CVVH Orders for Adult ICU Patients with AKI and Fluid Overload

Vascular Access

Place a dual-lumen, uncuffed, non-tunneled dialysis catheter in the right internal jugular vein as first choice. 1, 2

Alternative sites in order of preference: femoral vein (avoid in obese patients), left internal jugular vein, subclavian vein (last resort due to thrombosis/stenosis risk) 3, 2
Use ultrasound guidance for insertion and obtain chest X-ray before first use for jugular or subclavian placement 2
Consider cuffed catheter only if prolonged RRT (>2-3 weeks) is anticipated 3

Prescribe an effluent dose of 25-30 mL/kg/h to ensure delivery of 20-25 mL/kg/h. 3, 1, 2, 4

The prescribed dose must be higher than target because delivered dose is typically 15-20% lower due to downtime and interruptions 4
For a 70 kg patient, this translates to approximately 1,750-2,100 mL/h effluent prescription 1

Use bicarbonate-based replacement fluids exclusively; avoid lactate-based solutions. 3, 1, 2, 4

Bicarbonate is mandatory in hemodynamically unstable patients, those with shock, liver failure, or lactic acidosis 3, 1, 2
Lactate-based solutions can worsen acidosis in critically ill patients 3
Ensure physiologic electrolyte concentrations; avoid supraphysiologic glucose to prevent hyperglycemia 3
Pre-dilution mode can be used to enhance ultrafiltration rates and reduce filter clotting 3, 4

Order regional citrate anticoagulation as first-line unless contraindicated. 3, 1, 2, 4

Citrate provides longer filter life and lower bleeding risk compared to heparin 3, 1
If citrate is contraindicated (severe liver failure, shock liver, citrate accumulation risk), use unfractionated heparin with aPTT monitoring 3, 1
In trauma, post-operative, or bleeding-prone patients, run without anticoagulation 1
Avoid low-molecular-weight heparin due to accumulation risk in AKI 3

Target negative daily fluid balance of 1-3 liters per day, adjusted to hemodynamic tolerance. 5, 6, 7

Even 5% fluid overload is associated with increased mortality and reduced renal recovery 6
Positive daily fluid balance during CRRT independently predicts mortality (OR 4.55) 7
Avoid excessive ultrafiltration causing hypotension, which impairs renal recovery 4
Use integrated fluid-balancing systems designed for CRRT rather than adapted IV pumps 3, 4

Monitor hourly: circuit pressures, blood flow rate (target 150-200 mL/min), effluent rate, and fluid balance. 3, 2, 4

Check electrolytes (including ionized calcium if using citrate), acid-base status, and phosphate every 6-12 hours 2, 4, 8
Monitor for CRRT-induced hypokalemia and hypophosphatemia, especially with high-dose therapy 4
If using citrate, monitor total calcium/ionized calcium ratio to detect citrate accumulation 4
Assess filter performance and clotting; replace circuit when transmembrane pressure exceeds manufacturer limits 3

Warm replacement fluids to prevent hypothermia; maintain core temperature >35°C. 3

Do not base CVVH initiation solely on BUN or creatinine thresholds; clinical context (fluid overload, hemodynamic instability, uremic complications) drives the decision 1, 4
Do not use subclavian access except as last resort due to high thrombosis risk 3, 2
Do not accept positive fluid balance as inevitable; it is modifiable and strongly associated with mortality 6, 7
Do not assume renal recovery based on declining creatinine during CVVH; creatinine is artificially lowered by dialysis, not kidney function 4

Consider transitioning to intermittent hemodialysis when all of the following are met: 3, 1, 2, 4

Vasopressor support discontinued and hemodynamic stability achieved 3, 1, 2
Intracranial hypertension resolved (if present) 3, 1, 2
Fluid balance controllable with intermittent therapy (typically <1-2 L positive per day) 3, 2

Integrate CVVH with the ECMO circuit based on institutional protocol. 3, 2, 4

CVVH is essential for preventing fluid overload that impairs ECMO function 2
Anticoagulation is typically managed through the ECMO circuit; coordinate with ECMO team 3, 2