Anticoagulation rebound after hemodialysis

Characteristics of software used in self-management of vitamin K antagonist therapy: A systematic review

INTRODUCTION AND GOAL

Currently, 1-2% of the population in developed countries are under treatment with oral anticoagulants. An appropriate strategy to deal with this increase in demand of treatment with oral anticoagulants and to manage the costs is the transfer of part or all of the responsibility for managing treatment to the patients. The use of information technology, particularly electronic health software, can be an appropriate method to improve the quality of self-management of treatment with these drugs. Therefore, this systematic review investigated studies that discuss the characteristics of electronic health software in self-management of oral anticoagulation therapy.

METHOD

A systematic review based on PRISMA protocol was conducted. In this study, articles were investigated that were in English. Articles existing in Cochrane, EMBASE and PubMed databases were searched up to 14 May 2017. Then, articles searched through Google Scholar were added to this study.

FINDINGS

The common characteristics used in most software included 'encryption in exchanging information', having an 'instruction module' and 'being Android-based'. In terms of functionality, 'communication between the patient and healthcare team' existed in most of the software.

CONCLUSION

The results of the study showed that the accuracy of administration of the dose of the drug using computer to reach a target international normalized ratio level was not less than those administered with experienced medical staff. In addition, the results indicated that important characteristics of the software include encryption in exchanging information, instruction module and Android-based instruction module. The most important characteristic was the interaction between the patient and the healthcare team.

Hemodialysis without Anticoagulants in Patients with High Bleeding Risk

Twenty hemodialysis were performed in six uremic patients with high bleeding risk, with a technique avoiding any anticoagulant drug before or during the treatment.

The treatment was well tolerated in all patients and no alterations were observed in the intrinsic clotting system evaluated before, during and after hemodialysis.

During the study, devices were never lost because of clotting or rupture, and their performances were similar to those obtained on heparin hemodialysis.

We suggest that in critically ill patients, needing dialysis, hemodialysis without heparin is possible and safe.

Continuous Renal Replacement Therapy (CRRT) in the Intensive Care Unit

This review is specifically designed to address the topic of CRRT based on the needs and interests of intensivists. Some of the materials, concepts, and formulas presented in this review have been drawn from a previous chapter authored by myself and intended for individuals whose primary interest is specifically dialysis[1]. Since this previous chapter was authored in 1994, similar material presented in this review has been updated in order to present the most current information.

How sick are dialysis patients undergoing cholecystectomy? Analysis of 92,672 patients from the American College of Surgeons National Surgical Quality Improvement Program database

BACKGROUND

Although cholecystectomy is one of the most common surgical procedures performed in the United States, there is an absence of data on the risks of cholecystectomy in dialysis patients. Our objective was to analyze the outcomes of cholecystectomy in dialysis patients.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program database, we selected all patients who underwent cholecystectomy from 2005 to 2010. Univariate analysis was performed and logistic and linear regression models were used to obtain risk-adjusted outcomes. The main outcomes were morbidity, mortality, and length of stay.

RESULTS

Dialysis was associated with a higher risk of 30-day postoperative morbidity (16.1% vs 3.8%, adjusted odds ratio 1.91, 95% confidence interval 1.18 to 3.10), but not mortality. The average length of stay following any cholecystectomy was 4.1 days longer for dialysis patients (5.5 vs 1.4 days, P < .0001).

CONCLUSION

Patients on dialysis who undergo cholecystectomy are at a higher risk for postoperative morbidity, but not mortality.

Use and safety of unfractionated heparin for anticoagulation during maintenance hemodialysis

Anticoagulation is essential to hemodialysis, and unfractionated heparin (UFH) is the most commonly used anticoagulant in the United States. However, there is no universally accepted standard for its administration in long-term hemodialysis. Dosage schedules vary and include weight-based protocols and low-dose protocols for those at high risk of bleeding, as well as regional anticoagulation with heparin and heparin-coated dialyzers. Adjustments are based largely on clinical signs of under- and overanticoagulation. Risks of UFH use include bleeding, heparin-induced thrombocytopenia, hypertriglyceridemia, anaphylaxis, and possibly bone mineral disease, hyperkalemia, and catheter-associated sepsis. Alternative anticoagulants include low-molecular-weight heparin, direct thrombin inhibitors, heparinoids, and citrate. Anticoagulant-free hemodialysis and peritoneal dialysis also are potential substitutes. However, some of these alternative treatments are not as available as or are more costly than UFH, are dependent on country and health care system, and present dosing challenges. When properly monitored, UFH is a relatively safe and economical choice for anticoagulation in long-term hemodialysis for most patients.

An Official ATS/ERS/ESICM/SCCM/SRLF Statement: Prevention and Management of Acute Renal Failure in the ICU Patient: an international consensus conference in intensive care medicine

OBJECTIVES

To address the issues of Prevention and Management of Acute Renal Failure in the ICU Patient, using the format of an International Consensus Conference.

METHODS AND QUESTIONS

Five main questions formulated by scientific advisors were addressed by experts during a 2-day symposium and a Jury summarized the available evidence: (1) Identification and definition of acute kidney insufficiency (AKI), this terminology being selected by the Jury; (2) Prevention of AKI during routine ICU Care; (3) Prevention in specific diseases, including liver failure, lung Injury, cardiac surgery, tumor lysis syndrome, rhabdomyolysis and elevated intraabdominal pressure; (4) Management of AKI, including nutrition, anticoagulation, and dialysate composition; (5) Impact of renal replacement therapy on mortality and recovery.

RESULTS AND CONCLUSIONS

The Jury recommended the use of newly described definitions. AKI significantly contributes to the morbidity and mortality of critically ill patients, and adequate volume repletion is of major importance for its prevention, though correction of fluid deficit will not always prevent renal failure. Fluid resuscitation with crystalloids is effective and safe, and hyperoncotic solutions are not recommended because of their renal risk. Renal replacement therapy is a life-sustaining intervention that can provide a bridge to renal recovery; no method has proven to be superior, but careful management is essential for improving outcome.

Regional anticoagulation and antiaggregation for CVVH in critically ill patients: a prospective, randomized, controlled pilot study

BACKGROUND

The aim of this study is to assess the efficacy and clinical safety of regional anticoagulation (heparin pre-filter plus post-filter protamine) plus antiaggregation (pre-filter prostacyclin) [Group 1 (G1)] vs. only systemic heparin anticoagulation without antiaggregation [Group 2 (G2)] in critically ill patients with acute renal failure undergoing continuous veno-venous haemofiltration (CVVH).

METHODS

One hundred and ten patients were randomized in a prospective, controlled pilot study. G1 patients received 1000 U/h pre-filter heparin, 10 mg/h post-filter protamine sulphate and 4 ng/kg/min pre-filter prostacyclin, while G2 patients received 1000 U/h pre-filter heparin. The haemofilter transmembrane pressure (TMP) and lifespan, as well as the platelet count were observed 1 h before, and at 6, 12, 18, 24 and 36 h from the beginning of CVVH.

RESULTS

Haemofilter TMP remained unchanged in G1 while it increased up to three times in G2 (P=0.0002). The median filter lifespan was 68 h in G1 and 19 h in G2. The rate of spontaneous circuit failure was 24% in G1 and 93% in G2 (P=0.0001). The platelet count was stable over the treatment period in G1 while in G2 it decreased progressively (P=0.0073).

CONCLUSION

In critically ill patients suffering from acute renal failure, regional anticoagulation with pre-filter heparin and post-filter protamine plus antiaggregation during CVVH is a simple and safe procedure that prevents increases in filter TMP and increases circuit life time compared with systemic anticoagulation with pre-filter heparin only.

Anticoagulant-free Genius® haemodialysis using low molecular weight heparin-coated circuits

BACKGROUND

Regional citrate anticoagulation or saline flushes are often used in haemodialysis patients at high risk of bleeding. In an alternative approach we evaluated the effects of covalent circuit coating with low molecular weight heparin (LMWH) for intermittent haemodialysis.

METHODS

In vitro, we compared the thrombogenicity of an uncoated polyvinylchloride (PVC) tubing set with LMWH-coated tubing (AOThel) and a reference tubing with end-point attached heparin coating (Carmeda Bioactive surface) under dynamic blood contact. In vivo, five chronic haemodialysis patients were studied using the Genius dialysis system and F60S filters. Each patient underwent three dialysis sessions separated by a standard haemodialysis each: (1) standard dialysis (uncoated circuit and regular dalteparin dosage), (2) dialysis with LMWH-coated circuit and regular dalteparin dosage and (3) dialysis with a completely LMWH-coated circuit without anticoagulant use.

RESULTS

In vitro, both coated tubings showed significantly reduced thrombin-antithrombin (TAT) complex levels compared with PVC. The reference coating (Carmeda) released substantial antifactor Xa (antiXa) activity into the plasma. The LMWH coating (AOThel) released low antiXa activity only during the initial rinsing. In vivo, all dialysis sessions were well tolerated and completed without major clotting. Antithrombin levels and platelet counts were similar in all groups. P-selectin and D-dimer levels increased similarly in all groups. TAT levels were comparable in all groups during the first 3 h and significantly increased in the anticoagulant-free group after the fourth hour.

CONCLUSIONS

LMWH surface coating reduces thrombogenicity in vitro without releasing significant amounts of heparin from the surface. In vivo, anticoagulant-free haemodialysis using a completely LMWH-coated circuit is feasible and safe in stable chronic dialysis patients with normal coagulation.

Intermittent saline flushes during haemodialysis do not alleviate coagulation and clot formation in stable patients receiving reduced doses of dalteparin

BACKGROUND

Heparin-free haemodialysis (HD) with intermittent saline flushes (ISF) in patients with bleeding risk is widely used. The aim of this study was to investigate if ISF reduce coagulation and clotting in stable patients receiving reduced doses of dalteparin.

METHODS

Inclusion criteria were stable chronic HD patients >or=18 years of age and haemoglobin >or=11 g/dl. Exclusion criteria were use of warfarin and acetylsalicylic acid. Six HD sessions were evaluated per patient. Dalteparin was given as one bolus dose at start of HD (50% of the conventional dose). In HD number 1, 3 and 5, 100 ml saline solution was flushed through the filter each 30 min. In HD 2, 4 and 6, no ISF were given. Potential clotting in the bubble trap was visually observed each hour and graded on a 4-point scale: 1 = normal, 2 = fibrinous ring, 3 = clot formation and 4 = coagulated system. The dialyser was visually inspected at the end of each session: 1 = normal, 2 = a few blood stripes (affecting less than 5% of the surface fibres), 3 = many blood stripes (more than 5% of the fibres) and 4 = coagulated filter. The coagulation marker PF1+2, the platelet activation marker beta-TG and anti-FXa activity were repeatedly measured during HD.

RESULTS

Six men and two women were included. In four cases (four different patients), HD was stopped due to a coagulated system, all cases on days with ISF performed. Multiple linear regression analyses with repeated measurements showed that ISF adjusted for dalteparin dose/kg significantly increased mean clot in the bubble trap, estimate (B) = 0.717, P = 0.0001 and also showed that ISF increased PF1+2, B = 0.16, P = 0.001 when adjusted for anti-FXa activity and hours of dialysis, whereas beta-TG was only borderline increased, B = 0.09, P = 0.055.

CONCLUSIONS

ISF during HD does not alleviate visible clotting or intravascular coagulation activity in stable patients receiving reduced doses of dalteparin and polysulphone dialysers. Whether this applies to unstable patients with increased bleeding risk not receiving any anticoagulation remains to be shown.

Uremic bleeding: pathogenesis and therapy

BACKGROUND

We reviewed current understanding of the pathophysiology of the uremic bleeding diathesis and discuss accepted therapeutic interventions that minimize the risk of bleeding in the uremic patient.

METHODS

Computerized literature searches and references from previous publications, including articles describing original research and reviews pertaining to the pathophysiology of and clinical approach to uremic bleeding.

RESULTS

The most common hemorrhagic manifestations in uremia are prolonged bleeding from puncture sites; nasal, gastrointestinal and genitourinary bleeding; and subdural hematomas. The most useful clinical laboratory test to assess both bleeding risk and response to therapy is bleeding time. It correlates better with clinical bleeding complications than indices of azotemia (eg, blood urea nitrogen [BUN], creatinine) or in vitro platelet aggregation tests. A low hematocrit is also correlated with increased bleeding risk. Anemia plays an important role in the bleeding diathesis of uremia and its correction with red cell transfusions or human recombinant erythropoietin is critical. Anticoagulation during hemodialysis may transiently exacerbate the bleeding diathesis. Hemodialysis and peritoneal dialysis improve the hemostatic defect and renal transplantation totally corrects it. Cryoprecipitate has been largely replaced by desmopressin acetate, which acts promptly (in less than 1 hour) but has a short duration of action (hours) and exhibits tachyphylaxis. Conjugated estrogens are slower in the onset of action (about 6 hours) but their effect lasts for about 2 weeks.

CONCLUSIONS

The pathophysiology of the bleeding diathesis of uremia is complex and incompletely understood but useful clinical tests and therapies have evolved empirically. Broadly available dialysis and the advent of erythropoietin are likely to reduce the magnitude of this problem.

Acute continuous hemodiafiltration: a prospective study of 110 patients and a review of the literature

One hundred ten critically ill patients with acute renal failure receiving acute continuous hemodiafiltration (ACHD) in our intensive care unit were studied prospectively. Acute continuous hemodiafiltration consisted either of continuous arteriovenous hemodiafiltration or of continuous veno-venous hemodiafiltration, and was used for 17,817 hours (mean duration of patient treatment, 161.9 hours), resulting in a fall from a mean pre-ACHD urea of 35.7 mmol/L to a plateau value of 16.8 mmol/L at 72 hours of treatment. The mean urea clearance achieved was 24.9 mL/min. Eighty of these patients (72.7%) were receiving artificial ventilation at the time of ACHD and 45 (40.9%) had more than four failing organs. The mean APACHE II score was 27.7. Despite the degree of illness severity, 42 patients (32.2%) survived to discharge from hospital. The use of ACHD was associated with hemodynamic stability, rapid normalization of electrolytes, and the ability to freely administer drugs, blood, and/or blood products. It also allowed for maintenance of an aggressive, nitrogen-rich, nutritional regimen. Support of these critically ill patients with acute renal failure using ACHD was achieved safely and without the employment of additional dialysis-trained nursing staff. Our own experience and a review of the available literature strongly suggest that the advantages associated with the use of ACHD therapies are clinically significant and support the view that ACHD is a modality of renal replacement most suited to critically ill patients with acute renal failure.

Critical care in uraemic children

The special problems posed by renal disease have to be considered when a uraemic child requires intensive care. This report gives an overview on the problems of dialysis treatment, circulatory support, infectious complications, coagulation disorders and increased intracranial pressure.

Biocompatibility issues in hemodialysis

Hemodialysis, as a life-saving treatment modality for uremic patients, implies a repeated and compulsory contact of blood with foreign materials. As a consequence, biocompatibility problems are unavoidable. The same applies for the material used for the creation of vascular access, and for the alternative dialysis method, CAPD (continuous ambulatory peritoneal dialysis), although each system might cause its own and specific problems. Although in early dialysis the focus has been on maintenance of life and elimination of toxins, later on the important morbid implications of this lack of biocompatibility have been recognized. Eight major problems will be discussed, especially in the perspective of recent new findings in this field: (1) coagulation and clotting; (2) complement and leukocyte activation; (3) susceptibility to infection; (4) leaching or spallation; (5) surface alterations of solid materials; (6) allergic reactions; (7) shear; (8) transfer of compounds from contaminated dialysate. After description of the major biochemical and clinical implications of these problems, ways to prevent morbid events and future perspectives will be described.

Low-dose and heparin-free hemodialysis in children

Successful heparin-free hemodialysis has been reported in adults but not in children. A preliminary study was carried out to determine whether heparin-free hemodialysis was possible in children who were considered to have a high risk of bleeding, and if so, to identify the children in whom this technique might be expected to succeed. Of 28 heparin-free procedures, 21 (75%) were successful, a major clot developed in 4, and a minor clot occurred in 3. These children were 6.76 +/- 4.57 years old and weighed 20.7 +/- 11.3 kg. An activated clotting time (ACT) of less than 170 s was recorded in five of the six patients in whom clotting was observed (normal value 146 s with a range of 110-180 s). In a second prospective study, low-dose heparin was prescribed for patients with an ACT of less than 170 s, while the remaining children again underwent heparin-free dialysis. In this study only those patients with double-lumen vascular access and a predialysis systolic blood pressure greater than 80 mmHg were included. Their mean age was 12.25 +/- 4.61 years and their weights 32.9 +/- 19.3 Kg. In 28 of 31 (90%) procedures, no clotting was observed. Minor clotting developed during the remaining 3 procedures, all in one child who weighed 8.5 kg (the only child weighing less than 10 kg). Heparin (9.6 +/- 3.2 IU/kg body weight per hour) was administered during 18 successful procedures. This study shows that heparin-free hemodialysis is possible in children, particularly, but not exclusively, those with a coagulopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety of regional citrate hemodialysis in acute renal failure

Regional citrate anticoagulation is an alternative to heparin anticoagulation for hemodialysis of patients at increased risk of bleeding. We report the successful use of this technique in 326 dialyses in 49 high bleeding risk patients with acute renal failure. Systemic anticoagulation did not occur as a result of any dialysis procedure, and in no instance was bleeding observed. Dialysis was effective, as judged by removal of creatinine. The safety of this procedure is demonstrated by the lack of bleeding complications and the small incidence of electrolyte and acid-base abnormalities. In addition we document the absence of citrate intoxication by serial measurements of serum citrate levels. Regional citrate anticoagulation is a safe and effective method of performing hemodialysis in patients with acute renal failure at increased risk of bleeding.

Epoprostenol (PGI2, prostacyclin) during high-risk hemodialysis: preventing further bleeding complications

The frequency of hemodialysis-associated hemorrhage was studied prospectively in two successive, parallel, heparin-controlled studies using epoprostenol (PGI2; average dose, 4.1 ng/kg.min) as the sole antithrombotic agent. Sixty-three patients with active or recently active bleeding underwent 163 hemodialysis treatments in each of which prospective bleeding risk was assessed. PGI2 was associated with up to 50% overall reduction in the frequency of bleeding, particularly in the highest risk circumstances. PGI2 also allowed successful completion of the full, prospectively prescribed hemodialysis time in the most treatments (82% versus 93% with heparin). Furthermore, the efficiency of hemodialysis using PGI2, as indicated by the reduction in concentration of blood urea nitrogen and serum creatinine, was equal to that using heparin, even though there was a tendency toward modest reduction in residual volume of the hollow fiber dialyzer and slightly more frequent early termination of treatment from dialyzer clotting with PGI2. No severe vasodilatory side effects of PGI2 were observed during these studies. Hypotension was equally frequent during hemodialysis with heparin as with PGI2. The current results suggest that PGI2 should be considered as a substitute for heparin during high-risk hemodialysis because PGI2 may reduce the incidence of dialysis-associated bleeding without severe adverse side effects.

Hemodialysis without anticoagulation. One-year prospective trial in hospitalized patients at risk for bleeding

This prospective study evaluated a protocol for hemodialysis without anticoagulation in a diverse group of hospitalized patients in unstable condition with relative contraindications to anticoagulation. Of 262 attempts at hemodialysis without anticoagulation in 49 patients, 239 hemodialysis treatments (91 percent) were successfully completed. Approximately 7 percent of the attempts required conversion to a low-dose heparin regimen because of clotting in the extracorporeal dialysis circuit. Fewer than 2 percent of the dialysis treatments resulted in clotting in the extracorporeal circuit sufficient to interrupt hemodialysis. Partial thromboplastin times and activated clotting times did not change during these hemodialysis treatments. Solute clearance, ultrafiltration rate, and decrements in arterial oxygen concentration and platelet count were not different from those in patients who underwent hemodialysis with anticoagulation. There were no episodes of accelerated bleeding associated with this dialysis method. This study indicates that hemodialysis without anticoagulation can be reliable and effective in closely monitored situations.

Reducing the hemorrhagic complications of hemodialysis: a controlled comparison of low-dose heparin and citrate anticoagulation

We report a randomized prospective study comparing the results of anticoagulation using hypertonic trisodium citrate and low-dose controlled heparin during 45 hemodialysis treatments performed on patients determined to be at high or very high risk for bleeding. Dialysis-associated bleeding was more frequent following low-dose controlled heparin anticoagulation than during hypertonic citrate therapy (P less than .05). Dialysis effectiveness measured by postdialysis chemistries and weight loss was equivalent in the two groups.

Anaesthesiological complications in renal transplantation: a retrospective study of 500 transplantations

This retrospective study consisted of 500 consecutive renal transplantations performed between September 1977 and September 1981. Preoperatively, congestive heart failure was registered in 262 cases (53.0%) and blood pressure disease in 352 cases (71.3%). The total number of patients with ischaemic heart disease was 22 (4.5%). General anaesthesia was given in 493 and regional anaesthesia in seven cases. In general anaesthesias, tubocurarine was the main relaxant and halothane the main inhalation agent used. Major complications during anaesthesia were blood pressure changes with a higher incidence of hypotension (49.6%) than hypertension (26.8%). Severe cardiac arrhythmias were rare and no intraoperative deaths occurred. One patient was successfully resuscitated in the ICU postoperatively, this being possibly related to hypoventilation caused by prolonged muscular relaxation. Other rare complications included one pneumothorax, one haemo- and hydrothorax, and two large haematomas all caused by preoperative central venous cannulation. In 69 cases (14.0%) additional neostigmine doses and in 34 cases (6.9%) naloxone was given at the end of anaesthesia. Pneumonia during the first postoperative week was recorded in 11 cases (2.2%), and occurred only in patients who received general anaesthesia. One of the three patients who died during the first week developed pneumonia postoperatively.

Hemodialysis without anticoagulation

Heparin is usually employed as an anticoagulant during routine hemodialysis. In patients at high risk of bleeding, however, use of heparin significantly increases their morbidity and, presumably, mortality. Over 1 year, we performed 156 hemodialysis procedures successfully without heparin in the transplant dialysis unit. Twenty-eight patients were included in the study; 23 patients had received renal transplants and five patients were in the mouth dental extraction, and parathyroidectomy). Only one of these patients had a coagulopathy. No dialysis procedure produced or aggravated bleeding. Conversely, a coagulopathy was not induced or worsened by dialysis without heparin. A significant complication, defined as complete clotting of the artificial kidney with or without clotting in the lines, occurred in eight dialyses (5.13% of the total) and resulted in an average blood loss of 150 ml. Partial clotting of the dialyzer did not interrupt the procedure and occurred nine times (5.8% of the total). These results compare favorably with previously documented complications from low-dose and regional heparin.

Hemodialysis using prostacyclin instead of heparin as the sole antithrombotic agent

Anticoagulation during hemodialysis is necessary to prevent clotting of the blood on contact with the dialysis membrane. Heparin is the usual anticoagulant used, but systemic anticoagulation may persist for hours, and hemorrhage is common. We successfully used an infusion of prostacyclin, which has an in vitro half-life of three to five minutes, as the sole anticoagulant in 10 patients on long-term hemodialysis and in one patient undergoing dialysis for acute renal failure (this patient bled severely on three occasions when heparin was used). Prostacyclin was infused intravenously for 10 minutes before dialysis and into the arterial line of the dialyzer during dialysis. We adjusted the rate of infusion into the dialyzer to prevent prostacyclin-induced hypotension. Each patient completed 240 minutes of dialysis and received a total of 423 +/- 91 ng of prostacyclin per kilogram of body weight (mean +/- S.E.M.; range, 56 to 780). Prostacyclin caused no clinically important changes in the intrinsic clotting system, and there were no hemorrhages or clotting of the coil. We conclude that prostacyclin can safely replace heparin as the sole antithrombotic agent during hemodialysis and may be more advantageous if anticoagulation is contraindicated.

Preventing hemorrhage in high-risk hemodialysis: regional versus low-dose heparin

Hemodialysis in patients with increased risk for hemorrhage can be accomplished with either a regional or a low, total dose of heparin. In a prospective study of 69 series of dialyses performed on an alternating schedule of heparinization for each patient, bleeding complications during and immediately following dialysis occurred in 23 of 122 dialyses (19%) with regional heparin compared to 13 of 133 dialyses (10%) with low-dose heparin (P less than 0.05). The incidence of hemorrhage correlated with the estimated degree of bleeding risk both at expected and at occult bleeding sites, and was the same or higher with regional heparin in all categories. Hemorrhage was not correlated with preexisting coagulation abnormalities, concurrent anticoagulant drugs, level of azotemia, or ability to successfully limit systemic heparinization during dialysis. The incidence of partial clotting of the dialyzer was 3 to 5% with both heparin protocols. We conclude that regional heparinization has no clinical or practical advantage over low-total-dose heparin in preventing bleeding associated with hemodialysis.

Wound infections in renal transplant wounds: pathogenetic and prognostic factors

The factors contributing to transplant wound infection, as well as those determining its outcome, have been reviewed in 27 transplant patients with wound infection. Unrelated cadaver kidneys, diabetes, urinary fistulas and wound hematomas are all factors predisposing to wound infection. Overall incidence of wound infection in this series was 6.1% (27/439). When infections secondary to known preventable causes (i.e. hematomas and fistulas) were excluded, the incidence of wound infection was only 1.6%. Furthermore, if diabetics and retransplanted patients were excluded, the incidence of wound infection in non-diabetic patients who had their first transplant was only 0.7%. Perinephric infections are much more serious and carry a worse prognosis than superficial infections. Overall mortality of wound infections was 40% (8/27), most deaths being caused by sepsis from deep infection. Only three patients (11%) healed their wounds and saved their kidneys, whereas the rest of the survivors (15/18) healed their wounds but lost their kidneys. It is emphasized that prevention of hematomas and urinary fistulas is the most important measure in the prevention of transplant wound infection.

General surgery in patients on maintenance hemodialysis

A review of the experience with 66 patients on chronic hemodialysis who underwent 67 major surgical procedures is presented. There were 58 general surgical procedures, and nine major cardiovascular procedures including four emergency cardiac valve replacements. The preoperative, intraoperative and postoperative management of these patients is discussed as well as the morbidity and mortality encountered. It is concluded that patients on well-managed chronic dialysis will tolerate minor and major surgery well and renal failure should no longer be regarded as a relative contraindication for appropriate elective or emergency surgery.