Canadian journal of anaesthesia = Journal canadien d'anesthésie
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The N-CAT is a newly developed arterial tonometer (TBP) able to determine systolic, diastolic and mean arterial blood pressures continuously and noninvasively. The aim of this study was to evaluate the accuracy and reliability of TBP relative to directly measured invasive blood pressure (IBP) in ten haemodynamically stable postoperative cardiac patients who were in rapid atrial fibrillation (HR > or = 100 bpm). ⋯ Although these biases are within the required standards for equivalency for noninvasive blood pressure to invasively determined blood pressure, approximately 20% of the readings were > +/- 10 mmHg while only 5% were > +/- 20 mmHg. Moreover, there were occasional discrepancies of sufficient magnitude and duration which may limit the clinical usefulness of the N-CAT in patients in whom continuous and accurate blood pressure measurement is required.
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Randomized Controlled Trial Clinical Trial
Perioperative gastric aspiration increases postoperative nausea and vomiting in outpatients.
The efficacy of aspiration of gastric contents to reduce postoperative nausea and vomiting was investigated in a controlled randomized, double-blind study of 265 outpatients. Patients in the treated group had their stomachs aspirated with an orogastric tube. In the control group no tube was inserted. ⋯ It was also comparable in the recovery room and the day surgery unit. However, treated patients had a higher incidence of both nausea (26.5% vs 12.0%, P < 0.005) and vomiting (16.7% vs 6.8%, P < 0.02) after their discharge from the day surgery unit. We conclude that aspiration of gastric contents with an orogastric tube does not decrease postoperative nausea and vomiting in outpatients and may increase it after discharge of the patient.
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To examine the effects of low-flow cardiopulmonary bypass (CPB) and circulatory arrest (PHCA) on cerebral pressure-flow velocity relationships, we studied 32 patients (< 9 mo of age) undergoing corrective cardiac procedures. Pressure-flow velocity relationships were studied during profound hypothermia (nasopharyngeal temperature < 20 degrees C). Cerebral blood-flow velocity (CBFV) was measured in the middle cerebral artery using transcranial Doppler sonography. ⋯ In 12 of these patients the pattern of recovery of CBFV was the same as that observed after low-flow CPB whereas the remaining five (29%) demonstrated a pattern of recovery identical to the ones recorded after PHCA. We conclude that after PHCA a higher CPP is necessary to re-establish and maintain detectable CBFV. Furthermore, during low-flow CPB, patients where CBFV becomes non-detectable and show a pattern of CBFV recovery similar to PHCA, cessation of cerebral perfusion must be considered.
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Randomized Controlled Trial Clinical Trial
Aortocaval compression in the sitting and lateral decubitus positions during extradural catheter placement in the parturient.
We prospectively studied the incidence of concealed aortocaval compression in parturients at term during identification of the extradural space. Forty ASA I or II parturients, at term and in active labour, who requested extradural analgesia were randomly allocated to one of two groups. Parturients in the first group (n = 22) were positioned in the left lateral decubitus position and those in the second group (n = 18) were in the sitting position. ⋯ In the left lateral decubitus position, 17 of 22 patients demonstrated a > 25% reduction in COTEB compared with five of 18 patients in the sitting position (chi 2, P < 0.01). The percentage change in COTEB in the lateral decubitus position (-29.8%, 95% CI -17% to -44%) was greater than the sitting position (-9.8%, 95% CI +36% to -32%) (P < 0.01). A decreased incidence of aortocaval compression during identification of the extradural space was demonstrated in the sitting position when compared with the left lateral decubitus position.