PubMed Health⌕ Search

Biomedical subjects

A Absalom

Publications and source records attributed to A Absalom.

15 recordsLinked to original sources
PubMed2003

Accuracy of the 'Paedfusor' in children undergoing cardiac surgery or catheterization.

BACKGROUND: A prototype paediatric propofol target-controlled infusion (TCI) system, the 'Paedfusor' has been developed. This system incorporates a paediatric pharmacokinetic data set and algorithm specific for children in a Graseby 3500 anaesthesia syringe driver. In this study we have evaluated the accuracy of the Paedfusor TCI system in children who underwent either cardiac surgery or cardiac catheterization procedures. METHODS: Twenty-nine children aged 1-15 yr were investigated. General anaesthesia was provided using propofol administered by the Paedfusor system. Accuracy of the system was evaluated by obtaining up to 9 arterial samples for measurement of propofol concentration both during anaesthesia and in the recovery period. Measured arterial propofol concentrations were then compared with values calculated by the Paedfusor. RESULTS: The predictive indices of median performance error (MDPE), and median absolute performance error (MDAPE) of the Paedfusor system were found to be 4.1% and 9.7%, respectively and the median value for wobble was 8.3%. These values are much better than those found with the adult 'Diprifusor' system. CONCLUSION: The Paedfusor performance was found to be within the accepted limits for use as a TCI system.

Adolescent↗
PubMed2002

Closed loop control of sedation for colonoscopy using the Bispectral Index.

Sixteen patients undergoing colonoscopy were sedated with propofol using a closed-loop control system guided by the Bispectral Index (BIS). Propofol administration, via a target-controlled infusion, was controlled by a proportional-integral-differential control algorithm. The median (range) propofol target concentration during closed-loop control was 2.3 (1.7-3.6) microg.ml(-1). The performance characteristics of the system were excellent, with a median absolute performance error of 7 (1-15). Patients were drowsy yet rousable, with a median (range) BIS set-point of 80 (75-85). No patient became apnoeic, required airway support or became haemodynamically unstable whilst sedated. Eight patients moaned or moved during colonoscopy and four had recall. Median (range) time to full consciousness was 4 (2-20) min after the end of closed-loop control. Patient and surgeon satisfaction were high. We conclude that BIS may be a suitable control variable for closed-loop control of sedation with propofol.

Adult↗
PubMed1999

Adrenocortical function in critically ill patients 24 h after a single dose of etomidate.

We compared the effects of single doses of etomidate and thiopentone on adrenocortical function in a randomised controlled clinical trial involving 35 critically ill patients who needed a general anaesthetic. Just before induction of anaesthesia, a baseline blood cortisol sample was taken. Twenty-four hours later we performed a short adrenocorticotrophic hormone stimulation test. No patient had a low cortisol level (< 160 nmol.l-1) at any time during the study. Baseline, pre-ACTH and post-ACTH cortisol levels were similar in the two groups. However, significantly more patients in the etomidate group had an ACTH-stimulated cortisol increment < 200 nmol.l-1. The clinical significance of these findings is not clear, but we conclude that single doses of etomidate may interfere with cortisol synthesis for at least 24 h in the critically ill.

Adolescent↗
PubMed1999

Current and future applications of target-controlled infusions.

Target-controlled infusions (TCI) aim to provide constant, user-defined blood concentrations of a drug. The infusion device of such a system is controlled by a microprocessor that uses population pharmacokinetic data and the individual patient's weight and age to continuously calculate the required drug infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. This technology has several exciting applications in anesthesia where stable blood concentrations of drugs are of benefit. TCI of propofol for general anesthesia and sedation are now widely used, but the technology is also being extended to the fields of intra- and postoperative analgesia and to patient-maintained sedation and analgesia. Early work on targeting the effect site (brain) is under way and target-controlled propofol infusions are being used in experimental closed-loop anesthesia systems.

Journal Article↗
PubMed1997

Two teenagers, traumatic aortic disruption, and transoesophageal echocardiography.

A report of two teenagers is presented who were passengers of the same vehicle when it was involved in a serious road traffic accident. Their vehicle was hit on the side at high speed by a second vehicle. Both teenagers sustained multiple injuries. On arrival at a district general hospital they required resuscitation, exploratory laparotomies, and postoperative intensive care. Neither had radiographic evidence to suggest any mediastinal injury, but transoesophageal echocardiography demonstrated aortic disruption in both patients. They were transferred to a regional cardiothoracic centre where their lesions were successfully repaired and both have made a full recovery.

Accidents, Traffic↗