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. Trial registration: ClinicalTrials.gov: NCT00879463

Existing data suggest that obesity correlates with airway hyper-reactivity. However, the incidence of bronchospasm during bariatric surgery in obese patients has not been well studied. This was a prospective observational study comparing 50 obese versus 50 non obese patients undergoing elective laparoscopic surgery over a 2 year period. Bronchospasm was detected clinically by auscultation and was confirmed by measuring peak airway pressure during mechanical ventilation. Blood gases were measured at predetermined time intervals intraoperatively. Categorical variables were analyzed using Fisher’s exact test, while numerical variables within and between groups were compared using repeated measures general linear model. The incidence of bronchospasm was significantly higher in obese compared to non obese patients (P = 0.027). Peak airway pressures and blood gases differed significantly when comparing non obese patients versus obese patients without bronchospasm versus obese patients with bronchospasm. Hypoventilation resulting in gradual increase of arterial PaCO2 was noted in all groups during surgery. The incidence of bronchospasm is higher in obese patients compared to non obese patients undergoing elective laparoscopic surgery. Airway pressures and blood gas values in obese patients are somewhere between values in non obese patients and values in patients with bronchospasm, thereby implying that obesity is associated with a state where bronchial smooth muscles are not fully relaxed. Consideration of increased airway reactivity in obese patients undergoing laparoscopic surgery is important for improved patient care and uneventful anesthetic course.

Objective: The existing evidence separately correlates morbid obesity with difficult intubation and bronchospasm. However, there is a lack of data on whether anaesthesia provider manipulations during difficult intubation contribute to an increased ratio of bronchospasm in these patients. Methods: This is a retrospective analysis of data prospectively taken from 50 morbidly obese patients involved in a previously published study. A possible difficult intubation was preoperatively investigated by recording the following specific physical examination indices: Mallampati and Cormack-Lehane (CL) classifications, cervical spine mobility (CSM), thyromental distance (Td) and patients' ability to open their mouth (mouth opening). Bronchospasm was clinically detected by auscultation and confirmed by measuring peak airway pressures during mechanical ventilation. The Kruskal-Wallis H test was used for data analysis, followed by the Mann-Whitney U test as applicable. Results: Different physical examination prognostic indices, including Mallampati and CL scales (p<0.001; the CSM excluded -p=0.790), showed that they are related to difficult intubation. Bronchospasm not attributable to difficult intubation was observed in six obese patients. Conclusion: Patients with morbid obesity constitute an increased relative risk group as far as difficult intubation is concerned, particularly if preoperative findings support a relationship between the two variables examined. In our study, difficult intubation and the concomitant use of special equipment and manipulations did not contribute to an increased rate of bronchospasm in obese patients, but in view of the lack of data, a large number of more sophisticated studies are required to elucidate such an assumption.

Background/Objectives: Chronic persistent postoperative pain after cardiac surgery, first described as Post CABG Pain Syndrome (PCPS), has been a well-recognized problem since 1989. This study investigated the effect of a single preoperatively administrated pregabalin dose on chronic persistent postoperative pain, in terms of pain intensity, rescue analgesia, and sleep disturbances, after elective cardiac surgery. Methods: This is a secondary analysis of a prospective double-blind single center study that took place in a tertiary/referral center (NCT01701921). Consecutive adult patients who underwent elective cardiac surgery with median sternotomy and extracorporeal circulation under general anesthesia were included. Patients were randomly assigned into three groups {placebo (group 1), oral pregabalin 75 mg (group 2), oral pregabalin 150 mg (group 3)}. Placebo or either dose of pregabalin were administered 1 h preoperatively. Postoperatively at 12 and 24 months, the presence of persistent chronic pain (Numeric Rating Scale, NRS), the need of daily intake of analgesics, and any potential sleep disturbances were assessed. Results: In total, 93 out of 108 patients completed this secondary analysis (86,1%). Patients from all three groups reported persistent postoperative pain at 12 and 24 months, respectively. The mean NRS scores at 12 months were 1.71 (0.588) group 1, 1.23 (0.560) group 2, and 1.19 (0.402) group 3. At 24 months, the mean NRS scores were 1.19 (0.543) Group 1, 0.84 (0.454) Group 2, and 0.84 (0.374) Group 3. No statistically important difference was detected between the two different pregabalin groups. Regarding the use of analgesics, Pearson Chi-Square showed p-values p = 0.027 in 12 months and p = 0.01 in 24 months and lower scores were detected in the high pregabalin dose group. As far as the sleep disturbances are concerned, there was no significant difference between groups. The number of patients who reported persistent postoperative pain at 12 and 24 months was significantly lower in the pregabalin groups (75 mg and 150 mg) than in the placebo group. Regarding the NRS score, Kruskal–Wallis showed a value of p = 0.001 and p = 0.005 in 12 and 24 months respectively. Regarding the use of analgesics, Pearson Chi-Square showed p-values p = 0.027 in 12 months and p = 0.01 in 24 months. Referring to sleep disturbances, there was no significant difference between groups. Conclusions: Based on the results of this study, it seems that oral administration of a single preoperative dose of pregabalin may exhibit a significant preventive effect on chronic persistent postoperative pain after elective cardiac surgery.