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Biomedical subjects

A Turley

Publications and source records attributed to A Turley.

10 recordsLinked to original sources
PubMed2006

The use of impedance respirometry to confirm tracheal intubation in children.

Accidental oesophageal intubation can occur in children and is a cause of morbidity and mortality. This study investigated the use of impedance respirometry to determine tracheal tube position in children aged 1-10 years. Eighty children were recruited and, after induction of anaesthesia, two identical tracheal tubes were inserted: one into the trachea and one into the oesophagus. The breathing system was attached to one of the tubes chosen at random. A blinded observer was asked to identify the position of the tube within six breaths using impedance respirometry. The positions of 76 out of 80 tubes were correctly identified. Of those incorrectly identified, one was in the trachea and three were in the oesophagus. The sensitivity of the test was 0.975 and the specificity 0.925. The median number of breaths needed to identify the position of the tubes was 2.0 for both groups. This is not a perfect technique in the population studied but when used with other methods of tracheal tube position identification, its use could decrease the time taken to identify incorrect placement.

Child↗
PubMed2004

The effect of mechanically-induced cricoid force on lower oesophageal sphincter pressure in anaesthetised patients.

In the United Kingdom, cricoid force is central to upper airway management in obstetric and emergency anaesthesia. A reduction in oesophageal barrier pressure (OBP) in these patients may increase regurgitation risk. This study investigated whether the application of cricoid force to anaesthetised patients reduced lower oesophageal sphincter pressure (LOSP) and consequently OBP. Anaesthesia was induced in 29 patients using a standard protocol. An oesophageal balloon catheter was inserted and gastric trace identified. The catheter was withdrawn incrementally and pressure readings recorded at each position before and during the application of 30 N cricoid force, with a sudden rise in pressure indicating lower oesophageal sphincter position. Oesophageal barrier pressure was calculated as the difference between LOSP and gastric pressure. Application of cricoid force significantly reduced OBP without influencing gastric pressure (p < 0.001). The use of cricoid force may increase the risk of gastroesophageal reflux in anaesthetised patients.

Adult↗
PubMed2003

Cricoid yoke: the effect of surface area and applied force on discomfort experienced by conscious volunteers.

BACKGROUND AND OBJECTIVE: The application of cricoid force is central to techniques that reduce the risk of gastric regurgitation and the subsequent pulmonary aspiration associated with obstetric and emergency anaesthesia. The discomfort associated with cricoid force in awake preoperative patients increases the incidence of coughing, struggling and pain during induction of anaesthesia. This study determined if increasing the surface area of a cricoid yoke reduced the associated discomfort in volunteers. METHODS: Fifty volunteers participated in a randomized single-blinded study. The cricoid yoke was positioned using standard anatomical landmarks and forces of 10, 20, 30 and 40 N were applied in a random order for 20s, using two different yoke attachments with surface areas of 3 and 10 cm2. A rest of 30s was allowed between the application of forces. Discomfort was graded by volunteers on a scale from 0 to 10 (0: no discomfort; 10: worse discomfort imaginable). A score of 10 was allocated if the volunteers could not tolerate the applied force for 20s. RESULTS: Median scores for the small yoke were always higher than those for the large yoke at each force. There were significant differences between the scores for the small and large yokes at 10 and 20 N (P < 0.001) and 30 N (P = 0.0233), but there was no significant difference at 40 N. CONCLUSIONS: The larger yoke was tolerated better by volunteers when clinically relevant cricoid forces were applied.

Adult↗
PubMed2002

An assessment of the ability of impedance respirometry distinguish oesophageal from tracheal intubation.

Accidental oesophageal intubation is still an important cause of anaesthetic morbidity and mortality. This study investigated the use of impedance respirometry to determine the position of a tracheal tube. Seventy-nine patients undergoing general anaesthesia requiring tracheal intubation with muscle relaxation were recruited to the study. After pre-oxygenation, tracheal tubes were placed in both the oesophagus and trachea; a breathing system was attached to one tube chosen randomly. A blinded observer was required to correctly identify the position of the tube within six tidal ventilations. The position of every tube connected to the breathing system was correctly identified. The median time to correctly identify tracheal and oesophageal tubes was 3 and 5 s, respectively. The median number of breaths to identify tracheal and oesophageal tubes was two for both groups. Every tube position was identified within the required six breaths. Impedance respirometry is a reliable method for diagnosing tracheal tube position.

Adult↗
PubMed1997

Glass bottle workers exposed to low-dose irritant fumes cough but do not wheeze.

Workers exposed to irritant fumes experience symptoms both during the acute episode and afterwards. High-dose irritant exposure can result in permanent asthma, but the effects of chronic low-dose irritant exposure are not known. Glass bottle workers are exposed to irritant fumes, and have previously been reported to have an excess of symptoms. We designed a study to compare irritant-exposed glass bottle workers with hospital workers matched for socioeconomic group, area of residence, age, sex, smoking habit, and allergic history. Symptoms reported, spirometry, flow cytometric indices of lymphocyte activation, and past medical and employment histories were compared. We also investigated the prevalence of bronchial hyperresponsiveness to inhaled methacholine and the cough response after inhalation of citric acid and capsaicin. Glass bottle workers showed an excess of upper respiratory tract symptoms, cough, and shortness of breath compared with matched hospital control workers. There was a significant excess of cough induced by citric acid and capsaicin in the bottle workers. However, wheeze, baseline spirometry, flow cytometry, and methacholine challenge were not significantly different between the two groups. These findings suggest that chronic irritant exposure produces an excess of symptoms and increased cough sensitivity but not asthma.

Adult↗
PubMed1991

The effect of dobutamine on middle cerebral artery blood velocity in volunteers: a preliminary study.

Five volunteers given dobutamine up to 4 micrograms/kg/min had significant increases in mean arterial blood pressure, systolic blood pressure, and stroke volume (P less than 0.05). Heart rate did not increase significantly. Pulsatility index, an index of middle cerebral artery maximum blood velocity waveform shape increased significantly in the dobutamine group (P less than 0.05). Time-averaged mean velocity did increase during the dobutamine infusion but the change was not statistically significant. Dobutamine significantly alters the blood velocity profile of the middle cerebral artery in volunteers even in low doses of 4 micrograms/kg/min. Transcranial Doppler may be a useful technique to monitor changes in cerebral artery blood velocity dynamics induced by dobutamine. These measurements can be performed easily and repeatedly at the bedside.

Adult↗
PubMed1990

Flumazenil: a twelve-month survey of use in a New Zealand public hospital.

As part of a program of postmarketing surveillance, the use of flumazenil was monitored prospectively in a New Zealand public hospital for a period of twelve months. A questionnaire on usage, efficacy and side-effects was completed by clinicians for 118 patients receiving the drug. Our conclusions are these: 1. Flumazenil was used most frequently after anaesthesia and in the initial management of intentional drug overdose. 2. In two-thirds of cases, flumazenil was used to antagonise benzodiazepines in the presence of non-benzodiazepine drugs and its efficacy was primarily determined by the presence of these latter drugs. 3. The complications of flumazenil are mild although important complications may arise from interaction with other drugs and unmasking of conditions such as postoperative pain. 4. Resedation was common (24%), although rarely a problem unless large doses of benzodiazepine agonist had been administered or if other hypnosedatives were given subsequently.

Adult↗