Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1979
Experimental studies on artificial ventilation using a tidal volume ventilator. Mechanics and dynamics of ventilation.
In 24 piglets (2.7-24.5 kg b.w.), the mechanics of ventilation, the accuracy of dosage of respiratory volumes, and the influence of the ventilator's volume/pressure characteristics (Cvent, "internal compliance") on the dynamic course of insufflation were studied. A linear relationship was shown to exist between tidal volume and end-inspiratory tracheal pressure and between tidal volume and insufflation time. The insufflation time was reduced to about 50% of previously registered values. ⋯ The use of greater power from the ventilator resulted in a significant shortening of the duration of insufflation and vice versa. The duration of insufflation is the parameter of choice in evaluating the efficiency of the ventilatory equipment. When the ventilator's performance is defined, measurements of the duration of insufflation may enable evaluation of conditions within the lungs.
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Acta Anaesthesiol Scand · Aug 1979
Influence of ventilatory frequencies and ventilator volume/pressure quotients on pulmonary ventilation using a tidal volume ventilator.
The influence of ventilatory frequency and the ventilator's "internal state of gas compression" (Cvent) on mechanics of ventilation, pulmonary ventilation, gas distribution, gas exchange and lung perfusion was studied with free airway and experimental regional airway obstruction in 10 piglets (7-12 kg b. w. ), using a tidal volume ventilator. The VDphy/VTexp ratio was greater at f = 30 than at f = 10.3 cycles/min. This could be related to a significant increase in the VDanat/VTexp ratio at f = 30, while VDc/VTexp and VDlav/VTexp were unchanged at both frequencies. ⋯ With Cvent 20, the ventilation of the lung bases was reduced, which was compensated for by a large increase in ventilation within the apical areas of the lungs, while gas distribution within the unobstructed areas was more evenly distributed with Cvent 80. Ventilation at Cvent 20 showed no essential advantage over Cvent 80. Only in lungs extremely difficult to ventilate and with ventilatory frequencies over 50 cycles/min could possible indications for Cvent 20 be seen.
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Acta Anaesthesiol Scand · Jun 1979
Importance of using proper techniques to teach cardiopulmonary resuscitation to laymen.
Immediate attempts to resuscitate patients with cardiac arrest by lay bystanders distinctly increase the chances of survival in such patients. In the present study we investigated possibilities of intensifying the cardiopulmonary resuscitation (CPR) training of laymen. A group of 46 young conscripts (test group) was given 2 hours of CPR instruction in what was considered the most efficient way. ⋯ The less intensive training given to the reference group did not improve the acceptability of resuscitation. It is concluded that CPR training for laymen may lead to failure to attain an adequate level of skill. Proper training techniques and equipment are important, but even their use does not guarantee that an adequate level of CPR performance will be attained by all laymen if their skills are not later refreshed.
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Acta Anaesthesiol Scand · Jun 1979
Randomized Controlled Trial Clinical TrialPostoperative arterial oxygen tension after peroperative PEEP-ventilation.
Forty otherwise healthy patients (29 women and 11 men), undergoing elective cholecystectomy, were randomly allocated to be ventilated during the operation either with a positive end-expiratory pressure of 1 kPa (10 cmH2O) (PEEP group) or with intermittent positive pressure ventilation without PEEP (control group). During the operation the mean arterial oxygen tension (PaO2) in the PEEP group increased from 14.6 to 16.5 kPa, while no changes occurred in the control group (13.5 and 13.6 kPa). On the first postoperative day, PaO2 decreased by 12% of the preoperative values in the PEEP group; the decrease was 20% in the control group. ⋯ In the postoperative period, no statistically significant difference in PaO2 could be demonstrated between the groups. Determinations of the forced vital capacity and forced expiratory volume in the first second showed no difference between the groups pre- or postoperatively. The present study demonstrated no clinically relevant beneficial effect of peroperative PEEP ventilation on the postoperative arterial hypoxaemia after an upper abdominal laparotomy.
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Acta Anaesthesiol Scand · Apr 1979
Clinical Trial Controlled Clinical TrialArrhythmias during halothane anesthesia IV. The influence of a single dose of suxamethonium.
The effect of a single dose of suxamethonium on cardiac rate and rhythm during halothane anesthesia with babiturate induction was studied in a prospective, triple-blind trial with 28 patients. No atropine was given and patients were not intubated. ⋯ Suxamethonium did not provoke ventricular ectopies or conduction disturbances. It is concluded that in anesthesia with barbiturate induction, but without atropine or intubation, the use of a single dose of suxamethonium is a safe procedure with regard to cardiac rate and rhythm.