Peritoneal dialysis (PD) can be provided in the form of several techniques.
Peritoneal dialysis (PD) can be
provided in several techniques. First, it is noteworthy to mention that
peritoneal blood and dialysate flows during PD are extremely lower that that
with hemodialysis (HDX) (both are > 400 mL/min). Consequently,
urea (toxin) clearance per unit time is too much lesser with PD than that via HDX.
Nevertheless, PD is usually provided in a continuous manner with net weekly
solute clearance approached that via HDX.
TYPES OF PD
modality can be provided in either a continuous or intermittent manner.
Continuous ambulatory PD (CAPD) encompasses several exchanges during the day (often 3)
with an overnight dwell usually added. A modification for this regimen is to
include one nighttime exchange via an exchange device, leading to 2 overnight
exchanges and 3 exchanges per day. This modification of CAPD is rarely used. An
automated PD (APD) may use a cycler to perform many overnight exchanges.
To modify this technique a continuous cycler PD (CCPD),
nightly intermittent PD (NIPD), and tidal PD (TPD)
can be performed:
Ø Continuous cycler PD (CCPD) hs a long per day dwell with multiple
cycles overnight. A small number of patients on CCPD do not perform daytime
Ø An intermittent module, e.g.,
nightly intermittent PD (NIPD) or intermittent PD (IPD), that provide periods
("wet" abdomen) with alternate times at which peritoneal cavity could
be drained of dialysate ("dry" abdomen).
Ø Tidal PD (TPD), composed of exchanges with
peritoneal cavity always contains some dialysate (at least one-half full), this
manner may improve sense of comfort and fasten drainage in certain
CAPD VERSUS APD
there’re any clinical progress in providing the CAPD or APD modules, a crucial
question that’s still unanswered. Despite paucity of data, CAPD and APD modalities
may behave similarly in regard to the clinical outcome.
institution of PD, most patients still have a reasonable residual kidney
function, so, they can cope with any type of PD. However, once the residual
kidney function starts to fade out, patient choice should be directed to a more
suitable modality to achieve the optimum level of fluid and solute (toxin)
clearance. At the beginning, dwell timing as well as dwell volumes should be
individualized first according to the current patient’s status.
current guides for PD adequacy, first, total Kt/V/week (adequacy
equation) for urea should be at least and, or rather to consider CrCl to be at least L/week per 1.73 m2 body surface area. These
targets should be monitored by time to guarantee an adequate PD modality. As
residual kidney function went away and the peritoneal membrane starts to lose
its physiological transport criteria by time, it is mandatory to augment the DX
prescription (either by increasing the number of exchanges or dwell volumes).
Residual renal function
maintained on PD usually have some preserved residual kidney function when they
commenced in this modality. However, this residual kidney function gradually
declines with time, to match “dwell time” to “transport type” gains more
importance in this situation.
CHOICE OF PD MODALITY
Both CAPD or CCPD
modalities are currently required by patients maintained on PD
dialysis. In regard to CAPD, 4 manual exchanges per day, 2 L each
in addition to another overnight exchange. Modification of this system can be achieved via timing,
volumes, and number of exchanges per day.
On the other hand, CCPD is
an automated module of PD in wch a cycler delivers 3-6 exchanges
while the is sleeping in addition to 12-15 hour per day dwell. The net weekly
clearance is simulating that gained with CAPD but
greater amount of dialysate is generally warranted per day. Patient’s
preference between CAPD and CCPD depends to a great extent on lifestyle or personal desires
(e.g., need to work, refusing to do exchange in day time, or, lack of ability
to perform the exchanges by themselves).
However, CCPD may provide more time for work, family, and social activities as compared to CAPD. Sleep apnea may also complicate the nocturnal PD. Generally, automated PD is superior to CAPD in fluid and solute removal optimization in certain patients. The automated module can provide larger amounts of dwells, longer noct