Haemodynamic and oxygen transport responses in survivors and non-survivors following thermal injury.

Resuscitation from shock based on invasive hemodynamic monitoring has been widely used in trauma and surgical patients, but has been only sparsely evaluated in thermally injured patients, probably due to fear of invasive monitoring in this group of patients. However, end-point resuscitation to fixed circulatory and oxygen transport values has been proposed to be associated with an improved survival rate following trauma and high-risk surgery. Furthermore, the early circulatory response to resuscitation has been shown to be predictive of survival in these patients. In this study the early hemodynamic and oxygen transport profile following thermal injury was analysed with the aim to detect possible differences in the response of survivors and non-survivors. The transpulmonary thermodilution technique was used for hemodynamic monitoring of 21 patients, who were admitted to our burn unit with severe burns. Six patients died and 15 patients survived to leave the intensive care unit. Survivors were found to have a significantly higher cardiac index and oxygen delivery rate during the early postburn period than non-survivors. Furthermore, initial serum lactate levels as well as the ability to clear elevated lactate were found to be significantly associated with survival. Blood pressure and heart rate were not significantly different between the two groups of patients. All patients received significantly higher volumes of crystalloids during the first 24 h than predicted from the Baxter formula, independent of outcome. We concluded that standard vital signs such as blood pressure and heart rate may be invalid as outcome related resuscitation goals, and too insensitive to ensure appropriate fluid replacement. The response to fluid therapy may be significantly associated with outcome; survivors responding with an augmentation of cardiac output and oxygen delivery not seen in non-survivors. Lactate levels seem to correlate with organ failure and death and appear a suitable end-point for resuscitation of severely burned patients.

Which patient is most likely to benefit from a rate responsive pacemaker?

In order to provide information about indications for rate responsive pacing, we examined the exercise capacity of a typical collective of pacemaker patients. One hundred seven patients participated in the study, 50/107 (46.8%) suffered from sick sinus syndrome, 37/107 (34.6%) showed complete AV block, 12/107 (11.2%) had bradyarrhythmia and 8/107 (7.4%) had other diseases. All patients underwent treadmill exercise with increasing workloads up to the individual's maximum workload. We monitored heart rate, respiratory rate, workload, the subjective perception of stress according to the Borg scale, and the reason for the termination of exercise. Calculation of oxygen uptake was done according to an equation given by Givoni. During the tests, all implanted pacemakers have been programmed to VVI 70 mode. We found that all pacemaker patients showed a reduction of their exercise capacity compared to the age-related normal values. Particularly in patients with AV block or bradyarrhythmia, the maximum achievable workload often did not even reach levels of everyday activities such as going upstairs; patients with sick sinus syndrome showed slightly better exercise capability, probably due to the higher increase of average heart rate. Despite objective differences of maximum workload, all patients had the same subjective perception at the end of the tests; the course of respiratory rate indicated that all persons finished the tests in the range of individual maximum exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)