Dialysate fluid flow in CVVHD: Does countercurrent flow increase clearance for small solutes?

Abstract

s / Australian Critical Care 27 (2014) 43–63 47 Conclusions: Participants described a challenging environment where they transitioned from being new and an outsider to feeling a valuable part of the team. Relationships were important in providing support and education around specialist knowledge and skills. Understanding thenewgraduate’s experience can assistwith this transition and encourage the new graduates to stay in the ICU. http://dx.doi.org/10.1016/j.aucc.2013.10.013 Dialysate fluid flow in CVVHD: Does countercurrent flow increase clearance for small solutes? I. Baldwin1,∗, M. Baldwin2, N. Fealy1, P. Carty1, R. Bellomo1 1 Austin Health, Australia 2 St. Vincent’s Public Hospital, Melbourne, Australia No study has assessed the effect of dialysate fluid flow direction on small solute clearance during haemofiltration. This ethics approved study recruited a convenience sample of 12 adult ICU patients requiring CVVHDF to assess urea and creatinine removal for concurrent vs. countercurrent flow direction. The circuit was adjusted to CVVHD 20min prior to sampling with no fluid removal. Blood and spent dialysate fluid were taken in both concurrent and countercurrent fluid flow at one (T1) and four (T4) hours with a new treatment. Blood flow was 200ml/min. Dialysate flow 33ml/min. Removal of urea (Uf/b) and creatinine (Cf/b) was expressed as the diafiltrate/plasma concentration ratio. Data are presented as medians with 25th and 75th inter-quartile ranges (IQR). The Wilcoxon Signed Rank Test for paired data was used for analysis. P<0.5 was considered significant. Patient median agewas 65yrs (43–68), median APACHE II score 19 (14–29) and all patients met RIFLE criteria ‘F’. Median pre treatment creatinine was 320.5 (260–443) mol/L and urea 21.4 (12.5 – 33.5) mmol/L. At both times countercurrent dialysateflowwas associatedwith higher diafiltrate/plasma concentration ratios: T1 0.92 (0.85–1.00) vs. 0.71 (0.64–0.79), P=0.0005; T2 0.95 (0.85–1.00) vs. 0.74 (0.66–0.77), P=0.0005 for creatinine, and T1 1.00 (0.99–1.02) vs. 0.83 (0.81–0.85), P=0.0005; T2 1.01 (0.97–1.03) vs. 0.83 (0.80–0.87), P=0.002 for urea. Countercurrent dialysate flow during CVVHD for ICU patients is associated with an increase of approximately 20% in diafiltrate/plasma creatinine and urea ratio. http://dx.doi.org/10.1016/j.aucc.2013.10.014 ECMO in an Australian tertiary ICU: A four year review J. Breeding1,∗, P. Nair1,2, H. Buscher1,2, S. Whittam1 1 St, Vincent’s Hospital Sydney, Australia 2 University of New South Wales, Australia Introduction: Evaluation of outcomes related to an ECMO programme requires clinically relevant data and access to comparisons with similar services. Objectives:Theprimary aimof this unit review for anAustralian mixed tertiary ICU including cardiothoracic, transplant, VAD and ECMO referral programmes, was to assess several baseline data points. Secondary goals were to compare endpoints with other reported results. Method: The ECMO database of this ICU was interrogated from 1/07/2009 to 30/06/2013 (4 years/161 runs). Baseline data included: mortality, diagnoses, run times, cannulae, settings, selected blood gas parameters, utilisation of additional therapies and selected complications. Analysis of the data involved simple comparative statistical techniques. Selected Results This centre Extracorporeal Life Support Organization Registry Report, International Summary, July 2013 VV (N=57) VA (N=80) E-CPR (N=10) VPA (N=14) Adult respiratory (N=4382) Adult cardiac (N=3401) E-CPR (N=969) Survived ECMO (%) 80.7 77.5 80 92.9 64 55 37 Survived to ICU discharge (%) 75.4 58.8 50 85.7 56 40 28 Run time (days)* 11.9 6.8 4.2 8.2 ∼9.9 ∼5.3 RRT (%) 42 57.5 30 35.7 44.5 42.7 Haemorrhagic complications (%) 36.8 63.7 50 57 42.1 55.2 Day 1 ECMO flow* 4.4 3.82 3.81 3.95 Day 1 PUMP Revs/min* 2187 3251 3256 3292 Day 1 PaO2mmHg * 109 260 289 294 Day 7 PaO2 mmHg * 95.3 169 NA 175