Acta anaesthesiologica Scandinavica. Supplementum
-
Acta Anaesthesiol Scand Suppl · Jan 1995
ReviewReversal of conscious sedation by flumazenil: current status and future prospects.
Flumazenil is safe and highly effective at reversing both benzodiazepine-induced sedation and amnesia. Bolus intravenous injection is the most appropriate technique when the goal is to fully reverse conscious sedation. Currently, the proven effective dose of flumazenil is 0.5 mg. ⋯ Depression of ventilatory responsiveness induced by benzodiazepines can be reversed effectively and promptly by flumazenil. Flumazenil must be immediately available as an emergency drug in any area where benzodiazepines are used. The clinical and economic benefits of elective and routine use of flumazenil have been demonstrated, but yet to gain widespread acceptance.
-
Acta Anaesthesiol Scand Suppl · Jan 1995
Comparative StudyA comparative study of two near infrared spectrophotometers for the assessment of cerebral haemodynamics.
Conventional near infrared spectroscopy (NIRS), introduced by Jöbsis in 1977, can be considered as a reliable trend monitor for cerebral oxygenation. Quantisation, however, is complex and cumbersome. Recently a relatively simple system for cerebral oximetry (INVOS 3100, Somanetics Corporation, USA) was developed, measuring the regional oxygen saturation (rSO2) in the capillary bed of the cerebrum, presented as a numerical figure for easy interpretation. ⋯ Increased cerebral blood flow induced by hypercapnia was detected by both conventional NIRS and the INVOS. Decreased cerebral blood flow induced by hypocapnia could only be detected by conventional NIRS. It was concluded that due to the variation in displayed rSO2 and the high amount of averaging in the algorithm the INVOS instrument does not yet provide more information than conventional NIRS.
-
A quantitative evaluation of metabolic acid-base component is described. The model is based on Stewart's analysis of acid-base chemistry. ⋯ The efficiency of the model is sufficient, quantitative partial results are given in the same units as base excess. In complex acid-base disturbances, such as are seen in critically ill patients, a detailed analysis of the specific components of the metabolic acid-base status allows one to plan specific therapeutic interventions.
-
Acta Anaesthesiol Scand Suppl · Jan 1995
The role of muscle relaxants in total intravenous anaesthesia.
For total intravenous anaesthesia (TIVA), all drugs that are required as part of the anaesthetic method are administered intravenously. This is usually taken to imply the use of intravenous infusions. It is normal practice to administer muscle relaxants intravenously, although other routes have been used. ⋯ It should cause negligible side-effects. For administration by infusion, an agent with an intermediate (e.g., atracurium) or short (e.g., mivacurium) duration of action is essential to ensure a rapid recovery of effect on termination of the infusion. The routine use of neuromuscular monitoring is recommended when a continuous infusion of a relaxant is used.
-
Acta Anaesthesiol Scand Suppl · Jan 1995
Review Comparative StudyFrom oxygen content to pulse oximetry: completing the picture in the newborn.
In recent years clinicians caring for sick preterm infants have come to depend on pulse oximetry to avoid hyperoxia, which means assuming saturation values for critical levels of oxygen tension. This prediction is made difficult by the shape of the haemoglobin-oxygen dissociation curve at critical values for arterial pO2 and by the effects of changes in acid-base balance on p50. Combined blood gas and co-oximetry measurements can be used to determine critical limits for pulse oximetry. ⋯ We demonstrated that, at 90% saturation, failure to use the fetal correction in the presence of high levels of fetal haemoglobin result in a 4% overestimate of saturation, with resultant underestimation of the safe range for pulse oximetry. Published values for extinction coefficients for fetal and adult blood at wavelengths used by pulse oximeters are inconsistent, but it appears that fetal haemoglobin does not bias pulse oximetry readings. Determining saturation limits by co-oximetry for use with pulse oximeters in preterm infants requires the description of the haemoglobin-oxygen dissociation curve with the correction for fetal haemoglobin.