Early tracheal extubation after paediatric cardiac surgery: the use of propofol to supplement low-dose opioid anaesthesia.

BACKGROUND: After institutional approval and parental consent, 103 children, aged 6 months to 18 years, who were undergoing repair of simple and complex congenital heart lesions using cardiopulmonary bypass (CPB) were studied and compared with a group of 135 children who had undergone similar surgery in our institution in the year before. METHODS: Anaesthesia for study patients included fentanyl (< 20 microg.kg-1) and isoflurane. Infusions of propofol (median infusion rate 70 microg.kg-1.min-1) and morphine (median infusion rate 20 microg.kg-1.h-1) were started after weaning from CPB and continued postoperatively. Preestablished criteria were used in the intensive care unit (ICU) to assess readiness for tracheal extubation. RESULTS: Median time from admission to ICU to tracheal extubation was 5 h. Fifty-six children were extubated within 6 h and 73 within 9 h of ICU admission. Mean ICU stay for study patients was 1.7 days [95% confidence interval (CI) 1.2-2.2] and 2.6 days (95% CI 2.3-2.9) in the comparison group (P<0.005). CONCLUSIONS: We found the propofol regimen to be satisfactory with a shorted ICU stay for these patients.

Perioperative complications of superior pharyngeal flap surgery in children.

A 7-year retrospective review of perioperative complications associated with surgical correction of velopharyngeal insufficiency was carried out. A total of 219 children who underwent surgery for velopharyngeal insufficiency between the years 1985 and 1992 were reviewed. Gender distribution was 58 percent male and 42 percent female. The mean age was 9.6 years, with a range of 4 to 22 years, at the time of surgery. Fourteen cases (6.4 percent) were considered a difficult intubation. There were 36 patients with early complications (16.4 percent incidence). Of these, 18 had postoperative bleeding and 20 developed airway obstruction. Most of these episodes occurred in the first 24 hours. Three patients required reintubation. Nine children developed sleep apnea after discharge. Four patients required take-down of the pharyngoplasty, while 7 others had revision of the flap. There was 1 death in the 219 patients. In summary, most complications following surgical correction of velopharyngeal insufficiency in our institution occur in the early postoperative period and are the result of bleeding and/or airway obstruction.

Adequacy of caudal analgesia in children after penoscrotal and inguinal surgery using 0.5 or 1.0 ml.kg-1 bupivacaine 0.125%.

To determine the optimal volume of bupivacaine 0.125% for postoperative caudal analgesia, we compared the effectiveness of 0.5 ml.kg-1 and 1 ml.kg-1 of bupivacaine 0.125% with 1:200,000 epinephrine in 80 children undergoing penoscrotal and inguinal surgery. The adequacy of caudal analgesia and supplemental analgesic requirements did not differ between the two groups at any time during the first 12 hr after surgery. We conclude that 0.5 ml.kg-1 of bupivacaine 0.125% with 1:200,000 epinephrine is as effective as 1 ml.kg-1 of the same solution and recommend its use for penoscrotal surgery. The evidence for effectiveness of 0.5 ml.kg-1 of bupivacaine 0.125% for inguinal surgery, however, is inconclusive because of an insufficient number of patients studied.

Is preoperative haemoglobin testing justified in children undergoing minor elective surgery?

The need for preoperative haemoglobin determination before the administration of general anaesthesia to paediatric patients has long been an issue for debate. This study was undertaken to determine the value of routine preoperative haemoglobin testing in paediatric patients scheduled for minor surgery. Two thousand patients ages one month to 18 yr scheduled for minor surgery were studied. The patients were grouped according to age, Group I less than or equal to yr, Group II 1-5 yr, Group III greater than 5 yr. The charts of patients whose preoperative haemoglobin concentration (Hb) was less than 100 g.L-1 were reviewed at a later date to determine the course of their anaesthesia and surgery. Eleven patients, all of whom were greater than 5 yr (0.5%), had a Hb less than 100 g.L-1. Of these, three patients, 27%, had their surgery deferred, whereas the remaining eight patients, 73%, underwent anaesthesia and surgery without complications. The three patients who were deferred returned for uneventful anaesthesia and surgery following oral iron therapy. We conclude that healthy paediatric patients five years and older scheduled for minor surgery do not require routine Hb determinations. Furthermore, the low incidence of anaemia and low deferral rate of anaemic children, 1-5 yr of age, lead us to question the value of preoperative Hb testing in this age group.

Flare reaction following caudal analgesia.

The following case reports describe obvious and marked vascular changes over the S3 dermatome in two children following the administration of bupivacaine 0.125 per cent via the caudal route. These flare reactions were typical of an axon reflex. Vasodilatation in these two case reports could have been mediated by direct stimulation of the S3 routes by the local anaesthetic solution.

Hypoxaemia produced by an oesophageal stethoscope: a case report.

A seven-month-old child with complex cyanotic heart disease desaturated dramatically following induction of anaesthesia. While a degree of hypoxaemia would have been acceptable in this infant, pulse oximetry detected an abrupt desaturation prompting the anaesthetist to consider other less common causes of cyanosis. This episode of desaturation subsided with the removal of a 12 french oesophageal stethoscope which had been inserted following induction. Further attempts to re-insert this oesophageal probe led to repeated episodes of desaturation. The most likely cause of this desaturation was a reduction in pulmonary blood flow due to compression by the oesophageal probe of an aorto-pulmonary collateral posterior to the oesophagus.

Arterial oxygen saturation following premedication in children with cyanotic congenital heart disease.

To determine the effects of premedication on arterial oxygen saturation (SaO2) and heart rate (HR), 11 children (ages three to seven years) scheduled for elective repair of cyanotic congenital heart defects were studied. Patients were premedicated with oral or rectal pentobarbitone 2 mg.kg-1 90 minutes prior to induction of anaesthesia followed by intramuscular morphine 0.2 mg.kg-1 and atropine 0.02 mg.kg-1 60 minutes prior to induction. The SaO2 and HR of each child were monitored continuously using a Nellcor pulse oximeter during two 90 minute periods: a control period commencing 25.5 hours preoperatively (day 1) and a post premedication period commencing 1.5 hours preoperatively (day 2). Data were compared at time 0 (corresponding to the time of administration of pentobarbitone on day 2), 30 (corresponding to the administration of intramuscular morphine and atropine on day 2), 60 and 90 minutes (the latter corresponding to the time of induction on day 2) after the administration of pentobarbitone. There were no significant differences in SaO2 or HR between day 1 and day 2 at time 0, 60, and 90 minutes. The SaO2 (mean +/- SD) decreased significantly immediately following intramuscular premedication at time 30 minutes on day 2 (72.7 +/- 5.9 per cent) compared to the corresponding time on day 1 (83.9 +/- 2.9 per cent) (p less than 0.05). The duration of this desaturation was 2.5 +/- 1.9 minutes. Heart rate (mean +/- SD) increased from 109.2 +/- 21.3 beats.min-1 at time 30 minutes on day 1 to 142 +/- 20.4 beats.min-1 on day 2 (p less than 0.05). We conclude that administration of intramuscular premedication preceded by oral or rectal pentobarbitone causes transient arterial desaturation and tachycardia in children with cyanotic congenital heart disease.

Arterial desaturation in healthy children during transfer to the recovery room.

The oxygen saturation in 71 healthy paediatric patients (3.5 months to 16.7 years) was measured by pulse oximetry during transfer from the operating room to the recovery room. These measurements were recorded continuously while the patients breathed room air. Of the patients studied, 28.1 per cent exhibited significant arterial desaturation of less than or equal to 90 per cent. The corresponding PO2 for this saturation level is less than or equal to 58 mmHg. In only 45 per cent of these desaturated patients was the desaturation recognized clinically by the presence of cyanosis. Age, type of anaesthetic, the use or avoidance of narcotics, and the use of controlled or spontaneous respiration had no significant relationship to the incidence of desaturation. Since more than a one quarter of all patients studied desaturated significantly, and since cyanosis can be difficult to detect clinically during the transfer period, the use of supplemental oxygen during transfer should be considered by the anaesthetist at the end of every paediatric general anaesthetic.

Freeman-Sheldon syndrome: report of three cases and the anaesthetic implications.

The Freeman-Sheldon syndrome is a rare congenital myopathy and dysplasia. Fibrotic contractures of the facial muscles result in the characteristic "whistling face". Difficulties with intubation may be attributed in part to microstomia and micrognathia. In addition to other deformities, limb myopathy results in ulnar flexion contractures of the hand and equinovarus/valgus deformities of the feet. Intravenous access may be difficult because of limb deformities and thickened subcutaneous tissues. Limbs may be encased in plaster casts or splints limiting the available sites for venepuncture. Three case reports of children with Freeman-Sheldon syndrome are presented. The pathophysiology and anaesthetic problems encountered are discussed.

Spinal anaesthesia for minor paediatric surgery.

Our recent experience using spinal anaesthesia for paediatric surgical procedures is reviewed. In 1984, 30 patients aged seven weeks to 13 years were anaesthetised in this manner. Lumbar puncture failed in four of 34 patients, 12 required sedation during the operative course and 11 required light general anaesthesia to complete these procedures. Tetracaine one per cent or bupivacaine 0.75 per cent were the drugs used. During the procedure and depending on their age, the patients were either sedated or were distracted with the use of Disney cartoons played on a video cassette recorder. There were no significant intraoperative or postoperative complications.

Fentanyl pharmacokinetics and hemodynamic effects in preterm infants during ligation of patent ductus arteriosus.

A bolus of 30 micrograms X kg-1 fentanyl was given to nine preterm infants (gestational age 31.8 +/- 4.7 weeks, weight 1100 +/- 309 g) for induction of anesthesia for ligation of a patent ductus arteriosus. Thirty minutes after the injection, fentanyl plasma concentrations were between 7.7 and 13.6 ng X ml-1. Elimination half-life was 6-32 hr (mean +/- SD, 17.7 +/- 9.3). Systolic blood pressure remained stable throughout surgery. There was a gradual increase in heart rate from 159 +/- 12 min-1 at the time of skin incision to 173 +/- 15 min-1 at the time of skin closure (P less than 0.05). Fentanyl plasma concentrations remained virtually unchanged between 30 min (10.6 +/- 1.9 ng X ml-1) and 120 min (9.6 +/- 1.6 ng X ml-1); whereas at the end of surgery most infants moved and breathed spontaneously. This phenomenon can be explained by redistribution of fentanyl from brain into pharmacodynamically inert tissues.

Intraoperative aspiration in a paediatric patient.

Aspiration around uncuffed endotracheal tubes in paediatric patients is an uncommon event. Uncuffed endotracheal tubes are commonly used in paediatrics even when the risk of gastric aspiration is significant. A case history is presented of an 81/2-year-old who aspirated during a laparotomy for bowel obstruction. The patient was intubated with an uncuffed #6.0 Portex endotracheal tube. A small leak was noted during positive pressure ventilation. The aspiration was significant such that the patient required 24 hours of positive end-expiratory pressure (PEEP) in an intensive care unit. Uncuffed endotracheal tubes are used because post-intubation stridor is minimized, the lungs are compliant and the funnel-shaped trachea is more likely to secure the airway from aspiration. An uncuffed tube however, does not completely seal the airway, particularly in the presence of an audible "leak." As a result of this case, we now consider the use of a cuffed endotracheal tube in children whenever a 5.5 internal diameter or larger is required. When the risk of pulmonary aspiration is present, the cuff is inflated to reduce the likelihood of contamination of the airway.