ECMO Induced Renal Issues Transient renal dysfunction Improvement in renal function ECMO & Renal Failure Epidemeology Renal failure & effect on out come With or Without RRT Renal replacement Therapy
Utilizes either serum creatinine or urine output to estimate glomerular filtration rate in order to categorize ARF into isk or renal injury njury to the kidney ailure of kidney function oss of kidney function ndstage kidney disease
Crit Care Med 2006, Vol. 34 No 7
Transient decline in renal function for first 36 48 hrs Hypertension Fluid overload Electrolyte imbalance Haemolysis Non pulsatile flow
Usually seen in both VA & VV ECMO Lasts for first 36 48 hrs. Urine output decreases to 0.5 1 ml/kg/hr with mild rise in BUN & creatinine. Does not require any treatment.
Mechanism Release of chemical mediators leading to vasodilatation. Cytokine storm occurs on initiation of ECMO due to surface interaction of blood with the membrane and tubing, leading to SIRS reaction Renal function is altered by lack of pulsatile flow
Pre existing conditions like Hypotension Hypoxia Sepsis & toxins Iatrogenic Inotropes, antibiotics, etc Non pulsatile flow Initial SIRS reaction Haemolysis Increased volume load
Due to better oxygentio Improved hemodynamics Improved tissue perfusion
In critical Care & during ECMO
The incidence of renal failure in a critical care unit ranges widely from 4.5 to 85% avg is 17 ~ 25 % 5 ~ 10% of cases will require CRRT Incidence of renal failure high in adult (36% in resp, 52% in card) during ECMO almost 3 4 times neonates (9% to 16%) Mortality with renal failure is high almost ~ 60 70% as compared to overall mortality of ECLS (~ 40%)
ECMO & Renal Issue ELSO DATA 2016 Respiratory ECMO Complications Neonates Paediatrics Adults Reporte d n (%) Creatinine1.5-3.0 1901 (6.5%) Survive d n (%) 955 (50%) Reporte d n (%) 651 (8.9%) Survived n (%) 223 (34%) Reporte d n (%) 1490 (16%) Survive d n (%) 674 (45%) Creatinine >3.0 373 (1.3%) 138 (37%) 306 (4.2%) 102 (33%) 874 (9.4%) 389 (45%) Dialysis required 922 (3.2%) 360 (39%) 831 (11.3%) 273 (33%) 959 (10.3%) 405 (42%) Hemofitration required 4189 (15.7%) 2461 (54%) 1694 (23%) 812 (48%) 1674 (17.9%) 903 (54%) CAVHD required 613 (2.1%) 261 (43%) 645 (8.8%) 262 (41%) 1098 (11.8%) 494 (45%)
ECMO & Renal Issue ELSO DATA 2016 Cardiac ECMO Complications 0 30 days 31 days < 1 yr 1 yr < 16yr 16 yrs & above Reporte d n (%) Survive d n (%) Reporte d n (%) Survive d n (%) Reporte d n (%) Survive d n (%) Report ed n (%) Survive d n (%) Creatinine1.5-3.0 722 (10.7%) 170 (24%) 361 (8.1%) 86 (24%) 479 (12.9%) 168 (35%) 1813 (21.4%) 616 (34%) Creatinine >3.0 126 (1.9%) 38 (30%) 77 (1.7%) 23 (30%) 254 (6.3%) 80 (31%) 1064 (12.6% 301 (28%) Dialysis required 535 (7.9%) 101 (19%) 400 (9%) 84 (21%) 375 (10.1%) 116 (31%) 906 (10.7%) 243 (27%) Hemofitration required 1763 (26.1%) 505 (29%) 1025 (23%) 364 (36%) 467 (20.4%) 201 (47%) 1130 (13.4%) 346 (31%) CAVHD required 456 (6.7%) 79 (17%) 239 (5.4%) 61 (26%) 166 (8.2%) 68 (43%) 1164 (13.8%) 343 (29%)
12 studies included Total 1763 pt 52% had CRRT during ECMO
With or without RRT
Remains a common problem for the patient on ECMO for first 48 hrs. Causes Increased circulatory volume due to ECMO circuit SIRS reaction due to initiation of ECMO, needs massive fluid to maintain haemodynamics & for adequate flow Transient reduced renal function for first 36 48 hrs leading to oliguria Increases the morbidity & mortality. Prompt attempt should be made to get rid off extra fluid either with the help of diuretics or dialysis
Meyer RJ, et al Pediatr Crit Care Med 2001 15/ 35 ( 42.9 %) neonatal and pediatric survived 14/15 (93%) RENAL RECOVERY 1/15 (7%) Wegener s
Shah SA et al. ASAIO J 2005 41/ 84 (48.9%) post-operative congenital heart disease patients with AKI CVVH NOT associated with : Ability to wean off ECMO Survival to discharge Kolovos et al. Ann Thorac Surg 2003 26 / 74 (35%) post-operative congenital heart disease patients Hemofiltration = 5.01 X increased risk of death
Hoover et al. Intensive Care Med (2008) Case-control study Cases 26/86 - received CVVH for >24 hours Controls no CVVH Significant differences in fluid balance Significant treatment differences
No treatment if it is ECMO related transient ARF (output ~ 0.5 1 ml/kg/hr), should get normalized in 36 48 hrs Adequate fluid support & maintain euvolaemia Diuretic infusion Maintain U/O ~ 2 ml/kg/hr Alkalinization of urine if Haemolysis is significant
Goal of renal replacement Time of initiation Principle of Renal replacement therapy Types of renal replcement Precaution for RRT during ECMO
Sustain life till adequate renal function recovers Preserve residual renal function Give better environment for the organs to recover
Should be started early - For Definitive indications Prophylactically in ARF when life threatening events appear imminent Fluid overload > 10% inspite of diuretics Favourable outcome with early dialysis
In retrospective analysis, multiple authors have found fluid overload (>10-15%) to be independently associated with mortality. Associated with longer duration of ECMO Inability to return to dry weight during the ECMO course is also an independent risk factor for mortality with acute renal failure.
study by Hoover et al. noted that Early intervention with CRRT improved fluid balance and caloric intake and reduced the need for diuretics. Tended towards higher survival when compared to patient not requiring dialysis. Leads to survival rates equal to patients that do no require CRRT.
Diffusion Ultra-filtration Convection Adsorption Solute from higher concentration to lower concentration Fluid trough semi-permeable membrane driven by pressure gradient Solute and fluid (Depending on molecular weight and size) by ultra-filtration Molecular adhesion to inner surface of semi-membrane NEJM 336:1303-1309
Conventional Haemodialysis Peritoneal dialysis Slow low efficiency daily dailysis Continuous renal replacement therapy SCUF CVVH/ CVVHD/ CVVHDF CAVH/ CAVHD/ CAVHDF
Simple to manage / low work-load Inexpensive Reliable and predictable ( solute and water removal) Optimal survival and complication profile Optimal recovery of renal function
CRRT (Continuous Renal Replacement Therapy ) EDD ( Extended daily dialysis ) SLEDD ( Slow Low-efficient Daily Dialysis ) SLEDD-f (Sustained Low-Efficiency Daily Diafiltration ) IHD ( Intermittent Hemo-dialysis )
Residual renal function Volume status Cardiovascular status Comorbid conditions like Sepsis Arrhythmias Electrolyte
Preferred mode of dialysis as it shows less haemodynmic disturbances & relatively cheaper Helps to Get rid of extra water Electrolyte balance Acid base balance Started at earlier stage when there is Ologuria for >24 hrs in spite of fluid correction, domapine renal dose & lasix infusion trial Fluid overioad status at the early stage Progressively rising creatinine,acidosis,hyperkalaemia
Advantage Faster clearance of end products, acids & potassium as compared to CRRT Continued for only 6-9 hours only Cheaper Less haemodynamic disturbance compared to hemodialysis Disadvantage Haemodynamical disturbances are more as compared to CRRT Does not help in clearance of inflammatory mediators
Advantage Haemodynamic stability as UF is gradual Gives space for nutrition without volume overload Better correction of azotaemia & acidosis ( seven hours of intermittent dialysis are necessary to clear similar level of urea clearance as CRRT) Removes inflammatory mediators & there by helps in sepsis & MOF eg CVVHDF Less metabolic disturbances Disadvantage Higher anticoagulation Increased nursing support Slower onset of removal of electrolyte Vascular access related problem Cost 2 5 times the HD or SLEDD
It will help to remove fluid It should be started when there is fluid overload especially in cardiac patient in absence of acidosis,hyperkalaemia & severe azotaemia
Advantage It helps us to get rid off extra fluid It has less impact on haemodynamics One dose not require dialysis machine just filter to be added in circuit Disadvantage - It just clears fluid out but acidosis, electrolyte imbalance & azotaemia remains as it is It should be done when fluid overload is only a prime concern,while not much of electrolyte or acid base imbalance
It will help to Remove solute by convection i.e solute is dragged out as plasma removed Fluid is removed with the help of pump Here no dialysate is used. Replacement fluid is given
It will help to Remove the solute by diffusion i.e. solutes are removed by concentration gradient i. e. By countercurrent mechanism Fluid is removed with the help of pump Here dialysate is used Replacement fluid is not used
It will help to Remove the solute by diffusion i. e. Solutes are removed by concentration gradient i. e. By countercurrent mechanism. Fluid is removed with the help of pump Here dialysate is used Replacement fluid is also used
Dialyzer to be connected to circuit arterial side (input for dialyzer) to be connected to post pump but pre oxygenator port (Point of highest pressure) & venous end to be connected to either Pre pump port or Post oxygenator port ECMO flow to be increased to compensate for the additional dialysis circuit. Increase the pump flow slowly until post membrane pressure approaches prior level
Check for heparinization Heparin primed dialyzer can increase heparin effect Increase in circuit length might require additional heparin Increased clearance of heparin due to dialysis Increasing volume requirement suggests haemofiltration rate is too high
Arterial line Venous line HEAT EXCHANGER OXYGENATOR ( MEMBRANE ) PUMP H RENAL REPLACEMENT
Arterial line Venous line HEAT EXCHANGER OXYGENATOR PUMP H RENAL REPLACEMENT
Arterial line Venous line HEAT EXCHANGER OXYGENATOR PUMP H RENAL REPLACEMENT
Poor flow SCUF Hypovolaemia Electrolyte imbalance leading to arrhythmias Hypotension at the time of starting or during CRRT Recurrent filter clotting Air entering into the circuit
Bradykinin release syndrome it is characterized by hypotension & bronchospasm & is due to mixing of acidic blood with filter membrane. It can be prevented by using NaHCO3 2meq/kg before starting Infection as the blood remains extracorporeal for long time
Renal problems are common in ECMO Renal failure is an independent factor for mortality & has high mortality Fluid mobilization & resolution of edema is primary determinants of ECLS duration Early intervention is associated with good outcome
ECMO&CRRT Can be Safely done in a variety of setups No additional regional Anticoagulation is needed since the patient and the entire circuit is already heparinized for ECMO Circuit prime for the CRRT can usually be saline Due to the relative size of the CRRT circuit in ratio to the larger ECMO circuit
When starting Ultrafiltation careful monitoring of fluid goals over a time period will prevent Hct and viscosity changes that are unwanted CRRT Support on ECMO Effect on Mortality is yet to be more clearly defined as to timing of Initiation of both supports and Subsequent Outcomes.