Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jan 1992
A new ventilator converter with the Siemens Servo Ventilator--evaluation in a lung model.
A ventilator converter device (Anmedic) for connecting a non-rebreathing ventilator (Servo Ventilator 900 B; Siemens-Elema) to a circle anaesthesia system was evaluated in a lung model. Recorded minute ventilation was slightly lower than dialled in most cases. We furthermore found inadequate expiratory expansion of the ventilator converter bellows, with progressive loss of tidal volume and consequently recorded minute volume, when fresh gas flow to the circle system was low (1 l.min-1), expiratory time was short (less than 40%) and respiratory obstruction was present.
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Acta Anaesthesiol Scand · Jan 1992
Comparative StudyPost-dural puncture headache in young orthopaedic in-patients: comparison of a 0.33 mm (29-gauge) Quincke-type with a 0.7 mm (22-gauge) Whitacre spinal needle in 200 patients.
The incidence of postdural puncture headache (PDPH) following spinal anaesthesia with a 0.33 mm (29-gauge) and two types of 0.7 mm (22-gauge) Whitacre needles was investigated in 400 patients less than 40 years old. The incidence of PDPH was 2% in the 0.33 mm group, and 3.5% in the 0.7 mm group. ⋯ The failure rate was significantly higher in the 0.33 mm group (8.5% vs 2%) than in the 0.7 mm group (P less than 0.05). It is concluded that the 0.33 mm needle is associated with a low incidence of PDPH in young patients, but has a significantly higher failure rate than the Whitacre 0.7 mm needle, which is also a suitable choice in this age-group because of its ease of handling and the low incidence of PDPH.
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Acta Anaesthesiol Scand · Jan 1992
Comparative StudyEffectiveness of pressure support ventilation for mechanical ventilatory support in patients with status asthmaticus.
We compared the effects of pressure support ventilation (PSV) with those of assist control ventilation (ACV) on breathing patterns and blood gas exchange in six patients with status asthmaticus. Both PSV and ACV delivered adequate minute ventilation (PSV: 7.5 +/- 1.4 l/min/m2, ACV: 7.3 +/- 1.3 l/min/m2) to correct respiratory acidosis (pH = 7.33 +/- 0.12 during both PSV and ACV) and prevent hypoxia. ⋯ The oxygen cost of breathing estimated by oxygen consumption was equivalent in both modes. We conclude that PSV is effective in supplying tidal volumes adequate to improve hypercarbia at markedly lower airway pressures than ACV.
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In order to evaluate postoperative pain treatment following thoracic surgery, 214 medical records of patients who were operated during 1986-1988 were examined. Nurses' comments concerning pain and the amounts of analgesics given during the 2 postoperative days were recorded. The 150 patients who were still alive in December 1989 were sent a postal questionnaire which asked about the pain and the efficacy of pain relief they had received after their operation. ⋯ During the first postoperative week little pain was experienced by 60% of the patients, considerable pain by 35% and excruciating pain by 5% of the patients being interviewed. The postoperative pain relief was rated as good in 60% of the answers, satisfactory in 38% and poor in 2%. Persistent post-thoracotomy pain lasting for more than 6 months was reported by 44% of the patients, of whom 66% had received treatment for the pain.
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Acta Anaesthesiol Scand · Jan 1992
Pulmonary effects of body position, PEEP, and surfactant depletion in dogs.
The influence of position (sphinx, lateral, supine), surfactant depletion, and different positive end-expiratory pressure (PEEP) on functional residual capacity (FRC), series dead space (VdS) and compliance of the respiratory system (Crs) were evaluated in five dogs. Ventilation homogeneity as measured by an index (multiple breath alveolar mixing efficiency), oxygenation, and cardiovascular hemodynamics were additionally examined. The dogs were anesthetized with halothane, paralyzed, and mechanically ventilated. ⋯ Surfactant depletion by lung lavage with 37 degrees C saline caused an immediate and stable decrease in FRC, Crs, and oxygenation (P less than 0.05, respectively) for about 5 h without marked effects on the circulatory system. FRC and VdS increased with increasing PEEP. At the highest PEEP, 10 cmH2O (1 kPa), Crs decreased (P less than 0.05) and ventilation became more uneven, indicating alveolar overdistension.