A mini volume loading test (mVLT) using 2.5-mLkg-1 boluses of crystalloid for indication of perioperative changes in hydration status.

BACKGROUND AND OBJECTIVE: A mini volume loading test (mVLT) evaluating hemodilution during step-wise crystalloid infusion has established that the arterio-capillary plasma dilution difference is inversely correlated to the body hydration level of subjects. This observational study aimed to test whether this can be replicated in a perioperative setting using a 2.5-mLkg-1 boluses. MATERIALS AND METHODS: The mVLT was performed before induction of regional anesthesia and 24h later. Step-wise infusion implied six mini fluid challenges. These consisted of 2.5-mLkg-1 boluses of Ringer's acetate infused during 2-3min and followed by 5-min periods with no fluids. Invasive (arterial) and noninvasive (capillary) measurements of hemoglobin were performed before and after each mini fluid challenge, as well as after a 20-min period without fluid following the last bolus. Hemoglobins were used to calculate the arterio-capillary plasma dilution difference which is used as an indication of changes in body hydration level. The 24-h fluid balance was calculated. RESULTS: Subjects were 69.5 (6.0) years old, their height was 1.62m (1.56-1.65), weight was 87.0kg (75.5-97.5) and body mass index (BMI) was 33.5kg/m2 (31.0-35.1). Preoperative arterio-capillary plasma dilution difference was significantly higher than postoperative (0.085 [0.012-0.141] vs. 0.006 [-0.059 to 0.101], P=0.000). The perioperative 24-h fluid balance was 1976mL (870-2545). CONCLUSIONS: The mVLT using 2.5-mLkg-1 boluses of crystalloid was able to detect the higher postoperative body hydration level in total knee arthroplasty patients.

A role of anesthesiologist in reducing surgical bleeding in endoscopic sinus surgery.

Visibility in the surgical field reduced by bleeding is one of the most important problems of endoscopic sinus surgery. It causes the risk of serious complications and reduces intervention quality. Recently, an increasing number of patients undergo surgical interventions under general anesthesia. Since general anesthesia may influence surgical bleeding in physiological and pharmacological pathways, the role of an anesthesiologist is extremely important in reducing bleeding. The impact of different anesthesia methods on quality of the surgical field is being investigated, and the most effective medicines are being sought.

Application of controlled arterial hypotension in endoscopic rhinosurgery.

Intraoperative bleeding is one of the major problems in endoscopic surgery of sinuses. In the case of the expanded process, still more numerous interventions are performed with general anesthesia. The objective of research is to compare intraoperative hemorrhage and the visibility of the operative field during normotension and hypotension anesthesia caused by nitroglycerin and captopril when performing endoscopic operations of accessory nasal sinuses. Fifty-two patients of physical health state 1-2 according to ASA were examined: for 32 the controlled hypotension (Group H) was applied, 20 patients underwent operations in normotension (Group N). All patients on the eve of the operation were premedicated with diazepam; Group H patients on the day of operation received 6.25 mg of captopril. Anesthesia was carried out with fentanyl and halothane steam in the 50:50% mixture of oxygen and laughing gas. In Group H arterial blood pressure was lowered by nitroglycerin infusion. The average arterial blood pressure was maintained in GroupH within the limits of 50-60 mmHg. Hypotension was coordinated with the rising of the head-bed of the operating table at 5 degrees. Hemorrhage was measured by collecting blood with the pump graded with the precision of 25 ml. The visibility of the operative field was evaluated subjectively every 15 minutes according to the scale of 5 points proposed by Fromm. In both groups the average arterial blood pressure values as well as the values of the frequency of heart contractions differed statistically significantly. In the hypotensive group, hemorrhage during operation was less, on the average, (208 ml) than in Group N (349.2 ml). The visibility of the operative field was by one point, on the average, better than in Group H. No anesthetic complications were observed during investigation. In summary, it is possible to state that the controlled arterial hypotension caused by captopril and nitroglycerin reduced significantly intraoperative hemorrhage and improved the visibility of the operative field in endoscopic rhinosurgery.