Sternal Precautions

Introduction

During open heart surgery, a median sternotomy (division of the sternum from top to bottom) is performed to allow surgeons to gain access to the heart. Upon closure, surgeons use materials such wires, cords, and plates to hold the sternum in place. To promote normal healing and prevent sternal complications, patients typically receive a list of actions or activities to avoid. This set of activity restrictions is known as sternal precautions.

Sternal instability, infection, and wound dehiscence are among the primary complications of median sternotomy. Although the incidence of complications is rare, rates of subsequent morbidity and mortality are high. This makes proper healing of the sternum a priority for ensuring good patient outcomes.

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Traditional Sternal Precautions

There is no universal definition of sternal precautions. As a result, the type and duration of activity restrictions vary widely across facilities. Common elements include:

• No lifting more than 5-10 lbs;
• No reaching behind the back; and
• No pushing or pulling through the arms.

Additional instructions may prohibit reaching overhead with one or both arms, or driving. Recommended adherence may last anywhere from 4 to 12 weeks.

Supporting Evidence

Evidence supporting the efficacy of traditional sternal precautions is low. For the most part, precautions are based on anecdotal evidence, expert opinion, and cadaver studies.. Multiple reviews suggest that traditional practice is overly restrictive and may lead to negative outcomes such as disuse atrophy and kinesiophobia (fear of movement).

Modified Sternal Precautions

In recent years, researchers have proposed less restrictive sternal precautions. Cahalin et al. recommend using risk classifications to prescribe appropriate levels of restriction. From there, they suggest patient presentation be used to guide a progressive return to activities. Likewise, Adams et al. advocate a set of recommendations known as "Keep Your Move In The Tube." It encourages patients to perform unloaded arm movements within a pain free range of motion. In addition, loaded arm movement is permitted as long as the upper arms stay close to the body. Load progression is informed by patient tolerance. The following video describes the concept and some of the proposed benefits in more detail:

https://www.youtube.com/watch?time_continue=89&v=55TXpW763AQ&feature=emb_logo

Finally, Brocki et al. compiled evidence regarding risk factors for sternal complications and sources of mechanical stress to make seven recommendations:

1. Bilateral movements of the arms in the horizontal level, backwards or over the shoulder level, should only be performed within pain-free limits during the initial 10 days following sternotomy or until the wound is healed.
2. Loaded movements of the arms should only be done at a pain-free level.
3. In general, patients should keep the upper arms to the body initial 6–8 weeks following sternotomy.
4. Patients with BMI≥35 should wear a supportive vest for sternal protections initial 6–8 weeks following sternotomy.
5. Patients should be taught “self- hugging” when coughing and sneezing during the initial 6–8 weeks following sternotomy.
6. Patients who cough frequently should wear a sternal vest supporting the entire circumference of the thorax.
7. Patients with large breasts should use a supportive brassiere that fastens in the front.

In summary, modified sternal precautions acknowledge that the relationship between arm movement, pain, and mechanical stress to the sternum is inconsistent. As a result, these guidelines place less emphasis on strict avoidance of specific activities and more emphasis on patient characteristics and presentation.

Supporting Evidence

Direct evidence for the use of modified sternal precautions is limited. To date, Katijjahbe et al. have performed the only randomized control trial comparing standard restrictive sternal precautions to modified sternal precautions. They found no difference in rates of sternal complications or patient outcomes (pain, physical function, upper limb function, quality of life, kinesiophobia), suggesting that less restrictive precautions may be a suitable alternative to traditional practice.

Clinical Applications

Physical therapy professionals should refer to the policies of their treating institution to determine how and when to apply sternal precautions. Common interventions for patients with sternal precautions may include:

• Patient education on sternal precautions and the signs of sternal instability (excessive movement of the sternum, clicking or popping, difficulty performing functional tasks)
• Functional mobility (ex. bed mobility, transfers, gait)
• Activities of daily living (ex. toileting, dressing, and other lifting or reaching activities)
• Caregiver training
• Pain control (ex. hugging a pillow over the surgical incision when coughing or sneezing)
• Exercise for the upper and lower extremities as allowed by sternal precautions

Clinicians involved in developing and revising hospital protocols may use emerging evidence to advocate for the the use of modified over restrictive sternal precautions.