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Biomedical subjects

P Hole

Publications and source records attributed to P Hole.

52 records · Page 3Linked to original sources
PubMed1981

Carbon dioxide tensions in manually ventilated, prone patients.

The distribution of arterial carbon dioxide tensions (PaCO2) in 288 anaesthetized, healthy patients in the prone position was investigated during non-monitored manual ventilation. Four equal groups of 72 patients were compared employing a conventional anaesthetic system with and without CO2-absorption and a modified Mapleson D rebreathing system using high and low fresh gas flows. No fundamental difference between the Mapleson D system and the circle system without CO2-absorption could be demonstrated. With the Mapleson D system a high fresh gas flow resulted in a loss of rebreathing characteristics, the scatter of PaCO2-values then approaching that of a conventional circle system with CO2-absorption. The results demonstrate that during manual ventilation a CO2-absorption results in unpredictable levels of PaCO2 with unacceptably wide ranges. On the other hand, prevention of hypocapnia could be obtained with the rebreathing systems using a low fresh gas flow. Hypercapnia was modest and similar in all groups, PaCO2 never exceeding 7.3 kPa. In terms of PaCO2-levels it seems, compared to recent literature, of no importance whether the patient is prone or supine or whether or not ventilation is monitored, performed by hand or by means of anaesthetic ventilators. Accurate levels of PaCO2 can probably only be obtained by frequent analyses of PaCO2, or monitoring of the end-tidal CO2 concentration.

Adult↗
PubMed1980

Haemolytic uraemic syndrome and accumulation of haemoglobin-haptoglobin complexes in plasma in serum sickness caused by penicillin drugs.

2 patients treated with penicillin and ampicillin, respectively, suffered from haemorrhagic diathesis, haemolysis, cerebral symptoms and renal insufficiency, resembling a haemolytic-uraemic syndrome. Their plasma was red due to the presence during several days of haemoglobin-haptoglobin complexes, the P-haemoglobin being 2.8 and 1.6 g/l, respectively. Coagulation tests showed an unusual pattern with prolonged activated partial thromboplastin times, an extremely long thrombin time and very high levels of fibrinogen degradation products. Repeated transfusion had no effect. The patients were considered to have developed a drug-induced serum sickness associated with insufficient function of the reticuloendothelial system, and secondary to this an accumulation of haemoglobin-haptoglobin complexes in plasma. When the penicillin drugs were discontinued, all measured variables rapidly normalised and the patients recovered completely. Thus, the haemolyticuraemic syndrome seemed to be caused by the serum sickness, possibly via circulating or cell-associated immune complexes. The possibility of a type III allergic reaction should be considered in patients with haemolytic-uraemic-like syndromes.

Adult↗
PubMed1979

Comparison of anti-pollution modifications of Mapleson A and D anaesthetic systems.

Hafnia A and Hafnia D anaesthetic systems are non-polluting modifications of the Mapleson A and D systems. The excess gas is vented in the Hafnia systems directly and continuously via a calibrated ejector flowmeter. Sixteen adult patients anaesthetized for abdominal surgery were ventilated and either Hafnia A or D systems at six different fresh gas flows. No difference between the Hafnia A and D systems could be demonstrated in the values of arterial carbon dioxide tension measured with the same fresh gas flow, despite gas flows in opposite directions.

Aged↗
PubMed1979

Method for continuous measurement of carbon dioxide output during anesthesia. An assessment.

Employing the Mapleson D circuit, a modified closed-circuit flow-through technique for the continuous measurement of carbon dioxide production (VCO2) was tested for accuracy and precision in a lung model. The recovery of carbon dioxide production was found to be between 90 and 110%, the maximized errors for a single estimate of carbon dioxide production were between +/- 4 and +/- 28%, with the highest errors at high gas flows and low carbon dioxide inputs. Accepting arbitrarily chosen limits of maximized errors of +/- 10%, it could be shown that the system did not work acceptably when the mean carbon dioxide concentration was below 1.5 vol.% within the fresh gas flow rates (2.2--7.7 1 min-1) and the range of minute ventilation (4--10 1 min-1) employed. The half-life of carbon dioxide washout varied between 41 and 138 s, thus limiting the suitability of the system for detecting changes in carbon dioxide output. The method may be used as an approximate monitor of VCO2 in anaesthetized patients, but cannot be regarded as sufficient for research purposes.

Anesthesia↗
PubMed1979

Arterial carbon dioxide tensions during anaesthesia with manual ventilation. A descriptive study of the effects of various non-polluting circuits.

In 660 supine, intubated and anaesthetized, healthy patients scheduled for various elective surgical procedures, the distribution of arterial carbon dioxide tension (PaCO2) was investigated during manual non-monitored ventilation. The study comprised six equal groups: group 1: ventilation with a circle circuit absorber system; group 2: ventilation with the Hafnia A circuit using a total fresh gas flow (FGF) of 100 ml . kg-1 . min-1; groups 3-6: ventilation with a Hafnia D circuit with fresh gas flows of 100, 80, 70 and 60 ml . kg-1 . min-1, respectively. The mean PaCO2's of the first three groups were situated in the lower range of normocapnia (the observations in the first group having the greatest total range), whereas the rebreathing (Hafnia A and D) circuits resulted in a clustering of observed data. Employing the rebreathing circuits, protection against hypocapnia can be achieved by lowering the fresh gas flow. The most satisfying result was obtained with the Hafnia D circuit with a fresh gas flow of 70 ml . kg-1 . min-1 resulting in normocapnia with a modest and limited spread towards hypo- and hypercapnia. FGF in excess of this level must be considered as wasted. The study indicates that corrections of fresh gas flows for age are superfluous. Use of relaxants and type of surgery had no influence on the observations.

Adolescent↗