Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Transcranial Doppler sonography: nitrous oxide and cerebral blood flow velocity in children.
To determine the effect of nitrous oxide (N2O) on cerebral blood flow velocity (CBFV) and cerebrovascular resistance index (RI+) in children, ten ASA physical status I or II patients aged one to eight years old, scheduled for urological procedures, were studied. Anaesthesia was induced with thiopentone 2 mg.kg-1, fentanyl 5 micrograms.kg-1 and diazepam 0.3 mg.kg-1. Muscular relaxation was ensured by using vecuronium 0.1 mg.kg-1. ⋯ Ventilation was adjusted to achieve normocapnia. The CBFV increased when 70% N2/O2 was replaced by 70% N2O/O2 (P less than 0.05) while the CBFV decreased when 70% N2/O2 was readministered (P less than 0.05). Likewise, the CBFV decreased when 70% N2O/O2 was replaced by 70% N2/O2 (P less than 0.05) while the CBFV increased when 70% N2O/O2 was readministered (P less than 0.05).
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The pulse oximeter was evaluated for use in neonates in the delivery room. One hundred neonates, delivered vaginally or by Caesarean section with general or epidural anaesthesia, were studied. After delivery, pulse oximetry probes were placed simultaneously on the ulnar side of the right hand and on the right Achilles tendon to determine whether there was a difference in arterial oxygenation (SpO2). ⋯ These results can be explained by the presence of R-L shunting at the ductus arteriosus level, producing reduced SaO2 in the lower extremities. Oxygen saturation did not differ between neonates delivered vaginally or by Caesarean section, regardless of the presence or type of anaesthesia. We concluded that neonates remain relatively desaturated in the immediate postpartum period and that the SpO2 obtained from the right hand is a better index of neonatal oxygenation than that obtained from the heel.
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The purpose of this study was to evaluate the stability of the arterial PCO2 (PaCO2) to end-tidal PCO2 (PETCO2) partial pressure difference (Pa-ETCO2) during surgery using PETCO2 monitoring, in children with congenital heart disease (CHD). Forty children with CHD were studied: ten children with no interchamber communication and normal pulmonary blood flow (PBF) (normal group); ten acyanotic children with increased PBF (acyanotic-shunting group); ten cyanotic children with mixing type lesions and normal or increased PBF (mixing group), and ten cyanotic children with right-to-left intracardiac shunts demonstrating decreased and variable PBF (cyanotic-shunting group). Simultaneous PaCO2 recordings and PETCO2 measurements were obtained for each patient during five intraoperative events: (1) control time, arterial line placement under anaesthesia; (2) time 1, patient preparation; (3) time 2, immediately after sternotomy; (4) time 3, after heparin administration; and (5) time 4, immediately after aortic cannulation. ⋯ We conclude that the Pa-ETCO2 of children with acyanotic-shunting and mixing congenital heart lesions is stable intraoperatively, although patients with mixing congenital heart lesions may demonstrate large individual variations. In children with cyanotic-shunting congenital heart lesions, the Pa-ETCO2 is not stable. The PETCO2 cannot be used during surgery to estimate reliably the PaCO2 in children with cyanotic CHD.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Bolus administration of esmolol for controlling the haemodynamic response to tracheal intubation: the Canadian Multicentre Trial.
A multicentre trial was designed to determine the dose-response and side-effects of esmolol when administered as a single iv bolus prior to induction of anaesthesia for controlling the haemodynamic response to tracheal intubation. Five hundred and forty-eight patients from 12 university-affiliated centres across Canada were randomized prospectively to receive either placebo (PLAC) or esmolol (E) in a dose of 100 mg (E100) or 200 mg (E200). Study medication was given immediately before induction of anaesthesia with thiopentone 3-5 mg.kg-1 and succinylcholine 1.5 mg.kg-1. ⋯ Other side-effects, such as bradycardia, bronchospasm or pain on injection, occurred no more frequently in either esmolol group than with placebo. It is concluded that a 100 mg bolus of esmolol is safe and effective for controlling the haemodynamic response to tracheal intubation. This dose of esmolol combined with a low dose of narcotic (fentanyl 2-3 micrograms.kg-1 or equivalent) results in effective control of both heart rate and blood pressure, while avoiding important side-effects.