| Abstract|| |
This study was designed to evaluate the attitudes of the physicians in Saudi Arabia towards the use and monitoring of heparinization in hemodialysis patients. A questionnaire was sent to 162 physicians who collectively looked after 7390 patients in the 144 active dialysis centers in Saudi Arabia. A total of 142 out of the 164 (87.6%) physicians answered the questionnaire. Physicians who used conventional heparin were the vast majority; 131 (92.3%), while only four (2.8%) used low molecular weight heparin and seven (4.9%) used either of the two types. The method used for routine heparinization was constant infusion by 96 (84.5%) respondents, repeated bolus doses by 40 (28.2%) and either method by six (4.2%). A protocol for the use of heparin was available for only 100 (70.4%) of the respondents. To monitor heparinization, whole blood partial thrompoplastin time was used by 81 (57%) respondents, although 106 (74.6%) respondents believed that this test was reliable, reproducible and proportional to the serum concentration of heparin. The activated clotting time was used by only 39 (17.6%) and not available to 47 (33.1%); 84 (59.2%) believed in its reliability and reproducibility, while 11 (7.7%) did not and 47 (33.1%) had no idea. The Lee White clotting time was used by only 25 (17.6%) of the respondents; 37 (26%) considered it reliable and reproducible. The use of the automated devices at the bedside to perform the clotting time tests in the dialysis unit was believed to facilitate the monitoring process effectively by 106 (74.6%) respondents, while 19 (13.4%) did not believe in them. Accordingly, 127 (89.4%) respondents would use the automated devices in case they were available to them. In conclusion, a protocol to guide the heparinization in dialysis in Saudi Arabia is lacking in many centers and there is a need to provide them with automated bedside devices that monitor the clotting time for better implementation of the protocols.
Keywords: Heparin, Chronic renal failure, Clotting time, Hemodialysis.
|How to cite this article:|
Souqiyyeh MZ, Shaheen FA. Attitude of Physicians in Saudi Arabia Towards Heparin Administration and Monitoring in Hemodialysis Patients. Saudi J Kidney Dis Transpl 2003;14:475-80
|How to cite this URL:|
Souqiyyeh MZ, Shaheen FA. Attitude of Physicians in Saudi Arabia Towards Heparin Administration and Monitoring in Hemodialysis Patients. Saudi J Kidney Dis Transpl [serial online] 2003 [cited 2020 Jan 19];14:475-80. Available from: http://www.sjkdt.org/text.asp?2003/14/4/475/32912
| Introduction|| |
Surveys of attitude of the treating physicians about their practice in the dialysis units are one of the tools available to evaluate the quality of care provided to the patients on regular dialysis. ,,
The extracorporeal blood-circuits in hemodialysis expose the blood of the chronic dialysis patients to a variable degree of thrombogenecity. , Anticoagulation with heparin is still the standard method to prevent thrombosis in this circuit  and, there are pharmacological models for its application in dialysis patients. ,
Assessment of anticoagulation with heparin includes visual inspection of the dialyzer and tubing during and after the dialysis session, observation of the circuit pressures, measurement of the residual dialyzer volume in reused dialyzers and performing the clotting time tests.  The latter may in addition, predict the clotting events, and help in adjusting the dose of heparinization. , Minimizing blood clotting during dialysis is essential to prevent blood loss in the already anemic patients on dialysis. 
Despite the control of the factors that favor clotting such as low blood flow and dialysis access recirculation, heparin remains the cornerstone in the dialysis units. Units that use protocols to apply and regularly monitor heparin may have better quality hemodialysis service. 
We attempt in this study to evaluate the attitude of the physicians in Saudi Arabia towards the methods (clinical and laboratory) that guide them in their decisions about maintaining the heparin anticoagulation. This includes the perception to the significance of the heparin anticoagulation and a protocol for its administration, the preferences of the heparin preparation, the monitoring method to guide the heparin administration and the strategies of the physicians towards the heparin dosing during chronic hemodialysis.
| Methods|| |
We sent a questionnaire to 162 nephrologists working in the 144 active dialysis centers in Saudi Arabia. These doctors cared for more than 7390 chronic hemodialysis patients. The questionnaire was mailed in February 2003 and responses were received at the Saudi Center for Organ Transplantation, Riyadh in March to May 2003.
The questionnaire was intended to evaluate the following aspects in the practice of physicians who take care of the dialysis patients in Saudi Arabia:
a) The methods (clinical and laboratory) that guide the physicians in their decisions about maintaining the heparin anticoagulation.
b) The perception of the physicians to the significance of the heparin anticoagulation and the need for a protocol for its administration.
c) The preferences of the physicians of the heparin preparation
d) The need for automated bed side monitoring of the anticoagulation parameters to guide the heparin administration.
e) The strategies of the physicians towards the heparin dosing during chronic hemodialysis.
Furthermore, we compared the responses according to the affiliation of the dialysis center [Ministry of Health (MOH), non-MOH, and private], the presence of a protocol for hepariniazation in the dialysis centers and the availability of the bedside tests for assessing heparinization.
Data were entered in a Microsoft Excel file, and the description of data and analysis was done by using the statistical program SPSS.
Pearson Chi-Square test was used throughout the analysis to test the significance of differences between groups and sub-groups. Significance is set as P< 0.05.
| Results|| |
There were 142 (98.6%) active dialysis centers that participated in the study; 106 (74.6%) were MOH centers, 14 (9.9%) were governmental non-MOH centers and 22 (15.5%) were private centers. The questionnaire was answered by 142 of the 162 physicians (87.6%) with similar ratios to the centers' participation. Not all the questions were answered by all the 142 respondents; hence the results were computed accordingly.
Regarding the type of heparin, 131 of the 142 respondents (92.3%) used conventional heparin, four (2.8%) low molecular weight heparin, while seven others (4.9%) used either preparation. The method of routine heparinization was constant infusion by 96 (84.5%) respondents, repeated bolus doses by 40 (28.2%) and both methods by six (4.2%). On the other hand, 71 (50%) respondents would use constant infusion of heparin as the method of choice for tight heparinization versus 46 (32.4%) who would use repeated boluses instead, and 25 (17.6%) said that they would use either method. Furthermore, 77 (54.2%) respondents would use constant infusion in new patients started on chronic hemodialysis, while 54 (38%) would use repeated bolus doses and 11 (7.7%) would use either method. Heparin would be used by 120 (84.5%) respondents for priming the dialyzers at start of the dialysis and a protocol for use of heparin was available for only 100 (70.4%) of the respondents.
[Table - 1] shows the usage of the laboratory investigations to guide heparinization in chronic dialysis patients. Whole blood partial thrompoplastin time (WBPTT) was used by 81 (57%) respondents although 106 (74.6%) believed it was reliable, reproducible and proportional to the serum concentration of heparin. The active clotting time (ACT) was used by 39 (17.6%) and was not available to 47 (33.1%). There were 84 (59.2%) respondents who believed in its reliability and reproducibility, while 11 (7.7%) did not and 47 (33.1%) had no idea. The Lee White clotting time (LWCT) was used by 25 (17.6%) of the respondents and 37 (26%) considered it reliable and reproducible.
Regarding the practical aspects of use of heparin as an anticoagulant in dialysis, 79 (55.3%) respondents would perform the clotting time tests frequently during the initial dialysis for a new patient to establish the suitable dose of heparin, while 59 (41%) would use the tests only if heparin dose needed adjustment. Once the dose of heparin was established for a patient, 93 (65.5%) respondents would use the clotting time tests only in case of clotting events, while 41 (28.9%) would use the tests at least once a month. Ninety-five (66.9%) respondents would obtain the blood sample for the clotting time tests from the arterial side of the extracorporeal circuit, while 41 (28.9%) would obtain the samples from the venous side. Poor blood access was believed to be a major cause of clotted dialyzers by 51 (35.9%) respondents, while 60 (42.3%) believed the clotting events were operator and access-related.
The use of the automated devices at the bedside to perform the clotting time tests in the dialysis unit was believed to facilitate the monitoring process effectively by 106 (74.6%) respondents, while 19 (13.4%) did not believe in them. Also, 127 (89.4%) respondents would use the automated devices in case they were available to them.
We compared the answers of the study participants after regrouping the respondents according to their dialysis center affiliation, adoption of protocols for administration of heparin and the usage of clotting time tests that evaluate heparinization in dialysis patients. We found that the centers affiliated to the MOH had a higher statistically significant use of conventional heparin than other sectors (96.2%), (P<0.0001). However, in comparison to the private dialysis centers, MOH centers had lesser use of constant infusion in routinechronic, tightly heparinized as well as new patients (61.3%, 42.5%, 48.1%), respectively, (P<0.02). Furthermore, the respondents from MOH hospitals believed more in the efficiency of the automated bedside devices for measuring clotting time than those in the private hospitals (77.4% vs. 63.6%), (P<0.04). On the other hand, we found that the dialysis centers, which had set protocols for administration of heparin, used the clotting time tests more frequently to monitor the heparinization in the chronic dialysis patients than those that did not have such protocols (85% vs 65%), (P<0.04).
| Discussion|| |
The current study attempted to detect the attitudes of physicians in-charge of hemodialysis centers in Saudi Arabia towards heparinization in chronic hemodialysis patients.
There was a consensus among the respondents to the importance of heparinization of the extracorporeal dialysis circuit. Almost all used conventional heparin, while a small percentage used low molecular weight heparin (LMWH). The use of the latter is efficacious and may have advantages of improving lipid profile and ameliorating hyperkalemia but, it is hampered by the cost. ,,
There has been no consensus on the method of administration of heparin namely, continuous infusion or repeated bolus injections. According to our study, the majority of the dialysis centers in Saudi Arabia used constant infusion for the routine as well as the new patients started on dialysis but less frequently for patients requiring tight heparinization. Although still used in dialysis, the repeated bolus heparinization necessitates higher initial doses and may give variable concentrations during the dialysis session. ,
Priming dialyzers with heparin is the logical practice with the available dialyzers , and the majority of the respondents in our study practiced it routinely. Standard protocol to guide the staff in the dialysis unit for heparinization was available to only 70% of the dialysis units in Saudi Arabia.
The use of the clotting time tests to guide dosing of the heparinization in the dialysis patients is recommended and practiced universally. , The choice of the ideal test depends on the quality of the tests. Availability of the tests at the bed side would help facilitating the decision about the tests. ,,, Heparin has a short half life and increasing the dose is feasible immediately in case the target clotting time is not attained by the initial estimation. , The WBPTT is the best available test of the clotting time that is reproducible and reliable because of its high correlation with the level of heparin in the serum.  The ACT follows the WBPTT in its reliability and reproducibility.  Both tests can be performed by portable automated devices that can be used at the bedside in the dialysis room. ,,, The LWCT, which is determined by a slide test, is a crude method to measure the level of heparinization, and has been abandoned according to the recommendation of the Clinical Laboratory Improvement Amendments of 1988 that effectively prohibited manual determination of coagulation times.  Our study found that the majority of the dialysis physicians believed in the reliability of the WBPTT and ACT over the LWCT and use of the automated bedside devices to measure them. However, only half of the respondents would use the guidance of the clotting time tests in determining the dose of heparin in the new patients and adjusting for the dose in case of a clotting event or regular check-up of the dose on monthly basis. This may be due to the nonavailability of the automated devices at bedside. The majority of the respondents welcomed having such devices at the bedside.
The findings of our study also suggest that other features of the practices of heparinization should be revised, such as the blood sampling for the tests. A small minority of the respondents believed that the samples should be obtained from the venous side of the dialysis circuit, while taking samples from the arterial side is more prudent due the location of the pore of heparin injection on that side on all the panels of the available dialysis machines.
The comparisons in our study showed important observations. The trend to use LMWH was more by the private and nonMOH dialysis centers. The respondents from the MOH dialysis centers believed more in adding the automated bedside devices to their units in order to measure the clotting time than those in the private hospitals. The presence of a protocol for heparinization in the dialysis centers helped implementing the clotting times tests more in this process than the dialysis units that did not have such protocol. 
We suggest that protocols for anticoagulation during hemodialysis should include instructions about the method of administration of heparin (infusion, bolus, or both), priming of dialyzers, and the use of clotting tests to guide dosing of heparin. The method and the frequency of sampling blood for clotting tests should be part of the protocol. The automated devices to measure WBPTT should be utilized to establish norms of heparin dosing in the dialysis population in each dialysis center; such norms should be specified in the protocol by each dialysis center for its population. Furthermore, noheparin and low-dose heparin protocols should also be made available for the staff of each unit.
We conclude that the current practices concerning heparinization in the dialysis centers in Saudi Arabia require refinement. There is a need to enforce the use of a protocol to guide heparinization in each dialysis unit that includes the use of clotting times especially in the presence of treatment with erythropoietin that may increase the clotting events in the shadow of inadequate heparinization. The presence of bedside automated devices to measure the clotting time can be very helpful in this regard. There is also a need to increase awareness among the dialysis staff to the importance of standardization of heparin use through in-services.
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Muhammad Ziad Souqiyyeh
Saudi Center for Organ Transplantation P.O. Box 27049, Riyadh 11417
[Table - 1]