Does an objective system-based approach improve assessment of perioperative risk in children? A preliminary evaluation of the 'NARCO'.

BACKGROUND: This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children. METHODS: A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated. RESULTS: NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores. CONCLUSIONS: Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.

Anaesthetic management and outcomes in patients with surgically corrected D-transposition of the great arteries undergoing non-cardiac surgery.

BACKGROUND: Patients with effective repair of D-transposition of the great arteries (D-TGA) increasingly present for non-cardiac surgery. These patients may be predisposed to heart failure, arrhythmias, and sudden death, especially after the atrial switch repair. This retrospective study was undertaken to review the care and outcomes of patients with D-TGA who presented for non-cardiac surgery. METHODS: Records for patients with surgically corrected D-TGA undergoing general anaesthesia for non-cardiac surgery between October 2000 and April 2008 were reviewed. The anaesthesiology records, operative note, admission history and physical examination records, and discharge summaries of these patients were reviewed and the following data collected: patient characteristics; comorbidities; surgical procedure; anaesthetic and monitoring techniques; intra- and postoperative complications; and admission status. RESULTS: Fifty procedures, including 43 in the paediatric setting and seven in the adult setting, comprised the final sample. The majority of these patients received anaesthesia on an outpatient basis in the paediatric hospital, without invasive monitoring and without complication. There were four adverse events including a significant bradycardia, failed extubation after two of the procedures, and postoperative bleeding requiring return to the operating theatre in another. CONCLUSIONS: Data suggest that the majority of patients with surgically corrected D-TGA can safely undergo general anaesthesia, often as outpatients, with no invasive monitoring. However, given the incidence of adverse events, it remains imperative that the perioperative care be individualized based on the presence of comorbidities, type of repair, residual cardiac disease, severity of planned surgery, and experience of the provider.

False alarms and sensitivity of conventional pulse oximetry versus the Masimo SET technology in the pediatric postanesthesia care unit.

UNLABELLED: We compared the incidence and duration of false alarms (FA)and the sensitivity of conventional pulse oximetry (CPO) with Masimo Signal Extraction Technology (Masimo SET; Masimo Corporation, Irvine, CA) in children in the postanesthesia care unit. Disposable oximeter sensors were placed on separate digits of one extremity. Computerized acquisition of synchronous data included electrocardiograph heart rate, SpO(2), and pulse rate via CPO and Masimo SET. Patient motion, respiratory, and other events were simultaneously documented. SpO(2) tracings conflicting with clinical observations and/or documented events were considered false. These were defined as 1) Data dropout, complete interruption in SpO(2) data; 2) False negative, failure to detect SpO(2)

Cancellation of pediatric outpatient surgery: economic and emotional implications for patients and their families.

STUDY OBJECTIVE: To determine the cause and timing of case cancellation in a pediatric outpatient surgical population, and to examine the economic and emotional impact of such cancellations on patients and their families. DESIGN: Questionnaire survey. SETTING: Outpatient surgery unit of a large university children's hospital. PARTICIPANTS: 127 parents of children whose elective outpatient surgery had been cancelled. INTERVENTIONS: A total of 200 questionnaires were mailed to the parents of children who had their outpatient surgery cancelled. MEASUREMENTS AND MAIN RESULTS: Of those children whose surgery had been cancelled, 34.6% were due to upper respiratory infections (URIs), 30.7% for other medical reasons, and the balance for scheduling errors, because the child had not fasted, or for difficulties with transportation. The majority of surgeries (58.3%) were cancelled prior to their scheduled surgery date. However, 18.9% were cancelled on the day of surgery prior to leaving for the hospital and 22.8% were cancelled on arrival at the outpatient surgery clinic. Of those patients whose surgeries were not cancelled until they arrived at the hospital, 38.5% of mothers and 50.0% of fathers missed a day of work and, of these, 53.3% and 42.1%, respectively, went unpaid for the work day missed. The mean number of miles driven (round trip) to the hospital for a cancelled operation was 158.8 miles (range 8 to 1,350 miles). Additional testing and new appointments were ordered in 25.2% of the cancelled cases. 45% of parents and 16% of children were disappointed by the cancellation; 16% of parents were frustrated by the cancellation and 3.3% were angry. CONCLUSIONS: This study suggests that last-minute cancellation of surgery has an important impact on patients and their families and suggests a need to review present protocols for screening patients prior to surgery.

Effect of preemptive acetaminophen on postoperative pain scores and oral fluid intake in pediatric tonsillectomy patients.

Postoperative pain is a significant problem that continues to be undertreated in the pediatric population. Preemptive administration of analgesics has recently emerged as a method to enhance pain management associated with surgery. The purpose of this study was to compare postoperative pain scores, rescue analgesic use, and oral fluid intake in children who received acetaminophen preoperatively to children who received postoperative acetaminophen. The sample consisted of 28 children, 2-8 years of age, scheduled for elective tonsillectomy. Children were randomized into the control or the experimental groups. Anesthesia induction and maintenance were standardized. The experimental group received 15 mg/kg of oral acetaminophen preoperatively, and the control group received 20 mg/kg of rectal acetaminophen postoperatively. Pain was scored with the FLACC (faces, legs, activity, cry, consolability) behavioral assessment tool. Scores were significantly lower for the experimental group at 30 minutes after awakening and significantly lower for the control group at 240 minutes (P < .05). Eight patients (57%) in the control group and only 4 (28%) in the experimental group required rescue morphine postoperatively. Total postoperative morphine was not significantly different between groups. There were no differences in time to initial oral fluid intake and total oral fluid intake postoperatively. Incidence of nausea and vomiting was high in both groups (64-78%). These results provide evidence that preemptive acetaminophen may enhance analgesia in pediatric tonsillectomy patients. Preoperative acetaminophen is a safe, quick, and inexpensive intervention that can readily be incorporated into anesthesia practice.

Stent redilation in canine models of congenital heart disease: pulmonary artery stenosis and coarctation of the aorta.

In a canine puppy model, pulmonary artery stenosis was created by banding the left pulmonary artery to 30-40% of its original diameter. Animals underwent right heart catheterization and angiography 1-2 mo later, and Palmaz P308 stents were implanted. Stent redilation was performed 3-5 mo later. One mo postredilation, the animals were restudied and sacrificed. Coarctations of the aorta were created by transverse aortic incision and longitudinal repair. P308 stent implantation was performed 2-3 mo later. Stent redilation was performed after 6-10 mo, and the animals were restudied and sacrificed 1-2 mo later. Stent implantation was performed in 6 puppies with pulmonary artery stenosis, as 2 animals developed postoperative pulmonary arterial hypoplasia, precluding stenting. The stenosis diameter increased from 4.8 +/- 0.5 mm to 7.4 +/- 0.6 mm (mean +/- SE) following stenting (P = 0.005), and increased further to 9.2 +/- 0.7 mm following redilation (P < 0.001). There were no significant vessel tears or ruptures. Coarctation stenting was performed in 8 animals. The coarctation was dilated from 5.8 +/- 0.9 mm to 9.8 +/- 0.6 mm (P < 0.001), and to 13.5 +/- 0.5 mm at redilation (P = 0.002). Redilation could not be performed in 1 animal. Aortic rupture and death occurred in 2 of 7 animals at redilation. Stent implantation and redilation in experimental pulmonary artery stenosis appears safe and effective. Though stent implantation for coarctation of the aorta appears safe, there was a 28% aortic rupture rate at stent redilation in this model.

Lumbar epidural morphine infusions for children undergoing cardiac surgery.

OBJECTIVE: To determine whether outcomes and costs in children undergoing cardiac surgery are affected by the method of postoperative pain management. DESIGN: Retrospective, case control. SETTING: Tertiary care children's hospital in a university setting. PARTICIPANTS: Two groups of children undergoing cardiac surgery for palliation or repair of congenital heart disease oer a 21-month period between January 1993 and September 1994. INTERVENTIONS: Lumbar epidural morphine infusions (LEM) in one group, and IV opioid (IVO) medication in the other for postoperative pain control. MEASUREMENTS AND MAIN RESULTS: Hospital courses of 27 LEM patients and 27 IVO patients were analyzed. In LEM patients, epidural catheters were placed following anesthetic induction, but before anticoagulation. A bolus of 50 micrograms/kg of preservative-free morphine sulfate was administered through the catheter, followed by a continuous infusion at 3 to 4 micrograms/kg/h for 22 to 102 (median, 46) hours postoperatively. The IVO patients received 50 micrograms/kg, IV, of fentanyl before incision followed by a continuous infusion at 0.3 microgram/kg/min. The fentanyl infusion rate was decreased to 0.1 microgram/kg/min postoperatively and maintained for 24 hours. Although the LEM group was demographically similar to the IVO group, times to tracheal extubation, transfer from the intensive care unit, and resumption of regular diet were significantly shorter in LEM patients. LEM and IVO patients received similar amounts of fentanyl during surgery (10.4 +/- 19.3 micrograms/kg/h v 13.7 +/- 8.1 micrograms/kg/h, p = 0.4). However, during postoperative recovery, LEM patients who were extubated late received significantly less supplemental opioid medication than IVO patients extubated late during the first 5 postoperative days. No complications related to dural puncture, bleeding into the epidural space, or respiratory depression were encountered. Pruritus and nausea/vomiting were the most commonly reported morbidities in both groups. Fifty-six percent (15/27) of LEM patients and 41% of IVO patients reported pruritus (p = 0.4). There was no significant difference in the incidence of nausea and vomiting between the groups (34% v 30%, respectively). CONCLUSIONS: Given the present methodologic limitations, the authors found improved outcomes only in LEM patients extubated late compared with IVO patients. Randomized, prospective studies to evaluate this conclusion and to determine the comparative efficacy and safety of LEM infusions are in progress.

Percutaneous feeding tube placement in pediatric patients: immediate and 30-day results.

PURPOSE: To evaluate fluoroscopically guided percutaneous feeding tube placement in pediatric patients. MATERIALS AND METHODS: Sixty-one procedures were performed. Periprocedural care protocol was changed after patient nine. Forty-eight-hour and 30-day outcomes were assessed. RESULTS: Almost 97% of procedures were successful. The 48-hour major and minor complication rates were 1.9% and 9.6%, respectively, after the initial nine procedures. Risk factors for early complications were the use of the initial care protocol (P < .01) and patient weight below the 50th percentile (P < .05). Major and minor 30-day complication rates were 8.3% and 12.0%, respectively. Risk factors for delayed complications were placement of a gastrojejunostomy tube rather than a gastrostomy tube (P < .05) and immunosuppression (P < .05). CONCLUSION: Percutaneous feeding tubes can be placed in children with a high rate of technical success. Optimal results require attention to periprocedural care. Morbidity is common during the first month of tube use.

Factors that influence an anesthesiologist's decision to cancel elective surgery for the child with an upper respiratory tract infection.

STUDY OBJECTIVE: To examine factors that anesthesiologists consider when making decisions regarding elective surgery cancellation of the pediatric patient with an upper respiratory infection (URI). DESIGN: Questionnaire survey. SETTING: Anesthesiology departments and/or practices throughout the United States. PARTICIPANTS: 212 anesthesiologist members of the Society for Pediatric Anesthesia (SPA). MEASUREMENTS AND MAIN RESULTS: A total of 400 questionnaires were mailed to anesthesiologists randomly selected from the membership of the SPA. Of these questionnaires, 212 (54%) were completed and returned. Of these respondents, 71 (34.5%) reported that they seldom (1% to 25% of the time) cancelled cases due to an URI, and 43 (20.9%) stated that they usually (76% to 99% of the time) cancelled in the event of an URI. Two respondents (1%) reported never cancelling due to an URI, and six (2.9%) stated that they always cancelled. Frequency of cancellation was independent of type of practice. However, anesthesiologists who had been in practice for more than 10 years were significantly more likely to cancel than those who had been in practice for less than 10 years (p < 0.05). Factors that were considered most important in making decisions regarding cancellation included the urgency of the surgery and the presence of asthma. Other important considerations included fear of complications and the anesthesiologist's previous experience anesthetizing children with URIs. Factors related to the economics and inconvenience of cancellation did not influence the decision to cancel surgery. These factors included distance traveled, cost of cancellation, attitude of the parents, fear of litigation, and pressure to complete cases expediently. CONCLUSIONS: The results of this survey demonstrate a wide range of opinions and approaches to this enduring clinical dilemma. However, it appears that the practice of cancelling elective surgery for children with URIs may be changing over time, since younger anesthesiologists appear to cancel less often than their more experienced counterparts. It is hoped that this information will be useful to practioners in their evaluation and management of children with colds and will stimulate further investigation into this important clinical problem.

Comparison of the analgesic and emetic properties of ketorolac and morphine for paediatric outpatient strabismus surgery.

In a prospective, double-blind, randomized study, we have compared i.v. ketorolac and morphine in paediatric outpatients undergoing strabismus surgery. Forty-two ASA I or II children, aged 2-12 yr, were allocated randomly to receive either ketorolac 0.75 mg kg-1 i.v. or morphine 0.1 mg kg-1 i.v. and metoclopramide 0.15 mg kg-1. Anaesthesia was induced with propofol and maintained with propofol and nitrous oxide. Pain was assessed at 15-min intervals until discharge, and the incidence of nausea and vomiting was recorded for the first 24 h. There was no difference in pain behaviour scores or recovery times. The incidence of nausea and vomiting during the first 24 h was 19% in the ketorolac group and 71% in the morphine group (P < 0.001). We concluded that ketorolac was an effective analgesic for this type of surgery and that it was associated with less postoperative emesis than morphine and metoclopramide.

Balloon-expandable stent treatment of experimental coarctation of the aorta: early hemodynamic and pathological evaluation.

The present study was intended to evaluate the acute and short-term hemodynamic, angiographic, and pathological response to balloon-expandable stent treatment of experimental coarctation of the aorta. A discrete thoracic coarctation was surgically created in six mongrel dogs (two adults, four puppies). Two months postoperatively all six dogs (8.9-30 kg) underwent left heart catheterization and coarctation stenting performed through a femoral artery cutdown. A Palmaz PS-30 stent was advanced to the coarctation through a 10 French sheath, and expanded with an angioplasty balloon chosen to equal the diameter of the proximal aorta (9-12 mm). Stent implantation was successful in each dog. The systolic pressure gradient decreased from 26.3 +/- 9.1 mmHg (mean +/- SE) to 0.5 +/- 0.5 mmHg (P = 0.04), and the coarctation diameter improved from 50 +/- 6% to 82 +/- 6% of the diameter of the proximal descending aorta (P less than 0.01). Follow-up catheterization 4-7 weeks after stenting documented no stent migration, early restenosis, thrombosis, obstruction of arterial side branches, or aneurysm formation. Pathological evaluation of the explanted segments of stented aorta documented that by 6-7 weeks the stents are covered by a neointima composed of intimal proliferation and fibrosis with an endothelial cell surface. These data suggest that balloon-expandable stainless steel stents provide excellent acute and short-term relief of coarctation in this experimental model. Larger and longer-term studies are needed to better assess the incidence of restenosis or aneurysm formation following stenting of coarctation of the aorta.

Propofol infusion and the incidence of emesis in pediatric outpatient strabismus surgery.

A prospective, randomized, double-blind study was conducted to examine the effect of a propofol infusion on the incidence of postoperative emesis in children undergoing outpatient strabismus surgery. Seventy-eight children, aged 3-12 yr, were allocated randomly to receive either nitrous oxide and halothane or nitrous oxide and a propofol infusion for the maintenance of anesthesia. The overall incidence of vomiting during the first 24 h was 64% in those receiving halothane and 41% in those receiving the propofol infusion; this difference was statistically significant (P < 0.05). In children who received no opioids postoperatively, the incidence of vomiting in the first 24 h was 71% in the halothane group and 24% in the propofol group; this difference was also significant (P = 0.001). We conclude that propofol was effective in reducing the incidence of postoperative emesis in pediatric outpatient strabismus surgery.

Effect of P6 acupressure on postoperative vomiting in children undergoing outpatient strabismus correction.

A prospective, double-blind study was conducted to compare the effect of pressure at the P6 (Neikuan) point with placebo as an antiemetic in children. Sixty-six patients, ages 3-12 yr, undergoing outpatient surgery for correction of strabismus, were allocated randomly to receive either bilateral P6 acupressure or placebo during the perioperative period. The study was designed to detect a 50% difference in the incidence of postoperative vomiting between the two groups, with a 90% power of achieving a statistically significant result at the 5% level (two-tailed). The incidence of postoperative vomiting for the placebo group was 58% before discharge from hospital, 73% at home and 82% in the first 24 h after surgery. The corresponding results for the acupressure group were 58% before discharge, 71% at home and 94% in the first 24 h. These differences were not significant; P6 acupressure did not reduce the incidence of postoperative vomiting in children undergoing strabismus surgery.

Changes in resistance to mouth opening induced by depolarizing and non-depolarizing neuromuscular relaxants.

Mouth opening was measured in 43 children anaesthetized with isoflurane and paralysed with vecuronium or suxamethonium. Measurements of mouth opening were made for up to 10 min after loss of the adductor pollicis twitch and cessation of muscle fasciculations. In 22 patients receiving suxamethonium, a significant (P less than 0.001) reduction in mean mouth opening occurred in the 60 s after loss of twitch and cessation of fasciculations. Mouth opening reductions could last for up to 10 min after the loss of twitch, beyond the return of the twitch. One patient experienced "masseter spasm"; he did not develop malignant hyperpyrexia during 2.5 h of isoflurane anaesthesia. Patients receiving vecuronium showed a significant (P less than 0.0006) increase in mouth opening. In 20 subjects, mouth opening was generated with a small (1.67 N) and a larger (4.32 N) force. Proportionally equal reductions in mouth opening were obtained with either force after suxamethonium administration. Relatively equal increases with either force followed vecuronium administration. Isolated masseter spasm is not pathognomonic for malignant hyperpyrexia. If the diagnosis of malignant hyperpyrexia is contemplated, signs of hypermetabolism, such as increases in end-tidal carbon dioxide concentration during constant minute ventilation, should be sought.

Differing effect of agonist and antagonist muscle relaxants on cat jaw muscles.

Mouth closure and an increased resistance to mouth opening follow succinylcholine administration in humans. To elucidate the effects of succinylcholine on masticatory muscle function, mouth opening in the cat, produced by a constant test force, was measured during steady state halothane anesthesia. After baseline measurements, either succinylcholine (0.3 mg.kg-1 of body weight) or vecuronium (0.1 mg.kg-1 of body weight) was infused intravenously, and mouth opening measurements were repeated for up to 30 min. Concomitantly, muscle relaxant effect was quantified by measurement of the neurally-evoked tibialis anterior muscle response. All animals given succinylcholine displayed active jaw closure, which was followed by an increased resistance to mouth opening. This increased resistance was present after cessation of fasciculations and during complete twitch suppression. It lasted beyond the time at which the limb muscle twitch had fully recovered. Vecuronium administration was associated with a decreased resistance to mouth opening without a closing action. The initial jaw closure and the subsequently increased resistance to mouth opening after succinylcholine administration during halothane anesthesia in the cat are comparable with mouth opening changes after succinylcholine administration during inhalation anesthesia in humans. The cat may serve as an animal model for study of the mechanisms involved in responses of jaw muscles to succinylcholine with use of techniques inappropriate in humans.

The onset of ablation of the evoked adductor pollicis muscle twitch in children: a clinical perspective.

The time to loss of the adductor pollicis muscle response to ulnar nerve stimulation at 1 Hz (twitch) after succinylcholine, 1.5 mg.kg-1 intravenously (IV), or vecuronium, 0.1 mg.kg-1 (IV), administration was assessed visually in 134 children, age 2-13 yr, during clinically determined, deep halothane, enflurane and isoflurane anaesthesia. The overall time to twitch ablation and duration of succinylcholine's action is in agreement with published times obtained under controlled experimental conditions; the onset time following vecuronium is comparable to those observed during a similar anaesthetic background measured under controlled experimental conditions. Twitch ablation after succinylcholine was achieved in half the time needed following vecuronium regardless of anaesthetic agent. Succinylcholine's and vecuronium's onset time as well as succinylcholine's duration is adequately assessed by the outlined, simple clinical means. The choice of inhalation agent does not affect the time to visible twitch ablation in a clinically relevant manner; nor does it make an appreciable difference, in clinical terms, in succinylcholine's duration of action.