Clinical considerations in hemodialysis access infection

Surgical Management of Thoracolumbar Spondylodiscitis in End-Stage Renal Disease

BACKGROUND

In recent times due to the advancement of haemodialysis techniques, there is increase in the life span of the patients with end-stage renal disease, which tends to increase the risk of complications of bacteraemia due to skin penetration for blood access and leading to propensity for more skeletal and spinal complications. Hence, early diagnosis of spine infection and early initiation of appropriate therapy are important in ensuring successful treatment and preventing further morbidity.

MATERIALS AND METHODS

The study included 22 males and 12 females who were known case of end-stage renal disease undergoing haemodialysis therapy and diagnosed with spondylodiscitis based on the clinical and radiological signs. The included patients required surgical stabilization based on the instability, neurological status, and epidural abscess, and non-responsive to medical line of treatment. To measure the degree of pain, Visual Analog Scale was used and British Medical Research Council grading system was used for motor evaluation. Radiography was undertaken one immediately and later at 1, 3, 9, and 12 months and at yearly interval thereafter. Fusion assessment was done by features of consolidation of graft and absence of loosening of implants in both anteroposterior and lateral views will be an indirect evidence of fusion in short-term follow-up.

RESULT

Average age of the patients was 62 years (range 40-75 years). Twenty-two patients were male (64.7%) and twelve (35.3%) were female. Sixteen patients had diabetes mellitus and fifteen patients had chronic glomerulonephritis with various underlying causes. All patients presented with back pain with a duration range from 3 to 8 weeks. 13 patients gave a history of on/off fever which was mild grade and 3 patients with high-grade fever. Eighteen patients presented with neurological deficits. The most common organism isolated was Methicillin-Resistant Staphylococcus Aureus (MRSA). At the final follow-up, radiographs revealed a good interbody fusion in 30 of the 34 cases, with 3 cases showed delayed fusion. The mean hemoglobin (Hb) level was 8.8 g/dl and elevated total leucocyte level with mean of 14,425; mean C-reactive protein (CRP) level was 55.6 mg/dl and erythrocyte sedimentation rate (ESR) was 47.5. All patients showed improvement in back pain. Preoperatively, the VAS had a mean of 8.5; post-operatively on day 2, the mean VAS was 3.2, and on 1 month follow-up mean VAS was 2.4.

CONCLUSION

In end-stage renal disease patients presenting with back pain, the diagnosis and treatment of spondylodiscitis becomes difficult. Where fever may not be a presenting feature even in cases with severe destructive osteomyelitis, and at times presenting as latent infection. Hence, spinal infection should be suspected as a possible cause of back pain in patients presenting with ESRD, even if they are presenting without fever and MRI study should be performed for the early diagnosis. Surgical intervention with debridement and posterior instrumentation should be considered as a modality of treatment in all cases of spondylodiscitis, with improved clinical outcome in terms of functionality, disability, and rehabilitation and acceptable complication rates in the perioperative period which can be adjusted to the individual cases.

Hemodialysis-Associated Infections

Hemodialysis patients are at increased risk of infections, which are common adverse events among this patient population. We review factors contributing to infections among hemodialysis patients and epidemiology of common infections and outbreaks, including bloodstream infections, vascular access infections, and infections caused by bloodborne pathogens. Recommendations for prevention are discussed with emphasis on essential infection control practices for hemodialysis settings.

Surgical treatment of infectious spondylitis in patients undergoing hemodialysis therapy

Treatment of infectious spondylitis in hemodialysis patients remains a challenge because of comorbidities. This study aimed to evaluate the impact of end-stage renal disease (ESRD) on the clinical manifestations and surgical outcomes of patients with spinal infection. Sixteen patients who underwent surgical intervention were included. There were 3 thoracic and 13 lumbar lesions. All patients presented with intractable back pain at the start of treatment. Six patients had a fever, nine had inflammation at the hemodialysis access site, and six of them had concomitant bacteremia. Ten patients had an elevated leukocyte count. Serological tests indicated an elevation of the C-reactive protein and erythrocyte sedimentation rate level in all patients. Five patients had a neurological compromise. Postoperative complications included two mortalities, two iliac bone graft and implant dislodgement, and one retroperitoneal wound dehiscence. The preoperative mean visual analog scale score was 7.7 (range, 6-9), which improved to 3.4 (range, 2-5) at the final follow-up for 14 surviving patients. Neurological improvement was obtained by at least one grade in four Frankel C category patients. The radiographs revealed a good bony fusion in 12 cases although with a variable bone graft subsidence. In conclusion, early diagnosis of infectious spondylitis is difficult due to latent symptoms. A spine infection should be suspected in hemodialysis patients with severe back pain, even when they are afebrile. Surgical intervention for infectious spondylitis in ESRD patients undergoing hemodialysis can be performed with acceptable outcomes; however, the complication and mortality rates are relative high.

Vascular access for hemodialysis

Establishing and maintaining adequate vascular access is essential to providing an appropriate dialysis dose in patients with end-stage renal disease. Complications related to vascular access have a significant role in dialysis-related morbidity and mortality. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) clinical practice guideline for dialysis access was last updated in 2000 and provides a framework for the optimal establishment and maintenance of dialysis access, and treatment of complications related to dialysis access. This paper reviews the 2000 K/DOQI dialysis access guideline as well as updated information published subsequently.

Management of hemodialysis access infections

Management of hemodialysis (HD) access infection is one of the most challenging and most common problems faced by surgeons, interventional radiologists, and nephrologists. The goal to eradicate infection is often at odds with the need to maintain access. Patients on HD are immunocompromised and typically have significant comorbid conditions placing them at high risk for the occurrence of access infection. Infection is most common with central-vein catheter access, followed by prosthetic arteriovenous grafts (AVG) and is rare with autogenous fistulas. The diagnosis is usually evident on physical exam, but it is not uncommon for these patients to present with atypical symptoms and lack of clinical findings. Although Staphylococcal species are the most common organism to cause infection, early empiric antimicrobial therapy should also include coverage for Gram-negative organisms. Management of central-vein catheter infection includes removal and delayed replacement or, in patients with mild clinical symptoms, catheter exchange over a guide wire. Our management of AVG infection includes total graft excision when patients present with sepsis or the entire graft is bathed in pus, subtotal graft excision when all of the graft is removed except a small oversewn cuff of prosthetic material on an underlying patent artery, and partial graft excision when only a limited infected portion of the graft is removed and a new graft is rerouted in adjacent sterile tissue to maintain patency of the original graft. This strategy has proven to be highly successful in the management of these complicated cases.

Improving dialysis access management

Renal replacement therapy requires either placement of a functional hemodialysis vascular access or peritoneal dialysis catheter. Early provision of a dialysis access improves patient care with reduction in morbidity and reduces the economic burden incurred as a result of delayed access placement. Vascular access dysfunctions (thrombosis and infection) pose the greatest burden on the end-stage renal disease population. This article reviews the current literature on the planning of dialysis access, with particular emphasis on issues pertaining to vascular access. Current concepts to maximize access patency and efficiently manage vascular access complications are highlighted.

Serum markers of periodontal disease status and inflammation in hemodialysis patients

BACKGROUND

Hemodialysis (HD) patients face a 25% annual mortality rate, with 50% of reported deaths attributed to cardiovascular disease. All-cause and cardiovascular mortality correlate with such acute-phase proteins as C-reactive protein (CRP). Hepatic CRP synthesis is upregulated by inflammation; however, elevated CRP values frequently are found in the absence of apparent infection or inflammation. Because destructive periodontal diseases have been associated with elevated CRP levels, we questioned whether destructive periodontal diseases could contribute to elevated CRP values in HD populations.

METHODS

Sera from 86 consecutive dentate HD patients were assayed for levels of immunoglobulin G (IgG) antibody to six periodontal species by means of an enzyme-linked immunosorbent assay.

RESULTS

CRP values for the subject population ranged from less than 6.9 to 159 mg/L (median, 8.2 mg/L). Univariate comparisons between subjects with or without elevated CRP levels (>10 mg/L) showed that CRP level elevation was associated significantly (P < 0.05) with greater doses of human recombinant erythropoietin and lower levels of hemoglobin, serum iron, transferrin saturation (TSat), albumin averaged over the 3 preceding months, total cholesterol, and triglycerides. Log serum IgG antibody levels to Porphyromonas gingivalis also were significantly greater in the group with elevated CRP levels (P = 0.013). Subsequent multivariate logistic regression showed that log serum antibody levels to P gingivalis remained significant (P = 0.02) after controlling for nonperiodontal sources of elevated CRP, hemoglobin, TSat, and triglyceride values.

CONCLUSION

These results suggest that elevated levels of IgG antibody to bacterial species associated with destructive periodontal diseases are associated with elevated CRP values in HD populations.

Infectious complications of the hemodialysis access

Infectious complications of the vascular access are a major source of morbidity and mortality among hemodialysis (HD) patients. Numerous reports implicate the vascular access in up to 48 to 73% of all bacteremias in HD patients. The incidence of vascular access-related infection is highest when central venous dialysis catheters are employed. Native arteriovenous fistulas carry the lowest risk of infection. Unfortunately, prosthetic arteriovenous grafts, which represent the most common type of HD access in the United States, have been repeatedly shown to be a risk factor for bacteremic and nonbacteremic infections. Silent infection in old nonfunctional clotted prosthetic arteriovenous grafts has recently been recognized as a frequent cause of bacteremia and morbidity among HD patients. High proportions of infections related to the vascular access are caused by staphylococcal organisms, which carry high rates of mortality, recurrence, and metastatic complications. Management of vascular access-related infection has two aspects: The first relates to the choice, duration, and mode of administration of antibiotic therapy. Empiric antibiotic therapy, guided by demographic data and severity of illness, should be employed when the causative organisms are unknown. Prolonged administration of specific parenteral antibiotics is crucial in decreasing complications of infection, especially in cases of staphylococcal bacteremia. The second aspect relates to management of the vascular access. Efforts directed toward bacteriological cure should be concurrent with efforts to preserve native venous access sites whenever possible. Efforts to prevent vascular access-related infection should focus on increasing placement of arteriovenous fistulas and minimizing insertion of central venous dialysis catheters. Careful inspection and monitoring of the vascular access is of paramount importance in early detection of vascular access site-related infections. Several new approaches aimed at preventing catheter and prosthetic graft-related infection are being explored.

Infections associated with uremia and dialysis

Patients with chronic renal failure are predisposed to infections. Infections in end-stage renal disease patients are caused by immunosuppressive effects of uremia. Patients with renal failure on dialysis have impaired host defenses and may develop infections related to vascular access. This article reviews the infectious complications related to chronic renal failure in dialysis.