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G Cold

Publications and source records attributed to G Cold.

8 recordsLinked to original sources

Per- and postoperative changes in the arterio-venous oxygen content difference (AVDO2) in patients subjected to craniotomy for cerebral tumours.

Sixteen patients with supratentorial cerebral tumours were subjected to craniotomy under thiopentone, fentanyl, nitrous oxide, halothane anaesthesia during moderate hypocapnia (PaCO2 level 4.0 kPa). The arterio-venous oxygen content difference (AVDO2) was measured peroperatively, and repeatedly during the first three hours after extubation. Peroperatively the level of AVDO2 averaged 8.0 vol% during opening of the dura, and decreased to 7.0 vol% during closure of the dura (P less than 0.05). Immediately after extubation the AVDO2 decreased to 4.3 vol% (P less than 0.05), and during the next 3 hours a gradual increase to 5.8 vol% (P less than 0.05) was disclosed. In individual cases the postoperative changes in AVDO2 correlated fairly well with changes in mean arterial blood pressure (MABP), but other factors including duration of the operation, age of the patients, size of the tumour, level of PaCO2 and adaptation to prolonged hyperventilation during operation are supposed to be responsible for the low levels of AVDO2 observed in the postoperative period.

Adult

Basophil histamine release in asthma patients after in vitro provocation with Althesin and etomidate.

Our aim was to compare the histamine-releasing effect of etomidate and Althesin on basophil leukocytes from asthmatic patients and normal persons. Blood from eight asthmatic patients and six normal persons was tested for histamine release after in vitro provocation with etomidate and althesin. In the group of asthmatic patients there was a significantly higher histamine release after provocation with althesin than after provocation with etomidate at all concentrations (P less than 0.05, P less than 0.01, P less than 0.02). There was significantly higher histamine release for asthmatic patients than for normal persons after provocation with althesin at all concentrations (P less than 0.05, P less than 0.01, P less than 0.02). There was no difference between the asthma group and the normal group after provocation with etomidate. Data were analysed using Wilcoxon's and Mann-Whitney's rank sum tests. We conclude that asthmatic patients may risk bronchospasm during induction of anaesthesia with althesin, and that etomidate may be suitable intravenous anaesthetic for asthmatic patients.

Alfaxalone Alfadolone Mixture

Dynamic changes in regional CBF, intraventricular pressure, CSF pH and lactate levels during the acute phase of head injury.

The authors measured regional cerebral 133xenon (133Xe) blood flow (rCBF), intraventricular pressure (IVP), cerebrospinal fluid (CSF) pH and lactate, systemic arterial blood pressure (SAP), and arterial blood gases during the acute phase in 23 comatose patients with severe head injuries. The IVP was kept below 45 mm Hg. The rCBF was measured repeatedly, and the response to induced hypertension and hyperventilation was tested. Most patients had reduced rCBF. No correlation was found between average CBF and clinical condition, and neither global nor regional ischemia contributed significantly to the reduced brain function. No correlation was found between CBF and IVP or CBF and cerebral perfusion pressure (CPP). The CSF lactate was elevated significantly in patients with brain-stem lesions, but not in patients with "pure" cortical lesiosn. The 133Xe clearance curves from areas of severe cortical lesions had very fast initial components called tissue peaks. The tissue peak areas correlated with areas of early veins in the angiograms, indicating a state of relative hyperemia, referred to as tissue-peak hyperemia. Tissue-peak hyperemia was found in all patients with cortical laceration or severe contusion but not in patients with brain-stem lesions without such cortical lesions. The peaks increased in number during clinical deterioration and disappeared during improvement. They could be provoked by induced hypertension and disappeared during hyperventilation. The changes in the tissue-peak areas appeared to be related to the clinical course of the cortical lesion.

Acid-Base Imbalance

Ventricular fluid lactate, pyruvate, bicarbonate and ph in unconscious brain-injured patients subjected to controlled ventilation.

In 35 unconscious patients suffering from traumatic brain injury and subjected to controlled hyperventilation within 12 hours of the acute trauma, we measured continuously the intraventricular pressure (IVP), ventricular fluid lactate, pyruvate, L/P ratio, pH and bicarbonate during the first 4 posttraumatic days, and related the findings to the clinical course. In patients in whom the follow-up study did not reveal severe mental impairment or dementia, the ventricular fluid lactate never exceeded 4 mmol/litre. In this group, the IVP level never exceeded 40 mmHg/hour, and the mean pressure/day never exceeded 20 mmHg. In half of the patients in whom dementia, vegetative survival or death occurred, ventricular fluid lactate exceeded 4 mmol/litre; the IVP level/hour exceeded 40 mmHg in two of 23 patients, and the mean pressure/day exceeded 20 mmHg in nine of 23 patients. The prognostic value of pyruvate was of less importance, although a significant increase in patients with a poor outcome was seen. No prognostic conclusions could be drawn from ventricular fluid, L/P ratio, pH and bicarbonate.

Bicarbonates