Critical care nephrology · KIMS Secunderabad
Hepatorenal Syndrome — When Liver Disease Leads to Kidney Failure
Hepatorenal syndrome (HRS) is a form of acute kidney injury that occurs in patients with advanced liver disease — cirrhosis, acute liver failure, or alcoholic hepatitis — in the absence of any primary kidney disease, obstruction, or nephrotoxic medication. The kidneys are structurally normal; the kidney failure is functional — driven by the profound haemodynamic and neurohormonal changes that advanced liver disease produces. If the liver disease were to be reversed — by liver transplantation — the kidneys would recover fully. The tragedy of HRS is that it typically occurs at a point where the liver disease is itself severe enough to limit treatment options, and the kidney failure both worsens prognosis and complicates the management of the liver disease.
HRS is classified into two types based on the speed of onset and severity: HRS-AKI (formerly HRS type 1) — rapidly progressive, occurring over days to weeks, often precipitated by a specific event — and HRS-CKD (formerly HRS type 2) — slower, associated with refractory ascites. The mechanistic target and the therapeutic approach differ between the two types.
The mechanism — why the liver causes kidney failure
The pathophysiology of HRS is centred on splanchnic vasodilation — the dilation of the mesenteric and splanchnic circulation that occurs in cirrhosis, driven by portal hypertension and the release of vasodilators (nitric oxide, prostacyclin) from the liver and intestinal vasculature. This dilation reduces the effective arterial blood volume — even though total body water is increased (hence the ascites). The underfilled arterial circulation triggers compensatory neurohormonal responses:
Activation of the renin-angiotensin-aldosterone system (RAAS) — angiotensin II causes renal vasoconstriction, particularly of the afferent arteriole, reducing renal blood flow and GFR.
Increased sympathetic nervous system activity — further renal vasoconstriction.
Release of vasopressin (ADH) — causes free water retention, contributing to hyponatraemia and further diluting the already reduced effective circulating volume.
Reduced renal prostaglandin synthesis — the failing liver produces less prostaglandins, which normally counterbalance the vasoconstrictor effect of angiotensin II on the afferent arteriole.
The net result is intense renal vasoconstriction, dramatically reduced renal blood flow, and a consequent fall in GFR — producing oliguria and rising creatinine. The urine sodium is typically very low (below 10 mEq/L) and the urine osmolality is high — the kidneys are avidly retaining sodium in response to the perceived underfilling, despite the total body sodium being elevated. This urine profile distinguishes HRS from acute tubular necrosis (where the kidneys have lost the ability to conserve sodium, producing urine sodium above 30 mEq/L).
Diagnostic criteria and types
HRS-AKI (acute onset, formerly HRS type 1)
Rise in serum creatinine of 50% or more from baseline over 7 days, to above 133 µmol/L (1.5 mg/dL), in a patient with cirrhosis and ascites, after: — exclusion of other causes of AKI (hypovolaemia corrected by albumin infusion, infection excluded, nephrotoxic medications stopped), and — no response to volume resuscitation with albumin (1 g/kg body weight per day for 2 days). HRS-AKI is rapidly progressive — median survival without treatment is 2 to 4 weeks. It is typically precipitated by spontaneous bacterial peritonitis (SBP), gastrointestinal bleeding, large-volume paracentesis without albumin replacement, or acute alcoholic hepatitis.
HRS-CKD (chronic, formerly HRS type 2)
Slower decline in kidney function (creatinine typically 133 to 220 µmol/L) associated with refractory ascites — ascites that does not respond to diuretics. Median survival is 3 to 6 months without liver transplant. HRS-CKD impairs quality of life through the combination of kidney failure, fluid overload, and the burden of refractory ascites requiring repeated large-volume paracentesis.
Precipitating factors — what triggers HRS
Spontaneous bacterial peritonitis (SBP)
The most common precipitant. Bacterial translocation from the gut into ascitic fluid triggers a systemic inflammatory response that further vasodilates the splanchnic circulation, worsening effective arterial underfilling. HRS develops in 30–40% of SBP cases. Albumin infusion at diagnosis of SBP prevents HRS.
GI haemorrhage (variceal or non-variceal)
Acute volume loss from haemorrhage reduces renal perfusion. The adrenergic response to haemorrhage intensifies renal vasoconstriction.
Large-volume paracentesis without albumin
Removal of large volumes of ascitic fluid (above 5 litres) without intravenous albumin replacement causes circulatory dysfunction — the splanchnic vasodilation worsens without the ascitic counterpressure.
Acute alcoholic hepatitis
Severe liver inflammation reduces synthetic function acutely and intensifies the haemodynamic derangements of cirrhosis.
Nephrotoxic medications
NSAIDs, aminoglycosides, and IV contrast in patients with cirrhosis precipitate kidney injury that fulfils HRS criteria or causes true ATN on top of the haemodynamic vulnerability.
Treatment at KIMS
First-line: terlipressin and albumin
Terlipressin — a vasopressin analogue that constricts the splanchnic vasculature, reversing the splanchnic vasodilation that drives HRS — combined with intravenous albumin (20 to 40g/day to expand the effective circulating volume) is the established first-line treatment for HRS-AKI. Response rates (defined as creatinine returning to within 0.3 mg/dL of baseline) are approximately 40 to 50%. Terlipressin is administered by continuous IV infusion or intermittent IV bolus. The main side effects are ischaemic complications — abdominal pain, peripheral ischaemia, and rarely myocardial ischaemia — from systemic vasoconstriction. Terlipressin plus albumin is available at KIMS for HRS management.
CRRT for kidney support
Patients with HRS-AKI who are critically ill — with severe uraemia, life-threatening hyperkalaemia, severe fluid overload, or haemodynamic instability — require CRRT for kidney support while terlipressin and albumin are given time to act. At KIMS, CRRT is available 24/7 in the ICU. CRRT in HRS serves a bridging function — managing the kidney failure consequences while the hepatic and haemodynamic cause is treated, or while the patient is stabilised for liver transplant evaluation.
Liver transplant — the only cure
Liver transplantation is the only definitive treatment for HRS — because it removes the cause: the failing liver and its haemodynamic consequences. After successful liver transplant, renal function recovers fully in the majority of HRS patients within weeks to months, confirming the functional (rather than structural) nature of the kidney failure. Simultaneous liver-kidney transplant (SLKT) is considered in patients with HRS-CKD who have been on dialysis for 8 or more weeks (a marker of sustained kidney injury) or who have CKD pre-dating the liver disease. At KIMS, the nephrology team coordinates with the transplant team for HRS patients being considered for liver transplant.
HRS-AKI is a medical emergency with a median untreated survival of 2 to 4 weeks. Any patient with cirrhosis who develops rapidly rising creatinine, oliguria, or confusion should be evaluated immediately for HRS and its precipitants (SBP, GI bleeding). Call KIMS on 040-4488-5000 — emergency nephrology and critical care available 24/7.
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Frequently Asked Questions — Hepatorenal Syndrome
Yes — if the underlying liver disease is treated (primarily through liver transplantation) or if the haemodynamic derangement is reversed with terlipressin and albumin. HRS is a functional kidney failure — the kidneys are structurally normal and capable of recovery if the physiological insult (splanchnic vasodilation and renal vasoconstriction) is reversed. After successful liver transplantation, most patients with HRS recover to near-normal kidney function within weeks. After terlipressin and albumin treatment without transplant, creatinine returns to baseline in approximately 40 to 50% of HRS-AKI patients, though liver disease progression means many relapse.
Both HRS and acute tubular necrosis (ATN) cause AKI in patients with cirrhosis, but they differ in mechanism and urine findings. HRS is a functional kidney failure — the kidneys are ischaemic from renal vasoconstriction but the tubules are intact and still functioning. ATN occurs when the ischaemia is severe enough or prolonged enough to actually damage the tubular cells. The urine distinction: in HRS, urine sodium is very low (below 10 mEq/L) because the intact tubules are avidly conserving sodium in response to the perceived underfilling. In ATN, urine sodium is typically above 30 mEq/L because the damaged tubules have lost their sodium-conserving ability. Fractional excretion of sodium (FENa) is below 1% in HRS and above 2% in ATN.
Dialysis (specifically CRRT in the acute setting) manages the consequences of HRS — uraemia, hyperkalaemia, fluid overload — but does not treat the cause. In a patient with HRS as a bridge to liver transplant, CRRT is valuable and appropriate — it keeps the patient alive while the transplant is arranged. In a patient with HRS who is not a transplant candidate and for whom liver disease is terminal, the appropriateness of dialysis must be carefully considered — CRRT prolongs life but does not reverse the underlying liver failure, and the decision to initiate or continue dialysis requires a frank conversation about prognosis and goals of care.
Spontaneous bacterial peritonitis (SBP) is infection of ascitic fluid — occurring in cirrhotic patients whose gut bacterial translocation into the ascites exceeds the capacity of the ascitic fluid's antimicrobial defences. SBP triggers a systemic inflammatory response (cytokine release, further nitric oxide production) that intensifies the splanchnic vasodilation already present in cirrhosis — worsening the effective arterial underfilling and triggering HRS in 30 to 40% of cases. The prevention of HRS in SBP is one of the most evidence-based interventions in hepatology: intravenous albumin given at the time of SBP diagnosis (1.5 g/kg on day 1, 1 g/kg on day 3) reduces HRS incidence by approximately 60% compared to antibiotics alone.
Without treatment, HRS-AKI has a median survival of 2 to 4 weeks — making it one of the most rapidly fatal complications of cirrhosis. With terlipressin and albumin, response rates of 40 to 50% are achievable, and survival improves significantly in responders. The best outcomes are achieved in patients who receive liver transplantation — 1-year survival after transplant in HRS patients approaches 70 to 80% in experienced centres. HRS-CKD has a median survival of 3 to 6 months without transplant — primarily limited by the progression of the underlying liver disease rather than the kidney failure itself.
Yes — NSAIDs (diclofenac, ibuprofen, naproxen, and others) should never be given to patients with cirrhosis and ascites. In cirrhosis, renal prostaglandins (particularly PGE2) play a critical compensatory role in maintaining renal blood flow against the intense renal vasoconstriction from RAAS and sympathetic activation. NSAIDs block prostaglandin synthesis, removing this compensatory vasodilation and precipitating AKI that fulfils HRS criteria. This is why the management of any painful condition in a cirrhotic patient requires careful avoidance of NSAIDs — paracetamol in standard doses, or low-dose opioids where appropriate, are the alternatives for pain management.
SLKT — transplanting both a liver and a kidney simultaneously from the same deceased donor — is considered when the kidney failure in a cirrhotic patient is unlikely to recover after liver transplantation alone. The indications for SLKT include: dialysis dependence for 8 or more weeks before liver transplant (a threshold indicating sustained kidney injury rather than purely functional HRS), CKD with eGFR below 30 mL/min that predates or is independent of the liver disease, or documented intrinsic kidney disease (on biopsy) with more than 30% fibrosis. KIMS coordinates SLKT decisions with the liver transplant and nephrology teams.
KIMS Secunderabad — Dr. E. Ravi (Senior Consultant Nephrologist, critical care nephrology lead), CRRT 24/7 in ICU, terlipressin and albumin protocol for HRS-AKI, liver transplant coordination for eligible patients, 24-hour emergency nephrology. NABH and NABL accredited. Emergency: 040-4488-5000.