The effects of hydroxyethyl starch solution in critically ill patients

AIM

In the treatment of the critically ill patients an adequate fluid therapy appears to be essential to optimize hemodynamics and to get a suitable tissue perfusion. In this study we have evaluated the effects of volume replacement, carried out with 2 different solutions: hydroxyethyl starch 6% (HAES) and albumin 20% (HA).

METHODS

Twenty patients suffering from sepsis were recruited and randomized into 2 groups. The first group was treated with hydroxyethyl starch 6% ( HAES treated group), and the second with albumin 20% (HA treated group). The volume of colloids was given to maintain pulmonary capillary wedge pressure (PCWP) between 15 and 18 mmHg. Daily, both hemodynamic parameters and blood gas analyses were monitored.

RESULTS

Groups were homogeneous for age, sex and pathology. During the treatment we observed that cardiac index (CI), right ventricular ejection fraction (RVEF), oxygen consumption index (VO(2)I), oxygen delivery index (DO(2)I), and rate between arterial oxygen pressure and fraction of inspired oxygen (PaO(2)/FiO(2)) were increased significantly only in HAES treated group (P<0.05). APACHE II score decreased significantly only in HAES treated group (P<0.05), contrarily to the HA treated group, in which we observed a non significant increase.

CONCLUSIONS

Since hydroxyethyl starch induced a hemodynamic and clinical improvement, these effects translated into an improvement of sensorium and a reduction of APACHE II score, without causing pulmonary edema, we can conclude that hydroxyethyl starch 6% ws 130,000 dalton ms 0.4 (Voluven) is an effective fluid for resuscitation of hypovolemic patients and represent an attractive alternative to albumin.

Conscious analgosedation for radiofrequency ablation of lung neoplasm

AIM

Radiofrequency ablation (RFA) is a minimally invasive therapy for pulmonary malignant cancers in patients with medical co-morbidities or refusal of surgery. The aim of this study was to evaluate a conscious analgosedation protocol for RFA of lung neoplasm.

METHODS

Ten RFAs were performed. Following analgesic premedication patients underwent local anesthesia (lidocaine 2%) and propofol infusion.

RESULTS

The procedures were always uneventful. Postoperative severe pain was not reported; a deep sedation was required to allow the quick and safe management of RFA.

CONCLUSIONS

Spontaneous breathing sedation is safe in monitored and well-oxygenated patients and may limit the incidence of tension pneumothorax. Postoperative period needs a proper pain control for the first 24 h. Data on the long-term efficacy of lung tumor RFA are not yet available.

Target controlled infusion: TCI

Progress in computing technology has allowed the development of target controlled infusion devices, with drugs delivered to achieve specific predicted target blood drug concentrations. Target controlled infusion (TCI) system has been developed as a standardised infusion system for the administration of opioids, propofol and other anaesthetics by target controlled infusion. A set of pharmacokinetic parameters has been selected using computer simulation of a known infusion scheme. The selected model is incorporated into a computer-compatible infusion pump. Clinical trials with such systems have provided appropriate target concentrations for the administration of target controlled infusion of anaesthetic drugs. The technique of TCI strongly influences the development of intravenous anaesthesia and opens a scenario of new and exciting applications in peri-operative anaesthetic management. The launch of ''Diprifusor'' as the first commercially available TCI system for propofol was the cornerstone of a successful research period within the last decade, which evaluated the pharmacokinetic foundations of computer assisted intravenous drug delivery. Nowadays TCI technology is becoming a part of routine anaesthesia technique for the practitioner rather than a research tool for specialists and those who are enthusiasts of intravenous anaesthesia. Besides clinical application in anaesthesia, target controlled systems will play a significant role as research tools in the evaluation of drug interactions in anaesthesia and in the development of new control techniques for the administration of sedative and analgesic drugs in the peri-operative period.

Reduced compliance of left ventricle

Diastolic function is essential for efficient systolic performance. A normal diastole allows left ventricle (LV) filling to occur under normal intracavitary pressure. It is an energy dependent process, as such affected by ischemia. Several factors influence diastolic function of the LV: the mitral valve area, the gradient between atrium and ventricle, LV relaxation and compliance, atrial compliance, the presence of sinus rhythm, the end-systolic volume. Echocardiography is the principal diagnostic tool to assess LV diastolic function noninvasively in clinical practice. Doppler evaluation allows to analyse each phase of LV diastole through measurement of transmitral and pulmonary veins flows velocities. Tissue Doppler echocardiography and color M-mode Doppler have also been introduced in the study of diastole. The use of echocardiography in the setting of diastolic dysfunction in ICU and operatory room has relevant implications in the management of haemodynamic instability, in vasoactive d rugs titration, in the detection of myocardial ischemia, and in performing prognostic stratification. These information can guide the management of cardiac patients undergoing cardiac and non cardiac surgery, in the perioperative phase, as well as in the management of critical ICU patients. On this basis evaluating the LV filling properties can contribute to improve the quality of treatments in such challenging situations.