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Biomedical subjects

B J Pollard

Publications and source records attributed to B J Pollard.

At least 19 recordsLinked to original sources
PubMed1992

Effect of physiotherapy on the auditory evoked response of paralysed, sedated patients in the intensive care unit.

Auditory evoked response (AER) was recorded before, during and after physiotherapy in 11 paralysed (atracurium 0.56 (SD) 0.13 mg kg-1 h-1), sedated (propofol 2.2 (1.0) mg kg-1 h-1; fentanyl 4.4 (2.3) micrograms kg-1 h-1) and critically ill patients undergoing ventilation in the intensive care unit (ICU). The latency of the negative wave, NB, was reduced by physiotherapy (mean 44.8 (SD) 7.9 ms before, 41.0 (6.8) ms during (P less than 0.01, non-parametric Friedman test) and 45.6 (6.3) ms after physiotherapy); NB amplitude showed no consistent change (-0.81 (1.4) microV, -0.81 (1.5) microV and -0.71 (1.3) microV, respectively). NB latency responded to patient arousal at constant levels of sedation and this requires further evaluation as a means of monitoring sedation in paralysed patients in the ICU.

Adult↗
PubMed1992

Effect of doxapram on neostigmine evoked antagonism of vecuronium neuromuscular block.

We have examined the effect of doxapram on neostigmine-evoked antagonism of vecuronium neuromuscular block in a double-blind study in anaesthetized patients. Neuromuscular transmission was measured with a Datex Relaxograph. The mean time to recovery of the first contraction of the train-of-four (T1) from 25% to 75% was significantly longer in the presence of doxapram (138 (SEM 21) s; n = 23) than in its absence (95 (13) s; n = 29) (P = 0.014). The recovery of the train-of-four ratio was prolonged also in the presence of doxapram, although this difference was not statistically significant.

Adult↗
PubMed1992

A nasal CPAP system. Description and comparison with facemask CPAP.

Nasopharyngeal pressures were compared in eight subjects breathing through either a nasal CPAP system or facemask CPAP system at a fresh gas flow of 50, 75 and 100 l.min-1. During nose breathing there was no significant difference in nasopharyngeal pressure between the two systems. During mouth breathing pressures were significantly lower with nasal CPAP. During nose breathing at 75 l.min-1 the mean inspiratory and expiratory pressures in cmH2O (SD) were 3.4 (0.68) and 5.9 (0.55) for nasal CPAP and 3.3 (0.71) and 6.3 (0.73) for facemask CPAP. The respective pressures during mouth breathing were 0.3 (0.73) and 2.9 (1.74) for nasal CPAP and 3.9 (0.73) and 5.8 (0.82) for facemask CPAP.

Adult↗
PubMed1992

Nasal CPAP after coronary artery surgery.

Two groups of 14 patients were compared after coronary artery bypass surgery where the left internal mammary artery had been used as a conduit. One group received nasal continuous positive airway pressure for 1 h, the other group acted as a control. Mean pulmonary shunt fraction was 16.3% before, 12.6% during and 15.7% after continuous positive airways pressure. In the control group the shunt fraction fell from 17.3% to 16.8%. The reduction in shunt fraction was significantly greater with nasal continuous positive airways pressure than in the control group (p = 0.016). There was a significant reduction (p = 0.025) in respiratory rate from 18.3 to 16.7 breath.min-1 during continuous positive airway pressure. Other measured cardiorespiratory variables did not differ significantly between the groups. Visual analogue scores showed no significant difference in chest pain or mask comfort between the groups. The ease of breathing score was, however, significantly better in the continuous positive airways pressure group, 7.5 (SD 1.8) cm and control 5.6 (SD 2.6) cm.

Coronary Artery Bypass↗
PubMed1991

Medical aspects of euthanasia.

The practice of euthanasia in the Netherlands is often cited as an example of progressive social reform. While the Dutch penal code outlaws active euthanasia, the courts have interpreted the law in such a way as to allow doctors to kill their patients under certain conditions, chiefly when the patient has asked to die in preference to enduring unbearable suffering. Current practice in the Netherlands now includes the killing of patients who do not have a terminal disease, the killing of older children without the consent of their parents, and the killing of patients without their consent in circumstances where consent could have been sought. Estimates of the number of euthanasia killings range up to 20,000 per year, but there is no accurate information because of the common medical practice of falsely certifying the cause of death to avoid the need to justify euthanasia. Euthanasia in the Netherlands is now an alarming practice that oversteps ethical bounds and administrative controls, compromising doctors' moral commitment to healing by allowing them to become medical killers.

Adult↗
PubMed1991

Withdrawing life-sustaining treatment from severely brain-damaged persons.

Ventilator support is commonly withdrawn from unconscious patients who cannot breathe when it is reasonably certain that their condition is permanent and further medical treatment is futile. However, there is no consistent practice with permanently unconscious patients who can breathe but cannot swallow, despite the fact that ongoing treatment of these patients is similarly futile. In both groups of patients, the withdrawal of treatment is not euthanasia, and the cause of death is properly considered to be the underlying illness. A review of the medical, legal and ethical literature shows that there is much disagreement about when and how to withdraw tube feeding from patients with severe brain damage. Criteria for withdrawal of treatment should include the permanent unconsciousness of the patient, the permanent absence of a life-sustaining function, the elapse of sufficient time to be certain about the prognosis, the concurrence of at least one independent and qualified medical specialist, and the informed consent of the patient's family or other legally qualified agents.

Australia↗
PubMed1991

Bioimpedance versus thermodilution cardiac output measurement: the Bomed NCCOM3 after coronary bypass surgery.

Values obtained for cardiac output (CO) were compared using thermodilution (TD) with those obtained using bioimpedance (Bi) as measured using the Bomed NCCOM3 (Revision 6) in 28 consecutive patients in the first 24 h after coronary artery bypass surgery (CABS). In 46 paired measurements made in the first 12 h after CABS Bi values for CO were significantly lower than TD values, the limits of agreement between the two methods were also unacceptably large (mean Bi 4.38 (SD 1.40) l/min, mean TD 5.46 (SD 1.19) l/min, limits of agreement -3.05 to +0.89). In 55 paired measurements made after 12 h (all in spontaneously breathing patients) there was no significant difference between the two methods and acceptable limits of agreement, mean Bi 5.69 (SD 1.2) l/min mean TD 5.6 (SD 1.2) l/min, limits of agreement -0.99 to +1.17). The significantly lower BiCO values obtained in the first 12 h after CABS show that BiCO measurement is not consistently reliable in the intensive care setting.

Bias↗
PubMed1991

Non-invasive measurement of cardiac output during induction of anaesthesia and tracheal intubation: thiopentone and propofol compared.

We have investigated the haemodynamic changes in response to induction of anaesthesia and tracheal intubation in patients who received either thiopentone 5 mg kg-1 or propofol 3 mg kg-1 followed by atracurium 0.5 mg kg-1 and fentanyl 1.5 micrograms kg-1. Anaesthesia was maintained with 0.6% enflurane and 50% nitrous oxide in oxygen with assisted ventilation. Cardiac output and heart rate (HR) were monitored continuously with a transthoracic impedence monitor. Mean HR did not change after induction in each group, but increased after tracheal intubation in both groups (P less than 0.01). Mean cardiac index (CI) decreased after induction (P less than 0.05) and decreased further after tracheal intubation in both groups (P less than 0.05). There was no difference between the two groups with respect to changes in CI and HR. Mean arterial pressure (MAP) and systemic vascular resistance (SVR) did not change significantly after induction in the thiopentone group. Both variables increased from preinduction values 1 min after tracheal intubation (P less than 0.001). In contrast, both MAP and SVR decreased after induction in the propofol group (P less than 0.001) and did not differ from preinduction values 1 min after tracheal intubation. MAP and SVR were greater in the thiopentone group compared with the propofol group after induction and tracheal intubation (P less than 0.01).

Adult↗
PubMed1991

General anaesthesia for gamete intra-fallopian transfer.

A retrospective survey was undertaken of all patients who had gamete intra-fallopian transfer (GIFT) under general anaesthesia at this hospital over an 18-month period. Of 47 patients, 21 (44.7%) became pregnant although only 10 (21.3%) proceeded to term. All of those who proceeded to term had had enflurane as part of their general-anaesthetic technique. Although a number of the patients who received halothane became pregnant, none proceeded beyond the second trimester. It would appear that the use of halothane may be inadvisable for general anaesthesia for this procedure.

Adult↗
PubMed1990

Concentrations of atracurium and laudanosine in cerebrospinal fluid and plasma in three intensive care patients.

We have measured concentrations of atracurium and laudanosine in cerebrospinal fluid (CSF) and plasma in three intensive care patients receiving atracurium infusions of 22.5-106 h duration to maintain neuromuscular block. Two patients had suffered severe closed head injuries and the third patient had developed respiratory failure following the clipping of two intracranial aneurysms. The total dose of atracurium given was 14.3-136.6 mg kg-1; rate of infusion was 0.6-1.38 mg kg-1 h-1. Plasma concentrations of atracurium and laudanosine were 0.73-3.11 micrograms ml-1 and 0.48-8.65 micrograms ml-1, respectively; CSF concentration of laudanosine was 70-440 ng ml-1. No adverse effects attributable to these concentrations of laudanosine were observed.

Adult↗
PubMed1990

An evaluation of combining thiopentone and etomidate for the induction of anaesthesia.

The characteristics of three combinations of thiopentone and etomidate [in the ratios of thiopentone (mg):etomidate (mg) of 5:1, 13:1 and 25:1] have been compared with the individual agents alone for the induction of anaesthesia. The incidence of pain on injection and abnormal movements was less with the combination containing the highest ratio of thiopentone to etomidate, when compared to etomidate alone. The mixtures did not otherwise confer any advantages over the individual agents.

Adult↗
PubMed1989

Renal transplantation and diabetic autonomic neuropathy.

This report describes six episodes of cardiovascular collapse in the perioperative period of a young diabetic woman undergoing general anaesthesia for renal transplantation and a similar episode after a second anaesthetic. She was subsequently found to have an autonomic neuropathy. Recommendations for the management of similar patients are made.

Adult↗