Showing papers by "Bruno Bissonnette published in 1990"

Hyperkalaemia during rapid blood transfusion and hypovolaemic cardiac arrest in children.

Abstract: A morbidity and mortality review documented a high occurrence of hyperkalaemia in cardiac arrests associated with rapid blood transfusion, which resulted in further study. In order to stimulate events during rapid blood transfusion and cardiac arrest, the central circulation was modeled as a linear one compartment, and used to stimulate a child who suffered a hypovolaemic cardiac arrest and was resuscitated with rapid blood transfusion (RBT). The simulation suggested that the combination of RBT and a low cardiac output state could be associated with hyperkalaemia, if the potassium concentration in the plasma fraction of the transfused blood was greater than or equal to 10 mmol.L-1. In an associated clinical study the plasma potassium concentration during cardiac arrest was documented from a retrospective review of 138 cardiac arrests in a paediatric population. Patients were divided into two groups. The RBT-group received a rapid blood transfusion during resuscitation. The non-RBT group did not receive blood during resuscitation. During cardiac arrest the plasma [K] in the non-RBT group was 5.63 +/- 2.39 mmol.L-1 compared with 8.23 +/- 1.99 mmol.L-1 in the RBT-group (P less than 0.05). The hyperkalaemia during cardiac arrest in the RBT-group could be explained as a consequence of RBT to a hypovolaemic child with a low cardiac output.

Hyperkalaemia during massive blood transfusion in paediatric craniofacial surgery.

Abstract: Children undergoing major craniofacial surgery (MCFS) often require transfusion in excess of one blood volume. Therefore they were the subject of a retrospective review which looked at the longitudinal trend of plasma potassium concentration [K+] during surgery. Ten of eleven children had a statistically significant increase in plasma potassium concentration during their intraoperative course and in five the potassium concentration exceeded 5.5 mmol · L−1. This was in contrast to the stable intraoperative plasma [K+] observed in a control group which did not receive blood transfusion. All MCFS children received a blood transfusion with red blood cell concentrates (RBCconc). The age of the units of RBCconc which had been transfused was 16.1 ± 8.4 days. The amount of extracellular potassium in 28 units of RBCconc was determined in order to estimate the amount of free potassium (Kdose) which the MCFS group received. The plasma [K+] in units of RBCconc 2 weeks it was > 40 mmol · L−1. The estimated Kdose was 0.2–1.6 mmol · kg−1. We concluded that the amount of extracellular potassium in units of RBCconc was clinically important and may give rise to hyperkalaemia during massive blood transfusion.

The thermoregulatory threshold in infants and children anesthetized with isoflurane and caudal bupivacaine.

Abstract: Hypothermia in anesthetized adults provokes centrally mediated, peripheral thermoregulatory vasoconstriction at threshold temperatures approximately 2.5 degrees C below normal. The weight dependence of thermoregulatory vasoconstriction was evaluated in 33 unpremedicated pediatric patients receiving isoflurane/oxygen anesthesia (end-tidal concentrations approximately 0.9%) and caudal anesthesia with bupivacaine. The patients were prospectively assigned to four weight groups (5-10 kg, 10-20 kg, 20-30 kg, and 30-50 kg). Central temperature was measured at the tympanic membrane, and average skin surface temperature was determined from four cutaneous sites; mean body temperature was calculated from central and average skin temperatures. Finger blood flow was determined using laser Doppler flowmetry and forearm-fingertip skin temperature gradients. Significant peripheral vasoconstriction was prospectively defined as a laser Doppler flow index 50% of the value recorded 10 min after induction of anesthesia. Thermoregulatory thresholds were defined as the tympanic membrane or mean body temperatures at which significant vasoconstriction occurred. Vasoconstriction occurred in 32 of the patients at temperatures ranging from 34.4 to 35.3 degrees C. Central and mean body threshold temperatures did not differ among the groups, and were similar to those observed previously in adults. There was a good correlation between laser Doppler flowmetry and forearm-fingertip skin temperature gradients in individual patients.

Pharmacodynamics of high-dose vecuronium in children during balanced anesthesia.

Abstract: To compare the speed of onset, intubating conditions, duration of action, and recovery from neuromuscular blockade with vecuronium to those with succinylcholine, 40 ASA physical status 1 or 2 children (ages 2-9 yr) were studied during N2O-O2-opioid anesthesia. Each child was randomly assigned to receive a bolus dose of one of the following muscle relaxants: succinylcholine 2.0 mg/kg (n = 10), vecuronium 0.1 mg/kg (n = 10), vecuronium 0.2 mg/kg (n = 10), or vecuronium 0.4 mg/kg (n = 10). The evoked electromyogram of the abductor digiti minimi to train-of-four stimulation was monitored. We found that with succinylcholine, the time to 95% twitch depression (speed of onset, mean +/- SD), 24 +/- 7 s, was significantly less than that with each dose of vecuronium: 0.1 mg/kg, 83 +/- 21 s; 0.2 mg/kg, 58 +/- 17 s; and 0.4 mg/kg, 39 +/- 11 s, respectively (P less than 0.05). The time to laryngoscopy and intubation did not differ significantly between succinylcholine (48 +/- 10 s) and vecuronium 0.4 mg/kg (57 +/- 13 s); however, both were significantly less than than with vecuronium 0.1 and 0.2 mg/kg (P less than 0.005). The intubating conditions were excellent in 100% of patients. The duration of action was least with succinylcholine (5.7 +/- 1.5 min) and increased with increasing doses of vecuronium: 0.1 mg/kg, 23.9 +/- 5.1 min; 0.2 mg/kg, 55.2 +/- 11.6 min; and 0.4 mg/kg, 74.6 +/- 9.9 min, respectively (P less than 0.001). The recovery index was most rapid with succinylcholine (1.6 +/- 0.4 min) and was slowest with vecuronium 0.4 mg/kg (22.6 +/- 2.1 min) (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Flare reaction following caudal analgesia

Abstract: 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.