Dialysis – Hemodialysis and Peritoneal Dialysis
At ABMH we have facilities to provide different forms of Renal Replacement therapies based on patient’s needs. The dialysis unit can provide-
•In-center Haemodialysis, where the blood circulates outside the body of the patient – it goes through a machine that has special filters. The blood comes out of the patient through a catheter (a flexible tube) or ‘arterio-venous fistula’ that is inserted into the vein. The filters do what the kidney’s do; they filter out the waste products from the blood. The filtered blood then returns to the patient via another catheter. The patient is, in effect, connected to a kind of artificial kidney.This can be done both as an out-patient or in-patient.
•Peritoneal Dialysis where a sterile (dialysate) solution rich in minerals and glucose is run through a tube into the peritoneal cavity, the abdominal body cavity around the intestine, where the peritoneal membrane acts as a semi-permeable membrane. Peritoneal dialysis uses the natural filtering ability of the peritoneum – the internal lining of the abdomen. In other words, peritoneal dialysis uses the lining of the abdomen as a filter of waste products from the blood.
The dialysate is left there for some time so that it can absorb waste products. Then it is drained out through a tube and discarded. This exchange, or cycle, is generally repeated several times during the day – with an automated system it is often done overnight. The elimination of unwanted water (ultrafiltration) occurs through osmosis – as the dialysis solution has a high concentration of glucose, it results in osmotic pressure which causes the fluid to move from the blood into the dialysate. Consequently, a larger quantity of fluid is drained than introduced.
Peritoneal dialysis can be done at home by the patient. It gives the patient a greater amount of freedom and independence because they do not have to come in to the clinic at multiple times each week.
There are two principal types of peritoneal dialysis:
• Continuous ambulatory peritoneal dialysis (CAPD) – this requires no machinery and can be done by the patient or a caregiver. The dialysate is left in the abdomen for up to eight hours. It is then replaced with a fresh solution straight away. This happens every day.
• Continuous cyclic peritoneal dialysis (CCPD) – a machine does the dialysis fluid exchanges. It is generally done during the night while the patient sleeps. This needs to be done every night. Each session lasts from ten to twelve hours. After spending the night attached to the machine, the majority of people keep fluid inside their abdomen during the day. A study found that a significant number of patients prefer “dialysis while you sleep” treatment. Nocturnal dialysis improves heart disease in patients with end-stage kidney failure.
• Continuous Renal Replacement Technique (CRRT)-is to diagnose patients in a more physiologic way, slowly, over 24 hours, just like the kidney. Intensive care patients are particularly suited to these techniques as they are, by definition, hemodynamically compromised, and, when acutely sick, intolerant of the fluid swings associated with IHD.
The benefits of CRRT are-
• Supports the renal system through continuous, gentle removal of excess metabolic waste products, while returning normal electrolyte and acid/base balance.
• Restores and maintains net neutral fluid balance (prevents accumulation that leads to fluid overload).
• Delivers continuous nutritional support without concern for fluid restrictions.
• Provides for optimized drug dosing.
• May improve patient survival rates.A 55% survival rate was realized in the largest randomized control trial to date.
• May increase renal recovery, defined as freedom from dialysis dependence. A 94% recovery rate was achieved in the same large randomized control trial noted above.
• May result in a higher rate of renal recovery when compared to conventional hemodialysis after AKI, as indicated by multiple large clinical studies.
CRRT is typically done in the ICU’s.