Research Protocol: Twenty-one subjects ≤18 years of age undergoing solid organ transplant, will be monitored during the intraoperative period transcutaneously for continuous PVI and hgb. Data collection will also include continuous CVP and MAP, significant operative events, concurrent blood loss, fluid administration, and conventional episodic Hgb sampling. Data from the hospital monitoring system will be time synchronized with Masimo derived measurements. The research team will coordinate recording of all events in the intra-operative period using standardized case report forms. Anesthesiologist and transplant team are blinded to Masimo data. Continuous Hgb and PVI will not be used to determine clinical treatment. The expected duration of this study will be two years based on the average number of pediatric solid organ transplant procedures participated in by the Anesthesiology Department at The Nebraska Medical Center.