Detection and quantification of perioperative heparin-like effects by rotational thromboelastometry in living-donor liver transplant recipients: A prospective observational study.

Background and Aims: Heparin-like effects (HLEs) can affect hemostasis during liver transplantation. The aim of this study was to assess the perioperative incidence and severity of HLE with rotational thromboelastometry (ROTEM) and activated partial thromboplastin time (aPTT). Material and Methods: ROTEM and aPTT were measured intraoperatively and on postoperative days (POD) 1, 3, and 7. HLE was identified if ROTEM INTEM/HEPTEM CT-ratio was >1.25 and severe forms of HLE when ratio was ≥2. Based on aPTT, HLE was defined when aPTT ratio was >1.25 (patient aPTT/control aPTT). Results: Thirty-eight recipients were included. Variable degrees of HLE were detected by aPTT-ratio and INTEM/HEPTEM CT ratio. No significant correlation existed between both ratios. Based on INTEM/HEPTEM CT ratio, HLE was detected in 7/38 during anhepatic phase, 19/38 post-reperfusion, 10/38 on POD1, 4/38 on POD3, and 0/38 on POD7. Four cases of severe HLE were identified by INTEM/HEPTEM CT ratio only in the anhepatic phase. Postoperative infusion of unfractionated heparin led to mild-moderate HLE on POD1 and 3 as evident by both tests. Red blood cell and plasma transfusion were higher with severe HLE (1350 ± 191 ml and 3558 ± 1407 ml). Composite adverse outcome of any complication or death within 3 months for patients without HLE, mild-moderate HLE, and severe HLE as detected by ROTEM was 27.8%, 42.9%, and 66.7%, respectively. Conclusion: INTEM/HEPTEM CT ratio was able to detect and quantify HLE as aPTT ratio. The ability of the INTEM/HEPTEM CT ratio to identify severe HLE earlier in the anhepatic phase needs to be studied in a larger population. HLE is self-limiting, but when identified in a severe form, it is associated with worse outcome.

Effects of perineural administration of dexmedetomidine in combination with bupivacaine in a femoral-sciatic nerve block.

BACKGROUND AND AIM: Perineural administration of dexmedetomidine, a α2-adrenoceptor agonist, prolongs the duration of analgesia. We hypothesized that adding dexmedetomidine to bupivacaine would prolong postoperative analgesia after below knee surgery. MATERIALS AND METHODS: After ethical approval, 60 patients scheduled for below knee surgery under combined femoral-sciatic nerve block were randomly allocated into two groups to have their block performed using bupivacaine 0.5% alone (group B) or bupivacaine 0.5% combined with 100 µg bupivacaine-dexmedetomidine (group BD). Motor and sensory block onset times; durations of blockades and analgesia were recorded. RESULTS: Sensory and motor block onset times were shorter by 20% in group BD than in group B (P < 0.01). Sensory and motor blockade durations were longer in group BD (+45% and +40%, respectively) than in group B (P < 0.01). Duration of analgesia was longer in group BD by 75% than in group B (P < 0.01). Systolic, diastolic arterial blood pressure levels, and heart rate were significantly less in group BD, six patients in group BD, and no patients in group B developed bradycardia (P < 0.05). CONCLUSION: The addition of dexmedetomidine 100 µg to bupivacaine 0.5% during ultrasound-guided combined femoral and sciatic block for below knee surgery was associated with a prolonged duration of analgesia. However, this may be associated with significant bradycardia requiring treatment.