Anaesthesia and intensive care
-
Anaesth Intensive Care · Oct 2002
Randomized Controlled Trial Comparative Study Clinical TrialCorrect positioning of the venous port-a-cath catheter: comparison of intravascular electrocardiography signal from guidewire and sodium bicarbonate flushed catheter.
A prospective study comparing the efficacy of wire-conducted intravascular ECG (IVECG) signal and signal from the port with a sodium bicarbonate (NaHCO3) flushed catheter to correctly place a catheter tip was carried out in 100 patients. The correct position of the catheter tip was confirmed as follows: with technique G, the IVECG signal was conducted from a guide wire to identify the tip position. With technique P, the IVECG signal was conducted from the port with a NaHCO3 (0.8 mmol/ml) flushed catheter to ascertain the tip position. ⋯ There was no obvious difference between the techniques in catheter tip placement time or the measured optimal catheter length. The incidence of atrial premature contractions was higher with technique G than with technique P (13% vs 2%; P=0.003). Therefore, technique P is a practical alternative for correctly placing the catheter tip of a Port-A-Cath.
-
Anaesth Intensive Care · Oct 2002
Review Case ReportsAirway management on placental support (AMPS)--the anaesthetic perspective.
Neonatal airway obstruction has been reported to have a high mortality. Antenatal diagnosis of this condition is now possible. ⋯ In particular, techniques for uterine relaxation and maintenance of placental circulation are explored. The history of these procedures and issues of planning and logistics are also discussed.
-
Anaesth Intensive Care · Oct 2002
Comparative StudyRemifentanil concentration during target-controlled infusion of propofol.
After institutional approval and with written informed consent, eight surgical patients were infused intravenously with remifentanil at 250 ngkg lean body mass (LBM)(-1) x min(-1) for 30 min. Cardiovascular and respiratory parameters were recorded and arterial blood samples were taken at regular intervals. In each patient, the same protocol was repeated 40 min later during propofol infused to a target concentration of 3.0 microg x ml(-1). ⋯ The median AUC during propofol infusion was greater than control in all subjects, although there was considerable variation of 94.4 (64.3-129.6) versus 64.6 (34.8-126.9) ng x ml(-1) x min; P=0.008, n=8. After 30 min, there was no significant difference in remifentanil concentration during propofol infusion when compared with remifentanil alone of 4.6 (3.2-5.7) versus 3.8 (1.6-4.9) ng x ml(-1); P=0.73, n=8. Co-administration of propofol and remifentanil may result in greater remifentanil concentrations than when remifentanil is infused alone.
-
Anaesth Intensive Care · Oct 2002
Comparative StudyThe ASA Physical Status Classification: inter-observer consistency. American Society of Anesthesiologists.
The American Society of Anesthesiologists (ASA) physical status classification system has previously been shown to be inconsistently applied by anaesthetists. One hundred and sixty questionnaires were sent out to all specialist anaesthetists in Hong Kong. Ten hypothetical patients, identical to those of a similar study undertaken 20 years ago, each with different types and degrees ofphysical disability were described. ⋯ Overall correlation was only fair in all groups (Kappa indices: 0.21-0.4). We found that the current pattern of inter-observer inconsistency of classification was similar to that 20 years ago and exaggerated between locally and overseas trained specialists (P<0.05). The validity of the ASA system, its usefulness and the need for a new, more precise scoring system is discussed.
-
The possibility of a potential mutagenic or carcinogenic action of chronic exposure to low concentrations of inhalational anaesthetics has been previously studied, with conflicting results. The purpose of this study was to assess whether occupational exposure to waste anaesthetic gases increases genotoxic risk. We examined peripheral lymphocytes from anaesthetists for both sister chromatid exchange (SCE) and for cells with high-frequency SCEs (HFCs). ⋯ This study does not support the existence of an association between occupational exposure to waste anaesthetic gases and an increase in SCEs in lymphocytes. The nature of our anaesthesia practice suggests exposure was likely to be low. It should be noted that some anaesthetic gases produce lesions that can be efficiently repaired in mitogen-stimulated lymphocytes in vitro but not in circulating lymphocytes.