Continuous Ambulatory Peritoneal Dialysis

MILESTONES IN NEPHROLOGY

J Am Soc Nephrol 10: 90 1-9 10. 1999

Con t inuous Am bulat ory Pe ritonea l Dia lys is ROB ERT P. PO POVICH, Ph .D.; JACK W. MONCRIEF, M .D.; KAR L D. NOLPH, M.D., F.A.C .P.; AHAD J. GHO DS, M .D.; ZBYLUT J. TWARDOWSKI, M.D.; and W. K. PYLE; Austin, Texas; and Col umbia, Mi ssouri W IT H

CO~·I:\'IE

'TS RY

J ACK VV. MONCRIEF .-\ND DAVID N. CHURCHILL Reprinte d from Ann. Intern. Med. 88: 449-456, 1978 The technique of continuous ambulatory peritoneal dialysis was evaluated in nine patients during 136 patient weeks. The major objectives were to see if continuous ambulatory peritoneal dialysis would provide (1 ] acceptable control of serum chemistries by usual criteria, (2] adequate removal of sodium and w ater, [3 ] tolerable protein losses, and 141 a low prevalence of peritonitis with episodes responsive to therapy with continuing continuous ambulatory peritoneal dialysis. Preliminary findings suggest continuous ambulatory peritoneal dialysis represents an effective ambulatory, portable, internal dialysis technique. Larger·solute clearances per week may approach values six times greater than w ith most hemodialysis techniques. Small-solute clearances approach dialysate flow rate (8.3 mUmin) and are comparable to other dialysis techniques on a weekly basis. Edema is r eadily controlled and protein losses should be tolerable with adequate protein intake. Peritonitis occurs on the average every 10 weeks but responds to therapy promptly with continuing continuous ambulatory peritoneal dialysis. If the prevalence of peritonitis can be reduced, continuous ambulatory peritoneal dialysis appears to represent a ve ry attractive dialysis technique.

in 1976. Popovich. Moncrief. Decherd. Bomar. and Pyle (1) described the technique of continuous ambulatory peritoneal dialysis for treatme nt of chronic renal fa ilure. More recen tly the Texas group haR de:,cribed the theoretical mass transfer characteristics of this procedure as well as some preliminary clinical experiences in three patients (2, 3). In January 1977, a continuous ambulatory peritoneal dialysis program was begun at the University of Missouri Medical Center in a cooperative study with the Texas group. This paper describes the preliminary findings of this cooperative study in nine patients treated with conti nuous ambulatory peritoneal dialysis for 136 patient weeks. This preliminary experience to date suggests that continuous ambulatory peritoneal dialysis deserves continued evaluation. Although frequent peritonitis is a major problem. the technique appears to provide conti nuous acceptable dialysis. Very simpl y. continuous ambulat01y peri toneal dialysis uses the continuous presence (24 h a day, 7 days a week) of From the Depanmem of Chemical Engineering and the Biom~dical Engineering Program. University of Texas: Department of Medicine. Austin Diagnostic Inc .. Austin. Texas; Depanment of Yledicine. Harry S. Truman Veterans Administration Hospital; and the Uni versiry of Missouri Medical Ct:.;l[er; Columbia. Missouri.

·. AUTHQ~~ COMlVIEN~ARY .·.- '.~ .. ·

..........

.Jack W. .M oncr-iet;·

.

•-:..

' ' ·.

Austin,. Texas

fie/ completing his studies ·: ~d r.eceiving a Ph.D. in biomedical .' en~heering from .· the: University of· · Washington, Dr. Robert Popovi~h accepted a position in.. the Engineering · Bepartment af.the University of Texas atAustin_He had benefited from·the c0l~ lab oration of the Engineering. Department- and .. .~_e.., Nephrology section at the University..ofWa.Shington, inchfd~·~· ing his . association with Dr. Belding .Scribner, Dr. Henry Tenckhoff, Dr. A. L. Babb, and Mr. Wayne Quimon. This Jed him to seek an association with me as a-clinical collaboramr. . . .. , . for.the study of transport phenomena. Beginning in 1971 this collaborci'rion included . n!gulillmeetings between myself, some of my nurses, Dr. Popovich, and many of his biomedical engineering students. The application of_engineering principles, specifically transport principles relating to dialysis: produced a wealth of pmjec~s,on which student and fac ulty focused. their ·energies. Many: .transport _projects were studied and included hemodialysis adequacy, surface area measurement, vascular access evaluation1' reuse technology, ultrafiltration. measurement, . ~d blood'pressl!l:e monitoring, to -mendon . only '~ few. ·. ·:; ,.~ -··: ·In. the '1970s, one of the projects · that was sponsored: by Natio nal Institutes oLf:Iealth i~cluded an att~~pt to -~P.t!mi~e inter mittent peritoneal dialy,sis. Our studies suggested ' that. to·; achieve· .c learance value"s with. i~ter~ . mittenc- peritmi.ealvdialysis similar to clearances .obtained. w.ith·.hem O'd ialysis··(e:g., ii-"1 m 2 h~~O'dialysis d~;ice used '.thr~e~ times per week for-4 h with a blood flow ' of 350' ml/min and_ a dial·y·~ai:e flo:..... of 500 rnl/ inin);: it· would be nec~ssary to· exchange approximately 4-L/h for .50:· to 55 :''li( wlc: A r:. tli
A

-l .;. \'"

·~. .

. r~

'•4• :,.·

~

_,~¥.:'(·~-..::·..' ;: ,.~:...,...

•'

1

~:.'

'•

.u:. ' ...~; :.,_,..,

:, • t

,f

f '';

_ .....u

..

~

• •·

>I

~ .. ~ .• ..::-.·~·

902

Journal of the American Society of Nephrology

Table 1. Patient Characteristics

Patient Center Numher

Sex

Age

Texas

Male

;m 40

2

Texas

Mule

37

3

Texas

Female 50

4

Texas

Female 59

5

Texas

Female 12

6

Texas

Male

47

7

Missouri

Male

76

8

Missouri

Male

35

9

Missouri

Female 50

Diagnosis

Previous Therapy

Incentive for CAPO*

Renal Ccr at Start ofCAPD*t

U vol at Start ofCAPD*:j:

Weeks on CAPO*

m/Jmin

m/Jday

no.

3

380

23

4.4

930

11

An uric

An uric

26

5

840

15

3

Unknown

7

4

350

5

0.7

230

15

2.0

325

18

1.0

10

16

End-stage None Blood-access renal disease failure Obstructive uropathy Peritoneal dialysis Lives far from hemodialysis during dialysis center (CAPO) training and has no trainable partner Hypertensive Hemodialvsis. Unsuccessful nephrosclerosis 5 months; transplant. fear transplant; reaction to 7 months; hemodialysis hemodialysis, centered around 12 months needle insert Chronic None Patient-physician glomerulonephritis preference, distance from dialysis center MembranoNone Patient-physician preference proliferative glomerulonephritis Patient-physician Membranous None preference proliferative glomerulonephritis Peritoneal Elderly nursing Obstructive nephropathy dialysis. home resident. 2 months failure of blood access Diabetic Recent myocardial Single peritoneal infarct with nephropathy dialysis, 48 h cardiac arrest Blood-access Nephrolithiasis and 4 years of failure hemodialysis, pyelonephritis one transplant. intermittent peritoneal dialysis

*CAPO= continuous ambulatory peritoneal dialysis. tCcr = renal creatinine clearance. :f:U vol = urine volume.

peritoneal dialysis solution in the peritoneal cavity except for periods of drainage and instillation of fresh solution five times per day. After each drainage and fresh instillation the patient is disconnected from all tubing. The chronic indwelling peritoneal catheter is capped and the patient is free to participate in his usual daily activities. Essentially, continuous ambulatory peritoneal dialysis represents a continuous, portable (primary internally) dialysis system. It trades relatively long dialysis sessions 3 days per week for five 30-to-45-min interruptions of daily activities every day. The major questions addressed in these preliminary studies are: [1] Does continuous ambulatory peritoneal dialysis provide acceptable control of serum chemistries? [2] Is removal of sodium and water adequate to control edema? [3] Are protein losses tolerable? (4] Does recurring peritonitis make continuous ambulatory peritoneal dialysis unacceptable with currently available catheters? Methods PATIENTS The project was reviewed and approved by the University of Texas and University of Missouri Committees for Research Involving Human Subjects,

anti patients were accepted after informed consent was obtained. All patients had chronic renal failure and were considered candidates for chronic dialysis either based on the degree of impainnent in renal function or findings suggestive of early uremia. Table 1 shows the sex, age, and diagnosis for each patient in addition to the reason for initiating continuous ambulatory peritoneal dialysis in lieu of other dialysis techniques. Table 1 also shows 24-h endogenous creatinine clearances and typical 24-h urine volumes at the start of continuous ambulatory peritoneal dialysis. On repeated measurements endogenous creatinine clearances remained essentially unchanged throughout the study. The number of weeks that the patients were carried on continuous ambulatory peritoneal dialysis at the time of this writing is also presented in Table I. It should be noted that many of these patients were poor candidates for chronic hemodialysis because of medical or technical problems. or both. A very elderly patient (Patient 7) and a patient with far advanced diabetes mellitus (Patient 8) were included.

TECHNIQUE OF CONTINUOUS AMBULATORY PERITONEAL DIALYSIS All patients had indwelling Tenckhoff chronic peritoneal catheters placed in the usual manner (4). The external end of the catheter was capped and held close to the skin by a dressing and supportive gauze belt. For most patients, fluid drainage and instillation (five exchanges per day) were at approximately 0700, 1100. 1500, 1900, and 2200 to 2300 h. Two litres of commercially available dialysis solution (Dianeal~ connected to its respective peritoneal dialysis tubing and drainage bag were prepared in the standard way. This solution contains Na. 141; Cl, 101; lactate, 45; Mg, 1.5; and Ca. 3.5 meq/litre; ~extrose was either 1.5% or 4.25%. No K was added. A new peritoneal tubmg and bag set were used for the 0700 exchange and at Missouri,

Milestones in Nephrology used throughout the day thereafter: fresh tubing was used for each exchange by Texas patients. Solutions were initiaHy warmed to body temperature; later, at home. several patients preferred, for convenience, to instill solutions at ambient temperature. Patients were taught to connect the peritoneal catheter to the tubing using sterile techniques. The peritoneal cavity was drained by gravity during 15 to 20 min. Fresh solution was instilled by gravity during 10 min. The patients then disconnected the catheter from tubing using sterile techniques. The catheter was recapped. If the tubing was to he reused, the tubing catheter connection was capped and submerged in hetadine; the empty bottle was left in place connected to the tubing until the next instillation. Most solutions contained 1.5% dextrose. Patients were told to weigh themselves daily, to examine their ankles for dependent edema, and to carefully record their drainage volumes. They were instructed to use up to two exchanges with 4.25% dextrose solutions depending on their weight, drainage volumes, and the presence or absence of edema.

MEASUREMENTS In addition to records of weight, blood pressure, and drainage volumes, routine measurements of serum urea nitrogen, creatinine, electrolytes, total protein, albumin, uric acid, calcium, inorganic phosphate, and hematocrit were done. Drainage volumes were periodically analyzed for urea, creatinine, total protein, and cell counts. Missouri patients periodically were admitted to the Clinical Research Center for inulin-clearance studies. A loading dose of insulin was given at least 2 h before an instillation, and inulin, urea, and creatinine clearances as well as protein losses were measured during several days for different types of long-dwell exchanges. In some patients, during these hospital studies, small volumes (5 to 10 ml) of dialysate were removed at frequent intervals (every 10 min) during single-dwell periods. This was carried out in order to follow dialysate to serum concentration ratios for the above solutes during these long-dwell exchanges. Three patients underwent serial total body K measurements with a whole body counter.

CHEMISTRIES Inulin concentrations were measured by the method of Walker, Davidson, and Orloff (5), modified as previously reported (6). Protein concentrations in dialysate were measured by a turbidimetric method suitable for low concentrations (7). Other chemistries were by standard autoanalyzer techniques.

CALCULATIONS Peritoneal clearances (mVmin) of urea. creatinine, and inulin were calculated as (dialysate/serum concentration) X (drainage volume/total exchange time).

PERITONITIS Patients who developed findings suggestive of peritonitis (abdominal tenderness, fever, cloudy dialysate or increased neutrophils in dialysate or a combination of these) were admitted to the hospital for their first episode. Gram stains and cultures of dialysate were obtained. Where bacterial peritonitis was suspected antibiotics were administered either by simply adding antibiotics to dialysis solution or in combination with parenteral or oral antibiotics. Continuous ambulatory peritoneal dialysis was continued; the frequency of exchanges was occasionally increased for several days. Pending clinical results and the results of culture and Gram stain, these patients were maintained on an intraperitoneal antibiotic, an oral antibiotic, or both, for 3 weeks. lntr.1peritoneal antibiotics chosen for therapy included gentamicin, keflin, and ampicillin in peritoneal dialysis solution concentrations as recommended by Tenckhoff (4). Most patients were hospitalized only 2 to 3 days per episode. Two patients who, at home, developed abdominal pain, fever, and cloudy drainage were instructed to collect dialysate drainage to be sent for Gram stain and culture to either their community hospital or respective medical center. They were told to begin immediately adding antibiotic to peritoneal dialysis solution. If there was relief of pain and a clearing of dialysis solution within 12 to 24 h they were not hospitalized.

DIET After the first week on continuous ambulatory peritoneal dialysis, protein intakes were increased to 1 glkg body weight or more. Potassium intakes were 50 meq/day; fluid intake, 1 to 2 litres; sodium intake, 88 to 200 or more meq/day (some patients preferred to ingest more sodium and water depending on one or two 4.25% dextrose exchanges to remove it, whereas others preferred to restrict their fluid and sodium intakes). Most patients were thus permitted a diet that they felt was essentially unrestricted.

Results Figure I shows mean serum urea nitr
903

long.;,term management, and the comm.i6nent . of time . and materials .was economically· impractical. At.approximately.·.the same. time,. we encounterecLapatient who had reached near:'end-stage· retial disease. secondary· to": diabetes mellitus. Attempts.were made· to establisaa~yascular access for hemodialysis. The·.patient was. hypercoaguable ' each attempt to crea~:a fistula WaS· met With··thromboSis. and-' ;.fail~.: ·Nter.s~vei1·.~~~pts~~T·~iscussed· \Vi~·. the :Plitient·the~ ·. :adviSability: