Early intravenous cannulation in children during inhalational induction of anaesthesia.

Intravenous cannulation is obtained in almost all patients scheduled for operative intervention under anaesthesia. In our practice, inhalational induction precedes cannulation in children in order to avoid pain and discomfort, and cannulation is delayed until the child is adequately anaesthetized in fear of precipitating laryngospasm due to painful stimulus of venepuncture in the light stage of anaesthesia. This study was performed on 150 patients between two to eight years of age to determine if there is a difference in the incidence of untoward incidents, if cannulation is performed when children are lightly anaesthetized (Early, Group E), as compared to when they are deeply anaesthetized (Late, Group L). In patients randomized to early cannulation, the results showed that there was a significantly shorter time from induction to venous cannulation, the halothane concentration was lower at the time of cannulation, there was a greater incidence of movement on cannulation and a greater incidence of changes in heart rate, blood pressure, and respiratory rate. There was no significant differences in the incidence of laryngospasm or in the success rate of intravenous cannulation between the two groups. We conclude that venous cannulation can be safely performed during the light stages of anaesthesia.

Analgesia for venepuncture in a paediatric surgery centre.

OBJECTIVE: To establish an effective and efficient method of painless venepuncture in children 8 years and older in an ambulatory paediatric surgery centre. METHODOLOGY: Sixty patients aged 8-21 years were randomized to one of three groups: (i) nitrous oxide with EMLA cream; (ii) nitrous oxide with intradermal lidocaine; and (iii) nitrous oxide alone (n = 20 in each group). Patients in all three groups received oral midazolam for pre-operative anxiolysis. The degree of patient sedation and anxiolysis was noted by two observers before and 2 min after the administration of 50% nitrous oxide. The patient's response to venepuncture or intradermal lidocaine was rated by the two observers using an Observer Response Score. After successful venepuncture, the nitrous oxide was discontinued and the patient was asked to rate the pain of venepuncture using a Patient Response Score. RESULTS: There were no differences in the degree of sedation and anxiolysis between the three groups before or after the administration of nitrous oxide. Patients in the control group (nitrous oxide alone) had a higher incidence of withdrawal or vocalization with venepuncture. When the patients rated the pain of venepuncture, there were no differences between the three groups. CONCLUSIONS: Oral midazolam in combination with 50% nitrous oxide provides adequate analgesia and anxiolysis for venepuncture in patients 8 years and older. The addition of EMLA cream or intradermal lidocaine will decrease the likelihood of patient movement.

The safety of continuous pleural lignocaine after thoracotomy in children and adolescents.

Several studies have proven pleural bupivacaine effectively provides postthoracotomy analgesia for both children and adults. When 0.25% bupivacaine is administered as a continuous infusion or repeated bolus, serum bupivacaine levels frequently approach the toxic range. The hazards of bupivacaine toxicity are more difficult to monitor, especially in children who may not report symptoms of local anaesthetic toxicity. Because of this concern, we initiated the use of pleural lignocaine to provide postthoracotomy analgesia for paediatric patients. The records of all patients receiving pleural lignocaine from January 1991 to December 1992 were reviewed. A total of 98 pleural catheters were inserted in 96 patients ranging in age from five months to 20 years. Seven patients had lignocaine levels that exceeded 5 micrograms.ml-1 and no patient manifested symptoms of systemic toxicity. This study shows that the administration of pleural lignocaine is a safe method of providing postthoracotomy analgesia. Lignocaine infusions in the dosage range of 20 to 40 micrograms.kg-1.min-1 rarely produce toxic levels, and monitoring of lignocaine levels every 12 h is an effective method of screening for toxicity.

Anaesthesia for the patient with neonatal adrenoleukodystrophy.

The authors present and discuss the care of a nine-month-old with neonatal adrenoleukodystrophy who required general anaesthesia for gastrointestinal endoscopy. Neonatal adrenoleukodystrophy is an inherited disorder of peroxisomal enzymes. Anaesthetic care may be affected by the presence of hypotonia, liver function abnormalities, gastroesophageal reflux, and impaired adrenocortical function. Preoperative sedation is contraindicated because of the risk of precipitating airway obstruction due to pre-existing hypotonia. Anaesthetic induction and tracheal intubation should be performed to minimize the risk for aspiration of gastric contents. The choice of muscle relaxant should take into account the pre-existing hypotonia as well as the possibility of hyperkalaemia in response to succinylcholine. Anaesthetic agents known to decrease the seizure threshold should be avoided in patients with a seizure disorder. In addition, anaesthetic agents that rely on the liver for metabolism should be used with caution in patients with cirrhosis. When time permits, these patients should be screened for adrenocortical insufficiency before surgery, and perioperative steroid coverage is advisable when preoperative testing of adrenocortical function is not feasible. While these patients eventually die after progressive deterioration, full recovery from the effects of anaesthesia and surgery can be achieved with attention to neurological, metabolic, and physical problems.

Bacterial endocarditis prophylaxis: what is recommended and what is practiced?

STUDY OBJECTIVE: To determine how often pediatric anesthesiologists follow the American Heart Association (AHA) recommendations for the administration of prophylactic antibiotics to prevent bacterial endocarditis (BE). DESIGN: Questionnaires mailed to all members of the Society for Pediatric Anesthesia regarding their use of antibiotics to prevent BE. SETTING: Anesthesia department at a university-affiliated children's hospital. MEASUREMENTS AND MAIN RESULTS: 898 questionnaires were mailed, and 465 questionnaires were returned, yielding a response rate of 52%. When anesthesiologists administer BE prophylaxis intravenously (IV), they perform an inhalation anesthetic 76% of the time prior to establishing IV access. Ninety percent of the respondents stated that if administration of antibiotics occurs after a mask induction, they do not delay incision or instrumentation for 30 minutes. Therefore, respondents do not follow AHA recommendations for BE prophylaxis 55% of the time. Of the 465 respondents, only 4 recalled pediatric patients who developed perioperative BE. CONCLUSIONS: The majority of anesthesiologists responding to this survey routinely do not follow the current AHA recommendations for BE prophylaxis when caring for children. Since there are no studies demonstrating that administering antibiotics 30 minutes prior to invasive procedures is more effective than administering antibiotics immediately prior to invasive procedures, it may be appropriate to follow a time sequence that is more comfortable and convenient for pediatric patients. We believe that a reconsideration of the current AHA recommendations for BE prophylaxis is warranted.

Tracheal tube leak test--is there inter-observer agreement?

Although the leak test is recommended as a method of assessing the appropriate size of uncuffed endotracheal tubes for use in children, the reproducibility of this test has not been validated. Patients from newborn to ten years of age requiring tracheal intubation for elective surgery were studied. The endotracheal tube size was calculated using the formula: (age + 16) divided by 4 for patients > or = two years of age and at the discretion of the attending anaesthetist for patients < two years of age. After the induction of anaesthesia and administration of a nondepolarizing muscle relaxant, the patient's trachea was intubated and mid-tracheal placement was confirmed. Two of the three staff anaesthetists participating in the study assessed the leak pressure consecutively. Each participant performed a single leak determination. The leak pressure was determined as follows: the patient was supine with the head in a neutral position, fresh gas flowed into the breathing circuit at 5 L.min-1, a stethoscope was placed on the skin over the larynx and the pressure relief valve was completely closed. Pressure slowly increased in the breathing circuit until an audible leak occurred around the tracheal tube. The inter-observer difference was calculated in 212 patients. The absolute value of the difference between that of two observers increased as the mean leak pressure increased. However, the variation between observers expressed as a percent of the absolute measurement remained constant. An average variance in measurement of 38% was found at both low and high leak pressures. In conclusion, we found considerable variation between two experienced observers in assessing leak pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma cholinesterase deficiency in a neonate.

We report a two-day-old infant who had a period of apnoea lasting six hours following the intravenous administration of succinylcholine (Sch). The results of her plasma cholinesterase level and dibucaine number indicate a congenital absence of plasma cholinesterase (PChE) enzyme, although both parents and siblings had normal cholinesterase levels and dibucaine numbers. This is believed to be the youngest reported case of prolonged apnoea after the administration of succinylcholine.