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Biomedical subjects

B Bissonnette

Publications and source records attributed to B Bissonnette.

At least 91 records · Page 5Linked to original sources
PubMed1990

Hyperkalaemia during massive blood transfusion in paediatric craniofacial surgery.

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 less than 1 week of age was less than 20 mmol.L-1, whereas in units aged greater than 2 weeks it was greater than 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.

Blood Transfusion↗
PubMed1990

[Lidocaine aerosol following tonsillectomy in children].

Post-tonsillectomy analgesia was compared using ten per cent aerosol lidocaine or 1.5 mg.kg-1 intramuscular codeine. Thirty ASA physical status I or II children between two and ten years of age were assigned, in a random fashion, to one of two groups: Group A received codeine 1.5 mg.kg-1 intramuscularly, Group B received a total dose of 4 mg.kg-1 of ten per cent aerosol lidocaine on the tonsillar beds. For both groups, the treatment was administered at the end of the surgical procedure. The postoperative comfort state was assessed on a global scale using the following statement: (1) comfortable = 1, (2) agitation = 2, (3) uncontrollable = 3. Assessment of postoperative comfort was recorded after 20 min in the post-anaesthetic recovery room. Blood samples for lidocaine concentration estimation were obtained at 5, 7.5, 10, and 15 min after administration. Finally, the time of recovery was recorded. The immediate post-anaesthetic comfort observed with ten per cent aerosol lidocaine was statistically superior to that obtained with 1.5 mg.kg-1 intramuscular codeine. The maximal systemic lidocaine concentration which was 2.1 +/- 0.2 micrograms.ml-1 was well below the accepted toxic level of 5.3 micrograms.ml-1. The recovery room times were not statistically different between the two groups. In conclusion, 4 mg.kg-1 of ten per cent aerosol lidocaine applied directly on the tonsillar beds was shown a superior immediate post-tonsillectomy analgesic technique.

Aerosols↗
PubMed1990

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

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.

Adolescent↗
PubMed1990

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.

Analgesia, Epidural↗
PubMed1990

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

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.

Anesthesia, Caudal↗
PubMed1989

Single breath end-tidal CO2 estimates of arterial PCO2 in infants and children.

To determine whether single breath end-tidal carbon dioxide (PE'CO2) measurements accurately estimate arterial PCO2 (PaCO2) in infants and children, 68 healthy infants and children, ASA physical status I or II scheduled for peripheral and lower abdominal surgery requiring endotracheal intubation were studied. A 3 ml single breath sample was obtained with a 23-gauge needle which was inserted through the wall of the endotracheal tube below the connector. The mean +/- SD PE'CO2 33.6 +/- 6.9 mmHg did not differ significantly from the corresponding mean +/- SD PaCO2 33.6 +/- 5.6 mmHg. The coefficient of determination, r2, was 0.97. The authors conclude that single breath PE'CO2 measurements from the proximal end of the endotracheal tube accurately estimate the PaCO2 in infants and children.

Adolescent↗
PubMed1989

Passive and active inspired gas humidification in infants and children.

The hypothesis that both active and passive airway humidification prevents hypothermia in infants and children, but that neither decreases the duration of postoperative recovery was tested. Twenty-seven ASA physical status 1 or 2 patients were studied who weighed between 5 and 30 kg, underwent superficial operations, were anesthetized with halothane and 70% N2O, and whose lungs were ventilated via a Rees modification of an Ayre's t-piece. The children were randomly assigned to receive active airway humidification and warming using an MR450 Servo airway heater and humidifier set at 37 degrees C (n = 10), passive airway humidification using the Humid-Vent 1 heat and moisture exchanger placed between the Ayre's t-piece and the endotracheal tube (n = 8), or no airway humidification and heating (control, n = 9). Distal tracheal and tympanic membrane temperatures and airway humidity were recorded during the first 90 min of surgery. Rectal temperature was measured during the postanesthetic recovery period. Relative humidity of inspired respiratory gases was approximately 30% in the control group and approximately 90% in the group given active airway humidification. Initial inspired humidity in the passive humidification group (50%) increased to approximately 80%, a level not significantly different from that in the active group after 80 min of anesthesia. Central body temperature increased 0.25 degrees C during active active airway humidification and heating, whereas temperature decreased 0.25 degrees C during passive humidification and 0.75 degrees C without airway humidification. Distal tracheal temperature was significantly higher in the groups given passive and active humidification than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia Recovery Period↗
PubMed1989

Passive or active inspired gas humidification increases thermal steady-state temperatures in anesthetized infants.

We tested the hypothesis that active and passive airway humidification minimize hypothermia in infants, but that maintaining normothermia does not decrease the duration of postoperative recovery. A circle system was used to ventilate the lungs of anesthetized, intubated infants who were randomly assigned to active airway humidification and warming with use of an MR450 Servo airway heater and humidifier set at 37 degrees C (n = 10), passive airway humidification with use of the Humid-Vent Mini heat and moisture exchanger placed between the Y-piece of the circle and the endotracheal tube (n = 10), or no airway humidification and heating (control, n = 10). Anesthesia was induced with thiopental and maintained with isoflurane and nitrous oxide in oxygen. The relative humidity of inspired respiratory gases was approximately 35% in the control group and approximately 90% in the group undergoing active airway humidification. Initial inspired humidity in the passive humidification group (45%) increased to approximately 80% after 1 h of anesthesia. Humidity differed significantly across groups at all times (P less than or equal to 0.05). Steady-state rectal temperatures (100-120 min after induction) were 36.2 +/- 0.7 degrees C in patients given active humidification and heating, 35.7 +/- 0.9 degrees C in the passively humidified group, and 35.2 +/- 0.4 degrees C in the control group (P less than or equal to 0.05 between each group). Recovery from general anesthesia was rapid in all patients and did not correlate with central temperature changes or type of humidification (P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗