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Last updated: Lesson of the Month - October 2017…
on 17 Oct 2017

March 2013

 Matthew Graham-Brown

A 43 year old man was referred urgently by his GP for outpatient review in the renal clinic. He had been feeling unwell for the preceding 4 weeks and had noticed some swelling in his ankles and his hands that had been getting steadily worse over roughly the same period of time. He had also noticed that his urine had become rather frothy, but he was passing normal volumes of normal coloured urine. His GP did some blood tests that triggered the referral to clinic:

  1. U&E:    Na - 138 , K - 3.7, Ur - 14.6, Cr - 135, eGFR - 48
  2. LFTs:   ALP - 45, ALT - 22, Alb - 23, Bili - 7
  3. FBC:     Hb - 11.0, Plt - 245, WCC - 7.2, Neut - 4.8
  4. CRP - 11,  INR - 1.1

The GP had also dipped the patients urine, which had showed protein +++, but no blood and had arranged an early morning urine PCR between receiving the results and the clinic appointment:

Urine PCR - 426mg/mmol

In clinic the patient was normotensive (BP 126/69), and the clinical picture had not changed. On systems review he had no history of weight loss, change in bowel habit, shortness of breath, cough/expectoration/haemoptysis, chest pain, palpitations, syncope, headache, visual problems/loss, problems with balance or lower urinary tract symptoms. With nephrotic range urine PCR, low albumin, peripheral oedema and deranged renal function tests a diagnosis of nephrotic syndrome (underlying cause not yet clear) was made and he was booked for a renal biopsy the same week. Repeat blood tests showed U&E's were stable, and albumin was also stable at 24.

Vasculitic screen was negative and ultrasound scan of the renal tract showed 2 normal sized kidneys, and no signs of obstructions. He was also booked for fasting lipids and started on oral furosemide and ACE-i prior to biopsy.

He presented for renal biopsy on the unit 2 days later and was consented by the renal registrar for renal biopsy, with the risks explained as:

  1. Bleeding
  2. Infection
  3. Pain
  4. Failure to obtain sample
  5. Damage to kidneys and possible deterioration of renal function

Pre-procedure, platelets were 257, INR was 1.1, Hb was 13.1 and the patient was happy to proceed with biopsy. Biopsy was done at 13:00 on a Friday of the left kidney. It was performed under ultrasound guidance, with strict aseptic technique and local anaesthesia. The registrar required 2 passes to get an adequate tissue sample, and was satisfied that the second core was a good quality sample. The patient was well immediately post-procedure and was monitored with observations as per protocol.

At 17:00 the patient was keen to be discharged and was asking to be reviewed to go home. The renal SHO was called down to review the patient who was dressed and standing next to his bed ready to leave. Most recent observations showed:

BP - 116/87, Pulse - 94, Temp - 36.5, RR - 14, Sats - 99% OA

He had passed urine, which had ++ Blood,  and +++ Protein, but nil else, and he denied any pain in his back or shortness of breath. The renal SHO discharged the patient with follow-up in outpatient clinic the following Friday for results.

The patient was re-admitted via A&E at 23:00 the same evening and was reviewed by the on-call medical registrar in A&E resus. The patient was cold , but fully orientated and talking in full sentences. He had passed frank haematuria 2 hours previously and had started to feel progressively more week since being discharged home. Observations had been done:

BP - 90/75, Pulse - 123, Temp - 36.1, RR - 19, Sats - 99% OA

The A&E team had already obtained IV access and were giving IV fluids - they had also sent FBC, U&E, clotting screen and Group and Save, as well as a venous blood gas, which showed Hb 8.1, but was otherwise normal. The patient had also been catheterised and was passing heavily blood stained urine. Repeat FBC showed:

Hb - 7.8, WCC - 7.3, Plt - 228

The patient was given 2 units of packed red cells and IV fluid and his blood pressure improved to 110/76 , and pulse settled to around 100 beats per minute. The on-call Med SpR called the renal consultant overnight, who advised to ensure the patient was well resuscitated with packed red cells and IV fluids, and to book and urgent USS for the following morning to look for a perinephric haematoma.

Fortunately in this case, the bleeding settled with supportive treatments overnight. The on-call radiology registrar did the USS on Saturday morning, and it showed only a small peri-nephric haematoma. The patients blood counts were stable over the weekend, and haematuria resolved. He was discharged home on the Monday morning (Incidentally his renal biopsy was consistent with idiopathic membranous nephropathy and he started immunosuppressive treatments).

Lessons

  1. Often a high index of suspicion is needed to spot bleeding from renal biopsy in the early stages. Although massive bleeding following biopsy is rare, it does happen occasionally, and is potentially life threatening.
  2. The biopsy was carried out appropriately, with appropriate indications, and the registrar ensured all pre-biopsy parameters were acceptable, and it was safe to proceed. Although it took 2 passes for an adequate core, this is not uncommon, and the patient was observed for a period afterwards.
  3. Although the patient was keen to be discharged home, there were signs there that suggested he needed to be observed for a longer period. He had haematuria, and although his pulse was <100 it was 94 and probably higher than it had been on admission, suggesting a mounting tachycardia. Likewise, although the blood pressure was normal at 116/87, the pulse pressure had started to narrow, which can be an early sign of bleeding.
  4. The presence of blood on urine dip is relatively common after biopsy, and up to 3% will have macroscopic haematuria. Again, on it's own this is not concerning, but you with retrospect you could say it added weight to the argument that the patient should have been kept in for observation.
  5. A simple bedside test you can perform to see if a patient has early signs of hypovolaemia from bleeding is a lyning and standing pulse and blood pressure. Tachycardia or postural drop are early signs of hypovolaemia.
  6. Absence of back pain does not rule out significant bleeding - indeed this can be a late sign.
  7. 4 hours (in truth) is probably not a long enough period of observation following renal biopsy. Most hospitals will have their own protocols and guidelines on observations post biopsy - you must look these up if you are ever faced with a similar situation. 
  8. The 'small peri-nephric haematoma' seen on USS, is not in keeping with the degree of blood loss seen on the patients blood counts. It is possible that there was a retroperitoneal bleed, missed on scan, or the  haematoma was actually much bigger than was interpretted by the on-call radiologist performing the scan.
  9. It is not necessary to quote infection as a complication of renal biopsy when consenting a patient for biopsy. It is sometimes useful to quote how likely the vairous complications are to occur, to give patients a better (more informed) idea of what they are consenting to - the figures you quote should obviously be adjusted for patients who are lower or higher risk.

Discussion

Bleeds following renal biopsy are usually small and self-limiting and manifest as:

  1. Peri-renal haematoma: common, and usually self-limiting
  2. Non-visible haematuria:  common, and usually self-limiting
  3. Visible haematuria: Usually resolves spontaneously within 2 days, but in approximately 0.5% of patients, it continues for 2 to 3 weeks 
  4. Major bleed: Rare, but serious and potentially life threatening

Major bleeding is obviously the thing that you don't want to miss and key things to remember for patient safety are:

  1. Tachycardia may be the first sign of bleeding – take it seriously
  2. Classic signs of shock and back pain may be late signs of bleeding
  3. If you have clinical concern or shock develops call blood bank and X-match 2 (or more) units of blood from the Group and Save sample taken pre-procedure - don't wait or ask someone else to do this
  4. Ensure the patient has good (wide bore) IV access and replace volume loss with IV saline/colloid in the first instance
  5. Arrange an urgent ultrasound to see if there is a peri-renal haematoma
  6. CT angiogram can be useful to identify peri-renal haematoma or the possible site of active bleeding
  7. Always, always, always contact the oncall renal consultant/registrar if you have any concerns and in the case of large bleeds inform the interventional radiologists early, as well as the surgeons. In the case of ongoing bleeds that show no signs of stopping, interventional radiologists can often embolise the bleeding vessel/area, but it is wise to have your surgical team on standby as very rarely nephrectomy is required as a life-saving procedure

Key message is be vigilant, resuscitate with fluid and blood, and get help by involving seniors early.

RenalMed has an excellent article on renal biopsy with lots more important information



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