Volume 20, Issue 4 , Pages 467-471, April 2009
Tunneled Hemodialysis Catheter Outcomes in Elderly Patients
Article Outline
Purpose
This retrospective study evaluated tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis.
Materials and Methods
Patients aged 75 years or older receiving hemodialysis comprised the study group. A control group of patients 40–60 years of age was randomly selected from the same dialysis quality assurance database. Demographic data, medical comorbidities, and catheter-specific data regarding indwelling time, function, interventions, and complications were recorded.
Results
Sixty-nine tunneled catheters were identified in 23 patients who comprised the study group (13 men and 10 women; mean age, 81.3 years; range, 75–88 y). The mean number of catheters per patient was three (range, 1–8). The mean indwelling time was 137.4 days (range, 2–622 d). Seventy-eight catheters were identified in the control group (n = 29; 14 men and 15 women; mean age, 50.6 years; range, 41–59 y). The mean number of catheters per patient was 2.7 (range, 1–9). The mean indwelling time was 139.7 days (range, 1–994 d). There was no statistically significant difference in the mean number of catheters per patient (P = .83) or the mean indwelling time (P = .93) between the two groups. There was no significant difference between the two groups in the indications for catheter removal or exchange: infection (P = 1.0), catheter no longer needed (P = 1.0), and physical catheter malfunction (P = .48). The calculated infection rates in the elderly patient and younger control groups were 0.30 per 100 catheter-days and 0.26 per 100 catheter-days, respectively.
Conclusions
Tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis do not vary significantly compared with those in a younger cohort.
IN recent decades, the number of patients in the developed world undergoing renal replacement therapy has been rapidly increasing. From 1980 to 2005, the number of patients in the United States with end-stage renal disease had increased eightfold to 477,583 (1). The trend is pronounced among elderly subjects, as the number of patients older than 75 years of age undergoing hemodialysis continues to increase, representing 22.2% of the patient population, compared with 4.9% in 1980 (2) (Fig 1).
Figure 1.
Graph illustrating the increasing proportion of patients aged 75 and older relative to the patient population with end-stage renal disease (1).
There is a common, albeit anecdotal, opinion among clinicians that elderly subjects fare poorly after beginning renal replacement therapy in comparison with younger patients. This perception includes clinical tolerance of hemodialysis, the impact on daily life, morbidity related to repeated access procedures, and suboptimal vascular access outcomes. The presence of comorbidities such as diabetes and cardiovascular disease may increase the risk of infection, contribute to the failure of vascular accesses to mature, or lead to decreased survival (3, 4, 5, 6). Although tunneled catheters carry a greater risk of infection, thrombosis, and central vein stenosis compared with arteriovenous (AV) fistulas and grafts, they continue to serve as an important option for patients with end-stage renal disease who are (i) awaiting a permanent AV access creation or maturation, (ii) in need of acute hemodialysis, (iii) have exhausted traditional access routes, and (iv) experiencing graft infection or extravasation episodes (7).
There is a paucity of literature evaluating tunneled hemodialysis catheter performance in elderly subjects. Are there age-based differences in outcomes of tunneled catheters that should be considered when making vascular access choices? These data would be important in selecting the appropriate vascular access type and in counseling older patients at initiation of their hemodialysis.
The purpose of this study was to compare outcomes of tunneled hemodialysis catheter placements in an elderly population (age ≥75 years) versus those in a control group of younger patients.
Materials and Methods
The study plan was approved by the institutional committee for the protection of human subjects. It was retrospective, and no individual patient consent for study inclusion was required.
The study population was obtained from our computerized quality assurance hemodialysis database (FileMaker Pro 4.0; FileMaker, Santa Clara, California). Patients aged 75 years or older who had undergone tunneled hemodialysis catheter placement (Opti-Flo; Bard Access Systems, Salt Lake, Utah; Hemo-Flow, Medcomp, Harleysville, Pennsylvania) between May 1999 and August 2006 were identified and comprised the study group. A control group of similar size was randomly selected by choosing every fifth patient between the ages of 40 and 60 years who had also undergone tunneled hemodialysis catheter placement during this time from the chronologically recorded database.
The study group (69 catheters) was comprised of 13 men and 10 women with an average age of 81.3 years (range, 75–88 y). There were 29 patients (78 catheters) in the control group with a mean age of 50.6 years (range 41–59 y; 14 men, 15 women).
All patients underwent tunneled catheter placement from a right or left internal jugular vein approach. Ultrasound guidance was used for the initial venipuncture; the remainder of the procedure was completed with intermittent fluoroscopic observation. Depending on individual operator preference, the target catheter tip position was the distal superior vena cava or the junction of the superior vena cava and right atrium.
Demographic data collected included age, sex, medical comorbidities, tobacco use, and use of anticoagulant or antiplatelet medication. Length of time undergoing dialysis was calculated for each patient, defined as the number of days from the start date of hemodialysis until (i) death, (ii) the end of the study if the last known catheter remained functional, (iii) the date of the last catheter removal (ie, last patient data point), or (iv) the date of a functioning renal allograft. Catheter-specific data were also recorded, including the number of catheters per patient, catheter indwelling time, interventions, and complications (eg, mechanical dysfunction, malposition, infection). Catheter survival, defined as the number of days from insertion to catheter removal, was the primary endpoint. Secondary endpoints included the number of catheters required per patient and complications.
Catheter infection was defined by one of the following: positive blood cultures, catheter-related bacteremia (with or without overt sepsis), and/or tunnel or exit-site infection necessitating removal or exchange based on the attending nephrologists' judgment.
Statistics
The data were entered into a computerized spreadsheet program (Excel; Microsoft, Redmond, Washington). We compared demographic data and the presence of medical comorbidities between the two patient groups with a standard χ2 test. The two groups were then also compared for differences in duration of time undergoing hemodialysis and the recorded catheter-specific variables. A P value of .05 or less was considered significant. Comparison of the reasons for catheter removal was initially evaluated by applying a χ2 test. Subsequently, logistic regression analysis was performed with use of a generalized estimation equation to correct for multiple observations (ie, clustering) from a single patient.
Evaluation for differences in catheter patency was performed by creating a Kaplan-Meier curve for each population and determining the statistical significance of potential disparity. Specified endpoints of catheter function were catheter removal for infection, occlusion/dysfunction/malposition, or physical catheter malfunction. Removal of the catheter because it was no longer needed, patient death with a functioning catheter in place, or the presence of a functioning catheter at the study end date were considered censored events for the purpose of survival analysis.
Results
Demographic data are summarized in Table 1. There was no statistically significant difference between the two groups with respect to diabetes, hypertension, or use of antiplatelet or anticoagulant agents. Atherosclerotic cardiovascular disease was defined as coronary artery disease, peripheral vascular disease, and/or carotid occlusive disease. Instances of the latter two disorders were too few for valid conclusions to be drawn, and therefore the three subcategories were combined for statistical purposes under the broader category of atherosclerotic cardiovascular disease. This yielded a P value of .10, which was not significant. The sole demographic factor that was significantly different was tobacco use (study group, n = 1 [4.2%]; control group, n = 11 [37.9%]; P = .003).
Table 1. Patient Demographics
Age (y) | |||
|---|---|---|---|
| Characteristic | ≥75 | 40–60 | P Value |
| No. of patients | 23 | 29 | NS |
| Mean(range) age(y) | 81.3(75–88) | 50.6(41–59) | <.001 |
| Sex(M/F) | 13/10 | 14/15 | NS |
| Diabetes | 14 | 21 | NS |
| Hypertension | 18 | 22 | NS |
| Atherosclerotic cardiovascular disease | 29 | 17 | NS |
| Antiplatelet/anticoagulant use | 19 | 22 | NS |
| Tobacco use | 1 | 11 | <.007 |
The mean durations of time receiving dialysis were 688.4 days in the study group (median, 503 d; range, 61–2,607 d) and 666.3 days in the control group (median, 332 d; range, 77–3,355 d). This difference was not statistically significant.
Seventeen of 23 study patients (74%) and 17 of 29 control subjects (59%) required multiple catheters to maintain adequate hemodialysis access during the study interval. There was no significant difference in the numbers of patients with multiple catheters between the two age groups (P = .25).
We found no significant difference between groups for any of the recorded catheter-specific variables (Table 2), including total number of catheters, mean number of catheters per patient (P = .83); mean indwelling time (P = .93), total catheter-days, and reasons for catheter removal (see Table 2 for P values). Kaplan-Meier curves plotting catheter patency (Fig 2) revealed no significant difference between the two groups (P = .98).
Table 2. Comparison of Catheter Variables between the Two Age Groups
| Age(y) | |||
|---|---|---|---|
| Variable | >75 | 40–60 | P Value |
| Total number of catheters | 69 | 78 | |
| Mean(range) catheters per patient | 3(1–8) | 2.7(1–9) | .83 |
| Mean(range) indwelling time per catheter(d) | 137.4(2–622) | 139.7(1–944) | .93 |
| Total number of catheter-days | 9,481 | 10,895 | |
| Reasons for catheter removal⁎ | |||
| Infection | 19(42) | 29(37) | 1.0 |
| Non- or malfunction | 4(6) | 9(11) | .56 |
| Damaged, exposed cuff, fell out, etc. | 11(16) | 12(15) | .48 |
| No longer needed | 16(25) | 25(32) | 1.0 |
⁎Values in parentheses are percentages. |
Figure 2.
Kaplan-Meier survival curves of tunneled hemodialysis catheter patency in the elderly patient group (age ≥75 y; dotted line) and control group (age 40–60 y; solid line). There is no significant difference between curves (P = .98).
Discussion
The United States Renal Data System statistics from 2005 reveal 314,162 patients actively receiving hemodialysis in the United States. Of these patients, 69,605 were aged 75 years or older, comprising 22.2% of the total number of patients. This represents a significant increase from 20 years earlier, when the age group of 75 years or older accounted for only 10.4% of the hemodialysis population (2).
We sought to investigate the outcomes of tunneled hemodialysis catheters in an elderly patient population and compare them with those in a younger control group. Although current Dialysis Outcomes Quality Initiative clinical practice guidelines designate the autologous vein AV fistula as the optimum vascular access for hemodialysis, followed by prosthetic grafts, these are not always possible, and the need for acute access placement often dictates tunneled catheter insertion (7). In addition, AV fistulas have higher primary failure rates and inferior primary patency rates in the elderly population (6). In a metaanalysis of hemodialysis access outcomes in elderly patients, Lazarides et al (6) reported a 50% increased risk of radiocephalic AV fistula failure at 1 year compared with nonelderly patients, and the risk of failure at 2 years remained statistically greater in elderly patients. The higher fistula failure rate in the elderly leads to increasing reliance on tunneled hemodialysis catheters to maintain adequate access during the time after fistula revision or new fistula placement. Catheter-based access is known to have an associated increase in morbidity and mortality compared with AV grafts or fistulas. Not unexpectedly, this has been observed in older patients as well. In an examination of United States Renal Data System data between 1995 and 1997 (8), elderly patients (defined in this particular study as age ≥67 years) receiving catheter-based dialysis were found to have an increased risk of mortality compared with those receiving dialysis via AV grafts or fistulas. However, is catheter performance in an elderly population different than in a younger population? Are the incidences of complications such as infection and catheter malfunction greater in elderly patients as a result of their increased comorbidities? We have not identified any published series evaluating catheter performance in this growing segment of the hemodialysis population.
We initiated this study to determine whether catheter-based vascular access would have different outcomes in elderly patients compared with younger patients. One could postulate suboptimal catheter performance based on increased comorbidities in elderly patients and higher percentages of patients who may have their daily personal care delivered by caregivers of various levels of training with regard to sterility and catheter care. Our data demonstrated no significant differences in the presence of commonly occurring comorbidities, antiplatelet medications, or anticoagulant medications between the two age groups, and therefore did not support this assumption.
We found no significant difference in the outcomes of tunneled hemodialysis catheters in elderly patients compared with a younger population. The most frequent indication for catheter removal in the elderly patient and control groups in our study was infection, occurring in 42% and 37%, respectively. This observation is in agreement with a recently published study of indications for tunneled dialysis catheter removal (9). The overall infection rates per 100 catheter-days (0.30 for the elderly group, 0.26 for the control group) were also similar to those reported in larger studies (9, 10, 11, 12).
The second most common reason for catheter removal was elective removal on the basis of a functioning AV access, renal transplantation, conversion to peritoneal dialysis, or return of adequate renal function. This occurred in 25% of the elderly patient group and 32% of the control group. These findings are very similar to those of Schnabel et al (13) and Alomari and Falk (9), but the incidences are lower than those reported by Trerotola et al (14), who reported elective removal in 58% of patients.
Malposition and/or mechanical dysfunction represented the third most common cause for catheter removal (22% in the elderly patient group, 26% in the control group). This included catheter-related sheath or thrombosis; catheters physically requiring removal for damage, such as a crack in the connecting hub; or the accidental withdrawal and exposure of the retention cuff from the subcutaneous tunnel. These rates are concordant with previously published rates ranging from 19% (12) to 32% (9, 13, 15). Despite concerns about tissue and skin integrity and thickness in elderly patients, the incidences of mechanical failure of catheters did not differ between the two groups.
We believe the relatively small size of our patient population is a limitation of our study. This is offset by the number catheters from each group available for evaluation and the unanticipated similarity of the study results. The authors also acknowledge the inherent limitations of any retrospective patient review.
In summary, our data showed no significant difference in catheter performance in elderly patients and a younger control group, which is an unexpected but encouraging result. There were no significant differences in the number of catheters per patient, indwelling times, infection rates, or indications for removal/exchange. In addition, the results in both our patient populations were concordant with observations previously published in the literature collectively evaluating all age groups (9, 13, 14, 15). As we look ahead to the aging of the United States population in general, and the population of patients with end-stage renal disease population in particular, our data suggest that tunneled hemodialysis catheter placement is a viable option for vascular access in elderly patients that carries outcomes similar to those in their younger counterparts.
This evaluation of catheter performance in this population is useful, especially in light of the fact that catheter use in elderly patients may be greater than that in the younger population because of the higher failure rates of radiocephalic AV fistulas in elderly subjects.
References
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- . Catheter-related bacteremia and outcome of attempted catheter salvage in patients undergoing hemodialysis. Ann Intern Med. 1997;127:275–280
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- Image-guided insertion of the Udall tunneled hemodialysis catheter: technical success and clinical follow-up. J Vasc Interv Radiol. 1997;8:579–586
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From the SIR 2007 Annual Meeting.
None of the authors have identified a conflict of interest.
PII: S1051-0443(09)00015-3
doi:10.1016/j.jvir.2009.01.013
© 2009 SIR. Published by Elsevier Inc. All rights reserved.
Volume 20, Issue 4 , Pages 467-471, April 2009