Pain management in liver transplant recipients: a focus on current and future strategies.

Liver transplantation is the only curative treatment option for patients with end-stage liver disease. Anesthesiologists and intensivists are fully involved in this procedure due to the perioperative care focus on hemodynamic, respiratory and metabolic support. However, quite surprisingly, postoperative pain management does not have clinical primary consideration in this class of patients due to a combination of factors including the thought that liver transplantation recipients have less pain and require lower doses of analgesics than patients who undergo other types of major abdominal surgery. Other factors contribute to make the management of postoperative pain somewhat complex in this class of patients: 1) drug pharmacokinetics and metabolism by the new liver is not predictable; 2) the multifactorial nature of liver graft recovery; and 3) the alterations of homeostasis, including circulatory, respiratory and metabolic vulnerability, in the days postoperative period. As a result, post-liver transplantation analgesia is underestimated not only from the clinical point of view but also in the literature and only a few papers deal with the management of postoperative pain in this particular class of patients. Thus, in the experts' opinion paper we aimed to report the possible strategies for managing post-LT pain with a focus on opioids alternatives and possible future developments in this particular clinical setting also in the view that improvements in perioperative care have made it possible to adopt fast track and Enhanced Recovery After Surgery-oriented protocols also in this class of patients.

Hemodynamic variations in arterial wave reflection associated with the application of increasing levels of PEEP in healthy subjects.

Positive end-expiratory pressure (PEEP) may affect arterial wave propagation and reflection, thus influencing ventricular loading conditions. The aim of the study was to investigate the hemodynamic variations in arterial wave reflection (i.e., wave reflection time, augmentation index, left ventricular ejection time, diastolic time, SEVR) associated with the application of increasing levels of PEEP in healthy subjects. We conducted a prospective observational study. Study population was selected from students and staff. Pulse contour wave analysis was performed from the right carotid artery during stepwise increase in PEEP levels (from 0 cmH2O, 5 cmH20, 10 cmH2O) with applanation tonometry. Sixty-two healthy volunteers were recruited. There were no significant changes in heart rate, augmentation index (AIx), left ventricular ejection time, Diastolic time (DT) among all of the different steps. A significant increase of time to the inflection point (Ti) was observed during all steps of the study. Diastolic area under the curve (AUC) divided by systolic-AUC (SEVR) increased from baseline to PEEP = 5 cmH2O, and from baseline to PEEP = 10 cmH2O. AIx and Ti were significantly correlated (directly) at the baseline and during PEEP = 10 cmH2O. Ti and DT were significantly correlated at the baseline and during PEEP = 5 cmH2O. In our preliminary results, low levels of PEEP played a role in the interaction between the heart and the vascular system, apparently mediated by a prolongation of the diastolic phase and a reduction in the systolic work of the heart.Clinical trials registration number: NCT03294928, 19/09/2017.