Perioperative bioelectrical impedence analysis in neurosurgery

The use of bioelectrical impedence [BI] measurement to assess body composition has recently attracted the attention of anesthesiologists. Analysis of BI provides a non-invasive method to quantify fluid distribution in different body compartments. This study was designed to assess whether BI analysis reflects fluid depletion in neurosurgical patients with moderate blood loss. Six adult male patients scheduled for elective craniotomy under general anesthesia were studied. Exclusion criteria included patients with cardio-respiratory disease. BI analysis was performed at three stages, A, day before operation, B, during surgery and c, on the first postoperative day. Total body resistivity was measured by BI analysis with a four-terminal portable impedence analyzer. At each frequency, impedence was calculated as resistance [Rx][2] + reactance [Rc][2]. The mean values of total body water [TBW] at stages A, B and C were 39.8 L [range: 33.1-46.7 L], 43.2 L [range: 33.1-66.2 L] and 36.8 L [range: 22.4-36.3 L] respectively with significant differences [P<0.05]. The impdence at the three frequencies during stages A, B and C showed significant differences [P<0.05]. In conclusion, we have found that in male neurosurgical patients multiple frequency BI measurements has reflected fluid balance perioperatively. Whether this observation remains true for other surgical procedures with massive blood loss, yet to be further investigated

Anesthetic implications for video assisted thoracoscopic thymectomy in myasthenia gravis

Thymectomy is an established therapy in the management of generalized myasthenia gravis [MG]. However, the optimal surgical approach to thymectomy has remained controversial. There are advocates for transternal, transcervical approaches for "maximal" thymectomy. Video-assisted thoracoscopic thymectomy [VATT] presents new approach to thymectomy. By minimizing chest wall trauma, VATT not only causes less postoperative pain, shortens hospital stay, gives better cosmetic results but also leads to wider acceptance by patients for earlier surgery. Anesthesia for thymectomy in MG is challenging. Currently we are using non-muscle relaxant technique [NMRT] which we adopted in 1994, for maximal thymectomy. In this paper, we present our limited experience with two cases of VATT using two different NMRTs. Two cases of MG underwent VATT under general anesthesia [GA] and one lung ventilation [OLV] using double lumen tube [DLT]. In both cases NMRT was used which encompass, light GA plus thoracic epidural analgesia [TEA] in one case and without TEA in the other case. We believe that the use of NMRT provides good operative and postoperative conditions. In this report we have described two different NMRTs, one with TEA and the other without. Further studies are needed on large number of cases to establish an anesthetic protocol for VATT