Anaesthesia
-
The construction of a new, valid and reliable questionnaire to measure patient satisfaction is a complex and time-consuming task. It must follow a rigorous, step-by-step approach, and should as a minimum include elements of content validity, criterion validity, construct validity and reliability. The objective of this review is to present a protocol for the construction of a psychometric questionnaire, supplemented by practical aspects for researchers and clinicians.
-
Using Schnider's pharmacokinetic model, propofol pharmacodynamics were modelled during total intravenous anaesthesia. The method involved adjusting a pharmacokinetic/pharmacodynamic model according to data obtained from 42 patients having operative procedures with remifentanil analgesia. Parameters Ce50 and γ were estimated for induction and maintenance by analysing patients' bispectral index. ⋯ As γ is related to the concentration-effect slope, patient response is accentuated during maintenance compared with induction. The influence of sex and age on the model was analysed. Sex had no significant influence on the model, although a linear relation was found between age and Ce50 .
-
Cardiac output can be measured non-invasively using supra-sternal Doppler (USCOM, Sydney, NSW, Australia). However, scanning can be difficult in practice in older patients, the reason for which has not been elucidated previously. Chest radiographs from 60 previously studied anaesthetised patients were reviewed and scored for aortic unfolding, enlargement and calcification, and cardiac enlargement. ⋯ Twenty patients who were difficult to scan, aged 60-88 years, had mean (SD) radiological scores of 5.9 (2.5) out of 12, while 20 adult controls, 40-60 years, and 20 older patients who were easy to scan, 60-80 years, had radiological scores of 0.9 (1.1) and 1.7 (1.4), respectively (p < 0.001). Over 75% of the patients who were difficult to scan had two or more radiological features suggestive of aortic unfolding and cardiac enlargement. Morphological or anatomical changes associated with ageing within the upper chest play an important part in the success of using supra-sternal Doppler in older patients.
-
In 2008, the UK National Patient Safety Agency (NPSA) made recommendations for safe arterial line management. Following a patient safety incident in our intensive care unit (ICU), we surveyed current practice in arterial line management and determined whether these recommendations had been adopted. We contacted all 241 adult ICUs in the UK; 228 (94.6%) completed the survey. ⋯ Others have been incompletely implemented and many areas of practice (prescription of fluids, two-person checking at shift changes, use of opaque pressure bags, arterial sampling technique) were highly variable. More importantly, the use of the wrong fluid as an arterial flush was reported by 30% of respondents for ICU practice, and a further 30% for practice elsewhere in the hospital. Our survey provides evidence of continuing risk to patients.
-
We investigated the rate of injections interpreted as intravascular during imaging of lumbosacral transforaminal epidural injections, using fluoroscopy alone or with digital subtraction. We evaluated 732 injections performed on 348 patients: 8.1% (59/732) and 10.5% (77/732) of injections were interpreted as intravascular during fluoroscopy and digital subtraction, respectively, p = 0.13. The odds ratio (95% CI) for interpreting injections as intravascular increased for both fluoroscopy and digital subtraction fluoroscopy, with: each year of age, 1.04 (1.01-1.07) and 1.03 (1.00-1.06), p = 0.011 and 0.024, respectively; sacral compared with lumbar injections, 10 (5-19) and 8 (5-15), p < 0.001 for both. The odds ratio for intravascular injection increased with three other variables during digital subtraction fluoroscopy: spinal stenosis, 5.1 (1.5-17.1), p = 0.009; failed back surgery syndrome, 4.3 (1.2-15.8), p = 0.025; compression fracture, 8.0 (1.6-39.4), p = 0.011.