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Biomedical subjects

A Holdcroft

Publications and source records attributed to A Holdcroft.

At least 73 records · Page 4Linked to original sources
PubMed1979

The ocular effects of etomidate.

Etomidate, a new intravenous hypnotic agent, significantly lowered the mean intraocular pressure (IOP) of fifty patients within 30 s of an intravenous injection from 15.7 to 9.5 mmHg. This effect was present even during the administration (to twenty patients) of low doses (0.25 mg/kg) when the mean reduction was from 15.6 to 7.6 mmHg. The reduction in IOP was unaffected by the presence of muscle movement. Low frequency pendular nystagmus was observed in five patients.

Adolescent↗
PubMed1979

Redistribution of body heat during anaesthesia. A comparison of halothane, fentanyl and epidural anaesthesia.

Epidural anaesthesia and high dose fentanyl (50 micrograms/kg) when used to supplement nitrous oxide and oxygen anaesthesia for a standard lower abdominal operation were associated with a mean fall in deep body temperature, as measured in the external auditory meatus, of 0.46 degrees C and 0.6 degrees C/hr respectively. This is significantly different from the mean values of 0.14 degrees C and 0.2 degrees C/hr which were recorded when moderate dose fentanyl (10 micrograms/kg) or 0.5% halothane were used to supplement anaesthesia. When mean skin temperature is combined with the core temperature to provide an estimate for total body heat, there is no difference between the groups. Redistribution of body heat occurs and this may be related to reduced adrenergic stimulation and altered regional blood flow. Where the facilities and environments are inadequate for the maintenance of normothermia, care should be taken in the choice of anaesthetic technique. In the recovery period mean body heat gain showed a wide scatter of results but those patients receiving epidural anaesthesia were slow to rewarm despite a high incidence of shivering in this group. The implications of this are discussed.

Adult↗
PubMed1978

Heat loss during anaesthesia.

The superficial and deep body temperatures of 23 patients were studied during prolonged anaesthesia for microscopic surgery of the fallopian tubes. The patients were divided randomly into three groups, receiving either halothane 0.5%, halothane 1% or low-dose fentanyl as a supplement to nitrous oxide, oxygen and myoneural block. Other variables were kept constant, and the theatre temperature was maintained at 24 degrees C. Temperature changes were unrelated to both the type of anaesthesia and the percentage of subcutaneous fat to body weight. Halothane 1% decreased the rate of heat loss in the 3rd hour. Large heat losses occurred on transfer to the recovery room, where the total heat produced increased rapidly and was unrelated to shivering.

Adult↗
PubMed1977

Airway closure and pregnancy.

During pregnancy there is a fall in functional residual capacity and expiratory reserve volume. The point of airway closure in relation to vital capacity and the expiratory reserve volume was determined in 11 post-partum patients who had previously been studied during pregnancy. The lung volume at which airway closure occurred in pregnancy and the post-partum period did not change in relation to the vital capacity whereas the expiratory reserve volume did, so that airway closure became imminent in the pregnant women during tidal ventilation, especially whilst in the suping position. The significance of this alteration in pulmonary function to obstetric anaesthesia is discussed.

Adult↗
PubMed1976

Effect of dose and premedication on induction complications with etomidate.

The induction characteristics of etomidate, a new i.v. hypnotic agent, were studied in 400 patients. Two hundred were premedicated with atropine and anaesthesia was induced with 0.2, 0.25, 0.3 or 0.35 mg/kg of etomidate. The remainder received one of four standard premedications and anaesthesia was induced with etomidate 0.3 mg/kg. Involuntary muscle movements occurred in more than 60% of patients receiving atropine alone. The frequency was reduced in the second group, but remained unacceptable in over 8% of patients. The incidence of other excitatory phenomena, such as cough and hiccup, was 10% approximately. Cardiovascular changes were minimal and no serious allergic phenomena were observed. Nausea and vomiting occurred after surgery in up to 30% of patients and was unrelated to the dose of etomidate or to premedication. Pain on injection occurred in up to 80% of patients when the drug was injected into small peripheral veins and occurred in more than 7% when using more normal veins.

Adult↗
PubMed1976

Maternal complications of obstetric epidural analgesia.

The maternal complications associated with 1,000 consecutive obstetric epidurals are described. Although the analgesia provided was very satisfactory, complications were common. A dural puncture rate of 1-7 per cent resulted in 13 patients suffering from "spinal headache". Blood vessel puncture occurred in 45 patients, while the presence of unblocked segments and unilateral block was troublesome. There were no serious sequelae, but it is suggested that the provision of an epidural service for women in labour requires the immediate availability of an experienced anaesthetist to attend the labour ward.

Anesthesia, Epidural↗
PubMed1975

Althesin as an induction agent for Caesarean section.

Thirty patients for elective lower segment Caesarean section were randomly divided into two groups. One group received 50 mulitre/kg of Althesin for induction of anaesthesia and the other, 100 mulitre/kg. The two maternal groups were similar. There was no significant difference in the clinical or biochemical status of the infants except that infants in the low dose group had a significantly higher PO2 in the umbilical venous and arterial blood.

Adult↗
PubMed1974

Comparison of effect of two induction doses of methohexitone on infants delivered by elective caesarean section.

Observations were made on 26 infants delivered by elective caesarean section under general anaesthesia. A standard anaesthetic technique was employed using a methohexitone, relaxant, nitrous oxide-oxygen sequence with regulated ventilation and the administration of papaveretum after clamping the umbilical cord. In 12 patients the induction dose of methohexitone was 1.4mg/kg and in 14 it was reduced to 1.0 mg/kg. There were no significant differences between the two groups in the clinical status of the mothers, in operative technique and timing, or in the value of PO(2), PCO(2), and pH in the umbilical cord venous blood.The infants whose mothers received the lower dose of methohexitone were in better condition, as assessed by the number needing assisted ventilation, the time taken to establish regular respiration, the Apgar score, and the "Apgar minus colour" score.

Anesthesia, Obstetrical↗