What is acute kidney injury?
Acute kidney injury (AKI) is a sudden decrease in the ability of the kidney to filter the blood, resulting in a reduction in urine production. This decrease disturbs the balance of body fluids and electrolytes, causing the body to retain wastes.
Although a problem worldwide, acute kidney injury is more common in Africa than elsewhere. Available data indicates that the disease is common among 10 - 40% of adults in sub-Saharan Africa.
Symptoms and signs of AKI
Most patients do not know that they have an acute kidney injury because the condition does not often present with clinical symptoms. However, the following symptoms might be present in some:
- Decreased urine output
- Edema: generalized body swelling
- Hypertension
- Weakness
- Nausea
- Coma, in severe cases
Classification of AKI
Acute kidney injury is classified based on the location of the cause of the injury. The classifications could be:
- Pre-renal AKI - if the cause of the injury is before the kidney
- Renal or intrinsic AKI - if the injury is within the kidney
- Post renal AKI - if the injury is caused by factors after the kidney, such as the obstruction of the ureter, a tube that carries urine from the kidney to the bladder, by a stone.
Only the intrinsic acute kidney injury represents true kidney disease. Pre-renal and post-renal forms of the disease are the consequences of non-kidney diseases that lead to a decreased glomerular filtration rate (GFR).
Stages of acute kidney injury
There are four main stages in the development of an acute kidney injury:
- Initiation
- Oligo-anuria
- Polyuria
- Restitution
These four stages restore kidney functions and should last a maximum period of three months, if the injury does not cause significant damage to the kidney.
However, the injury can progress to a chronic kidney disease if it persists for more than three months.
Causes of AKI in sub-Saharan Africa (SSA)
The most common causes of acute kidney injury in Africa include:
- Malaria
- HIV
- Nephrotoxic agents such as traditional herbal concoctions
- Envenomation from snakebite
- Chronic conditions like diabetes mellitus and hypertension
- Obstetric complications
- Use of skin lightening (bleaching) creams containing mercury
Who is at risk of acute kidney injury?
Anyone can come down with acute kidney injury but some classes of people are especially at higher risk. These sets of people include:
- People living with chronic illnesses like diabetes mellitus, hypertension, and sickle cell disease
- Patients with sepsis
- Patients with poorly treated urinary tract infection
- People who abuse nonsteroidal anti-inflammatory drugs (NSAIDs)
- Elderly patients
- People with blocked urinary tract
- Users of certain antibiotics like aminoglycosides
- Patients with dehydration from diarrhea or exercise
- Patrons of traditional practices that involve lacerations of people with unsterilised tools
- People observing prolonged fasting without water
- Poor people who drink herbal concoctions
