Nephrolog case

A 67 year old male presents to the ER with a creatinine of 450  mmol/L. His JVP is low, his mucous membranes are dry and he has postural tachycardia and hypotension. He is felt to be volume depleted and IV normal saline is started. An abdomal ultrasound shows no evidence of hydronephrosis or hydroureter. 3 days later, the patient is clinically euvolemic but the serum creatinine is still 400 mmol/L.

Has obstruction been truly ruled out? Provide two explanations describing how the patient could be obstructed despite an unremarkable ultrasound on admission.

Answer

Obstruction is generally noted on ultrasound due to the accumulation of urine causing the physical distension of the collecting system. If a patient is obstructed but also severe volume contracted, they may not make enough urine to sufficiently distend the collection so that hydronephrosis and/or hydroureter is notable on ultrasound. However, a repeat ultrasound may show hydronephrosis and/or hydroureter after re-expansion of the extra-cellular fluid volume.

Some patients have renal insufficiency due to extrinsic compression of the collecting system, such as in retroperitoneal fibrosis or malignancy. In these cases, one will not see a dilated collecting system on routine ultrasonography.

Compartment syndrom

Compartment syndrome is a limb threatening and life threatening condition, defined as the compression of nerves, blood vessels, and muscle inside a closed space (compartment) within the body. This leads to tissue death from lack of oxygenation due to the blood vessels being compressed by the raised pressure within the compartment. Compartment syndrome most often involves the forearm and lower leg, and can be divided into acute, subacute, and chronic compartment syndrome. An alternative definition of compartment syndrome, according to Rankin, is characterized by pressure within a closed space thus compromising the circulation and function of tissues in that space .





What types of injuries may cause a compartment syndrome?

Type of injury

• Fractures — account for about 75% of compartment syndrome
• especially tibia, humeral shaft, combined radius and ulna fractures, and supracondylar fractures in children
• may be open or closed

• Compartment syndrome can also occur after a soft tissue injuriesdue to:
  • crush injury
  • snake bite
  • excessive exertion
  • prolonged immobilisation
  • constrictive dressings and plaster casts
  • soft tissue infection
  • seizures
  • extravasation of intravenous fluids and medications
  • burns
  • tourniquets

Patients with a coagulopathy are at particular risk of compartment syndrome.


 hat are the clinical features of compartment syndrome?

Remember the 6Ps

1. pain (especially on passive stretching)
2. pallor
3. perishingly cold
4. pulselessness
5. paralysis
6. paraesthesiae

Pain is the key symptom. It occurs early, is persistent, tends to be disproportionate compared with the original injury and is not relieved by immobilisation. The pain is exacerbated by passive stretching, which is the most sensitive sign.
The affected compartments may feel tense and tender on palpation. Assess loss of sensation by light touch and two-point discrimination, rather than just pinprick, which is less sensitive.

Measure compartment pressures if compartment syndrome is suspected — do not rely on clinical signs — have a high index of suspicion!

Case Presentation

Young male presented in emergency as a referral case for complaint of :

Left leg swollen after fall 7 days back

Oligourea to anuria for 3 days

Short of breath for 1 day.

According to the attendant, Patient was mechanic by profession and had no addiction to any substance. He was leading normal life till 7 days back, when he fell while working on terrace, resulted in injury to left leg, which soon got swollen and paining.

Next day he visited doctor who got xrays done which revealed no fracture, but soft tissue swelling.

He was restricted to bed and latter on decrease developed anorexia ,decrease urine output and short of breath. He was investigated and found renal failure and hyperkalemia and reffered here.

Here we sent labs and passed Double lumen femoral and connected to dialysis.

He was in advance uremia, high anion gap met. acidosis and hyperkalemia. His CPK was high. Rhabdomyolysis was the diagnosis made.