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Biomedical subjects

A E Cameron

Publications and source records attributed to A E Cameron.

At least 19 recordsLinked to original sources
PubMed2000

'Fast track' carotid duplex scanning in a district general hospital.

UNLABELLED: 'Fast track' carotid scanning is designed to rapidly identify patients with significant symptomatic carotid stenosis and, thereby, allow prompt surgery. We review the outcome of patients referred to our open-access scanning service over 3 years and 6 months. A total of 807 cases (62% males and 38% females with a mean age of 64 years) were referred. The main presenting symptoms were TIA in 69%, amaurosis fugax in 11% and minor CVA in 8.3%. The mean time between referral and scan was 17 days. In 80% of the cases, the scan showed no significant disease and the patients were not seen in the clinic. Significant abnormality (stenosis > 70% or occlusion) was found in 20% of the patients. Of the total, 12% were reviewed in the out-patient clinic following which no action was taken, 2% had angiography but no surgery, while 5% had angiography and surgery. 1% were lost to follow-up. The mean delay from scan to operation was 36 days. CONCLUSION: Fast track scanning has led to early detection of surgically relevant carotid lesions and avoidance of delay in surgical intervention. It is an efficient and cost-effective practice.

Adolescent↗
PubMed1998

Pressure changes over the anterior neck during tracheal and oesophageal intubation.

Pressure changes were measured on the skin over the cricoid and thyroid cartilages during intubation of the oesophagus or trachea in 21 consenting patients. A 100-ml bag of saline was firmly fixed to the anterior neck and the pressure changes in the bag recorded. Typical and distinctively different pressure patterns for tracheal and oesophageal intubation were recorded. Oesophageal intubation was accompanied by a statistically significantly higher and longer pressure rise and, most characteristically, by an obvious and sustained rise in baseline pressure. This method is, however, neither practical nor recommended for clinical use in detecting accidental oesophageal intubation. Capnography should always be used during tracheal intubation as an ongoing capnographic waveform provides the only guarantee of correct tracheal placement.

Adult↗
PubMed1998

Complications of endoscopic sympathectomy.

Four cases are presented in which complications occurred during or after thoracic endoscopic sympathectomy (TES). In one patient inappropriate TES resulted in disabling hyperhidrosis. In one patient laceration of the subclavian artery required major surgery. In two cases intraoperative cerebral damage occurred. Training in TES is essential.

Adolescent↗
PubMed1998

Simulation methodology for estimating financial effects of telemedicine in West Virginia.

Understanding the full financial effects of telemedicine systems on payers, providers, and patients has been hampered by the lack of data from full-fidelity systems operating at a steady state. The vast majority of telemedicine systems in the United States have yet to achieve their full potential in serving their target populations and are operating well below capacity. The purposes of this research are two-fold: (1) to develop a methodology that compensates for the limited availability of empirical data on the financial effects of telemedicine; and (2) to test this methodology in a comprehensive telemedicine system in West Virginia. The proposed methodology utilizes simulation modeling techniques for evaluating the financial performance of a mature telemedicine system. It is particularly suitable for analyzing large, complex systems that have not yet achieved steady-state operation. Although complex, the methodology can be described simply as consisting of two major steps. The first is the identification of all of the relevant variables and parameters for modeling. The second consists of simulating "real world" decision situations involving all relevant variables and parameters. The relation among the variables and parameters are described in terms of mathematical equations. The ability of the researcher to estimate the financial effects of a given telemedicine system is a function of the extent to which the resulting model approximates conditions of the real world; i.e., the fit between model and reality.

Algorithms↗
PubMed1997

The Stresst'er ergometer as an alternative to treadmill testing in patients with claudication.

OBJECTIVES: To compare a new pedal ergometer (the Stresst'er) with conventional treadmill examination in patients with leg pain on exercise. DESIGN: Patients presenting with claudication were assessed by standard treadmill test and by the new device in two District General Hospitals. METHODS: Ninety-four subjects were studied. Symptoms induced by both types of exercise were compared. Distance walked on the treadmill was compared to the number of pumps using the Stresst'er. The percentage change in ankle systolic pressure produced by the two tests was compared. RESULTS: Subjective symptoms induced by the tests were similar. Distance walked did correlate with pumps on the ergometer, as did change in systolic pressure. Analysis of a subgroup of 41 cases with receiver operator curve (ROC) tests showed that the new device is sensitive and specific. CONCLUSION: This new device is comparable with treadmill testing, but being easier to use, may have a place in the vascular clinic.

Adult↗
PubMed1997

Detection of accidental oesophageal intubation. Role of the anaesthetic assistant.

Three situations in which an anaesthetic assistant might be able to detect accidental oesophageal intubation during or immediately after intubation were assessed. These were: firstly, whilst applying cricoid pressure, secondly, whilst applying gentle palpation over the trachea just above the suprasternal notch and, thirdly, after intubation by means of a 'roll test'. During cricoid pressure, tracheal intubation was correctly diagnosed in all of 10 cases. However, deliberate oesophageal intubation was only detected in six out of 10 cases. During suprasternal palpation, three cases out of 10 oesophageal and three cases out of 10 tracheal intubation were misdiagnosed. In the 'roll test', two out of 10 tracheal and five out of 10 oesophageal intubations were misdiagnosed. In conclusion, no method could be relied on entirely and may indeed give false reassurance. Nonetheless, any doubt expressed about the tracheal tube position by the assistant should be taken seriously and a careful check made.

Adolescent↗
PubMed1996

Gas leakage and the laryngeal mask airway. A comparison with the tracheal tube and facemask during spontaneous ventilation using a circle breathing system.

The ability of the laryngeal mask airway, tracheal tube and facemask to provide a leak free seal in a clinical setting was assessed by measuring the minimal fresh gas flows needed in a closed circle system during spontaneous ventilation on 60 subjects. The fresh gas flow was reduced until no spillage occurred from the pop-off valve. This fresh gas flow was taken to represent the sum of gas uptake by the subject and gas leakage from the circuit. The median fresh gas flow after 20 minutes was 350 ml.min-1 in the laryngeal mask airway group, 350 ml.min-1 in the tracheal tube group and 450 ml.min-1 in the facemask group. The fresh gas flow required for the facemask group was significantly higher than that for the laryngeal mask airway or tracheal tube groups (p < 0.01). There was no significant difference between the fresh gas flows required for the tracheal tube and laryngeal mask airway group. We conclude that the laryngeal mask airway provides as good a gas tight seal as a tracheal tube in this context and would be of benefit in reducing anaesthetic gas pollution.

Adult↗
PubMed1994

A system for audit of obstetric anaesthesia.

A modification to a computer based system of audit, widely used in anaesthesia for general surgery, is described, which permits a more detailed analysis of obstetric anaesthetic workload. By adjusting entries, in the operation input field, further information can be collected automatically. This allows the total number of regional anaesthetic procedures, including those in patients with epidurals for labour who progressed to caesarean section, to be calculated. It identifies the total number of caesarean sections, including anaesthetic technique and whether an epidural catheter was, in any case, present. This modification may be applicable to other computerised audit systems.

Journal Article↗
PubMed1992

Timing of peak pressor response following endotracheal intubation.

The study was designed to measure the timing of the peak cardiovascular response following laryngoscopy and endotracheal intubation. Thirty patients ASA 1 or 2 were studied, with arterial pressure being continuously monitored using the Ohmeda 2300 Finapres. Patients were randomised to receive either propofol 2.5 mg.kg-1 (Group A) or thiopentone 4.5 mg.kg-1 (Group B). The mean time to complete laryngoscopy and intubation was 26 s in Group A and 20 s in Group B. The peak response occurred on average 31 s after the start of the stimulus in Group A and after 32 s in Group B. In 8 out of the 30 cases the peak response occurred during the period of stimulation. Systolic pressure fell on average by 2.6 kPa (20 mmHg) (range 0 to 5.9 (45 mmHg)) from its peak value to the value measured at the 1-min time mark in the propofol group, and by 2.3 kPa (17 mmHg) (range 0.4 (3 mmHg) to 3.8 (29 mmHg)) in the thiopentone group. We conclude that the use of slow arm-cuff-based arterial pressure measurement techniques may miss important hypertensive episodes during laryngoscopy and endotracheal intubation. The effectiveness of agents in obtunding the pressor response may thus be misinterpreted.

Adolescent↗
PubMed1990

Cardiovascular response to insertion of Brain's laryngeal mask.

This study was designed to investigate the cardiovascular effects related to insertion of the Brain laryngeal mask airway and to compare these effects with those after insertion of a Guedel oral airway. Arterial pressure and heart rate in 100 patients were measured using an Ohmeda 2300 Finapres arterial pressure monitor. Arterial pressure decreased significantly (p less than 0.001) and heart rate increased significantly (p less than 0.001) after induction of anaesthesia with 2.5 mg/kg of propofol. A significant increase in arterial pressure (p less than 0.02) and in heart rate (p less than 0.001) followed insertion of the laryngeal mask and the Guedel airway, with no difference between the two groups at any time. The changes in arterial pressure and heart rate returned to 'at insertion' levels within 60 seconds of the stimulus.

Adolescent↗