Journal of Ergonomics

Human errors in dialysis care can cause injury and death. One of the basic steps to increase reliability in this critical process is to analyze the error and identify the weaknesses of doing this process [4].
One of the most sensitive, yet susceptible, activities to human error in hospitals is the dialysis process. Due to its complexity on one hand the increase in number of patients needing this process on the other hand, the occurrence of errors in this process increases and, depending on the sensitivity of the subject, leads to adverse consequences including patient death. One of the quantitative methods of estimating the probability of human error is the assessment of human reliability by the Standardized Plant Analysis Risk Human Reliability (SPAR-H) method. Limited studies have been performed using this method in health care units, including studies of human errors in cardiac care and radiology units [11, 12].
This study aimed to quantitatively evaluate human error using the SPAR-H method in a dialysis process in one of Shiraz hospitals.

 

The present study is a cross-sectional descriptive-analytical study that was performed to identify and evaluate the probability of human error in the dialysis process of one of the hospitals by SPSR-H method. The studied hospital consisted of six dialysis units, each with 2 dialysis machines (ability to accommodate 1 patient), with 2 nurses in each ward participating in the dialysis process. Nurses' work experience ranged from 3 to 12 years. The data collection was also carried out with the help of dialysis process, interviews with the nurses of the unit, review of documents, procedures and working procedures.

The stages of implementation of the study are as follows.
1. Analyzing job tasks and determining their type in the dialysis process
2. Quantifying human error by SPAR-H method:
     2.1. Determine the type of base event
     2.2. Identification and determination of factors affecting human fault occurrence (PSF) in diagnostic and functional tasks
 

Table 1. How to evaluate the factors affecting human error in diagnostic and functional activities

The probability stage of human error was calculated for each of the job tasks according to the levels selected for the PSFs using Equations 1 and 2.
Relation # 1 (human error probability for diagnostic activity): HEP_D = 0.01×∏PSF
Relation # 2 (human error probability calculation for functional activity): HEP_A = 0.001×∏PSF   
In the above relationships, the basic human error probability [BHEP] values for diagnostic and functional activities are 0.01 and 0.001, respectively [13]. In tasks with at least 3 PSFs [negative PSFs] having a coefficient greater than 1, the probability of human error was calculated using Equation 3, taking into account the adjustment coefficient.

Table 2. Determining dependency level and how to calculate the probability of human error in dialysis nursing job tasks

The present study showed that the probability of human error in the duties of a dialysis nurse is in the range of 0.02-0.44 (except for devices related to disorder), which is related to sub-duty preparing patient as lowest rate and sub-duty of the pump set-off as highest error rate (Tables 3 and 4).

Table 3. Hierarchical Job Task Analysis for Dialysis Nurse

1. Pre-dialysis nursing care
     1-1. Weight control
     1-2. Symptoms control
     1-3. Determination of heparin
     1-4. Filter Selection [coefficient]
     1-5. Determine the type of dialysis solution and its amount
     1-6. Client preparation and location of access
2. Preparation of hemodialysis machine and patient connection to the device
     2-1. Preparing and stamping the device
          2-1-1. Adjust the pump pump according to the overweight and hypertension
          2-1-2. Adjust the concentration and temperature of the dialysis solution on the machine
     2-2. Priming the arterial set
     2-3. Testing the device
     2-4. Connect the dialysis machine to the patient
3. Nursing care during dialysis
     3-1. Control vital signs every hour
     3-2. Control of intravenous and arterial pressure of the device
     3-3. Calculation of Liquid Harvesting Rate [TMP]
     3-4. Straight control of bleeding and ...
     3-5. Heparin injection
     3-6. Blood and Drug Injection in ...
     3-7. Take the necessary measures in case of device failure ...
4. Post-dialysis nursing care
     4-1. Weight loss control
     4-2. Control Vital Signs
     4-3. Control of the place of perforation of vessels from …
     4-4. Disassemble the device correctly
 

Table 4. Results of quantifying the probability of human errors in the dialysis process

Discussion

The purpose of this study was to estimate the probability of human error in the dialysis process by nurses using SPAR-H method.
The present study showed that the probability of human error among the dialysis unit nursing tasks was in the range of 0.020 to 0.442 (excluding device disorders) which were related to the main tasks of pre-dialysis nursing care and Hemodialysis device preparation, respectively. As shown in Table 5, the most likely human error in the sub-pump adjustment sub-task with a probability of 0.442 followed by heparin quantification and filter selection with a probability of 0.337 and sub-dialysis task, Solution concentration and temperature adjustment and priming were obtained with a probability of 0.336. The least human error probability was related to client preparation task and access location with probability error of 0.020.

 

Conclusion

To reduce and control the human error in nursing duties in the dialysis department, control measures should be done such as increasing the number of personnel, changing the time shift of nurses, and training, preparing and revising the instructions.

The authors of the article consider it necessary to extend their sincere appreciation for the cooperation of the hospital staff, especially the nursing staff of the dialysis unit.

 

The authors declared no conflict of interest regarding the publication of this article.