A comparison of two studies researching the outcomes from application of an alternative sternal precaution as compared to standard precautions after Median Sternotomy.
By Simon Turnbull Date: 18/10/2020
Background and relevance
In Australia in 2017 there was 1.2 million hospitalisations where cardiovascular disease was the primary or additional diagnosis (Australian Institute of Health and Welfare, 2020). For those requiring surgical intervention, isolated coronary artery bypass graft (CABG) is the most common cardiac procedure (Australian and New Zealand Society of Cardiac and Thoracic Surgeons, 2016). During CABG surgery median sternotomy is performed to gain access to the heart. Subsequently, sternal precautions play a significant role in the post-operative guidance from surgeons, cardiologists and health care professionals (Cahalin, Lapier, & Shaw, 2011). Many of these recommendations are expert opinion rather than evidence based practice (Cahalin et al., 2011). It has been proposed that providing an alternative sternal precaution pathway that is less restrictive would have potential improvements in rehabilitation outcomes for patients (Adams et al., 2016). There have been two recent studies into the application of modified sternum precautions. Ali et al. (2018) completed a multicentre randomised controlled trial to study the outcomes from alternative sternal precautions which they referred to as the Sternal Management Accelerated Recovery Tool or SMART (Ali et al., 2018). Holloway et al. (2020) completed a single centre cross sectional study comparing the less restrictive post sternotomy protocol with standard precautions (Holloway et al., 2020). Holloway et al. (2020) used a modified sternal precaution tool called. Keep Your Move in the Tube, that had been used in four facilities in Texas USA in 2016 (Adams et al., 2016). The following analysis compares the population, interventions and outcomes of the two studies and identifies their application to clinical practice.
Comparison of study population groups
The Ali et al. (2018) study included 72 adults as compared to the Holloway et al. (2020) study that included a larger cohort of 364 participants. The Ali et al. (2018) study included 90% of participants as males, compared to the Holloway et al. (2020) study that included 70.25% participants as males. The percentage of male participants in the two studies is similar to the percentage of males who undergo coronary bypass surgery in Australia, which was 80% in 2016 (Australian and New Zealand Society of Cardiac and Thoracic Surgeons, 2016). The average age of the Holloway et al. (2020) study was 66 years old and Ali et al. (2018) average age was 63.5 years old. The average participant age groups of both studies were similar to Australian data that shows the highest proportion of male and female patients who had a coronary artery bypass graft were aged 50-69 (Australian and New Zealand Society of Cardiac and Thoracic Surgeons, 2016). Both studies’ participants were similar in age to the Australian male populations and validated findings could be considered for applying to Australian males in health care setting. Translating findings from the Ali et al. (2018) study to apply to female participants in health care practice would be best done with caution as there was only a total of five female participants in the modified sternal precaution group and only two in the control group.
Exclusion criteria for the Holloway et al. (2020) study included those participants designated to be high risk for sternal complications by the physician. The physician used the Society for Thoracic Surgeons (STS) formulated risk score and clinical indicators. Exclusion criteria for the Ali et al. (2018) study included those living outside metropolitan area, post-operative complications, psychiatric and cognitive instability, unstable coronary condition, readmission to intensive care, non-English speaking, or no fixed address. Ali et al. (2018) recommended the creation of a sternal precaution tool to stratify a patients risk based on their individual presentations (Ali et al., 2018). Ali et al. (2018) and Holloway et al. (2020) applied differing exclusion criteria. However, both support the use of risk stratification in health care practice. Cahalin et al. (2010) proposed an algorithm to assist with risk classification and subsequent sternal precautions pathways. It is appropriate for this algorithm to be used in the application of modified sternal precautions in health care practice. The findings of Holloway et al. (2020) study can be applied to patients in clinical practice with low to moderate risk of sternal complications.
Comparison of interventions
The Keep Your Move in the Tube protocol allowed for “any unrestricted, unweighted arm movement provided there is no increase in pain or feelings of instability in the sternum. Weighted movement was allowed using the concept of an imaginary tube over the body that keeps the elbows against the body to guide how patients may move’’ (Holloway et al., 2020, p. 1077). The SMART protocol encouraged the “use of upper limbs within the limits of pain or discomfort. This included being permitted to use the arms during transfers and other tasks within the limits of pain and discomfort, as well as encouragement to perform upper limb exercise three times daily within the limits of pain and discomfort” (Ali et al., 2018, p.98). The interventions of Keep Your Move in the Tube and SMART were very similar. Both precautions included a greater use of the arms in post-operative care. Use of these protocols could be beneficial to health care practice as they avoid reinforcing fear avoidance behaviours (Bertoch, 2016; Silverberg, Panenka, & Iverson, 2018). This has been found to improve health care outcomes in rehabilitation (Bertoch, 2016; Silverberg et al., 2018).
Comparison of outcomes
The Ali et al. (2018) study concluded that “Modified (ie, less restrictive) sternal precautions for people following cardiac surgery had similar effects on physical recovery, pain and health-related quality of life as usual restrictive sternal precautions.” (Ali et al., 2018, p. 97). The groups had no statistical difference in measured outcomes at either 4 weeks or 12 weeks following median sternotomy (Ali et al., 2018). This was similar to the Holloway et al. (2020) study that concluded that “Keep Your Move in the Tube, had no adverse effect on outcomes 2 to 3 weeks following median sternotomy.” (Holloway et al., 2020, p. 1074). The conclusions of both Ali et al. (2018) and Holloway et al. (2020) studies were very similar. This was despite the outcome measures being quite different, and those outcomes being recorded at different time frames during the continuum of care.
Holloway et al. (2020) had a primary outcome of sternal instability measured with the Sternal Instability Scale and patient report, and a secondary outcome of self-reported pain and function using a non-standardised participant questionnaire. Ali et al. (2018) had a primary outcome of function as measured by the Short Physical Performance Battery and secondary outcomes including functional difficulties questionnaire, hand dynamometer, pain intensity with numerical rating scale, pain quality with short form McGill Pain questionnaire V2, 11 item Tampa Scale of Kinesiophobia, SF36 quality of life and sternal stability with the modified Sternal Instability Scale. Neither the Ali et al. (2018) study or the Holloway et al. (2020) study identified increases in adverse outcomes on sternum stability when using modified sternum precautions including the SMART and Keep Your Move in the Tube protocols. Both studies provide evidence for the safety of using a modified sternal precaution protocol in health care practice.
Ali et al. (2018) included two assessment tools for assessing psychological outcomes from use of the modified sternal precautions. This included the SF36 and the 11 item Tampa Scale of Kinesiophobia. The SF36 measures some aspects of mental health. There was no statistical difference in the mental health outcomes of the control or experimental groups (Ali et al., 2018). However, Ali et al. (2018) concluded that both of their participant groups had high levels of Kinesiophobia particularly after surgery. Both the Ali et al. (2018) study and Holloway et al. (2020) study did not specifically measure anxiety as an outcome. This is despite anxiety being recognised as a significant health care issue post Coronary Artery Bypass Graft surgery (Tully et al., 2015). Tully et al. (2015) used the MINI instrumental Neuropsychiatric Interview (MINI) and the Mood and Anxiety Symptoms Questionnaire (MASQ). These are possible tools to be used with future research into the psychological effects of using a modified sternal precaution pathway.
Ali et al. (2018) proposed that improvements in functional outcomes may have been achieved through a “targeted and progressive program of upper limb exercise during hospitalisation” (Ali et al., 2018, p. 104). Strength training post median sternotomy has been proposed as an area requiring further research (Pengelly et al., 2019). Further research would assist application of findings to health care practice as this would assist with specificity of exercise prescription post median sternotomy.
Summary of recommendations for practice and future research
In summary, modified sternal precautions have been found to be safe to use with Australian adult males at the 0-12 weeks period of care for patients with low or moderate sternal instability risk.
To assist in achieving improved rehabilitation outcomes from the use of modified sternal precautions, further research is warranted in the following areas:
- The beneficial psychological outcomes from an alternative sternum precaution, including Anxiety using the MINI and MASQ as assessment tools.
- The application of modified sternal precautions to Australian female population groups.
- The application of specific strength training within the 0-12 week period to improve functional outcomes whilst using modified sternal precautions.
Adams, J., Lotshaw, A., Exum, E., Campbell, M., Spranger, C., Beveridge, J., . . . Schussler, J. (2016). An alternative approach to prescribing sternal precautions after median sternotomy, “Keep Your Move in the Tube”. Baylor University Medical Center. Proceedings, 29(1), 97-100.
Australian and New Zealand Society of Cardiac and Thoracic Surgeons. (2016). National Annual Report. Retrieved 17 October 2020 from Australian and New Zealand Society of Cardiac and Thoracic Surgeons Web site: http://anzscts.org/wp-content/uploads/2017/11/171128-ANZSCTS-2016-National-Annual-Report-FINAL-medium.pdf
Australian Institute of Health and Welfare. (2020). Cardiovascular Disease. Retrieved 17 October 2020 from the Australian Institute of Health and Welfare Web site: https://www.aihw.gov.au/reports/heart-stroke-vascular-diseases/cardiovascular-health-compendium/contents/impact
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Pengelly, J., Pengelly, M., Lin, K.-Y., Royse, C., Royse, A., Bryant, A., . . . El-Ansary, D. (2019). Resistance Training Following Median Sternotomy: A Systematic Review and Meta-Analysis. Heart, lung & circulation, 28(10), 1549-1559. doi:10.1016/j.hlc.2019.05.097
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