Complications of acute peritoneal dialysis

Acute Peritoneal Dialysis in Eastern Nepal

Objective

B.P. Koirala Institute of Health Sciences is the only dialysis center outside the capital city of Nepal. Although the burden of renal failure in Nepal is high, limited resources and dialysis facilities are the major constraint on management of acute renal failure (ARF) and acute dialysis in chronic renal failure (CRF). In the present study, carried out from January 2000 to June 2002, we looked into the prospect of introducing peritoneal dialysis (PD) to the district hospitals for treatment of ARF and acute dialysis in CRF.

Patients and Methods

We designed a form to evaulate the causes of renal failure and the indications for, complications of, and outcomes of dialysis. During this study, junior doctors in our hospitals completed the forms. Resident doctors were trained to do intermittent peritoneal dialysis (IPD) and were responsible for the carrying out the procedure under supervision, together with a staff nurse.

Results

A total of 120 patients underwent IPD during the study period, including 66 men and 54 women. The most common indications for acute dialysis in CRF were metabolic acidosis (56%), uremic encephalopathy (45%), and fluid overload (44%). The most common causes of ARF were acute gastroenteritis (20%), sepsis (20%), and septic abortion (16%). Fifteen patients died of sepsis and multi-organ failure.

Conclusions

Lack of dialysis facilities in the geographic periphery means that most patients present late in the course of their disease, as evidenced by severe metabolic acidosis and uremic encephalopathy. Peritoneal dialysis is a simple procedure, easily tolerated by the patient and requiring less expertise than hemodialysis does. Moreover, nursing staff, technicians, and doctors can be easily trained in the technique. Despite certain limitations, PD still has much potential and can be successfully accomplished in district hospitals and less accessible areas.

Biocompatible dialysis fluids for peritoneal dialysis

BACKGROUND

Biocompatible peritoneal dialysis (PD) solutions, including neutral pH, low glucose degradation product (GDP) solutions and icodextrin, have previously been shown to favourably influence some patient-level outcomes, albeit based on generally sub-optimal quality studies. Several additional randomised controlled trials (RCT) evaluating biocompatible solutions in PD patients have been published recently. This is an update of a review first published in 2014.

OBJECTIVES

This review aimed to look at the benefits and harms of biocompatible PD solutions in comparison to standard PD solutions in patients receiving PD.

SEARCH METHODS

The Cochrane Kidney and Transplant Specialised Register was searched up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All RCTs and quasi-RCTs in adults and children comparing the effects of biocompatible PD solutions (neutral pH, lactate-buffered, low GDP; neutral pH, bicarbonate(± lactate)-buffered, low GDP; glucose polymer (icodextrin)) in PD were included. Studies of amino acid-based solutions were excluded.

DATA COLLECTION AND ANALYSIS

Two authors extracted data on study quality and outcomes. Summary effect estimates were obtained using a random-effects model, and results were expressed as risk ratios and 95% confidence intervals (CI) for categorical variables, and mean differences (MD) or standardised mean differences (SMD) and 95% CI for continuous variables.

MAIN RESULTS

This review update included 42 eligible studies (3262 participants), including six new studies (543 participants). Overall, 29 studies (1971 participants) compared neutral pH, low GDP PD solution with conventional PD solution, and 13 studies (1291 participants) compared icodextrin with conventional PD solution. Risk of bias was assessed as high for sequence generation in three studies, allocation concealment in three studies, attrition bias in 21 studies, and selective outcome reporting bias in 16 studies.Neutral pH, low GDP versus conventional glucose PD solutionUse of neutral pH, low GDP PD solutions improved residual renal function (RRF) preservation (15 studies, 835 participants: SMD 0.19, 95% CI 0.05 to 0.33; high certainty evidence). This approximated to a mean difference in glomerular filtration rate of 0.54 mL/min/1.73 m² (95% CI 0.14 to 0.93). Better preservation of RRF was evident at all follow-up durations with progressively greater preservation observed with increasing follow up duration. Neutral pH, low GDP PD solution use also improved residual urine volume preservation (11 studies, 791 participants: MD 114.37 mL/day, 95% CI 47.09 to 181.65; high certainty evidence). In low certainty evidence, neutral pH, low GDP solutions may make little or no difference to 4-hour peritoneal ultrafiltration (9 studies, 414 participants: SMD -0.42, 95% CI -0.74 to -0.10) which approximated to a mean difference in peritoneal ultrafiltration of 69.72 mL (16.60 to 122.00 mL) lower, and may increase dialysate:plasma creatinine ratio (10 studies, 746 participants: MD 0.01, 95% CI 0.00 to 0.03), technique failure or death compared with conventional PD solutions. It is uncertain whether neutral pH, low GDP PD solution use led to any differences in peritonitis occurrence, hospitalisation, adverse events (6 studies, 519 participants) or inflow pain (1 study, 58 participants: RR 0.51, 95% CI 0.24 to 1.08).Glucose polymer (icodextrin) versus conventional glucose PD solutionIn moderate certainty evidence, icodextrin probably reduced episodes of uncontrolled fluid overload (2 studies, 100 participants: RR 0.30, 95% CI 0.15 to 0.59) and augmented peritoneal ultrafiltration (4 studies, 102 participants: MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising RRF (4 studies, 114 participants: SMD 0.12, 95% CI -0.26 to 0.49; low certainty evidence) which approximated to a mean creatinine clearance of 0.30 mL/min/1.73m² higher (0.65 lower to 1.23 higher) or urine output (3 studies, 69 participants: MD -88.88 mL/d, 95% CI -356.88 to 179.12; low certainty evidence). It is uncertain whether icodextrin use led to any differences in adverse events (5 studies, 816 participants) technique failure or death.

AUTHORS' CONCLUSIONS

This updated review strengthens evidence that neutral pH, low GDP PD solution improves RRF and urine volume preservation with high certainty. These effects may be related to increased peritoneal solute transport and reduced peritoneal ultrafiltration, although the evidence for these outcomes is of low certainty due to significant heterogeneity and suboptimal methodological quality. Icodextrin prescription increased peritoneal ultrafiltration and mitigated uncontrolled fluid overload with moderate certainty. The effects of either neutral pH, low GDP solution or icodextrin on peritonitis, technique survival and patient survival remain uncertain and require further high quality, adequately powered RCTs.

Biocompatible dialysis fluids for peritoneal dialysis

BACKGROUND

The longevity of peritoneal dialysis (PD) is limited by high rates of technique failure, some of which stem from peritoneal membrane injury. 'Biocompatible' PD solutions have been developed to reduce damage to the peritoneal membrane.

OBJECTIVES

This review aimed to look at the benefits and harms of biocompatible PD solutions in comparison to standard PD solutions in patients receiving PD.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register (28 February 2013), through contact with the Trials Search Co-ordinator using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE and EMBASE, and handsearching conference proceedings.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs in adults and children comparing the effects of biocompatible PD solutions (neutral pH, lactate-buffered, low glucose degradation product (GDP); neutral pH, bicarbonate (± lactate)-buffered, low GDP; glucose polymer (icodextrin)) in PD were included. Studies of amino acid-based PD solutions were excluded.

DATA COLLECTION AND ANALYSIS

Two authors extracted data on study quality and outcomes (including adverse effects). The authors contacted investigators to obtain missing information. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for categorical variables, and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous variables.

MAIN RESULTS

Thirty-six eligible studies (2719 patients) were identified: Neutral pH, lactate-buffered/bicarbonate (± lactate)-buffered, low GDP PD solution (24); icodextrin (12). Allocation methods and concealment were generally incompletely reported, and adequate in only ten studies (27.8%). Patients lost to follow-up ranged from 0% to 83.4%. Neutral pH, low GDP versus conventional glucose PD solutionBased on generally sub-optimal quality evidence, the use of neutral pH, low GDP PD solutions was associated with larger urine volumes at the end of the studies, up to three years of therapy duration (7 studies, 520 patients: MD 126.39 mL/d, 95% CI 26.73 to 226.05). Improved preservation of residual renal function was evident in studies with greater than 12 month follow-up (6 studies, 360 patients: SMD 0.31, 95% CI 0.10 to 0.52). There was no significant effect on peritonitis, technique failure or adverse events with the use of neutral pH, low GDP PD solutions. Glucose polymer (icodextrin) versus conventional glucose PD solutionThere was a significant reduction in episodes of uncontrolled fluid overload (2 studies, 100 patients: RR 0.30, 95% CI 0.15 to 0.59) and improvement in peritoneal ultrafiltration (4 studies, 102 patients, MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising residual renal function (4 studies, 114 patients: SMD 0.12, 95% CI -0.26 to 0.49) or urine output (3 studies, 69 patients: MD -88.88 mL/d, 95% CI -356.88 to 179.12) with icodextrin use. A comparable incidence of adverse events with the icodextrin (four studies) was reported.

AUTHORS' CONCLUSIONS

Based on generally sub-optimal quality studies, use of neutral pH, low GDP PD solution led to greater urine output and higher residual renal function after use exceeded 12 months. Icodextrin prescription improved peritoneal ultrafiltration and mitigated uncontrolled fluid overload. There were no significant effects on peritonitis, technique survival, patient survival or harms identified with their use. Based on the best available evidence, the use of these 'biocompatible' PD solutions resulted in clinically relevant benefits without added risks of harm.

The impact of neutral-pH peritoneal dialysates with reduced glucose degradation products on clinical outcomes in peritoneal dialysis patients

Neutral-pH peritoneal dialysates, with reduced glucose degradation products (GDPs), have been developed to reduce peritoneal membrane damage. Here our review evaluated the impact of these solutions on clinical outcomes using data from The Cochrane CENTRAL Registry, MEDLINE, Embase, and reference lists for randomized trials of biocompatible solutions. Summary estimates of effect were obtained using a random-effects model of 20 eligible trials encompassing 1383 patients. The quality of studies was generally poor, such that 13 studies had greater than a 20% loss to follow-up and only 3 trials reported adequate concealment of allocation. Use of neutral-pH dialysates with reduced GDPs resulted in larger urine volumes (7 trials; 520 patients; mean difference 126 ml/day, 95% CI 27-226), improved residual renal function after 12 months (6 trials; 360 patients; standardized mean difference 0.31, 95% confidence interval 0.10-0.52), and a trend to reduced inflow pain (1 trial; 58 patients; relative risk 0.51, 95% CI 0.24-1.08). However, there was no significant effect on body weight, hospitalization, peritoneal solute transport rate, peritoneal small-solute clearance, peritonitis, technique failure, patient survival, or adverse events. No significant harms were identified. Thus, based on generally poor quality trials, the use of neutral-pH peritoneal dialysates with reduced GDPs resulted in greater urine volumes and residual renal function after 12 months, but without other clinical benefits. Larger, better-quality studies are needed for accurate evaluation of the impact of these newer dialysates on patient-level hard outcomes.

Peritoneal dialysis in renal replacement therapy for patients with acute kidney injury

Peritoneal dialysis (PD) was the first modality used for renal replacement therapy (RRT) of patients with acute kidney injury (AKI) because of its inherent advantages as compared to Hemodialysis. It provides the nephrologist with nonvascular alternative for renal replacement therapy. It is an inexpensive modality in developing countries and does not require highly trained staff or a complex apparatus. Systemic anticoagulation is not needed, and it can be easily initiated. It can be used as continuous or intermittent procedure and, due to slow fluid and solute removal, helps maintain hemodynamic stability especially in patients admitted to the intensive care unit. PD has been successfully used in AKI involving patients with hemodynamic instability, those at risk of bleeding, and infants and children with AKI or circulatory failure. Newer continuous renal replacement therapies (CRRTs) are being increasingly used in renal replacement therapy of AKI with less use of PD. Results of studies comparing newer modalities of CRRT versus acute peritoneal dialysis have been conflicting. PD is the modality of choice in renal replacement therapy in pediatric patients and in patients with AKI in developing countries.

Access-related complications in peritoneal dialysis in developing countries

Access-related complications differ considerably between acute and chronic peritoneal dialysis as a result of differences in catheter design, catheter material, number of cuffs, break in period, and the duration of peritoneal dialysis. Pain, which is the commonest complication of acute peritoneal dialysis, is seen in 56% to 75% followed by blood tinged dialysate effluent in 30%, pericatheter leak in 14% to 36%, catheter malfunction in 12% to 28%, bowel injury in 0.1% to 1.3%, rarely bladder injury and peritonitis in 2.5%. In chronic peritoneal dialysis, the incidence of exit-site infections are seen anywhere between 1 episode in 27.3 patients months to 1 episode in 41.9 patients months, and pericatheter leak is seen in 5.2%. Technique of exit-site care is variable in different countries, and regular use of mupirocin ointment at the exit site is practiced in different centers.

Comparison of bedside- and laboratory-inoculated Bactec high- and low-volume resin bottles for the recovery of microorganisms causing peritonitis in CAPD patients

There is not yet a universally accepted protocol for the recovery of microorganisms causing peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD). We prospectively analyzed 343 peritoneal effluent specimens by three protocols: 1) 10 ml of effluent centrifuged and the pellet plated onto blood, MacConkey agars, and into thioglycolate broth (routine method); 2) 5 ml and 10 ml inoculated at the bedside into Bactec 16A and 26A aerobic resin-containing blood culture bottles, respectively; and 3) 5 ml and 10 ml inoculated in the laboratory into Bactec 16A and 26A media, respectively. One hundred and forty (41%) peritoneal effluent specimens had microorganisms recovered, and, of these, 101 were recovered by routine culture compared to 117 (p < .021), 125 (p < .0001), 115 (p < .047), and 116 (p < .032) for bedside-inoculated 16A and 26A and for laboratory-inoculated 16A and 26A, respectively. Bedside-inoculated bottles were not significantly better than laboratory-inoculated bottles, and high-volume bottles were not significantly better than low-volume bottles for detection of patients positive for microorganisms; however, the number of total microorganisms recovered were significantly better from all inoculated blood culture bottles compared to routine culture. Bedside- and laboratory-inoculated resin-containing blood culture bottles are superior to the routine method for recovery of microorganisms causing peritonitis in CAPD patients.

Bicarbonate and bicarbonate/lactate peritoneal dialysis solutions for the treatment of infusion pain

A randomized, double-blind, cross-over study was undertaken to determine the effects of novel bicarbonate (38 mM) and bicarbonate (25 mM)/lactate (15 mM) containing peritoneal dialysis (PD) solutions on infusion pain in patients who experienced inflow pain with conventional lactate (40 mM) solution. Pain was assessed using a verbal rating scale and the validated McGill Pain Questionnaire (MPQ). Eighteen patients were recruited to the study. Both novel solutions resulted in highly statistically significant reductions in inflow pain compared to the control lactate solution, as assessed with both the verbal rating scale and the MPQ. For all pain variables assessed, the bicarbonate/lactate solution was more effective than the bicarbonate solution in alleviating pain. In conclusion, both solutions reduced the infusion pain experienced with control solution, but the bicarbonate/lactate solution appears to be the most effective. In contrast to the most widespread current treatment, which is the manual injection of sodium bicarbonate, the bicarbonate/lactate solution does not have the associated increased risk of peritonitis.

Non-peritonitis complications of continuous ambulatory peritoneal dialysis in Saudi Arabia

Although peritonitis is the major complication and leading cause of morbidity in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), there are other complications of this long-term renal replacement therapy (RRT) modality. In order to evaluate the non-peritonitis complications, we retrospectively studied 60 new patients who were accepted in our CAPD program over a period of eight years from 1984 to 1993. Out of the 60 patients, 31 were females and 29 were males, with a mean age of 37.0 +/- 18 years. Tenckhoff's catheter was implanted by surgeons under direct vision in the operating theater through a midline incision. Nine of our patients had previous abdominal surgery and 11 females had pregnancies before CAPD, ranging from one to 10 with a mean of four. A total of 49 episodes of complications were observed, 32 early and 17 late. Early complications were defined if they occurred within three months from starting the procedure and late complications were defined as occurring after this period. There were 15 catheter blocks (25%), nine dialysate leaks (15%) and five hemoperitoneums (8.3%). Two serious and unusual complications were observed. In one of our patients, a mesenteric blood vessel injury occurred during catheter insertion, which necessitated massive blood transfusions and laparotomy. The other patient developed intestinal obstruction due to obstruction of intestinal loops around the catheter; this was corrected by removal of the catheter without the need for laparotomy. The late complications included six hernias, three hydroceles, three exit site infections, three tunnel infections and one case of loss of ultrafiltration.

Evaluation of aerobic Bactec 6A non-resin- and 16A resin-containing media for the recovery of microorganisms causing peritonitis

Recovery of microorganisms causing peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) continues to be problematic. To date, there is no universally accepted protocol. We prospectively analyzed 430 peritoneal effluent specimens by three protocols: (a) 3 ml of effluent was centrifuged and the pellet plated onto blood and MacConkey agars and into thioglycolate broth (routine method), (b) 3 ml of each was inoculated at the bedside into Bactec 6A aerobic and 16A aerobic resin-containing media, and (c) 3 ml of each was inoculated in the laboratory into Bactec 6A and 16A media. Of the peritoneal effluent specimens, 104 (24%) had microorganisms recovered; 63 were positive by the routine method compared with 86 (P < .001) by bedside-inoculated 16A. Bedside-inoculated 16A (86) recovered more microorganisms than bedside-inoculated 6A (70) (P < .05). Laboratory-inoculated 16A (78) recovered more organisms than the routine method (63) (P < .05). Of 42 positive peritoneal effluent specimens delayed in transit > or = 1 day, 23 were positive by the routine method compared with 34 bedside inoculated 16A (P < .01) and 30 laboratory-inoculated 16A (P > .114). Bedside-inoculated 16A media is superior to the routine method for the recovery of microorganisms causing peritonitis in CAPD patients.

The epidemiology of peritonitis in acute peritoneal dialysis: a comparison between open- and closed-drainage systems

We performed a prospective study to examine the epidemiology and microbiology of peritonitis complicating acute intermittent peritoneal dialysis (IPD) performed in an in-hospital setting for the management of acute and chronic renal failure and to see the effect of a closed-drainage system on altering the frequency and cause of peritonitis. Over a 15-month period, 79 patients were treated with acute IPD for a total of 136 treatments each ranging in length from 2 to 40 days (median, 4 days). The majority of cases had acute renal failure (ARF; 65%) and were treated in intensive care units (ICUs; 74%) with serious comorbid conditions (60%). About half were treated with a two-bag, ventable (open)-drainage system with unprotected spikes, and the other half were treated with a single-bag, spike-protected, closed-drainage system. There were 27 cases of peritonitis for a rate of 4.5 cases/100 patient-days at risk. About half were gram-positive infections; the remainder were gram-negative or mixed (25%) or Candida sp (25%). The use of a closed-drainage system reduced the incidence of system-related peritonitis from 3.6 to 1.5 cases/100 patient-days. There was a high rate of peritonitis in the first 48 hours of treatment, which fell to a low stable rate thereafter and remained so for up to 15 days of continuous IPD. The use of a closed-drainage system eliminated the early (< 48 hours) high rate of peritonitis and maintained a low constant rate of peritonitis throughout treatment. There was an association of ARF and severe comorbid disease with more virulent organisms (gram-negative, mixed, and Candida sp), which, in turn, were both associated with antecedent broad-spectrum antibiotic therapy. Random positive surveillance cultures showed a frequency distribution similar to that of peritonitis cases over the duration of treatment, but with less virulent organisms. Peritonitis in acute IPD occurs when large or repeated inocula of organisms from the prevailing flora overwhelm the peritoneal immune clearance mechanisms. Prolonged courses of broad-spectrum antibiotic therapy provide no protection, but shift the resulting infecting flora toward more virulent pathogens. A closed-drainage system provides one method to reduce the frequency of peritoneal contamination.

Practical peritoneal dialysis--the Tenckhoff catheter in acute renal failure

The problem of acquiring secure peritoneal access encompasses most of the history of peritoneal dialysis. We review the catheters available for children and describe a simple method of insertion of Tenckhoff catheters for acute dialysis. Two series of Tenckhoff catheters inserted in this way are presented and compared with results obtained with trocar- and guidewire-inserted catheters. Tenckhoff catheters inserted as described allow significantly longer periods of dialysis (P < 0.02) with significantly fewer problem episodes (P < 0.001). We conclude that the use of the Tenckhoff catheter for acute dialysis, when inserted in the way described, confers significant advantages over other catheters and permits secure peritoneal access.

Emergencies in continuous dialysis patients: diagnosis and management

The number of patients undergoing long-term hemodialysis and peritoneal dialysis is growing in the United States. To provide adequate emergent care to these patients emergency physicians must understand the alterations in normal physiologies present in these patients and how this may affect care. Cardiovascular disease and infection (especially Staphylococcus aureus sepsis) are the leading causes of death among dialysis patients. These patients are also subject to a significantly higher incidence of life-threatening electrolyte disturbances, particularly hyperkalemia and hypercalcemia, than the general population. Suicide, cardiac tamponade, intracranial hemorrhage, bleeding disorders, and bowel infarction are also much more frequent. The inability of dialysis patients to excrete drugs, metabolites, toxins, and fluids significantly alters their responses to common emergencies and should directly influence their care. Failure to recognize these differences in physiology may result in the use of standard forms of emergency therapy that may compound, rather than treat, the underlying disorder. Although most dialysis patients who come into an emergency department have conditions that can, and should, be managed by their nephrologist, the presence of a life threatening emergency requires prompt, appropriate therapy by the emergency physician.

Comparison of temporary and permanent catheters for acute peritoneal dialysis

The records of 64 children who underwent acute peritoneal dialysis in the Hospital for Sick Children, Toronto, between 1 January 1982 and 31 December 1985 were reviewed. Rigid Trocath catheters were used in 33 patients and silastic Tenckhoff catheters in 34. The groups were comparable for age, weight, primary disease, duration of dialysis, and outcome. There were no significant differences in the incidences of leakage of dialysate, two way obstruction, bleeding, or peritonitis. Among those who had Trocath catheters there were significantly more episodes of outflow obstruction, and significantly more patients required two or more catheter insertions (12 of 33 compared with one of 34 among those who had Tenckhoff catheters). Furthermore, more catheters were removed because of complications (19 of 33 compared with five of 34 respectively). One patient who had a Tenckhoff catheter died of peritonitis directly related to insertion of the catheter. Overall, the Tenckhoff catheter was associated with fewer complications and is recommended for most patients.

Laboratory indices of clinical peritonitis: total leukocyte count, microscopy, and microbiologic culture of peritoneal dialysis effluent

Total leukocyte count, microscopy, and conventional bacteriologic culture (10-ml sediment) of dialysis effluent were assessed for their ability to detect peritonitis in patients on peritoneal dialysis. A total of 73 patients were surveyed over a 17-month period. Laboratory findings included an examination of 1,774 dialysate samples and culture results from blood, wounds, indwelling catheters, and other specimens. Of 90 peritonitis events, 72 were culture positive. Gram-stained films were positive in no more than 14% of the dialysates collected during periods of clinical peritonitis. Factors which adversely affected the microscopic or cultural detection of microorganisms in effluent included the concentration of organisms in dialysate, antibiotic therapy, and growth medium used. Seeding of the peritoneum with organisms originating from other sites of infection or colonization was documented, although infrequent, yet bacteremia secondary to peritonitis was not seen. Because of the frequent isolation of microorganisms from dialysates in the absence of clinical peritonitis, culture-positive findings were a poor predictor of peritonitis without other evidence of infection. Detection of peritonitis by total leukocyte count (without a differential count) of dialysate specimens was adversely affected by the overlap in cell counts between dialysates collected either during or in the absence of peritonitis. This was attributed in part to nonspecific increases in dialysate cell count in the absence of peritonitis and was associated with intermittent dialysis and extraperitoneal infection.

[Electroencephalogram before and after hemodialysis, peritoneal dialysis and renal transplantation: study of correlations between background activity and plasma biochemistry]

We report disorganization of background activity in the EEG of 49 patients with chronic renal failure. An electroencephalographic and biochemical study was performed in 20 patients before and after dialysis sessions. We did the same study before and after peritoneal dialysis in 14 patients. We analysed the EEG compared to biochemical blood abnormalities before and after renal transplantation in 15 patients. We observed worsening of the EEG after hemodialysis and peritoneal dialysis and improvement after renal transplantation, suggesting that in our patients the abnormalities in EEG caused by chronic renal failure were reversible. From our results, we found it difficult to establish correlations between the EEG and the biochemical blood abnormalities. However, there is statistical correlation between hypernatremia, improvement of metabolic acidosis, increase of the ratio of zinc to copper and worsening of the background activity in EEG.

Intermittent peritoneal dialysis. Review of three years' experience

A study has been made of 61 periods of peritoneal dialysis (PD), in 58 patients, Each period lasted 24–36 hours (mean 27.6 hours), using 18–40 litres (mean 27.31) of dialysis fluid per period. Due to technical faults PD was unsuccesful in 5 instances. In the remaining 56 periods of PD mean reduction of blood urea and serum potassium per period were 19.85 mmol/1 and 1.96 mEq/1 respectively. Clinical improvement was observed in 60.6% of patients. Of 11 patients with pulmonary oedema, 9 improved; and one patient with gross generalized oedema responded. Among 17 patients who died in hospital, only one death could be directly attributed to PD. Peritonitis was not encountered following PD. Dialysis for a period not exceeding 36 hours is adequate to avert life-threatening complications of renal failure in most patients. This “short-period” PD will be advantageous in developing countries with limited facilities.

An oesophageal thermal tube for rewarming in hypothermia

Five dogs were cooled externally with ice-bags to rectal temperatures of 21.8-24.8 degrees C. Rewarming was performed with a specially constructed double-lumen oesophageal tube with circulating water at 42 degrees C. With this device, rewarming of the dogs to 30 degrees C took place in 60-102 min (mean 82 min). Up to a temperature of 31 degrees C (the "cardiac safety temperature"), the rise in blood temperature was 4.5 degrees C/h +/- 0.79 (s.d.). Calculation of a "rewarming efficiency index" showed an inverse relationship between surface area and temperature rise per hour. The efficiency of this rewarming method is comparable to that of peritoneal dialysis. No after-drop in temperature was observed and there were no other complications during these experiments. Rewarming with an oesophageal thermal tube is very simple and safe to use.

Peritoneal dialysis. Current status

Peritoneal dialysis has a definite role in the treatment of acute or chronic renal failure and certain fluid and electrolyte disturbances. Its major advantages are simplicity and availability. On the other hand, it is less effective and causes more patient discomfort than hemodialysis. Many factors enter into the decision to use one method of dialysis or the other, and the two should be considered complementary. The numerous complications that may occur during peritoneal dialysis can be avoided by careful attention to technical details. With the recent development of indwelling catheters and automatic cycling devices, long-term peritoneal dialysis is being used increasingly and successfully in the home, particularly in patients for whom home hemodialysis is difficult or inappropriate.