People on hemodialysis (HD) are ten times more likely to suffer from a stroke, compared with the general population. In addition to this risk, patients on HD are at a three-fold higher risk of hemorrhagic transformation of ischemic stroke, an increased risk of disability progression, and mortality regardless of stroke subtype. Thus, we should spend some time thinking about the unique challenges in the management of patients on HD with acute stroke.
In the case of a patient on HD with an acute stroke, as with any other patient their care is best directed by dedicated stroke physicians, on a dedicated stroke unit. However, there are several important clinical questions that need to be addressed:
Does this patient need thrombolysis or thrombectomy? How should blood pressure (BP) and volume control be managed? What time of day is it best to dialyze patients, to ensure they can be optimized for intensive physical therapy?
As such these patients require individualized and carefully considered HD prescriptions with particular attention on:
- BP Control
- In acute haemorrhagic stroke the aim is for blood pressure to be brought beneath 140 mmHg, this can be achieved with aggressive IV agents if required.
- Fluid Shifts
- The fluid shifts which occur during HD have been associated with reductions in cerebral perfusion pressure, which in turn could worsen ischemia. Care should be taken when undertaking ultrafiltration in these cohorts. Likewise great shifts in Serum osmolality may worsen fluid shits, consideration should be made for using low pump speed, small tank dialysis to help mitigate this.
- Heparin Use
- It stands to reason that use of anticoagulation in acute intracerebral hemorrhages would worsen bleeding. But what about in ischemic stroke? Current UK guidelines suggest that any anticoagulation should be held for 14 days post ischemic stroke, thus should we be doing the same for our dialysis cohorts?
- Timing of Dialysis
- In the post-acute stroke phase treatment relies on intensive physical and occupational therapy sessions, to help harness neuronal plasticity to improve function. However, this is a challenge for patients on hemodialysis as important aspects of their care could be compromised because they hooked up to a dialysis machine (especially if they are having daily HD). It’s not possible to undertake a functional kitchen assessment, for example, during an HD session. Moreover, post dialysis, patients can be severely fatigued resulting in further disengagement in therapy sessions. It might therefore be beneficial to try to time dialysis sessions to the late afternoon/early evening slots, to help mitigate this.
Much of the emphasis in research has been focussed on patients requiring ICU level of care; but what about the patients who do not, but have complications due to acute stroke? In London, two of the six renal units have opted for a “halfway house” between CRRT and traditional thrice weekly HD. These utilize daily, heparin-free, low-pump speed HD sessions for patients with acute neuro-trauma. The other four units in London do not have a specific approach. Physiologically, it seems to make sense to undertake dialysis in this way, however there is no evidence to support improveed outcomes in acute stroke.
There is no clear answer yet as to how best balance the stroke therapy versus dialysis argument. Further studies should first examine whether there is evidence to support daily dialysis in acute stroke versus traditional intermittent HD prescriptions. This evidence should then be balanced against current known best practice in post-acute stroke, which is intensive therapy. Perhaps then a standardized approach can be made to treatment of hemodialysis in the post stroke period.
Post by: Charlie Hall, MD (@charleshallmd)
Renal Department, The Royal London Hospital, UK