Outcomes of arteriovenous fistulas and grafts with or without intervention before successful use.

OBJECTIVE: Arteriovenous fistulas (AVFs) are considered superior to arteriovenous grafts (AVGs) because of longer secondary patency after successful cannulation for dialysis. We evaluated whether access interventions before successful cannulation affect the relative longevity of AVFs and AVGs after successful use. METHODS: This retrospective study of a prospective database identified patients who initiated dialysis with a catheter and subsequently had a permanent access (289 AVFs and 310 AVGs) placed between January 1, 2006, and December 31, 2011, and were successfully cannulated for dialysis at a large medical center. Patients were monitored until June 30, 2014, and we evaluated the clinical outcomes (secondary patency and frequency of interventions) of the vascular accesses. RESULTS: An intervention before successful cannulation was required more frequently with AVFs than with AVGs (50.5% vs 17.7%; odds ratio, 4.74; 95% confidence interval [CI], 3.26-6.86; P < .0001). Compared with AVFs that matured without interventions, those that required intervention had shorter secondary patency after successful cannulation (hazard ratio, 1.84; 95% CI, 1.30-2.60; P < .0001) and required more interventions per year after successful use (rate ratio [RR], 1.81; 95% CI, 1.49-2.20; P < .0001). Similarly, AVGs that required intervention before successful cannulation had shorter secondary patency than those without prior intervention (odds ratio, 1.98; 95% CI, 1.52-4.02; P < .0001) and required more interventions per year after successful use (RR, 1.49; 95% CI, 1.27-1.74; P < .0001). AVFs requiring intervention before maturation had inferior secondary patency compared with AVGs that were cannulated without prior intervention (hazard ratio, 1.45; 95% CI, 1.08-2.01; P = .01), but required fewer annual interventions after successful use (RR, 0.57; 95% CI, 0.49-0.66; P < .0001). CONCLUSIONS: The patency advantage of AVFs over AVGs is no longer evident in patients requiring an AVF intervention before successful cannulation, but the AVFs require fewer interventions after successful use.

Pneumonia in hemodialysis patients: a challenging diagnosis in the emergency room.

BACKGROUND: Diagnosing pneumonia in hemodialysis patients is challenging. We hypothesized that pulmonary edema, which occurs commonly in hemodialysis patients, may frequently be misdiagnosed as pneumonia. METHODS: We retrospectively reviewed the records of 105 hemodialysis patients admitted with the diagnosis of pneumonia. Two experienced radiologists masked to the clinical course and subsequent imaging, independently interpreted the admission chest radiographs. In 68 of the patients, 2 internists independently reviewed the hospitalization records to diagnose pneumonia and pulmonary edema. The level of agreement among the radiologists was assessed using the kappa test. Using the clinical diagnoses, chest radiograph attributes were calculated. Logistic regression was performed to identify clinical and laboratory markers associated with pneumonia and pulmonary edema. RESULTS: The radiologist showed slight agreement on pneumonia (κ = 0.32) and pulmonary edema (κ = 0.28). Using clinical consensus, pneumonia was diagnosed in only 21% (14/68) of patients. Chest radiograph attributes for diagnosing pneumonia included: sensitivity 50%, specificity 58%, positive predictive value 25% and negative predictive value 81%. Pneumonia was associated with presenting temperature (odds ratio [OR] = 2.01; 95% CI, 1.03-3.93). Pulmonary edema was associated with shortness of breath (SOB) at admission (OR = 4.83; 95% CI, 1.25-18.6), presenting temperature (OR = 0.44; 95% CI, 0.21-0.92) and volume removed during hemodialysis (OR = 1.96; 95% CI, 1.16-3.31). CONCLUSIONS: The admission chest radiograph has significant limitations when used to diagnose pneumonia in hemodialysis patients. A high presenting temperature supports the diagnosis of pneumonia, while a low presenting temperature, SOB and large volume ultrafiltration favor the diagnosis of pulmonary edema.