Q.550. What are the strategies to minimize dialysis-induced hypotension in the elderly?

 

PERITONEAL DIALYSIS

 

Q.651.What is SEP.? How to manage?

A.SEP. (Sclerosing Encapsulating Pertonitis): ch.ch. by [extensive intra-Pr. fibrosis  + encasement of bowel loops + progressive loss of U.F.]🠞fluid retention & edema. Etiology: {not clear but may be: prior severe peritonitis, acetate DZt. buffer, a reaction to foreign agents e.g. plasticizers from cath., B.B., premature withdrawal from P.D. & extended duration of P.D.}.

Sn & Sm of SEP : [abdominal pain, nausea, loss of appetite, constipation, drr., abd. mass, ascites, wt. loss, vomiting & fatigue].

Dgx. SEP: by CT 🠞[Pr. calcification, bowel thickening, bowel tethering, and bowel dilatation]. Confirmation: by laparotomy and/or laparoscopy. (rarely used).

ttt. SEP: Stop P.D. & transfer to H.DX. (although it may developed or worsen after stopping PD), bowel rest+ TPN & (may be) im/m. therapy and/or surgery.

Q.652.What are the possible mechanisms of solute clearance and U.F. in P.D?

A. Pr. barrier🙏has 3 layers :[Pr. mesothelium, interstitium & cpll. endothelium]. According to the 3-pore model of solute transport, cpll. endothelium contains 🙏 3 different-sized pores which’re size-selective in restricting solute transport. Aqua-porin-1 is the smallest sized pore and is responsible for 40% of free water transport across Pr. membrane. Transport of different solutes is based on dhiffusion & convection. Trans-cpll. U.F. rate is determined by: [net pressure gradient & by Pr. membrane ch.ch. & by Starling’s law. Both crystalloids and/or colloid based Dx. solutions can be used to provide the required osmotic or oncotic gradients. Rate of solute transport varies between individuals, wch may hv therapeutic implications for Dx. adequacy as well as fluid overload.

U.F. failure occurs due]alterations in vasc. surface area (larger vasc. surface area 8more pores available for transport), which🠞Rapid loss of glucose gradient across the membrane & fluid retention. Selective loss of aquaporin-1 func. & other f. can 🠞U.F. failure, which can be determined by sp. studies on Pr. membrane.

Q.653.How to evaluate hypervolemia in P.D. patients?

A.Vol. overload in PD is mostly due to preventable/treatable causes, wch. incl.:[excessive sod. or water intake, too little sod. or water removal, or a new comorbid dis.]. Causes of  🠝 salt & water intake incl.:[noncompliance é dietary restrictions & absorption of fluid dur. dwells caused by failure of PD prescription🠞 adequate osmotic (or oncotic) stimulus for U.F.]. Causes of insuff. salt & water removal incl.:[prescription failure to provide adequate osmotic(or oncotic) stimulus for U.F., failure of Pr membrane to resp. to osmotic stimulus& loss of Kru].

Comorbid dis..:[new CVS event or worsening of heart dis., hypoalb. &🠟oncotic pressure or mech. or anatomical problem]. Evaluation of vol. overloaded incl.:[history & physical exam., fill & drain test, PET & radiogr. studies]. History: excl. CVS dis., determining loss of body mas & adherence é DX. prescription or salt & water intake. Exam. incl.:[exit site for fluid(dextrose +ve on dipstick), pres. of hernias, esp. in pericth., genital, inguinal & femoral areas & distribution of retained fluid: generalized, unilateral, or localized . Mech. or anatomical problems may be quickly excl. by performing a quick two liter "fill&drain" to determine nature & rate of Dzt flow. Fibrin clots, difficulty é inflow, or incomplete or positional drainage may be obs.. PET test allows ch.ch. of Pr. transport, U.F. capacity & pres. of sodium sieving or change fr. prior PET tests.

Radiographic eval.: used é cth. malposition or Dzt. leak. A flat plate of the abd. us. used to evaluate cth placement & positioning & may reveal constipation. Lateral film may excl. rotation or kink in S.C. part. Abdominal CT é intraPr. contrast or MRI without contrast us. used to excl. Dzt leak. Gadolinium-based imaging should beavoided. Dzt. prescription & U.F. shd be reviewed monthly. Routine monitoring of all ptns shd incl.:[ur. vol. &overnight drain volume (CAPD) or daytime drain vol.(APD)]. Baseline PET shd be done é initiation of Dx. & repeated if indicated. Measures to help prevent overload incl.: [diuretics, avoid nephrotoxic ag., monthly dietary counseling, enhancing compliance, optimizing s. glucose control (to maximize osmotic gradients) & matching dwell time to transport type].

Q.654.What are the noninfectious complications of P.D. catheters?

A.Non-infc. incl.: [outflow failure, pericth. leak, abdominal wall herniation, cth. cuff excursion & intestinal perforation]. Some complc. cn be managed conservative-ely, while others need laparoscopic, peritoneoscopic or traditional surgery.Outflow failure is commonly due to constipation or obstipation. Radiography is useful for clearing the cause esp. if rel. to constipation or cth. malposition. It’s important to exclude pericth. or Dzt. leakage as an underlying cause of incomplete recovery of instilled Dzt. Once leakage hs bn excluded, underlying cause of outflow failure is us. ascertained by history, physical exam and/or radiography. Prevention is optimized by proper positioning of cth. & ttt constipation. Outflow failure ttt. is causal. Pericth. leakage tends to occur early after cth. placement in ass. é high Dzt. volume & in those é weak abdominal walls. Incidence is widely variable and may relate to practice of s.c. embedding of the implanted cth. upon implantation. Pericth. leakage = pres. of fluid surrounding the cth. and may be initially subtle. S.c. swelling & 🠟 outflow vol. may precede frank leakage. Dgx. of pericth. leakage may be made by 🠝 glucose concentration of the leaking fluid. Confirmatory Dgx. & delineation of leak anatomy can be finally by CT. Management:🠟either Dzt. vol. and /or exertional activity. Temporary transfer to H.DX. may be sometimes necessary.

Erosion of cth. cuff through the skin may be a sequela of exit-site infection or excessive superficial cuff placement. Conservative ttt may be attempted if there’s no evidence of infection. Cuff shaving or cth. removal may be required in presence of infection. Intestinal perforation can occur at time of cth. implantation due to direct injury, or weeks to m.s after placement due to bowel erosion. It’s life-threatening & shouldd requires a high index of suspicion & urgent attention. Clues of perforation🠞 feculent or bloody Dzt, Dzt retention, drr. occ. after Dzt. instillation, or G.-ve peritonitis. Thpy: [cessation of P.D., cth. removal, i.v. A.B. & bowel repair.].