Intraperitoneal insulin with CAPD - an artificial pancreas

Experience with CAPD in Diabetic Patients in Toronto

During the first four years of the CAPD programs in Toronto, 409 patients completed CAPD training; of these 64 (15.7%) were diahetics. The mean age of the diabetics was 46.7 and of the non-diabetics 51.4 years. One and two-year survival rates were not significantly different between the two groups (93%-82% for the non-diabetics and 90%-72% for the diabetics}. The main cause of death was cardiovascular events, in both groups. During the first year on CAPD, diabetics were transplanted at a higher rate than non-diabetics (20% vs. 9%). The overall technique success rate, the rate of transfer to an alternative dialysis modality and the incidence of peritonitis were similar in the two groups. At least in the short -term, diabetics do well on CAPD. It is suggested that CAPD may be the dialysis modality of choice in diabetics with ESRD.

Management of the Diabetic Patients with End Stage Renal Disease

Twenty diabetics with end-stage renal disease who had never previously received dialysis treatment were treated with continuous ambulatory peritoneal dialysis for periods of two to 36 months (average, 14.5). Intraperitoneal administration of insulin achieved good control of blood sugar Even though creatinine clearance decreased significantly (P = 0.001), contro of blood urea nitrogen and serum creatinine was adequate. Hemoglobin and serum albumin levels increased significantly (P = 0.005 and 0.04 respectively). Similarly, there was a significant increase in serum triglycerides and alkaline phosphatase (P = 0.02 and 0.05). Blood pressure became normal without medications in all but one of the patients. Retinopathy, neuropathy, and osteodystrophy remained unchanged. Peritonitis developed once in every 20.6 patient-months a rate similar to that observed in nondiabetics. The calculated survival rate was 92 per cent at one year; the calculated rate of continuation on ambulatory peritoneal dialysis was 87 per cent.

IntraperitonealInsulin: A Protocol for Administration during CAPD and Review of Published Protocols

For many diabetics in end-stage renal failure, the initial therapy they receive will be continuous ambulatory peritoneal dialysis (CAPD) together with i.p. insulin. To date, all published protocols rely on empirical dosages based upon predialysis insulin requirements. A practical regimen for the institution of i.p. insulin administration during CAPD is described. The only endpoints used to determine insulin dosage were fasting plasma glucose 5 to 10 mmol/L and 2 h postprandial plasma glucose 8 to 15 mmol/L. An initial protocol related to body weight, dextrose content, volume, and timing of dialysate was based on a retrospective analysis of the results in our first 10 patients. Subsequently, a prospective assessment in an additional 22 patients confirmed the effectiveness of the regimen. The following protocol is recommended for the institution of i.p. insulin therapy in patients undergoing CAPD: Preprandial exchanges 1.36% dextrose-0.175 U/L dialysate/kg body weight 3.86% dextrose-0.25 U/L/kg Overnight exchanges 1.36% dextrose-0.1 U/L/kg 3.86% dextrose-0.15 U/L/kg Further adjustment of insulin dosage is then made on the basis of four hourly plasma glucose profiles. Self-monitoring of capillary blood glucose is recommended.

Practices of Insulin Administration in CAPD

A review of protocols for the administration of insulin in diabetics during CAPD in the various Toronto hospitals and from two other centers outside Canada show that they are similar but not identical. Toronto Western Hospital, Iowa Lutheran Hospital, Pitie-Salpetriere Hospital and Sunnybrook Medical Center use intraperitoneal insulin exclusively. Toronto General Hospital and the Wellesley Hospital used a combination of intraperitoneal and subcutaneous insulin. Most patients performed four exchanges daily, although some did three only. Nighttime insulin was reduced in most patients. Average insulin requirements were higher when given by intraperitoneal as opposed to subcutaneous injection. There was insufficient data to compare the control achieved with each protocol.

Realizing a Closed-Loop (Artificial Pancreas) System for the Treatment of Type 1 Diabetes

Recent, rapid changes in the treatment of type 1 diabetes have allowed for commercialization of an "artificial pancreas" that is better described as a closed-loop controller of insulin delivery. This review presents the current state of closed-loop control systems and expected future developments with a discussion of the human factor issues in allowing automation of glucose control. The goal of these systems is to minimize or prevent both short-term and long-term complications from diabetes and to decrease the daily burden of managing diabetes. The closed-loop systems are generally very effective and safe at night, have allowed for improved sleep, and have decreased the burden of diabetes management overnight. However, there are still significant barriers to achieving excellent daytime glucose control while simultaneously decreasing the burden of daytime diabetes management. These systems use a subcutaneous continuous glucose sensor, an algorithm that accounts for the current glucose and rate of change of the glucose, and the amount of insulin that has already been delivered to safely deliver insulin to control hyperglycemia, while minimizing the risk of hypoglycemia. The future challenge will be to allow for full closed-loop control with minimal burden on the patient during the day, alleviating meal announcements, carbohydrate counting, alerts, and maintenance. The human factors involved with interfacing with a closed-loop system and allowing the system to take control of diabetes management are significant. It is important to find a balance between enthusiasm and realistic expectations and experiences with the closed-loop system.

Diabetic nephropathy: changing concepts of pathogenesis and treatment

The metabolic changes which accompany hyperglycemia in a person with diabetes are thought to cause renal hyperperfusion and intraglomerular hypertension, especially in the person with a predisposition to essential hypertension. Intraglomerular hypertension causing deposition of protein in the mesangium leads to glomerulosclerosis and renal failure. Screening for microalbuminuria can predict which type I diabetic patients will develop nephropathy. The decline in renal function in established diabetic nephropathy can be slowed with aggressive treatment of hypertension. The use of ACE inhibitors may also decrease intraglomerular hypertension. Whether similar treatment in the person with preclinical diabetic nephropathy would delay or prevent the onset of diabetic nephropathy is being investigated. Restricted protein intake, anti-platelet and rheolitic drugs may have a role in the treatment of established diabetic nephropathy. In end stage renal failure, renal transplantation is the treatment of choice. When transplantation cannot be performed, chronic ambulatory peritoneal dialysis is preferable to hemodialysis.

Peritoneal dialysis in diabetic end-stage renal disease

There has been a progressive improvement in the survival of diabetics with end-stage renal disease on peritoneal dialysis. Since its introduction in 1976, large numbers of diabetics have been preferentially treated by continuous ambulatory peritoneal dialysis (CAPD). CAPD offers the potential advantage of reduced cardiovascular stress, a steady biochemical state, good control of hypertension and extracellular fluid volume, and intraperitoneal administration of insulin. In addition, peritoneal access is easy to establish, CAPD offers freedom from a machine, and enables travel without upsetting facility dialysis schedules. The effects of intraperitoneal insulin are almost similar to normal insulin secretion. Although limited, the long-term experiences of CAPD in diabetics tend to show lower technique and survival results compared to nondiabetics. The incidence of peritonitis is no different between the diabetics and nondiabetics on CAPD. Continuous clyclic peritoneal dialysis is indicated in those who prefer nightly dialysis or those who are unable to do exchanges during daytime. Intermittent peritoneal dialysis is the least preferred therapy because of its inability to provide adequate dialysis.

Current concepts. Continuous ambulatory peritoneal dialysis

As a long-term dialysis therapy, CAPD has attractive features for use in children (in whom access to the circulation and immobility are often problems), adults in whom blood access is difficult, patients with diabetes, patients prone to hypotension, and patients seeking independence from a machine or medical facility. CAPD and related procedures are still evolving and improving. Efforts to reduce the rates of peritonitis are ongoing and should decrease the rates of treatment dropout and increase the use of this alternative method of dialysis. Continued research toward improvements in catheter configuration and connection devices and the tailoring of technique to meet the particular needs of patients have made peritoneal dialysis an acceptable replacement therapy in patients with end-stage renal disease. Neither peritoneal dialysis nor hemodialysis is the superior long-term dialysis therapy for all patients; the choice depends on numerous medical, social, geographic, and life-style considerations.

A 2 year evaluation of diabetic patients on continuous ambulatory peritoneal dialysis

Nineteen diabetic patients with end-stage renal disease on CAPD were evaluated over a 2 year period. All but one patient was insulin-dependent, with a mean age of 47.7 years. Average time on CAPD was 16.1 months (range, 2-28 months). Thirteen patients were followed for more than 12 months, and nine for more than 18 months. The mean training period was 22.9 days. Good blood glucose control was obtained with intraperitoneal (IP) insulin in all of the patients. Mean blood glucose levels of 125 +/- 23.08 mg/dl were achieved with 103 +/- 38.5 U/day of regular IP insulin. Glycosalated hemoglobin decreased from a mean of 12.7 +/- 2.35% before CAPD to 10.08 +/- 0.97% during CAPD. Peritoneal creatinine clearance remained stable during the study period, with a concommitant decrease (P less than 0.001) in the mean residual renal creatinine clearance. The incidence of peritonitis was one episode per 7.8 patient-months. Average length of hospitalization was 33.24 days/year. Visual acuity remained stable after 1 year in 73% of the 26 eyes evaluated. No amputations were required in more than 2 years of follow-up. Actuarial survival was 100% at 1 year and 86% at 2 years, and the technique survival of CAPD was 91 and 79%, respectively. These results demonstrate that CAPD is a good dialysis procedure for treating diabetic patients with chronic renal failure, and it offers the advantage of controlling glycemia better than other dialysis methods.

Continuous ambulatory peritoneal dialysis as a treatment for diabetic patients with end stage renal disease

Continuous ambulatory peritoneal dialysis (CAPD) is becoming the treat ment of choice for many diabetics with end stage renal disease (ESRD). Hy pertension is better controlled, neu ropathy and vascular calcifications re mains stable or improve, and few dietary or fluid restrictions are necessary. It is estimated that about 20% of all patients with ESRD will be using CAPD by 1985.

Continuous ambulatory peritoneal dialysis in diabetics with end-stage renal disease

Twenty diabetics with end-stage renal disease who had never previously received dialysis treatment were treated with continuous ambulatory peritoneal dialysis for periods of two to 36 months (average, 14.5). Intraperitoneal administration of insulin achieved good control of blood sugar. Even though creatinine clearance decreased significantly (P = 0.001), control of blood urea nitrogen and serum creatinine was adequate. Hemoglobin and serum albumin levels increased significantly (P = 0.005 and 0.04, respectively). Similarly, there was a significant increase in serum triglycerides and alkaline phosphatase (P = 0.02 and 0.05). Blood pressure became normal without medications in all but one of the patients. Retinopathy, neuropathy, and osteodystrophy remained unchanged. Peritonitis developed once in every 20.6 patient-months--a rate similar to that observed in nondiabetics. The calculated survival rate was 93 per cent at one year; the calculated rate of continuation on ambulatory peritoneal dialysis was 87 per cent. We conclude that continuous ambulatory dialysis with intraperitoneal administration of insulin is a good alternative treatment for diabetics with end-stage renal disease.

Intraperitoneal insulin in uraemic diabetics undergoing continuous ambulatory peritoneal dialysis

The kinetics of absorption of intraperitoneally administered insulin were studied in nine uraemic insulin-dependent diabetics undergoing continuous ambulatory peritoneal dialysis (CAPD). In each of three studies 20 U of regular insulin was directly injected as a bolus into the peritoneal cavity through an indwelling Tenckhoff catheter. In two procedures the insulin injection was followed by the instillation of either 2 litres of 1.5% dextrose dialysates or 2 litres of 4.5% dextrose dialysate. In the third 20 ml of saline was used to flush the tubing. Plasma free insulin values rose more rapidly and reached significantly higher concentrations (55.6 +/- 18.8 mU/l) when the insulin had been injected into an empty peritoneal cavity than when it was followed by dialysate. These differences were observed despite the fact that most of the insulin injected was retained by the patients. Since the plasma insulin values did not differ after instillations of dialysate containing 1.5% and 4.5% dextrose, the osmolality of the dialysate seemed not to affect insulin absorption, and the dilution of the insulin probably delayed its transfer through the peritoneum. These findings suggest that insulin given intraperitoneally to patients undergoing CAPD will be most effective if it is given into an empty peritoneal cavity at least 30 minutes before the dialysate is instilled.

A comparison of continuous ambulatory peritoneal dialysis in diabetic and nondiabetic patients

Between May of 1978 and December of 1980 we have treated 33 patients with continuous ambulatory peritoneal dialysis (CAPD) for a total of 1209 patient weeks. Thirteen patients were diabetic, 14 nondiabetic but with complications that made CAPD the treatment of choice, and six were nondiabetic without complications. Good control of plasma glucose was obtained n diabetics by the use of intraperitoneal insulin. Overall plasma glucose control, as estimated by glycohemoglobin and fasting plasma glucose levels was the same in both groups. Plasma triglyceride levels were normal in most of the diabetic patients and elevated in most of te nondiabetic patients. Visual difficulties did not prevent self-dialysis in seven diabetic patients who were legally blind, and these patients spent the least time in hospital and had the least peritonitis. Diabetic patients seem at least as able to cope with CAPD as nondiabetic patients and may derive some special advantages from the technique.

Three years' experience of continuous ambulatory peritoneal dialysis

Patients on continuous ambulatory peritoneal dialysis (CAPD) were studied for three years. 29 of them who had been on CAPD for six months or more were compared with patients on intermittent peritoneal dialysis (IPD) and on haemodialysis (HD). CAPD patients had significantly higher levels of HDL-cholesterol than HD patients. Urea, potassium, phosphate, and urate levels were significantly lower, and haemoglobin levels significantly higher, than in the IPD and HD groups. 43 CAPD patients studied had a peritonitis rate of 2.22 episodes per patient-year. CAPD offers an alternative form of dialysis to those unsuitable for HD, but until peritonitis rates can be reduced CAPD cannot rival HD as a long-term treatment.

Diabetes, intraperitoneal insulin, and CAPD

In patients on continuous ambulatory peritoneal dialysis (CAPD), hemoglobin A1 was measured in order to assess the effect of the high content of glucose in the dialysate solution. In five diabetics on CAPD, insulin was added to the dialysate in an attempt to maintain continuous control of blood glucose throughout the day. Glycosylated hemoglobin was elevated in seven diabetics prior to the initiation of CAPD (12.0 +/- 2.3%) as it was in six non-diabetics after several months on CAPD. (9.6 +/- 0.90%). With the use of intraperitoneal insulin, satisfactory control of blood glucose could be achieved and the rate of peritonitis was not increased. However, regardless of whether blood glucose was well-controlled or not, hemoglobin A1 as well as triglyceride values rose in diabetics on CAPD.

Treatment of diabetes mellitus by devices

A very important aspect of diabetes mellitus is whether or not normalization or near-normalization of blood glucose and/or other metabolites and hormones may reduce or eliminate the chronic complications of this disease. To answer this question and to provide a more "physiologic" approach to insulin administration, a constellation of devices have reached the stage of clinical investigation. These include small portable pump systems that can provide variable rates of insulin infusion via the subcutaneous intravenous or intraperitoneal routes. In addition, bedside artificial "beta cells" having the capability of providing insulin infusions, with the rate varying as a function of continuous glucose measurements, are available for short-term studies. Under development are implantable continuous infusion devices and implantable glucose sensors that could in the future lead to a miniaturized implantable glucose-controlled insulin administration system.