Philip Ragg

The severity and duration of postoperative pain and analgesia requirements in children after tonsillectomy, orchidopexy, or inguinal hernia repair

Objectives:  To provide parents of children with accurate information regarding postoperative pain, its management, and functioning following common surgical procedures.

Postoperative Mortality in Children After 101,885 Anesthetics at a Tertiary Pediatric Hospital

BACKGROUND: Mortality is a basic measure for quality and safety in anesthesia. There are few anesthesia-related mortality data available for pediatric practice. Our objective for this study was to determine the incidence of 24-hour and 30-day mortality after anesthesia and to determine the incidence and nature of anesthesia-related mortality in pediatric practice at a large tertiary institution. METHODS: Children ⩽18 years old who had an anesthetic between January 1, 2003, and August 30, 2008, at the Royal Childrens Hospital, Melbourne, Australia, were included for this study. Data were analyzed by merging a database for every anesthetic performed with an accurate electronic record of mortality of children who had ever been a Royal Childrens Hospital patient. Cases of children dying within 30 days and 24 hours of an anesthetic were identified and the patient history and anesthetic record examined. Anesthesia-related death was defined as those cases whereby a panel of 3 senior anesthesiologists all agreed that anesthesia or factors under the control of the anesthesiologist more likely than not influenced the timing of death. RESULTS: During this 68-month period, 101,885 anesthetics were administered to 56,263 children. The overall 24-hour mortality from any cause after anesthesia was 13.4 per 10,000 anesthetics delivered and 30-day mortality was 34.5 per 10,000 anesthetics delivered. The incidence of death was highest in children ⩽30 days old. Patients undergoing cardiac surgery had a higher incidence of 24-hour and 30-day mortality than did those undergoing noncardiac surgery. From 101,885 anesthetics there were 10 anesthesia-related deaths. The incidence of anesthesia-related death was 1 in 10,188 or 0.98 cases per 10,000 anesthetics performed (95%confidence interval, 0.5 to 1.8). In all 10 cases, preexisting medical conditions were identified as being a significant factor in the patients death. Five of these cases (50%) involved children with pulmonary hypertension. CONCLUSIONS: Anesthesia-related mortality is higher in children with heart disease and in particular those with pulmonary hypertension. The lack of anesthetic-related deaths in children who did not have major comorbidities reinforces the safety of pediatric anesthesia in healthy children.

Apnea after Awake Regional and General Anesthesia in Infants: The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

Background:Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (GA) on neurodevelopment. A secondary aim is to compare rates of apnea after anesthesia. Methods:Infants aged 60 weeks or younger, postmenstrual age scheduled for inguinal herniorrhaphy, were randomized to RA or GA. Exclusion criteria included risk factors for adverse neurodevelopmental outcome and infants born less than 26 weeks gestation. The primary outcome of this analysis was any observed apnea up to 12 h postoperatively. Apnea assessment was unblinded. Results:Three hundred sixty-three patients were assigned to RA and 359 to GA. Overall, the incidence of apnea (0 to 12 h) was similar between arms (3% in RA and 4% in GA arms; odds ratio [OR], 0.63; 95% CI, 0.31 to 1.30, P = 0.2133); however, the incidence of early apnea (0 to 30 min) was lower in the RA arm (1 vs. 3%; OR, 0.20; 95% CI, 0.05 to 0.91; P = 0.0367). The incidence of late apnea (30 min to 12 h) was 2% in both RA and GA arms (OR, 1.17; 95% CI, 0.41 to 3.33; P = 0.7688). The strongest predictor of apnea was prematurity (OR, 21.87; 95% CI, 4.38 to 109.24), and 96% of infants with apnea were premature. Conclusions:RA in infants undergoing inguinal herniorrhaphy reduces apnea in the early postoperative period. Cardiorespiratory monitoring should be used for all ex-premature infants.

Intrathecal morphine provides effective and safe analgesia in children after cardiac surgery.

Background:  The purpose of this prospective, randomized, blinded to observer study was to assess the analgesic effect and safety of intrathecal morphine (ITM) in post‐operative pain control in children after heart surgery with a sternotomy incision.

External and internal biphasic direct current shock doses for pediatric ventricular fibrillation and pulseless ventricular tachycardia

Objective: To determine energy dose and number of biphasic direct current shocks for pediatric ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). Design: Observation of preshock and postshock rhythms, energy doses, and number of shocks. Setting: Pediatric hospital. Patients: Shockable ventricular dysrhythmias. Interventions: None. Measurements and Main Results: Forty-eight patients with VF or pulseless VT received external shock at 1.7 ± 0.8 (mean ± sd) J/kg. Return of spontaneous circulation (ROSC) occurred in 23 (48%) patients with 2.0 ± 1.0J/kg, but 25 (52%) patients remained in VF after 1.5 ± 0.7J/kg (p = .05). In 24 non-responding patients, additional 1–8 shocks (final dose, 2.8 ± 1.2 J/kg) achieved ROSC in 14 (58%) with 2.6 ± 1.1 J/kg but not in 10 (42%) with 3.2 ± 1.2 J/kg (not significant). Overall, 37 (77%) patients achieved ROSC with 2.2 ± 1.1 J/kg (range, 0.5–5.0 J/kg). Eight patients without ROSC recovered with cardiopulmonary bypass and internal direct current shock. At 13 subsequent episodes of VF or VT among eight patients, five achieved ROSC and survived. In combined first and subsequent resuscitative episodes, doses in the range of 2.5 to <3 J/kg achieved most cases of ROSC. Survival for >1 yr was seen in 28 (78%) of 36 patients with VF and seven (58%) of 11 patients with VT, with 35 (73%) overall. Lack of ROSC was associated with multiple shocks (p = .003). Repeated shocks with adhesive pads had significantly less impedance (p < .001). Pads in an anteroposterior position achieved highest ROSC rate. Internal shock for another 48 patients with VF or VT achieved ROSC in 28 (58%) patients with 0.7 ± 0.4 J/kg but not in 20 patients with 0.4 ± 0.3 J/kg (p = .01). Nineteen of the nonresponders who received additional internal 1–9 shocks at 0.6 ± 0.5 J/kg and one patient given extracorporeal membrane oxygenation all recovered, yielding 100% ROSC, but 1-yr survival tallied 43 (90%) patients. Conclusions: The initial biphasic direct current external shock dose of 2 J/kg for VF or pulseless VT is inadequate. Appropriate doses for initial and subsequent shocks seem to be in the range of 3–5 J/kg. Multiple shocks do not favor ROSC. The dose for internal shock is 0.6–0.7 J/kg.

The cardiac analgesic assessment scale (CAAS): a pain assessment tool for intubated and ventilated children after cardiac surgery.

Background : This study evaluated the reliability and validity of the Cardiac Analgesic Assessment Scale (CAAS) as a postoperative pain instrument for children after cardiac surgery.

Plasma concentrations of bupivacaine after combined spinal epidural anaesthesia in infants and neonates

The unbound and bound plasma concentration of bupivacaine in 50 infants less than 55 weeks postconceptual age was determined following combined spinal and epidural anaesthesia (CSEA). Plasma concentrations were determined at 15‐min intervals up to 60 min postspinal anaesthesia. Maximum plasma bupivacaine levels were recorded between 45 and 60 min post CSEA. Total plasma concentrations above a toxic threshold level of 4 μg·ml−1 were recorded in 4% of patients and above 2.5 μg·ml−1 in 10% of patients. Unbound bupivacaine levels were greater than a presumed toxic level of 0.25 μg·ml−1 in 16% of cases and above 0.3 μg·ml−1 in 14% of cases. A wide range of protein binding was measured (varying from 53.8–98.2%) and could not be correlated with standard indicators of local anaesthetic binding. Two neonates had brief apnoeas in the immediate perioperative phase but no adverse cardiac or central nervous system events attributable to the performance of CSEA were demonstrated.

Predictors of Failure of Awake Regional Anesthesia for Neonatal Hernia Repair: Data from the General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes

Background:Awake regional anesthesia (RA) is a viable alternative to general anesthesia (GA) for infants undergoing lower abdominal surgery. Benefits include lower incidence of postoperative apnea and avoidance of anesthetic agents that may increase neuroapoptosis and worsen neurocognitive outcomes. The General Anesthesia compared to Spinal anesthesia study compares neurodevelopmental outcomes after awake RA or GA in otherwise healthy infants. The aim of the study is to describe success and failure rates of RA and report factors associated with failure. Methods:This was a nested cohort study within a prospective, randomized, controlled, observer-blind, equivalence trial. Seven hundred twenty-two infants 60 weeks or less postmenstrual age scheduled for herniorrhaphy under anesthesia were randomly assigned to receive RA (spinal, caudal epidural, or combined spinal caudal anesthetic) or GA with sevoflurane. The data of 339 infants, where spinal or combined spinal caudal anesthetic was attempted, were analyzed. Possible predictors of failure were assessed including patient factors, technique, experience of site and anesthetist, and type of local anesthetic. Results:RA was sufficient for the completion of surgery in 83.2% of patients. Spinal anesthesia was successful in 86.9% of cases and combined spinal caudal anesthetic in 76.1%. Thirty-four patients required conversion to GA, and an additional 23 patients (6.8%) required brief sedation. Bloody tap on the first attempt at lumbar puncture was the only risk factor significantly associated with block failure (odds ratio = 2.46). Conclusions:The failure rate of spinal anesthesia was low. Variability in application of combined spinal caudal anesthetic limited attempts to compare the success of this technique to spinal alone.

Critical incidents and mortality reporting in pediatric anesthesia: the Australian experience

Since 1960, the collection and analysis of mortality data for anesthesia in Australia has been of significant benefit to practising anesthetists. These figures include pediatric deaths which fortunately have been rare and often inevitable because of severe underlying disease and patient risk factors.

Let them drink

Pediatric anesthetists the world over wrestle daily with the dilemma of unhappy children desperate for a drink before surgery. We try to console the families and patients with the knowledge that this unavoidable situation is in their child’s best interest, as we do not want them to ‘inhale vomit’. Now, at last, we have some new evidence to support what many of us have believed for a long time; that clear fluids are safe any time before a procedure. The paper by Anderson, Zaren, and Frykholm from Uppsala University in this issue (1) demonstrates that the practice of allowing children to drink fluids freely up until the time they are called for surgery does not increase their risk of pulmonary aspiration. In their hospital where they had been using this liberal fluids regime preoperatively for over a decade, the authors studied over 10 000 anesthetic episodes during a 6-year period and encountered only three episodes of confirmed aspiration, and none resulting in case cancelation, need for postoperative ventilation, or intensive care admission. Interestingly it included one patient with stomach ache and vomiting whom many would have excluded from a free fluid regimen. Although it occurs more frequently than in adults, perioperative pulmonary aspiration in children is still uncommon, with an incidence of between 1 and 10 per 10 000 anesthetics (2). It is associated with low morbidity and mortality, and while never totally avoidable, it is reduced in incidence by two common strategies; prevention of gastric contents entering the lungs, and reducing gastric contents. Strategies to reduce the former include appropriate identification of children at risk of high gastric volumes or increased intra-abdominal pressure, followed by appropriate choice of airway devices, and cricoid pressure during induction. Reducing gastric contents is achieved by preoperative fasting. And if ever there was a minefield of issues and opinion it is on this topic. Clear fluids are relatively easy, as they have been considered safe up to two hours before surgery for some years (3). The evidence for guidelines on milk products and solids, however, is not as robust. We know that human breast milk has a higher whey to casein ratio and behaves more like water than cow’s milk in having a faster transit time through the stomach and lower potential to form curd. The controversy is how long to fast an infant as breast milk changes its constitution due to factors such as feeding duration and maternal age (4). Also, many babies are on formulae with varying absorption characteristics. Cow’s milk separates into a solid and liquid phase in the acid environment of the stomach and can remain undigested for hours. Solids are even more controversial with very few studies looking at their digestion and gastric transit times in children. Indeed, we know that a high calorific meal in adults will be significantly present in the stomach for 9 h (5)! And I think we can assume that most children, if permitted, will want to eat until satiety. How many of us, however, ever ask how much food the child has eaten? Most anesthetists will proceed with a case, regardless, if the required 6 h have transpired; yet the 6-h guideline for solid fasting is based on a light meal of toast and juice. In spite of a free fluid regimen, the patients in Anderson, Zaren, and Frykholm’s study were fasted on average for 1.7 h before induction of anesthesia and no child was anesthetized within 30 min of their last oral intake. This should probably be taken into consideration in high turnover departments but, nevertheless, there is evidence that clear fluids do not increase gastric volumes or acidity compared to long periods of fasting (3). There are obvious advantages for the child in allowing clear fluids up until being called to the operating theater. Patients are likely to be more content and at lower risk of dehydration and, in small infants, hypoglycemia. What are less obvious are the advantages to the operating room staff and schedulers. Even a 2-h window for clear fluids can be difficult to co-ordinate when attempting to accurately predict the timing of an operation. We are all aware of the frequent need for last minute changes to the theater program, which become very problematic if patients are unfasted. Clear fluids anytime mean these issues are potentially resolved. Compliance with fasting regimes and preoperative instructions is known to be less than 100% in even tertiary institutions with detailed patient information. Staff in pediatric day procedure centres have suspected that a significant percentage of the children presenting for surgery may be unfasted for reasons of misunderstanding, lack of observation or supervision of the child or deliberate breaches by carers because the child was upset. And these fasting transgressions may be quite risky if they include a large volume of solids. A more liberal fluid regime may result in fewer of these fasting guideline breaches.