Methodist Journal


Adult Congenital Heart Update

Vol 15, Issue 2 (2019)



The Growing Number of Adults Surviving with Congenital Heart Disease

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Drs. MacGillivray and Lin Take the Lead in Adult Congenital Heart Disease

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Advanced Cardiac Imaging for Complex Adult Congenital Heart Diseases

149 Fontan Conversions

Anomalous Aortic Origin of a Coronary Artery

Pulmonary Valve Replacement for Tetralogy of Fallot

Management of the Adult with Arterial Switch

Ebstein’s Anomaly

Heart Transplantation in Adults with Congenital Heart Disease

Cholesterol: Can’t Live With It, Can’t Live Without It


Simultaneous Transfemoral Mitral and Tricuspid Valve in Ring Implantation: First Case Report with Edwards Sapien 3 Valve

Uneventful Follow-Up 2 Years after Endovascular Treatment of a High Flow Iatrogenic Aortocaval Fistula Causing Pulmonary Hypertension and Right Heart Failure

Device-Related Thrombus: A Reason for Concern?

Retained Coronary Balloon Requiring Emergent Open Surgical Retrieval: An Uncommon Complication Requiring Individualized Management Strategies


Do I Look Fat in This? Multimodality Imaging Findings of a Cardiac Lipoma



The Kidney in Congenital Cyanotic Heart Disease


Talking Statins with Antonio Gotto


Lipids and Renal Disease


Addressing the Feedback Loop Between Depression, Diabetes, and Cardiovascular Disease


Letter to the Editor in Response to “Cardiac Autonomic Neuropathy in Diabetes Mellitus”

Vol 14, Issue 2 (2018)

Article Full Text


Continuous Venous-Venous-Hemodialysis versus Intermittent-Hemodialysis in Critically Ill Patients

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Article Citation:

Olivero JJ. Continuous Venous-Venous-Hemodialysis versus Intermittent-Hemodialysis in Critically Ill Patients. Methodist DeBakey Cardiovasc J. 2018;14(2):153-155.

doi: 10.14797/mdcj-14-2-153

acute kidney injury , renal replacement therapy ,  continuous venous-venous-hemodialysis ,  intermittent hemodialysis

Acute kidney injury (AKI) is a frequent complication in critically ill patients, adversely affecting outcomes. Renal replacement therapies, mostly continuous venous-venous-hemodialysis (CVVHD) and intermittent hemodialysis (IHD), have been used as bridges to allow recovery of kidney function and improve survival. Not only have these therapeutic modalities been used in the treatment of AKI, but they also have been used to treat other types of life-threatening emergencies—independent of kidney function—such as intoxication, accidental hypothermia, and profound metabolic disarray. Although there are specific advantages and disadvantages to both CVVHD and IHD, several meta-analyses have failed to show a clear advantage of one modality over the other in improving survival. Individual patient selection based on clinical status should determine the physician’s choice of treatment modality.1,2,3


 Hemodynamic Stability

  • Provides greater hemodynamic stability, leading to fewer hypotensive episodes. Recurrent hypotensive episodes interfere with the potential recovery of kidney function by causing repeated focal ischemic injury, which is aggravated by loss of circulatory intrarenal autoregulatory mechanisms due to AKI. The hemodynamic stability provided by CVVHD could be partially attributed to hypothermia due to extracorporeal circulation, resulting in improved venous return and arterial vasoconstriction as the body attempts to maintain its core temperature.4
  • Hemodynamic stability makes CVVHD better than IHD in patients with combined acute renal and hepatic failure.
  • Despite these observations, meta-analyses have failed to demonstrate superiority of CVVHD over IHD for preservation of kidney function.5
  • Better around-the-clock fluid removal, particularly when simultaneous exogenous fluids—such as parenteral nutrition, intravenous antibiotics, or blood products—must be infused into the oliguric patient.
  • Renal replacement therapy during surgery. As in the case of liver transplantation with simultaneous impaired kidney function and hemodynamic instability, CVVHD can effectively control metabolic acidosis and electrolyte imbalance (particularly hyperkalemia) during the reperfusion period and massive transfusions.6

 Removal of Cytokines

  • Removal of cytokines in a population with acute inflammatory response would be a desired effect. TNF-alpha and several interleukins can be found in the ultrafiltrate due to either absorption by the membrane or by transmembrane elimination. However, other studies have shown that removal of inflammatory markers is overwhelmed by a new generation of the same markers once the surface of the membranes is saturated. Thus, the indication for CVVHD as part of the treatment for severe sepsis has not been validated.7

 Select Patient Populations

  • Better than IHD in patients with acute brain injury, particularly those with cerebral edema or intracranial hypertension that results in decreased or absent autoregulation of cerebral circulation and cerebral blood flow.8
  • Better in patients with ongoing lactic acidosis and persistent acidemia. In comparison, IHD could only transiently correct those abnormalities, at times resulting in interdialytic rebound.9
  • Better in severe hyponatremia, fluid overload, and oliguric AKI. If hyponatremia is corrected rapidly (> 10-12 mEq/L the first 24 hours or > 18 mEq/L during the first 48 hours), it could result in central pontine myelinolysis with permanent neurologic sequelae. Azotemia may protect the brain from the development of osmotic demyelination in these patients by preventing intracellular cerebral edema. CVVHD would be safer and would provide more control in serum sodium changes; using frequent determinations (every 3 hours) allows adjustments of therapy to take place safely.
  • Rarely, lung transplant recipients can develop severe hyperammonemia. At times the only way to correct the problem is administering two simultaneous CVVHD units, which often lasts several days.10
  • End-stage renal disease patients needing CVVHD should have a central venous catheter to conduct CVVHD. The primary arteriovenous fistula or graft should not be accessed for this purpose because of potential needle dislodgment, pain at the needle site, the need for recannulation when dialysis is interrupted (e.g., each time the patient is transported outside of the ICU), and an increased incidence of access thrombosis.


  • More expensive than IHD.
  • Frequent interruptions due to equipment malfunction (clotted lines/hollow fibers) or patients traveling to diagnostic or therapeutic procedures.
  • Prolonged immobilization (although most patients may need complete bed rest anyway).


 Accidental Hypothermia

  • Hemodialysis is a better choice than CVVHD to correct severe hypothermia, setting dialysate flow and temperature to a maximum. Usually hypothermia is associated with coagulopathy, for which there is no need to use anticoagulants.11

 Removal of Toxic Substances

  • Toxic levels of lithium, methanol, ethylene glycol, iodine (in burned patients), valproic acid, isoniazid, and metformin are effectively removed by IHD. Salicylate intoxication, particularly when complicated by pulmonary or cerebral edema, can also be corrected by IHD much more efficiently than by CVVHD.12

 Select Patient Populations

  • Tumor lysis syndrome, resulting in profound metabolic imbalance such as severe hyperuricemia and cases of severe malignancy-related hypercalcemia, is more efficiently corrected by IHD than by CVVHD.
  • Rhabdomyolysis with hyperkalemia. However, if the degree of muscle injury is severe (creatine phosphokinase > 250K) and intracellular potassium release is constant, rebound hyperkalemia in the interdialytic period could become a problem, requiring longer dialysis sessions, often against a potassium-free dialysate.


  • Unsuitable for use in the hemodynamically unstable patient

The studies comparing survival outcomes between CVVHD and IHD in critically ill patients may be affected by the biases in patient selection since sicker patients are usually chosen to go on CVVHD, therefore skewing the results. These modalities are not mutually exclusive; CVVHD is frequently used during the early phase of the acute event then transitioned to IHD once the patient is more stable.

Conflict of Interest Disclosure

The author haS completed and submitted the Methodist DeBakey Cardiovascular Journal Conflict of Interest Statement and none were reported.

  1. Augustine JJ, Sandy D, Seifert TH, Paganini EP. A randomized controlled trial comparing intermittent with continuous dialysis in patients with ARF. Am J Kidney Dis. 2004 Dec;44(6):1000-7.
  2. Lins RL, Elseviers MM, Van der Niepen P, et al. Intermittent versus continuous renal replacement therapy for acute kidney injury patients admitted to the intensive care unit: results of a randomized clinical trial. Nephrol Dial Transplant. 2009 Feb;24(2):512-8.
  3. Bagshaw SM, Barthiaume LR, Delaney A, Bellomo R. Continuous versus intermittent renal replacement therapy for critically ill patients with acute kidney injury: a meta-analysis. Crit Care Med. 2008;36:610-7.
  4. Mehta RL, McDonald B, Gabbai FB, et al. A randomized clinical trial of continuous versus intermittent dialysis for acute renal failure. Kidney Int. 2001 Sep;60(3):1154-63.
  5. Uehlinger DE, Jakob SM, Ferrari P, et al. Comparison of continuous and intermittent renal replacement therapy for acute renal failure. Nephrol Dial Transplant. 2005 Aug;20(8):1630-7.
  6. Davenport A, Will EJ, Davison AM. Effect of renal replacement therapy on patients with combined acute renal and fulminant hepatic failure. Kid Int Suppl. 1993 Jun;41:S245-51.
  7. De Vriese AS, Colardyn FA, Philippé JJ, Vanholder RCDe Sutter JHLameire NH. Cytokine removal during continuous hemofiltration in septic patients. J Am Soc Nephrol. 1999 Apr;10(4):846-53.
  8. Davenport A. Renal replacement therapy in the patient with acute brain injury. Am J Kid Dis. 2001;37:457-66.
  9. Clark WR, Mueller BA, Alaka KJ, Macias WL A comparison of metabolic control by continuous and intermittent therapies in acute renal failure. J Am Soc Nephrol. 1994 Jan;4(7):1413-20.
  10. Gupta S, Fenves AZ, Hootkins R. The Role of RRT in Hyperammonemic Patients. Clin J Am Soc Nephrol.2016 Oct 7;11(10):1872-8.
  11. Caluwé R, Vanholder R, Dhont A. Hemodialysis as a treatment of severe accidental hypothermia. Artif Organs. 2010 Mar;34(3):237-9.
  12. Hoste EAJ. Clinical review: Use of renal replacement therapies in special groups of ICU patients. Crit Care. 2012 Jan;16(1):201-17.

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