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Biomedical subjects

R O Feneck

Publications and source records attributed to R O Feneck.

48 records · Page 3Linked to original sources
PubMed1987

Assessment of a high frequency ventilator breathing system for use in the operating theatre. An experimental and clinical study.

A breathing system capable of delivering positive pressure ventilation to the lungs at high frequencies and using anaesthetic gases and vapours is assessed. The recommended fresh gas flow at the ventilatory rates tested in this study was 100 ml kg-1. At 80 and 100 b.p.m. the system provided adequate ventilation, good oxygenation and haemodynamic stability. When compared with conventional positive pressure ventilation (CPPV), peak airway pressure (peak Paw) was lower and mean airway pressure (Paw) was lower (80 b.p.m.) or unchanged (100 b.p.m.). There was some inherent positive end-expiratory pressure (PEEP) associated with the technique.

Anesthesia, Inhalation↗
PubMed1987

A comparison between the effects of fentanyl, droperidol with fentanyl, and halothane anaesthesia on intra-ocular pressure in adults.

The effects of fentanyl 3.0 micrograms/kg (group 1), droperidol 0.1 mg/kg with fentanyl 3.0 micrograms/kg (group 2), and halothane 0.5% inspired concentration (group 3) on intra-ocular pressure were compared. In each group, a decrease in intra-ocular pressure was produced which was significantly lower than resting values (p greater than 0.01) and was independent of changes in arterial blood pressure. The recovery time in group 1 patients was significantly less than that of patients in group 3.

Aged↗
PubMed1987

Comparison of conventional intermittent positive pressure ventilation with high frequency jet ventilation. Studies following aortocoronary bypass graft surgery.

This study was designed to compare the cardiorespiratory effects of high frequency jet ventilation at 150 breaths/minute with and without added positive and expiratory pressure, with conventional intermittent positive pressure ventilation in 20 patients following aortocoronary bypass graft surgery. On comparison with intermittent positive pressure ventilation, there was a decrease in peak airway pressure during high frequency jet ventilation when positive and expiratory pressure of 0 or 0.5 kPa was applied, but not with 1 kPa, and an increase in mean airway pressure with positive end expiratory pressures of 0.5 and 1 kPa. On changing from intermittent positive pressure to high frequency jet ventilation with no added end expiratory pressure, there was an acute decrease in arterial oxygen tension and increases in cardiac output and total tissue oxygen delivery. On changing from intermittent positive pressure ventilation to high frequency jet ventilation with 1 kPa of positive end expiratory pressure, there was an acute decrease in arterial oxygen tension, cardiac output and oxygen delivery, and increases in pulmonary arterial, right atrial and pulmonary capillary wedge pressures. The addition of positive end expiratory pressure did not prevent the acute decrease in arterial oxygen tension which occurred on transfer to high frequency jet ventilation.

Adult↗
PubMed1987

Comparison of the haemodynamic effects of intermittent positive pressure ventilation with high frequency jet ventilation. Studies following valvular heart surgery.

The cardiorespiratory effects of intermittent positive pressure ventilation and high frequency jet ventilation with and without positive end expiratory pressure were compared in patients following valvular heart surgery (mitral and/or aortic). Twenty patients received intermittent positive pressure ventilation and high frequency jet ventilation with 0, 0.5 and 1.0 kPa positive end expiratory pressure. High frequency jet ventilation was well tolerated. The addition of 1.0 kPa positive end expiratory pressure was associated with preservation of the arterial oxygen tension without any increase in shunt or significant adverse haemodynamic effect. The results are discussed and compared with a previous study of high frequency jet ventilation following aortocoronary bypass graft surgery.

Adult↗
PubMed1986

The haemodynamic effects of bronchoscopy. Effect of pretreatment with fentanyl and alfentanil.

The cardiovascular responses to bronchoscopy under general anaesthesia were investigated in 36 premedicated patients. Twelve patients acting as controls received a standard intravenous anaesthetic of intermittent thiopentone and suxamethonium. A further 24 patients were given either fentanyl 6 micrograms/kg or alfentanil 18 micrograms/kg intravenously, one minute prior to induction. There were significant rises in systolic arterial blood pressure (p less than 0.05) and in rate pressure product (p less than 0.05) in the patients in the control group, but these changes were not seen in those patients receiving either fentanyl or alfentanil. However, dysrhythmias and ST segment changes indicative of myocardial ischaemia were present in some patients in all three groups.

Alfentanil↗
PubMed1986

Hemodynamic effects of atracurium, vecuronium and pancuronium during sufentanil anesthesia for coronary artery bypass.

A study was undertaken to evaluate the cardiovascular effects of sufentanil, in combination with three different muscle relaxants, used as sole anesthetic with 100% O2 in 30 patients undergoing elective coronary artery vein graft surgery. Patients were randomly allocated to receive pancuronium (P), vecuronium (V) or atracurium (A) for muscle relaxation. All patients received 15 micrograms/kg sufentanil at induction followed by 5-10 micrograms/kg sufentanil prior to sternotomy. At the 95% level of significance no statistical difference was found for any of the measured and derived cardiovascular parameters between groups P, V and A, except for a decreased systolic blood pressure in the atracurium group after induction. Sufentanil in combination with pancuronium or vecuronium provided stable hemodynamic conditions throughout anesthesia. Atracurium was less satisfactory. We conclude that there is no advantage to be gained, in the presence of beta blockade, from the use of the new generation muscle relaxants as compared to pancuronium during high-dose sufentanil anesthesia for coronary artery vein grafting.

Adult↗
PubMed1986

Effect of pretreatment with propranolol on intra-ocular pressure changes during induction of anaesthesia.

It is well documented that intra-ocular pressure (IOP) increases following the administration of suxamethonium and also after laryngoscopy and intubation. It is possible that there may be a final common pathway mediated by beta adrenergic transmission which leads to this pressure rise. If so, this mechanism should be inhibited by beta adrenoceptor blockade. Pretreatment with propranolol prevented a significant rise in IOP during a thiopentone, suxamethonium, intubation induction sequence. The change in IOP was even more pronounced during a thiopentone, alcuronium, intubation induction sequence as the base-line IOP was not regained, but there was significant cardiovascular depression. In both these methods the IOP did not remain stable; there was an initial reduction followed by a rise in pressure. Whether these changes in IOP are clinically important remains an open question.

Adult↗
PubMed1985

A comparison of the haemodynamic effects of propofol ('Diprivan') and thiopentone in patients with coronary artery disease.

Twenty patients scheduled for elective coronary surgery received either propofol ('Diprivan') 1.5 mg/kg in emulsion or thiopentone 2 mg/kg for induction of anaesthesia. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded every minute until 6 min after intubation. Anaesthesia with propofol was accompanied by a reduction in arterial pressure, the decrease being severe in two patients. This was largely due to a decrease in systemic vascular resistance. Thiopentone anaesthesia resulted in a smaller decrease in arterial pressure, but a marked increase in arterial pressure followed endotracheal intubation. Although the absence of haemodynamic changes following intubation during propofol anaesthesia is advantageous to the ischaemic myocardium, this has to be balanced by the variable and sometimes severe reduction in arterial pressure that occurred on induction.

Anesthesia, Intravenous↗
PubMed1983

Failure of diazepam to prevent the suxamethonium-induced rise in intra-ocular pressure.

The effects of intravenous suxamethonium chloride (1 mg/kg) on intra-ocular pressure (IOP) were studied following pretreatment with diazepam 0.05 mg/kg, tubocurarine 0.05 mg/kg, and in a control group, at induction of anaesthesia. In all three groups, a significant increase in IOP was seen during the induction sequence. In a further study, the effects of intravenous suxamethonium chloride (1 mg/kg) on IOP were studied following a period of stable general anaesthesia and pretreatment with diazepam 0.05 mg/kg. A significant rise in IOP was again seen following the administration of suxamethonium. The authors conclude that neither of the techniques described herein will reliably and predictably prevent the rise in IOP seen following the use of suxamethonium.

Adolescent↗
PubMed1981

A case of status epilepticus. Use of thiopentone and IPPV to control otherwise refractory convulsions.

A case of status epilepticus which was refractory to conventional anticonvulsants is described. The total dosage of thiopentone necessary to control the convulsions is greater than that previously reported. The use of regular plasma estimation of thiopentone levels, and of cortical monitoring with the Cerebral Function Monitor (Ormed Engineering) is described, and is recommended where anticonvulsants are used for prolonged control of status epilepticus and in dosages greater than is common practice.

Aged↗