesia in paediatric outpatients undergoing surgery reduces the risk of postoperative nausea and vomiting and the risk of behavioural disturbances compared with inhaled anaesthesia. This evidence is of poor quality. More high-quality studies are needed to compare the different types of anaesthesia in different subsets of children undergoing ambulatory surgery.

Effects of Clonidine on Recovery after Sevoflurane Anaesthesia in Children Undergoing Cataract Surgery

This trial assessed the effects of two doses of clonidine compared with placebo on the quality and speed of recovery in children premedicated with oral midazolam and anaesthetised with sevoflurane for cataract surgery.

One hundred and twenty American Society of Anesthesiologists physical status I to II children (aged one to six years), premedicated with oral midazolam 0.5 mg/kg and undergoing elective unilateral cataract surgery with sevoflurane anaesthesia were studied. Children were randomised to intravenous clonidine 1 μg/kg (group C1, n=39), 2 μg/kg (group C2, n=41) or normal saline (group NS, n=40). Clinically successful sub-Tenon local anaesthesia block was required for a patient to be included in the analysis.

The primary outcome was the incidence of postoperative agitation. Postoperative agitation was defined as a Pain Discomfort Score of ≥3 using items 3 to 5 only, which was assessed 15 minutely until discharge. Agitation was observed in 11/40 (27.5%) children in the NS group compared to 2/39 (5.1%) in group C1 and none in group C2 (P <0.001). Rescue medication to treat severe agitation was required in 5/40 (12.5%) in the NS group, 1/39 (2.6%) in group C1 and none in group C2 (P=0.025). Time to meet discharge criteria was significantly shorter in group C1 compared to the other two groups (48.4±14.0 minutes compared to C2 79.5±12.8 minutes and NS 73.1±20.4 minutes, P <0.001). There were no significant effects on blood pressure and heart rate.

Intravenous clonidine 1 μg/kg is effective for reducing agitation after sevoflurane anaesthesia and midazolam premedication in children undergoing cataract surgery. Intravenous clonidine 2 μg/kg was also effective and for a longer period, but was associated with a longer time to discharge.

Emergence Delirium in Children: Many Questions, Few Answers

The introduction of a new generation of inhaled anesthetics into pediatric clinical practice has been associated with a greater incidence of ED, a short-lived, but troublesome clinical phenomenon of uncertain etiology. A variety of anesthesia-, surgery-, patient-, and adjunct medication-related factors have been suggested to play a potential role in the development of such an event. Restless behavior upon emergence causes not only discomfort to the child, but also makes the caregivers and parents feel unhappy with the quality of recovery from anesthesia. Although the severity of agitation varies, it often requires additional nursing care, as well as treatment with analgesics or sedatives, which may delay discharge from hospital. To reduce the incidence of this adverse event, it is advisable to identify children at risk and take preventive measures, such as reducing preoperative anxiety, removing postoperative pain, and providing a quiet, stress-free environment for postanesthesia recovery. More clinical trials are needed to elucidate the cause as well as provide effective treatment.

Clinical and economic factors important to anaesthetic choice for day-case surgery

Clinical and economic factors that are important to consider when selecting anaesthesia for day-case surgery can differ from those for inpatient anaesthesia. Patients undergoing day-case surgery tend to be healthier and have shorter durations of surgery. They expect less anxiety before surgery, amnesia for the surgical experience, a rapid return to normal (normal mentation with minimal pain and nausea) after surgery, and lower expenses. However, the latter 2 expectations can conflict; older generic drugs have lower acquisition costs but often impose longer recovery times. Longer recovery periods can increase costs by prolonging the time to discharge from labour-intensive areas such as the operating suite or the post-anaesthesia recovery unit. The challenge for today's anaesthetist is to use newer drugs judiciously to minimise their expense without compromising the rate or quality of recovery. Several approaches can secure these aims. Most apply the least anaesthetic needed. 'Least anaesthetic' may mean the particular form of anaesthetic (e.g. local infiltration with monitored anaesthesia care versus a general anaesthetic), or may mean the delivery of the smallest effective dose, perhaps guided by anaesthetic monitors such as end-tidal analysers or the bispectral index. For patients requiring general anaesthesia, a combination of several drugs usually secures the closest approach to the ideal. Drug combinations used usually include a short-acting properative anxiolytic (e.g. midazolam), intravenous propofol (a short-acting potent anxiolytic and amnestic agent) for induction of anaesthesia (and sometimes for maintenance) and primary maintenance of anaesthesia with inhaled nitrous oxide combined with a poorly soluble (low solubility produces rapid recovery; the least soluble is desflurane) potent inhaled anaesthetic delivered at a low inflow rate (to minimise cost). Although old, nitrous oxide is inexpensive and has favourable pharmacokinetic and cardiovascular advantages; however, it is limited in its anaesthetic/amnestic potency, and has the capacity to increase nausea. In children, induction of anaesthesia is often accomplished with sevoflurane rather than desflurane; although sevoflurane is modestly more soluble than desflurane, it is non-pungent whereas desflurane is pungent. Moderate- or short-acting opioids (fentanyl is popular) or nonsteroidal anti-inflammatory agents (especially ketorolac), or local anaesthetics are added to secure analgesia during and after surgery. Similarly, when needed, moderate- or short-acting muscle relaxants are selected. Before the end of anaesthesia, an intravenous antiemetic may be given. With this drug combination, patients usually awaken within minutes after anaesthesia and can often move themselves to the vehicle for transport to the recovery unit. These combinations of anaesthetics and techniques minimise use of expensive drugs while expediting recovery (again minimising cost) with minimal or no compromise in the quality of recovery.