Heads Down, Thumbs Up

Acute ischemic stroke patients may benefit by simply lowering the head of their bed. An inverse relationship was demonstrated between bed angle and residual blood flow to ischemic brain tissue. Similarly, Jugular Venous Distension becomes clearer when a patient is reclined. Therefore, this finding is not totally surprising. What is compelling is that the improvement is distinct and occurs even across small gradients: 15 degrees is preferred to 30 degrees even if not as ideal as a patient laying flat.

Clinically implementing the finding still requires a bit of common sense judgement. Patients with dysphagia are at an increased risk of choking which is greater when they lay flat. Because the same patient who has suffered a midbrain stroke is often dysarthric, they are at risk to silently aspirate. A real risk of choking must be weighed against the perfusion benefit described in the study. Occupational therapy can help in the management of these stroke patients.

While the hospital bed controls which set head angle are simple, keeping a patient's head down can be more complex. Patient compliance is required. Those short of breath when laying down (orthopnea from Congestive Heart Failure), and those prone to choking (dysphagic after a midbrain stroke) desire to sit up. Many stroke patients spend the first hours after the diagnosis of stroke in the ER. Therefore, the ER staff must also understand the importance of heads down just as well as the specialized staff of a dedicated stroke team. Even once admitted to a stroke unit, visitors may raise a patient's head earlier than is desired. Technicians who perform cardiac echos may raise the bed or ask the patient to prop themselves up, into positions which obtain a better ultrasound image. A well-meaning family member will often raise the head of a patient's bed, allowing the patient to more easily see and interact with family, at the expense of critical perfusion.

The heads down study has encouraged neurologists to emphasize a seemingly small detail to physicians and practitioners outside their specialty. It can be found by referencing: Neurology. 2005 Apr 26;64(8):1354-7.Heads down: flat positioning improves blood flow velocity in acute ischemic stroke. Wojner-Alexander AW, Garami Z, Chernyshev OY, Alexandrov AV.

"Ischemic stroke is a potentially reversible process that is dependent on restoration of arterial blood flow within a window of cellular viability that varies according to the severity and duration of the flow deficit. Measures that promote blood flow during the acute phase of ischemic stroke may directly impact the subsequent development of brain infarction and associated clinical deficit. One such measure may be flat head-of-the-bed (HOB) positioning to promote a gravity-induced increase in arterial flow to ischemic brain tissue; however, patients with stroke and other neurologic diagnoses are routinely positioned using 30° HOB elevation by paramedics and emergency room personnel."

Source: Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA

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