Abstract
BackgroundHypotension is a frequent complication of intermittent hemodialysis (IHD) performed in intensive care units (ICUs). Passive leg raising (PLR) combined with continuous measurement of cardiac output is highly reliable to identify preload dependence, and may provide new insights into the mechanisms involved in IHD-related hypotension. The aim of this study was to assess prevalence and risk factors of preload dependence-related hypotension during IHD in the ICU.MethodsA single-center prospective observational study performed on ICU patients undergoing IHD for acute kidney injury and monitored with a PiCCO® device. Primary end points were the prevalence of hypotension (defined as a mean arterial pressure below 65 mm Hg) and hypotension associated with preload dependence. Preload dependence was assessed by the passive leg raising test, and considered present if the systolic ejection volume increased by at least 10 % during the test, as assessed continuously by the PiCCO® device.ResultsForty-seven patients totaling 107 IHD sessions were included. Hypotension was observed in 61 IHD sessions (57 %, CI95%: 47–66 %) and was independently associated with inotrope administration, higher SOFA score, lower time lag between ICU admission and IHD session, and lower MAP at IHD session onset. Hypotension associated with preload dependence was observed in 19 % (CI95%: 10–31 %) of sessions with hypotension, and was associated with mechanical ventilation, lower SAPS II, higher pulmonary vascular permeability index (PVPI) and dialysate sodium concentration at IHD session onset. ROC curve analysis identified PVPI and mechanical ventilation as the only variables with significant diagnostic performance to predict hypotension associated with preload dependence (respective AUC: 0.68 (CI95%: 0.53–0.83) and 0.69 (CI95%: 0.54–0.85). A PVPI ≥ 1.6 at IHD session onset predicted occurrence of hypotension associated with preload dependence during IHD with a sensitivity of 91 % (CI95%: 59–100 %), and a specificity of 53 % (CI95%: 42–63 %).ConclusionsThe majority of hypotensive episodes occurring during intermittent hemodialysis are unrelated to preload dependence and should not necessarily lead to reduction of fluid removal by hemodialysis. However, high PVPI at IHD session onset and mechanical ventilation are risk factors of preload dependence-related hypotension, and should prompt reduction of planned fluid removal during the session, and/or an increase in session duration.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1227-3) contains supplementary material, which is available to authorized users.
Highlights
Hypotension is a frequent complication of intermittent hemodialysis (IHD) performed in intensive care units (ICUs)
A pulmonary vascular permeability index (PVPI) ≥ 1.6 at IHD session onset predicted occurrence of hypotension associated with preload dependence during IHD with a sensitivity of 91 % (CI95%: 59–100 %), and a specificity of 53 % (CI95%: 42–63 %)
The main findings are that (1) the majority of first hypotension episodes occurring during IHD are not related to preload dependence and to fluid removal by IHD; (2) hypotension during IHD is unrelated to dialysis settings when ICU dedicated practice guidelines to prevent hemodynamic instability are applied, and is mainly related to preexistent cardiovascular and organ dysfunction; (3) high PVPI and mechanical ventilation are risk factors for preload dependence-related hypotension during IHD and may prompt, if identified at IHD onset, reduction of planned fluid removal during the session, or increased session duration
Summary
Hypotension is a frequent complication of intermittent hemodialysis (IHD) performed in intensive care units (ICUs). The common consequence of IHD-related hypotension is to discontinue the fluid removal for the rest of the IHD session, with the main consequence of impairing fluid balance control, which has been repeatedly shown as a major determinant of mortality in patients with septic shock or acute respiratory distress syndrome [7,8,9]. This management relies on the assumption that the underlying cause of hypotension is hypovolemia. Several other determinants of hypotension during hemodialysis have been identified such as reduced cardiac output of various origins (hypocalcemia, diastolic dysfunction,...) or alterations of the vasomotor tone related to positive thermal balance, membrane/circuit bio-incompatibility or ionic imbalance, among others [10,11,12,13]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
