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Biomedical subjects

A R Aitkenhead

Publications and source records attributed to A R Aitkenhead.

At least 37 records · Page 2Linked to original sources
PubMed1994

The tussometer: accuracy and reproducibility.

Tussometry is a new non-invasive technique for objectively assessing laryngeal function by analysis of the airflow waveform produced by a maximum effort voluntary cough manoeuvre. We describe the technique and present the calibration data. The tussometer has been calibrated for flows of up to 1100 litre min-1 using a flowmeter with a quoted accuracy of +/- 1.75%. The variables measured (cough peak flow rate (CPFR) and peak velocity time (PVT)) were found to be reproducible; the within-subject variability for CPFR was found to be 23.9% and for PVT 9%. There was no inter-observer variation. We found that the size of the mask used did not influence the readings obtained, providing an adequate seal was achieved.

Calibration↗
PubMed1994

Effect of topical anaesthesia on the motor performance of vocal cords as assessed by tussometry.

Tussometry involves a continuous measurement of airflow produced by a cough manoeuvre displayed as an airflow-time wave. There is a rapid rise to its peak (cough peak flow rate) and the time taken to reach the peak (peak velocity time) is determined by the laryngeal opening at the onset of cough. Cough peak flow and peak velocity time were measured in 10 healthy volunteers before and after topical anaesthesia of the larynx with lignocaine 100 mg sprayed under indirect laryngoscopy. Adequacy of anaesthesia was established by touching the cords deliberately with a fibreoptic laryngoscope. All subjects had excellent anaesthesia of the larynx. However, cough peak flow rate and peak velocity time remained unchanged following topical anaesthesia. We conclude that topical anaesthesia of the larynx does not impair the motor performance of the vocal cords during a voluntary cough.

Adult↗
PubMed1994

Antiemetic efficacy of metoclopramide when included in a patient-controlled analgesia infusion.

A double-blind, randomised, controlled trial was performed to assess the antiemetic efficacy of metoclopramide when included in a morphine patient-controlled analgesia regimen. Fifty ASA grade 1 or 2 patients scheduled for elective intermediate or major gynaecological surgery were allocated into one of two groups. All patients received a standardised anaesthetic and metoclopramide 5 mg was given intravenously 10 min before the end of the procedure. Group 1 received a patient-controlled analgesia regimen using morphine 1 mg.ml-1 solution. Group 2 received a patient-controlled analgesia regimen using morphine 1mg.ml-1 with metoclopramide 0.5 mg.ml-1 solution. Postoperative antiemetic treatment was with metoclopramide 10 mg intramuscularly or cyclizine 50 mg intramuscularly if this was ineffective. Pain scores, sedation scores, and morphine requirement were not significantly different between the groups. There was no difference in nausea scores between the groups, but more patients suffered moderate or severe nausea in group 1 (10 patients) than group 2 (three patients, p < 0.026). We conclude that metoclopramide, when included in a patient-controlled analgesia regimen, reduces the incidence of moderate to severe nausea, but not the overall incidence of nausea.

Adult↗
PubMed1994

Effect of three different surgical prone positions on lung volumes in healthy volunteers.

Ten healthy volunteers were placed in three different surgical prone positions (knee-chest, Eschmann frame and two supports, one each for the thorax and pelvis); the normal prone position without any supports was used as a control. Lung volumes using helium dilution and spirometry were calculated for each volunteer in each position. Compared with the control position, functional residual capacity, expiratory reserve volume, residual volume and total lung capacity were significantly higher in the knee-chest position. Functional residual capacity and expiratory reserve volume were significantly higher in the frame position. No advantage was gained with the use of the two supports position. We conclude that, of these three prone positions in awake volunteers, the knee-chest position causes least respiratory restriction.

Adult↗
PubMed1993

The effect of the anaesthetist's attire on patient attitudes. The influence of dress on patient perception of the anaesthetist's prestige.

Two groups of adult patients (55 each) were visited pre-operatively by an anaesthetist who was dressed either formally or casually. Their response to this visit, their opinions regarding anaesthetists and their knowledge of anaesthetic work were elicited afterwards by means of a questionnaire. Patients' satisfaction with the anaesthetist and his/her visit was not influenced by dress. The anaesthetist was awarded a high level of prestige and the length of his/her training was recognised to be comparable to that of other professionals; 81.8% of patients thought that anaesthetists held a medical degree but only 35.4% thought that they worked in the intensive care unit. Patients expressed a preference for doctors to wear name tags, white coats and short hair but disapproved of clogs, jeans, trainers and earrings.

Adolescent↗
PubMed1993

A comparison between propofol and desflurane anaesthesia for minor gynaecological laparoscopic surgery.

Fifty-seven healthy female patients who underwent gynaecological laparoscopic surgery received either desflurane or propofol for induction and maintenance of anaesthesia. Inhalational induction was generally well tolerated, and consciousness was lost in approximately 2 min (mean end-tidal concentrations of desflurane were 8.3% with 60% nitrous oxide, and 7.1% with oxygen). Recovery of consciousness and orientation were more rapid in patients in whom anaesthesia was maintained with desflurane than with propofol, but there were no differences in psychomotor function test scores at 30 min. The data suggest that desflurane provides controllable anaesthesia and rapid recovery of consciousness after laparoscopic surgery.

Adult↗
PubMed1993

Alfentanil in daycase anaesthesia. Assessment of a single dose on the quality of anaesthesia and recovery.

The effect of the addition of a single dose of 7 micrograms.kg-1 of alfentanil to a propofol/enflurane anaesthetic on the quality of anaesthesia and recovery was assessed. A total of 53 ASA grade 1 or 2 patients who underwent daycase dental surgery were allocated randomly to receive either alfentanil or saline. The study was blinded so that neither the anaesthetist nor the assessor was aware of which solution had been given. Patients in the alfentanil group took significantly longer to recommence spontaneous ventilation (p = 0.035). Both techniques provided good quality of anaesthesia. Postoperative morbidity was common (45% of patients), but there was no difference between the groups. The rate of recovery was similar in the two groups and no patient required hospital admission after the final assessment at 3 h. Drowsiness was only mild to moderate in both groups at 24 h. A single dose of alfentanil can be administered safely as part of a daycase anaesthetic without increasing morbidity, although there appears to be little advantage in doing so.

Adult↗
PubMed1993

Effect of priming dose of vecuronium on lung function in elderly patients.

We questioned whether the side effects outweighed the advantages of priming doses of nondepolarizing neuromuscular relaxants in awake patients. We have assessed lung function and clinical evidence of muscle weakness in 10 elderly patients, eight women and two men, aged 67-78 yr, ASA grade I or II, before and 3 min after a priming dose (0.01 mg/kg) of vecuronium. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximum midexpiratory flow rate (MMEF), peak expiratory flow rate (PEFR), inspiratory capacity (IC), functional residual capacity (FRC), expiratory reserve volume (ERV), residual volume (RV), slow vital capacity (SVC), and total lung capacity (TLC) were measured by using a Morgan transfer test machine and oxygen saturation (SpO2) was measured by pulse oximetry. All the patients developed ptosis, six had diplopia and were unable to perform the Valsalva maneuver for 10s, and four were unable to swallow or lift their head for > 4s, demonstrating significant muscle weakness. Significant reductions occurred in FVC, FEV1, FRC, ERV, SVC, and TLC. SpO2 decreased in 8 of 10 patients, and in 4 the decrease exceeded 4%. We conclude that priming with vecuronium 0.01 mg/kg in elderly patients causes significant impairment of lung function and a significant decrease in oxygen saturation.

Aged↗
PubMed1992

Therapeutic suggestions during general anaesthesia in patients undergoing hysterectomy.

In a double-blind, randomized study, we have examined the influence of positive therapeutic suggestions, presented to anaesthetized patients undergoing total abdominal hysterectomy, on postoperative morbidity and duration of hospital stay. Seventy-five patients were allocated randomly to be exposed to one of three tapes containing positive therapeutic suggestions, a modified history of the Queen's Medical Centre, or no message. We found that neither therapeutic suggestions nor the presence of a voice during anaesthesia improved postoperative outcome or reduced duration of hospital stay after total abdominal hysterectomy.

Adult↗
PubMed1991

Simple method for the determination of morphine and its active glucuronide metabolite in human plasma by high-performance liquid chromatography with electrochemical detection.

A simple method for the simultaneous determination of morphine and its pharmacologically active metabolite morphine-6-glucuronide in 0.5 ml human plasma is described. It is based on the method of Svensson [J. Chromatogr., 230 (1982) 427 and 375 (1986) 174], but uses only one solid-phase extraction cartridge prior to chromatography and only a 20-microliter injection volume. Mean recoveries of 90 and 85% for morphine and morphine-6-glucuronide, respectively, were obtained, the limit of detection being 2 nmol/l (at a signal-to-noise ratio of 3.0).

Chromatography, High Pressure Liquid↗
PubMed1991

Fetal distress.

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Electrocardiography↗
PubMed1991

Comparison of contemporaneous and retrospective assessment of postoperative pain using the visual analogue scale.

We have assessed postoperative pain in 50 patients who had undergone total abdominal hysterectomy, using repeated contemporaneous and single retrospective visual analogue scores. There were significant correlations between the median, mean and greatest contemporaneous scores, and the single retrospective scores, but there was a wide scatter of results among and within individual patients. We conclude that the wide variability between the two methods of assessment suggests that the two techniques should not be used interchangeably.

Adult↗
PubMed1991

Incidence of awareness with recall during general anaesthesia.

One thousand patients who were anaesthetised between February and April 1990 at University Hospital, Nottingham were interviewed between 20 and 36 hours after their operation. Patients under 16 years of age, those who had undergone obstetric or intracranial surgery, those who were unable to communicate and patients who were discharged from hospital before the postoperative visit were not interviewed. A standard set of questions was used to determine the incidences of recall of events and dreams during the operation. These incidences were 0.2% and 0.9% respectively, considerably lower than reported in previous comparable studies.

Adult↗
PubMed1990

Relationship between lower oesophageal contractility and type of surgical stimulation.

We have studied the effects of two discrete types of surgical stimulation on contractions in the lower oesophagus. Forty-four female patients undergoing either abdominal hysterectomy or varicose vein surgery were anaesthetized using a standard technique. The frequency of spontaneous oesophageal contractions (SLOC) and amplitude of provoked contractions (PLOC) were greater in those patients undergoing hysterectomy. The oesophageal index (OCI), a single index combining both types of contractions, was found also to relate to the nature of the surgical stimulus.

Adult↗