Acute Kidney Injury (AKI)
Acute kidney injury is a sudden drop in kidney function over hours or days. Unlike chronic kidney disease, which develops slowly, AKI can develop rapidly and is often reversible if recognised and treated promptly. Most cases occur in patients who are already unwell from another condition, but it can also happen in otherwise healthy people. Specialist input matters because early identification of the cause, rapid treatment, and careful follow-up can mean the difference between full recovery and lasting kidney damage.
Dr Rory McQuillan provides consultant nephrology care for AKI in Dublin, with appointments and inpatient consultations available across the major private hospitals.
What is acute kidney injury?
Acute kidney injury describes a rapid loss of kidney function, defined by a rise in serum creatinine, a fall in urine output, or both. It is most commonly diagnosed in hospital, but it can also develop in the community. AKI is graded as stage 1, 2, or 3, with stage 3 being the most severe.
AKI is not a single disease. It is a syndrome with many causes. The job of the nephrologist is to find the cause, treat it, support the kidneys while they recover, and protect the patient from long-term consequences.
Causes of acute kidney injury
Causes of AKI are conventionally grouped into three categories: pre-renal (problems with blood supply to the kidneys), intrinsic renal (damage to the kidney tissue itself), and post-renal (obstruction to the flow of urine).
- Pre-renal: dehydration, blood loss, severe infection, heart failure, low blood pressure
- Intrinsic: glomerulonephritis, acute tubular necrosis, interstitial nephritis, vascular injury
- Post-renal: kidney stones, prostate enlargement, urinary tract obstruction, bladder dysfunction
- Medication-related: NSAIDs, certain antibiotics, contrast dye, ACE inhibitors during illness
Symptoms and warning signs
AKI may have no symptoms in its earliest stages and is often picked up by a routine blood test. As it progresses, patients may notice reduced urine output, ankle or facial swelling, breathlessness, nausea, confusion, or fatigue. Anyone with these symptoms during or after an acute illness should seek medical assessment promptly.
Diagnosis and investigation
Diagnosing AKI involves blood tests, urine tests, and imaging. The cause is established through a structured assessment including:
- Detailed history including medications, recent illnesses, and procedures
- Examination for fluid status, blood pressure, and signs of infection
- Serum creatinine and electrolytes
- Urinalysis and urine microscopy
- Renal ultrasound to exclude obstruction
- Specialist tests including biopsy in selected cases
How AKI is treated
Treatment depends on the cause. The general principles are to restore blood flow to the kidneys, treat any underlying cause, stop nephrotoxic medications, and support the patient until kidney function recovers. A small proportion of patients will need short-term dialysis. Most do not.
Follow-up after recovery is critical. Patients who have had AKI are at higher risk of future kidney problems, even if their function returns to baseline. Specialist review at three to six months after an episode is recommended for moderate to severe cases.
Recovery and long-term outlook
Most patients with AKI recover kidney function, particularly if the cause is identified and treated promptly. Recovery can take days to weeks. A minority of patients develop chronic kidney disease as a result of AKI, and a smaller minority require long-term dialysis. The strongest predictors of recovery are the severity of the initial injury, the underlying cause, and the patient’s baseline kidney function.
Appointments and GP referrals
Appointments are arranged via GP referral. Inpatient consultations are available at all five hospitals where Dr McQuillan practises. Urgent referrals are accommodated through the practice office.
Frequently Asked Questions
AKI is a sudden reduction in kidney function. Severe AKI can produce kidney failure, but most cases are less severe and many resolve completely.
Yes, often. The key is early recognition and treatment of the cause. Most patients recover, though full recovery can take weeks.
Some blood pressure medications, particularly ACE inhibitors and ARBs, should be paused during an episode of AKI. This is a decision to be made with your doctor based on the cause and severity.
It can. Patients who have had AKI are at higher long-term risk of chronic kidney disease, hypertension, and future episodes of AKI. Specialist follow-up reduces these risks.
Only a minority of AKI patients need dialysis, and when they do it is usually short-term. The decision is based on severity, complications, and response to other treatments.
Have a Question?
If you’d like more information about Dr. McQuillan’s services or need assistance from the practice team, please get in touch below.
Please note: Appointments are arranged via GP referral.