ANSiscope™: Can it be the crystal ball of cardiac anesthesia?

Background: Autonomic dysfunction (AD) is infrequently evaluated preoperatively despite having profound perioperative implications. The ANSiscope™ is a monitoring device that quantifies AD. This study aims to determine the potential of the device to predict hypotension following anesthetic induction, occurrence of arrhythmias, and inotrope requirement for patients undergoing off-pump coronary artery bypass surgery (OPCAB). Study Design: Prospective observational double-blinded study. Materials and Methodology: Seventy-five patients undergoing OPCAB had their autonomic function assessed by ANSiscope™. They were classified into four groups based on their AD and compared to perioperative adverse events. Results: Patients with diabetes had a higher ANSindex (P = 0.0263). They had a greater decrease in systolic blood pressure (P = 0.001) and mean arterial pressure (P = 0.004) postinduction, had an increased incidence of arrhythmias (P = 0.009), required higher inotropic support immediately (P = 0.010) and at 24 h after surgery (P = 0.018), and longer duration of postoperative ventilation (P < 0.001). They also had a higher incidence of emergency conversion of OPCAB to on-pump surgery (P = 0.009). Conclusions: An increased association between AD as quantified by the ANSiscope™ and perioperative adverse outcomes was observed. An increased rate of emergency conversion of OPCAB to on-pump surgery with higher dysfunction was noted. The authors opine that the threshold for conversion must be lower in patients deemed to be at a higher risk. Proper evaluation of the autonomic nervous system empowers the anesthesiologist to anticipate and adequately prepare for complications.

Evaluation of risk scores in predicting perioperative blood transfusions in adult cardiac surgery

Objective: Allogeneic blood product transfusions are associated with an increased morbidity and mortality risk in cardiac surgery. At present, a few transfusion risk scores have been proposed for cardiac surgery patients. The present study is aimed to develop a new score and to compare with preexisting scores – Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST) score. Methodology: A total of 1014 adult patients undergoing cardiac surgery were enrolled in the retrospective study. Independent predictors of allogeneic blood transfusions were selected from TRACK and TRUST scores. A predictive score was developed from six variables using logistic regression analysis, and new score was compared to the other existing scores – TRACK and TRUST. Results: The new score had following predictors: age >58 years, weight <63 kg for males and <49 kg for females, gender (female), complex surgery, hemoglobin <13.5 g/dl, and creatinine >1.36 mg/dl. Validation of new score demonstrated an acceptable predictive power (area under the curve [AUC] 0.749) and a good calibration at the Hosmer–Lemeshow test. New score was comparable with TRACK score with P = 0.578 (AUC of TRACK 0.756 and AUC of new score 0.749). There was a significant difference between new score and TRUST score, P = 0.01 (AUC of TRUST 0.72 and AUC of new score 0.749). Conclusion: New score is a simple risk model based on six predictors having a similar accuracy and calibration in predicting the transfusion rate in cardiac surgery as compared to TRACK score.

Early prediction of acute kidney injury using serum phosphorus as a biomarker in pediatric cardiac surgical patients

Background: Acute kidney injury (AKI) is a strong predictor of morbidity and mortality after cardiac surgery. Lack of valid early biomarkers for predicting AKI has hampered the ability to take therapeutic measures for preventive cause. Hyperphosphatemia that occurs in AKI due to renal excretion defect was not studied in this context and could be simple marker of AKI. Therefore, we tested role of serum phosphorus in prediction of AKI as a biomarker after cardiac surgery in children. Methodology: We prospectively evaluated 51 children aged between 3 weeks and 12 years undergoing elective cardiac surgery. Serum creatinine and phosphorus were measured preoperatively and postoperatively at 24 and 48 h. As per the Kidney Disease Improving Global Outcomes criteria, patients were grouped into AKI and non-AKI on the basis of the development of AKI within 48 h postsurgery. The postoperative diagnostic performance of phosphorus thresholds was analyzed by the area under receiver operating characteristic curves (AUC-ROC). Results: From 51 children included, 10 developed AKI. In AKI group, serum phosphorus increased significantly from 4.47 ± 0.43 baseline to 6.29 ± 0.32 at 24 h postsurgery (P = 0.01) while serum creatinine increased from baseline 0.33 (0.24–0.46) to 0.49 (0.26–0.91) at 24 h which is statistically insignificant (P = 0.16). ROC analysis showed that serum phosphorus at 24 h, the AUC was 0.84 with sensitivity 0.75 and specificity 0.93 for a cutoff value of 6.4 mg/dl. Whereas serum phosphorus at 48 h, the AUC was 0.86 with sensitivity 66.67% and specificity 97.62% for a cutoff value of 5.4 mg/dl. Conclusion: Serum phosphorus can be an alternative biomarker as early as 24 h for early prediction of AKI in pediatric cardiac surgery.

A study on trend of relapse in leprosy and factors influencing relapse.

A retrospective analysis of data pertaining to the rural field operation area of the Central Leprosy Teaching and Research Institute, Chengalpattu, Tamil Nadu, was carried out to determine the magnitude of relapse after MDT and its significance with other variables. The study included 3248 leprosy patients who have successfully completed treatment during 1987-2003, of whom 2892 were PB and 356 MB cases. A total of 58 cases of relapse was reported which gives a crude cumulative relapse rate of 1.78% for the 16-year period of follow-up and the rates for PB and MB were 1.9% and 0.84% respectively. With respect to PB cases, 68% of relapses were reported in the first 3 years of RFT. The person-year relapse rate was highly significant with regard to the number of skin lesions (p<0.0002) and nerve involvement (p<0.0002). The person-year relapse rate did not differ significantly between PB and MB leprosy, male and female, and child and adult cases. RFT year cohort relapse rate reveals that the introduction of MB-MDT regimen for PB leprosy had resulted in the reduction of relapses among PB cases after 1998. The relapse rate with reference to the time gap after RFT reveals that relapse declines with passage of time after RFT. The risk of relapse was very low in both PB and MB leprosy which fact emphasizes that proper counselling about signs and symptoms of relapse during RFT is adequate to combat the problem. A majority of relapses occurred in the first three years after RFT. The number of skin lesions and involvement of nerves were the main risk factors for relapse.

Effect of hydroxyurea on subcellular activities of thymidine kinase in developing and aging rat brain.

Hydroxyurea, when injected intraperitoneally at a dose of 1 mg/g body weight, inhibited thymidine kinase activity in developing rat cerebrum (16-day-embryonic) and cerebellum (7-day-postnatal) within a few hours of administration. The inhibition was timedependent and both cytosolic and mitochondrial thymidine kinases were affected. Under the same conditions, the activities of certain other enzymes concerned with DNA metabolism, viz., DNA polymerase, and acid and alkaline DNases were not inhibited. Further, the addition of hydroxyurea in vitro had no effect on the activity of any of the enzymes studied. However, similar treatment given to 2-year-old rat failed to exert any inhibition on either the mitochondrial or soluble thymidine kinase activities in grey and white matter regions of cerebrum and cerebellum. It is inferred that hydroxyurea, apart from its already known effect on ribonucleotide reductase of replicating cells, also affects thymidine kinase.

Inhibition of thymidine kinase activity by hydroxyurea during highly and less proliferative regions of rat brain.

Hydroxyurea, when injected intraperitoneally, exerted marked inhibition on the activity of thymidine kinase in 5 day old postnatal cerebellum and 15 day old embryonic cerebrum. However, it failed to show any sustained inhibition on thymidine kinase activity in 5 day old postnatal cerebrum. In this case, the marginal decrease of thymidine kinase activity noticed during early intervals reversed back to more than normal value at a later time interval. These results along with our earlier findings are taken to indicate the differential action of this drug on thymidine kinase activity in rapidly and slowly proliferating regions of rat brain.