Introduction
Compartment syndrome is a devastating complication that can occur after experiencing an injury, trauma, or undergoing surgery to a limb and is considered to be a "life- or limb-threatening condition" (Malik, Khan, Chaudhry, Ihsan, & Cullen, 2009). Insufficient awareness of compartment syndrome delays the diagnosis and intervention, causing poor outcomes for the patient (Edwards, 2004; McQueen, Gaston, & Court-Brown, 2000). In as little as 30 minutes, nerve damage can occur, quickly followed by muscle damage within 2-4 hours (Andrews, 1990; Harvey, 2001). If left untreated, compartment syndrome results in irreversible damage in as little as 12 hours (Andrews, 1990) or may develop days after the initial injury (Pearse & Nanchahal, 2008).
Initial indicators for compartment syndrome can be non-specific (Pearse & Nanchahal, 2008; Wright, 2007) especially in children (Bae, Kadiyala, & Waters, 2001), which makes the early diagnosis of compartment syndrome difficult (Pearse & Nanchahal, 2008). Subtle changes in the neurovascular assessment over time may be critical to the early diagnosis of compartment syndrome (Cascio, Wilckens, Ain, Toulson, & Frassica, 2005). The key to preventing compartment syndrome is frequent neurovascular assessments, early recognition, and prompt intervention (Edwards, 2004; Pearse & Nanchahal, 2008).
Review of Literature
Frequent neurovascular assessments performed by nurses are one of the most useful assessments in the early identification of compartment syndrome (Eden-Kilgour & Miller, 1993; Judge, 2007). Assessment of circulation, motor function, and sensation are the basic functions involved in a neurovascular assessment. The peroneal, tibial, radial, ulnar, and median nerves are the five major nerve innervations that are to be assessed during motor and sensory assessments (Altizer, 2001; Andrews, 1990; Eden-Kilgour & Miller, 1993). In addition, a neurovascular assessment includes assessment of the five Ps: pain, pallor, and paraesthesia as early signs; pulselessness and paralysis as late signs (Eden-Kilgour & Miller, 1993). Furthermore, the increased use of pain medication or pain disproportionate to the apparent injury was found to be the most sensitive indicator of compartment syndrome followed by paresthesia, paralysis, pallor, and finally pulselessness (Bae et al., 2001; Edwards, 2004).
There are various neurovascular assessment tools that are used among different hospitals, although Wright (2007) validated the Wessex Paediatric Neurovascular Assessment tool and found that it facilitates nurses to recognize neurovascular impairment and compartment syndrome earlier. However, Wright (2007) further noted that adaptations of neurovascular assessment tools that allow for developmental- or age-appropriate testing of pediatric patients are needed, especially for casted patients.
Two-point discrimination (2-PD) test is commonly used for assessing tactile sensation, which correlated well with hand function (Menier, Forget, & Lambert, 1996). Orthopaedic and emergency physicians often use 2-PD test to evaluate patients with injuries of the extremities because of its ability to identify nerve dysfunction (Finnell, Knopp, Johnson, Holland, & Schubert, 2004). In addition, loss of 2-PD is a sensitive indicator of compartment syndrome and may aide in determining which compartment is affected (Edwards, 2004).
The 2-PD test is performed by touching two points on the skin simultaneously with an instrument and determining the minimum distance the patient can discern as two distinct points (Menier et al., 1996). Because of the lack of a standard protocol for performing 2-PD test, various techniques exist (Finnell et al., 2004). A common instrument used for 2-PD test is a discriminator disc that consists of two sturdy, rotating, plastic discs that are joined together with rounded tips spaced at standard testing intervals. Studies have shown the validity and reliability of the discriminator disc to be comparable to other methods of determining neurovascular discrimination (Crosby & Dellon, 1989; Finnell et al., 2004; Menier et al., 1996).
Although the neurovascular assessment is a part of routine nursing assessment of patients who are at risk of compartment syndrome, the 2-PD test is usually not included. Nursing skills need to be developed to aide early recognition of compartment syndrome (Edwards, 2004). Shooter (2005) found that the 2-PD test is a quick and easily reproducible test that could be administered by nonmedical staff. However, a lack of interrater reliability of the 2-PD test is a major barrier against inclusion in routine nursing neurovascular assessments (Menier et al., 1996; Patel & Bassini, 1999).
Purpose
The purpose of this study was to evaluate the effectiveness of 2-hour educational sessions covering compartment syndrome, neurovascular assessments, and 2-PD test among pediatric orthopaedic nurses. The specific objectives were (a) to compare the mean knowledge scores before and after the educational sessions and (b) to assess the interrater reliability of neurovascular assessments with 2-PD test between nurses and nurse experts before and after the educational sessions.
Methods
Study Design
A pre- and posttest study design was used to evaluate the effectiveness of educational sessions from October 2009 to May 2010. Five pediatric orthopaedic nurse experts were trained by pediatric orthopaedic surgeons on the correct technique of performing neurovascular assessment that included 2-PD test with a discriminator disc. A skill competency form, developed in collaboration with the nurse experts and orthopaedic surgeons, was used to document competencies of the nurses and nurse experts. The knowledge and skills of neurovascular assessment of nurse participants were measured before and after the 2-hour educational sessions.
Participants
All nurses employed on the orthopaedic unit at a Children's Hospital in southern California were invited to participate in this study. The inclusion criteria were full-time, part-time, or per-diem nurses. The traveler nurses were excluded from the study because of their short duration on the unit.
A convenience sample of children who were scheduled to have a surgery and admitted to the orthopaedic unit during the study period were invited to participate if they (a) were between the ages of 6 and 18 years; (b) had either an arm or a leg in a cast; and (c) spoke and understood English. For purpose of this study, nonverbal patients or patients speaking a language other than English were excluded, because 2-PD test relies on the patients' verbal report of tactile sensation.
Neurovascular Assessment Education
Several mandatory 2-hour educational sessions were provided by the five nurse experts over a period of 1 month so that all staff nurses could participate. The 2-hour educational sessions included a combination of lectures and return demonstrations of neurovascular assessment skills. The lectures covered the content related to compartment syndrome, neurovascular assessments with 2-PD test, motor function tests, interventions, and review of department standards. The staff nurses practiced neurovascular assessments until they reached the 100% agreement with the nurse experts in return demonstration using the skill competency form.
Instruments
The 15-question knowledge test was developed by the pediatric orthopaedic nurse experts. The knowledge test includes questions on topics such as compartment syndrome, neurovascular assessments, motor and nerve function tests for upper and lower extremities, 2-PD test with discriminator disc, interventions, physician notification criteria, and department standards. Face validity of the question items was established with a panel of three clinical experts in pediatric orthopaedic nursing.
The neurovascular assessment flow sheet was developed by the pediatric orthopaedic nurse experts by adding 2-PD test items and motor function assessment items to the existing computerized neurovascular assessment flow sheet. The existing neurovascular assessment includes the assessment of pain, color, capillary refills, swelling, temperature, movement, and sensation of the child's arm or leg that has a cast. This flow sheet was also modeled after Wessex Paediatric Neurovascular Assessment by Wright (2007) and a neurovascular chart by Judge (2007). The newly developed form allows options of "unable to assess" due to a cast or dressing and "unable to express" for patients who are unable to express either verbally or nonverbally abnormal sensation or pain.
The demographic data form was distributed to the nurse participants to collect the sample characteristics such as age, gender, ethnic background, educational level, and years of RN experience.
Ethical Considerations
The study was approved by institutional review boards of both the hospital and university involved in the study. Written informed consent was waived for nurse participants because of the anonymous nature of the data. Parental permission and assent from the patients were obtained prior to neurovascular assessments. All participants in the study, including nurses and patients, were reminded that their participation was voluntary and that they could decline participation at any time without any consequences or effect on care.
Procedures
One month prior to the educational sessions, the nurse experts approached the legal guardians of patients who met the study inclusion criteria to recruit patient participants. After obtaining the signed parental permission and assent from a patient participant, a nurse first performed the neurovascular assessments with 2-PD test. Then a nurse expert entered the room and repeated the same neurovascular assessments. The results of the paired assessments were recorded to assess the preeducation interrater reliability of neurovascular assessment at baseline.
After completion of preeducation data collection, several 2-hour educational sessions were provided over a period of 1 month. Nurse participants completed the knowledge test before the educational sessions. The posteducation knowledge test was done 2-4 weeks after the completion of educational sessions. The posteducation neurovascular assessments were collected after the educational sessions over a period of 7 months.
Data Analysis
Data were entered into a spreadsheet using SPSS version 16.0 (SPSS Inc., Chicago, IL). Descriptive statistics were performed to summarize the sample characteristics. The independent t-test was conducted to compare the mean pre- and posteducation knowledge scores. Chi-square test was used to compare the frequencies of the correct answer for each question between pre- and posteducation data. Cohen's kappa statistics and percentage observer agreement were calculated to assess interrater reliabilities of the items of neurovascular assessment and 2-PD. Cohen's kappa statistics report the agreement between two observers beyond that expected by chance alone. Cohen's kappa ranges from 0 to 1.0, where 1.0 indicates perfect interrater reliability. As a rule of thumb, values of kappa from 0.40 to 0.59 are considered to be moderately reliable, 0.60 to 0.79 to be substantial, and greater than 0.80 to be outstanding (Landis & Koch, 1977). The statistical significance level was set at .05 for all data analyses.
Results
Sample Characteristics
Of 64 eligible nurses employed on the orthopaedic unit, a total of 60 nurses completed the preeducation knowledge test and 37 nurses completed the posteducation knowledge test. Table 1 shows the participating nurses' demographic characteristics. The mean age of the nurses was 33 years and the majority were female and White and had an average of 5 years of pediatric orthopaedic RN experience.
A total of 64 patients met the eligibility criteria and enrolled into the study: 24 patients were enrolled in the preeducation period and 40 in the posteducation period. Table 2 shows the patient demographic characteristics. The mean age was 11 years. The majority of patients were male and White and a plurality had an open reduction internal fixation performed on either upper or lower extremity.
Pre- and Posteducation Comparison of Knowledge
The pre- and posteducation comparison of knowledge test scores is shown in Figure 1. A statistically significant improvement was noted in the mean knowledge score between pre- and posteducation (50.7% vs 67.3%, respectively; p < .001). Items regarding the definition of compartment syndrome, baseline neurovascular assessment, signs of circulatory compromise, and frequency of assessments had greater than 90% of nurses responding correctly at preeducation. Six of the remaining items improved significantly after the educational sessions, including timeframe of irreversible damage, indicator for compartment syndrome, upper and lower extremity 2-PD values, upper extremity 2-PD assessment, and physician notification criteria (p < .05).
Pre- and Posteducation Interrater Reliability of Neurovascular Assessments
Table 3 shows the pre- and posteducation interrater reliability of neurovascular assessments between the nurses and nurse experts. For the 2-PD test, the interrater reliability was poor at preeducation as indicated by Cohen's kappa of 0.24 (p = .064). After education, the interrater reliability improved moderately to Cohen's kappa of 0.48 (p < .001).
For assessments of skin temperature and voluntary movement, the preeducation interrater reliabilities were already substantial with Cohen's [kappa] > 0.60 and did not improve with education. The assessment of swelling was poor at preeducation ([kappa] = 0.09) and improved minimally with education to kappa of 0.21. The assessment of strength against resistance was also poor at preeducation ([kappa] = 0.26) but improved to a moderate reliability ([kappa] = 0.56) with education.
Discussion
To our knowledge, this is the first report on interrater reliability of neurovascular assessment with 2-PD test by pediatric orthopaedic nurses. Because frequent neurovascular assessments are critical for early recognition of compartment syndrome, pediatric orthopaedic nurses should have the basic knowledge and skills to carry out the neurovascular assessments including 2-PD test. The current study results indicate that the educational sessions were effective in improving nurses' general knowledge and skills related to compartment syndrome and neurovascular assessments.
There was a statistically significant improvement in the mean knowledge score after education even though the posteducation knowledge test was performed 2-4 weeks after the education. As expected, most nurses already had general knowledge regarding compartment syndrome, neurovascular assessment, and signs of circulatory compromise before attending the educational sessions. However, fewer nurses had more specific detailed knowledge related to the 2-PD test, timeframe of irreversible damage, or physician notification criteria, which improved significantly with education.
The simple interrater percent agreements shown in Table 3 do not take into account that vast majority of the patients had normal 2-PD test results and are not good indicators of interrater reliability. In contrast, Cohen's kappa does take this into account and kappa values less than 0.40 indicate poor interrater reliability whereas kappa values between 0.40 and 0.59 indicate moderate reliability (Landis & Koch, 1977). It is not surprising that the interrater reliability of 2-PD test as assessed by Cohen's kappa was poor before the education because this assessment was not a routine procedure for the nurses. Even for trained medical staff, the previous study of 2-PD test showed low interrater reliability (Patel & Bassini, 1999). In this study of nurses, the interrater reliability improved to modest level with education. Further improvement may occur with the routine use of this test, as well as with additional follow-up training.
There were several limitations in this study. First, the use of convenience sampling without a control group could have introduced bias or confounded the results, potentially limiting the validity of the findings. However, randomized controlled trials are difficult to execute in a single-institutional setting. Second, the knowledge test was not a validated instrument. It did not have test-retest reliability or other validity testing performed, except for the face validity testing. Third, the knowledge improvement after educational sessions may have been biased by 38% of nurses who did not complete the posteducation knowledge test. Fourth, it was noted that the usage of regional nerve blocks increased during the study period, which resulted in decreased sensation for several hours postoperatively. This made 2-PD test difficult in many of the patients. Fifth, the posteducation data collection was extended to 7 months because of an unforeseen drop in patient census and a limited number of patients who were eligible to participate in the study. Finally, no impending compartment syndrome occurred during the study period, which made it difficult to assess the effectiveness of the education to detect patients at risk for compartment syndrome.
Based on the results of this study, 2-PD test has been successfully incorporated into the routine neurovascular assessments at the study site. Future studies are necessary to see whether inclusion of 2-PD test into routine clinical practice would further improve the interrater reliabilities among nurses.
Conclusions
Among healthcare professionals, nurses have the most frequent contacts with patients following orthopaedic procedures and are in a unique position to assess subtle neurovascular changes in their patients. Having the knowledge and skills to identify patients experiencing neurovascular impairment and communicating the changes in assessment findings is critical for preventing the development of compartment syndrome. This study indicates that the 2-hour educational sessions may be effective in improving nurses' knowledge and the interrater reliability of neurovascular assessments with 2-PD test.
Acknowledgments
This study was performed as a part of the Master of Science in Nursing degree requirements at School of Nursing, Point Loma Nazarene University, San Diego, CA. The authors thank all participating nursing staff and hospital leadership team for making this study possible.
References