Regional cerebral blood flow and cellular environment in subarachnoid hemorrhage: A thermal doppler flowmetry and microdialysis study

Background Cerebral microdialysis enables assessment of regional metabolic physiology and provides biomarkers for clinical correlation in critical conditions, such as subarachnoid hemorrhage (SAH). The aim of our current study was to investigate the correlation between regional cerebral blood flow and microdialysis parameters (glucose, lactate, glycerol, pyruvate concentrations, and lactate/pyruvate metabolic ratio) in patients with SAH. Materials and methods Twenty-one patients with SAH were enrolled in our retrospective study. Cerebral blood flow (CBF) based on thermal diffusion methodology, the thermal coefficient K, and microdialysis biochemical markers were recorded. The duration of the brain monitoring was 10 days. Results Microdialysis glucose concentration was inversely related to the cerebral temperature and to the L/P ratio. Furthermore, it was positively correlated to all other microdialysis parameters but glycerol. The K coefficient was strongly and positively correlated with the temperature and marginally with the CBF. The L/P ratio was positively correlated with glycerol, while it was inversely correlated with the CBF. Patients who died had elevated L/P ratio and K coefficient compared to the survivors in our series. Conclusions Thermal conductivity coefficient may change over time as cerebral injury progresses and tissue properties alter. These alterations were found to be associated with the microdialysis metabolite concentrations and the CBF itself. The microdialysis biochemical indices of cell stress and death (glycerol, L/P ratio) were positively related to each other, while the measured L/P metabolic ratio was higher among patients who died

Endovascular Stent-Graft Repair of Major Abdominal Arteriovenous Fistula: A Systematic Review

Purpose: To evaluate the outcomes of endovascular stent-graft repair of major abdominal arteriovenous fistulas. Methods: The English literature was systematically searched using the MEDLINE electronic database up to January 2009. All reports on endovascular stent-graft repair of major abdominal arteriovenous fistula were considered. Our experience of abdominal arteriovenous fistula was involved in the data analysis. The primary outcome measures were technical success and perioperative, 30-day, and overall mortality. Results: Data for the final analysis were extracted from 21 papers reporting on 22 patients and from the medical records of a patient treated at our institution. The most common causal associations of these fistulae were the presence of an aortoiliac aneurysm and previous endovascular aneurysm repair, accounting for 56% and 13% of all associations, respectively. The technical success rate was 96% (22/23). No perioperative or 30-day mortality was noticed during a mean follow-up of 9 months. The most common procedure-related complication was type II endoleak, which was found in 22% (5/23) of the patients. This event was either self limiting or required minimal percutaneous intervention. Conclusion: Endovascular stent-graft repair of major abdominal arteriovenous fistula is a safe and effective treatment option, with good short- and midterm results. However, no long-term data exist, and larger series are required to draw solid conclusions regarding the outcomes of this method. J Endovasc Ther. 2009;16:514-52

Depth of anesthesia as a risk factor for perioperative morbidity

Introduction. The prognostic value of age, physical status, and duration of surgery on perioperative course has been extensively studied. However, the impact of deep hypnotic time (time when Bispectral Index values are less than 40) has not been well evaluated. Methods. We designed an observational study to clarify the relative influence of deep hypnotic time (DHT) on outcome. Eligible participants were mentally stable patients over 18 years old scheduled for elective major abdominal surgery. In total, 248 patients enrolled. Data were analyzed using Fisher's exact test and multiple logistic regression. Results. Five variables (DHT, hypotension, age, comorbidity, and duration of surgery) showed statistically significant association with complications, when examined independently. However, when all variables were examined together in a multiple logistic regression model, age and comorbidity were no longer associated with outcome. DHT, hypotension, and duration of surgery were significant predictors of "complications," and "hypotension" was a significant predictor of prolonged hospital stay (P < 0.001). Conclusion. Deep hypnotic time emerged as a new factor associated with outcome, and its impact compared to other factors such as age, surgery duration, hypotension, and comorbidity is redefined. Monitoring and managing depth of anesthesia during surgery are important and should be part of careful operation planning. © 2015 Argyro Petsiti et al

Impact of intraoperative hypotension on hospital stay in major abdominal surgery

Although the relationship between preoperative risk factors and outcomes has been extensively studied, the effect of intraoperative hemodynamic changes in a patient's postoperative course has been less well defined. We designed a prospective observational study to assess the impact of several variables, and especially hypotension, on postoperative outcome. Patients considered eligible for the study, all more than 18 years old, were mentally stable patients scheduled for major abdominal surgery with an expected duration of more than 2 h. Total hypotension time (THT), with other variables that possibly influence the outcome, was analyzed using multivariate logistic regression analysis in 100 consecutive patients. Total hypotension time was isolated as a factor significantly associated with morbidity [odds ratio, 5.1 (1.95-13.35)] and significantly prolonged hospital stay [odds ratio, 4.56 (1.85-10.96)]. Patients who had prolonged THT presented more complications (50 vs. 30), especially of the cardiovascular, pulmonary, and gastrointestinal systems. These complications led to delayed hospital discharge in a significant number of patients (36 with THT vs. 17 others). Finally, duration of surgery was associated with postoperative complications [odds ratio, 3.1 (1.2-8.0)]. Persistent hypotension during elective major abdominal surgery is a significant risk factor for postoperative complications and may prolong hospitalization and affect patient outcomes. Anesthetic management for the avoidance of hypotension, as much as possible, during major abdominal surgery may positively affect outcomes

Monitoring of brain oxygen saturation (INVOS) in a protocol to direct blood transfusions during cardiac surgery: a prospective randomized clinical trial

Background: Blood transfusions are common in cardiac surgery, but have been associated with increased morbidity and long-term mortality. Efforts to reduce blood product use during cardiac surgery include fluid restriction to minimize hemodilution, and protocols to guide transfusion decisions. INVOS is a modality that monitors brain tissue oxygen saturation, and could be useful in guiding decisions to transfuse. However, the role of INVOS (brain tissue oxygen saturation) as part of an algorithm to direct blood transfusions during cardiac surgery has not been evaluated. This study was conducted to investigate the value of INVOS as part of a protocol for blood transfusions during cardiac surgery. Methods: Prospective, randomized, blinded clinical trial, on 150 (75 per group) elective cardiac surgery patients. The study was approved by the Institution Ethics committee and all patients gave written informed consent. Data were initially analyzed based on "intention to treat", but subsequently were also analyzed "per protocol". Results: When protocol was strictly followed ("per protocol analysis"), compared to the control group, significantly fewer patients monitored with INVOS received any blood transfusions (46 of 70 patients in INVOS group vs. 55 of 67 patients in the control group, p = 0.029). Similarly, patients monitored with INVOS received significantly fewer units of red blood cell transfusions intraoperatively (0.20 +/- 0.50 vs. 0.52 +/- 0.88, p = 0.008) and overall during hospital stay (1.31 +/- 1.20 vs. 1.82 +/- 1.46, p = 0.024). When data from all patients (including patient with protocol violation) were analyzed together ("intention to treat analysis"), the observed reduction of blood transfusions in the INVOS group was still significant (51 of 75 patients transfused in the INVOS group vs. 63 of 75 patients transfused in the control group, p = 0.021), but the overall number of units transfused per patient did not differ significantly between the groups (1.55 +/- 1.97 vs. 1.84 +/- 1.41, p = 0.288). Conclusions: Our data suggest that INVOS could be a useful tool as part of an algorithm to guide decisions for blood transfusion in cardiac surgery. Additional data from rigorous, well designed studies are needed to further evaluate the role of INVOS in guiding blood transfusions in cardiac surgery, and circumvent the limitations of this study

Hybrid procedures for the treatment of multi-focal ipsilateral internal carotid and proximal common carotid or innominate artery lesions

We report three cases with concomitant ipsilateral proximal common carotid and internal carotid artery stenosis treated in one stage with carotid endarterectomy and retrograde primary stenting of the common carotid artery. The internal carotid artery was clamped during stenting to avoid cerebral embolization. All procedures were successfully completed and all patients remain asymptomatic at 18 months follow up. The one-stage hybrid approach appears to be a safe and effective procedure for the treatment of ipsilateral multifocal significant lesions