British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Arterial oxygen saturation during induction of anaesthesia and laryngeal mask insertion: prospective evaluation of four techniques.
In a prospective, randomized study of 87 patients, we have compared the incidence of hypoxaemia during induction of anaesthesia with subsequent Laryngeal Mask Airway (LMA) insertion in healthy adults when four different techniques were used: one without supplementary oxygen, and three with supplementary oxygen. Twelve patients did not receive supplementary oxygen before LMA placement, 25 underwent partial denitrogenation by breathing oxygen from the start of injection of the induction agent, 25 underwent formal denitrogenation by breathing oxygen for 3 min, and 25 received five tidal volume breaths of oxygen by face mask using positive pressure immediately after induction of anaesthesia. Anaesthesia was induced with propofol 2.0 mg kg-1 and fentanyl 1 microgram kg-1. ⋯ Desaturation occurred in 11 of 12 patients who did not receive supplementary oxygen, and in 19 of 25 patients who received manual ventilation with 100% oxygen after induction of anaesthesia before LMA insertion. Full denitrogenation and partial denitrogenation were equally successful in preventing desaturation. Failure to position the LMA successfully occurred in 3% of patients, and some difficulty was encountered in another 18%.
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We have examined in sheep the efficiency of the Hemopump during ventricular fibrillation. Circulatory arrest was induced by electrical stimulation and maintained for 30 min. ⋯ During fibrillation, the Hemopump sustained a mean arterial pressure of about 60 mm Hg with a blood flow rate of about 2.3 litre min-1. These perfusion conditions were sufficient for maintenance of aerobic myocardial metabolism, but with a borderline circulatory supply to the total organism.
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Randomized Controlled Trial Comparative Study Clinical Trial
IV diclofenac in post-thoracotomy pain.
We have studied the efficacy of a continuous i.v. infusion of diclofenac 2 mg kg-1/24 h given for 2 days after major thoracic surgery in 30 patients in a double-blind, placebo-controlled, parallel-group design. The patients were able to obtain additional pain relief as on demand morphine boluses. In the diclofenac group, the consumption of morphine was reduced by 60% during the first and by 76% during the second day after operation compared with the control group. ⋯ Urine output was significantly less during the first day after operation in the diclofenac group compared with the control group, but was normal on the second day after operation; plasma creatinine concentrations were unchanged. I.v. diclofenac infusion combined with opioids delivered via a patient-controlled analgesia device seems a valuable method of pain relief after thoracic surgery in patients in whom more invasive techniques, such as extradural local anaesthetics and opioids, cannot be used. However, non-steroidal anti-inflammatory drugs should be used cautiously, if at all, in patients who are at risk of acute renal failure.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of ketorolac trometamol on renal function.
We have compared the renal effects of ketorolac trometamol 10 mg administered 4-hourly by intermittent i.m. injection or by continuous i.m. infusion with placebo in a double-blind study in 67 patients who had undergone upper abdominal surgery. Ketorolac was supplemented during the 48-h postoperative study period with bolus doses of morphine delivered by a patient controlled analgesia system. ⋯ The overall changes caused by surgery alone were of much greater magnitude. Bleeding time was increased with ketorolac, but there were no adverse events related to this.
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Randomized Controlled Trial Comparative Study Clinical Trial
Reflective blankets used for reduction of heat loss during regional anaesthesia.
We have studied the ability of reflective blankets to reduce net loss of body heat during regional anaesthesia for total hip arthroplasty. Thirty patients were allocated randomly to either the study group (insulated with reflective blankets) or the control group (no reflective blankets). ⋯ Total body heat was deduced from core temperature (aural canal) and mean skin temperature (four measuring sites). After 2 h of surgery, loss of body heat was reduced significantly in patients wrapped in reflective blankets (26 kJ) compared with those in the control group (95 kJ).