Post-Reperfusion Syndrome in Liver Transplantation: Does a Caval Blood Flush Vent Help?

BACKGROUND Post-reperfusion syndrome (PRS) during liver transplantation can range from a benign event to a profound hemodynamic excursion from baseline with significant morbidity. Multiple variables can be responsible for the diverse presentations. Over time, our group noticed that a blood flush of the liver graft via a caval vent (in addition to a standard chilled flush via the portal vein) appeared to result in a milder reperfusion effect. Attenuation of PRS via caval vent seemed to minimize hemodynamic instability and reduce metabolic derangements associated with reperfusion. MATERIAL AND METHODS This was a prospective observational pilot study of standard practice with the addition of lab values and hemodynamic evaluations. We methodically observed normal clinical flow in 20 adult orthotopic liver transplant recipients. We analyzed blood and fluid samples at set time intervals during the peri-reperfusion phase. RESULTS Sixteen out of 20 patients received a blood flush via caval venting. Mean arterial pressure (MAP) and heart rate were better preserved in the patient population that received a caval blood flush vent. Elevations in central venous pressure (CVP) were similar between the 2 groups. Lab values (blood gas, electrolyte, and hemoglobin) of the patients' blood were similar, with no notable differences. Analysis of the initial blood flushed through the liver graft proved to be hypothermic, acidotic, and hyperkalemic. CONCLUSIONS Pre-reperfusion caval venting in liver transplantation (in addition to a portal vent and a chilled LR/albumin portal flush solution) appears to have favorable hemodynamic effects. The literature on this technique is sparse and larger studies are needed.

Detection of elevated intracranial pressure in robot-assisted laparoscopic radical prostatectomy using ultrasonography of optic nerve sheath diameter.

BACKGROUND: Robot-assisted laparoscopic radical prostatectomy (RALRP) is becoming an increasingly frequent procedure. Pneumoperitoneum and steep trendelenburg positioning associated with this surgery may increase patient's risk for elevated intracranial pressure (ICP). We conducted a prospective observational trial using ultrasonographic analysis of optic nerve sheath diameter (ONSD) to determine if ICP increased to levels >20 mm Hg during RALRP surgery. MATERIALS AND METHODS: The study includes 25 patients, without any history of increased ICP, undergoing RALRP. Ultrasonographic analysis of ONSD was performed immediately after induction of general anesthesia and again at the end of the procedure. A threshold value of ≥5.2 mm for ONSD was used for determination of raised ICP (>20 mm Hg). Age, race, body mass index, American Society of Anesthesiologists Physical Status Classification System class, total intraoperative IV fluids, and surgery duration were recorded, as well as, mean arterial pressure (MAP), end-tidal CO2, and end-tidal isoflurane concentration. RESULTS: Mean preinduction ONSD, in the 25 patients studied, was 4.5+0.5 mm and mean postoperative ONSD was 5.5+0.5 mm. Controlling for preinduction ONSD, postoperative ONSD was significantly associated with MAP (P=0.048) and the association of postoperative ONSD with end-tidal CO2 trended toward significance (P=0.072). CONCLUSIONS: This study demonstrates an increase in ONSD in patients undergoing RALRP. These findings confirm ICP rises to ≥20 mm Hg during RALRP surgery. This increase in ICP is significantly associated with increasing MAP. Patients with intracranial pathology should be counseled to the risks RALRP may pose with regard to intracranial hypertension.

Hydroxyethyl starch and acute kidney injury in orthotopic liver transplantation: a single-center retrospective review.

BACKGROUND: Acute kidney injury (AKI) is a frequent complication of orthotopic liver transplantation (OLT). Hepatic failure pathophysiology and intraoperative events contribute to AKI after OLT. Colloids are routinely used to maintain intravascular volume during OLT. Recent evidence has implicated 6% hydroxyethyl starch (HES) (130/0.4) with AKI in critically ill patients. METHODS: We performed a retrospective cross-sectional analysis of electronic anesthesia records, surgical dictations, and perioperative laboratory results. Postoperative AKI incidence was determined by RIFLE (Risk Injury Failure Loss End-Stage) criteria. AKI was staged into Risk, Injury, and Failure based on change in serum creatinine from preoperative baseline to peak level by postoperative day 7. Uni- and multivariate analysis was used to evaluate the association between type of intraoperative colloid administered and AKI. RESULTS: One hundred seventy-four adult patients underwent OLT and had complete records for review. Of these, 50 received only 5% albumin, 25 received both 5% albumin and HES, and 99 received only HES. Albumin-only, albumin and HES, and HES-only groups were otherwise homogeneous based on patient characteristics and intraoperative variables. There was a statistically significant linear-by-linear association between type of colloid(s) administered and AKI (Rifle Criteria-Injury Stage). Patients administered HES were 3 times more likely to develop AKI within 7 days after OLT compared with albumin (adjusted odds ratio 2.94, 95% confidence interval, 1.13-7.7, P = 0.027). The linear trend between colloidal use (5% albumin only versus albumin/HES versus HES only, ranked ordering) and "injury" was statistically significant (P = 0.048). A propensity-matched analysis also showed a significant difference in the incidence of AKI between the patients receiving albumin compared with HES (P = 0.044). CONCLUSIONS: Patients receiving 6% HES (130/0.4) likely had an increased odds of AKI compared with patients receiving 5% albumin during OLT. These retrospective findings are consistent with recent clinical trials that found an association between 6% HES (130/0.4) and renal injury in critically ill patients.

Rapid ventricular pacing: a novel technique to decrease cardiac output for giant basilar aneurysm surgery.

A case of a 49 year old man with a giant basilar artery aneurysm requiring rapid ventricular pacing is presented. Rapid ventricular pacing decreased aneurysm size and increased operative exposure, which aided surgical decision making. It also provided decreased wall tension in the aneurysm.