Stroke Unit Design: Intensive Monitoring Should Be a Routine Procedure
“That deaf dumb and blind kid sure plays a mean pinball.”
“Pinball Wizard” from “Tommy, ” The Who, 1969
Tommy, the protagonist of The Who’s first rock opera, became pinball champion although he was deaf and blind (a psychogenic disorder, as we all know). He plays the pinball machine by “intuition,” doesn’t see the ball or hear the whistles and sounds, and doesn’t see the lights and the flippers; nevertheless, he always wins.
However, only few are so gifted that they can champion demanding tasks by intuition, by intent neglecting helpful information that is easily available. In acute stroke management on a stroke unit, general patient management can be handled in several ways: (1) by intuition, (2) on the basis of results of repeated physical examinations and daily assessment of physiological parameters twice or 3 times daily, or (3) with the assistance of continuous monitoring of physiological variables such as blood pressure (BP), heart rate, respiration rate, fever, or oxygen saturation, also known as physiological continuous monitoring. Using the pinball machine example, option 1 would be Tommy’s approach, option 2 would mean playing the machine occasionally, and option 3 would represent a concentrated attempt to score high points.
What do we mean by “monitoring?” There are at least 2 aspects: first, physiological monitoring may serve as a surrogate for frequent clinical examinations that cannot be performed as often as desired because of a shortage of personnel; and second, monitoring may detect changes in physiological variables that cannot be assessed directly by clinical means. An explanation is also needed for “intensive” monitoring and what is meant by “routine.” The EUSI (European Stroke Initiative) recommendations for general stroke management comprise monitoring of clinical status (using validated neurological scales) and vital functions (pulse rate, respiration rate, BP, oxygenation, and temperature) continuously or discontinuously.1 The extent of monitoring depends on acuteness, severity, and the underlying cause of stroke: the risk of missing a critical episode may just be too high if only serial clinical monitoring is performed, eg, every 4 hours. For example, in a young patient with an unstable dissection of the left internal carotid artery, no one would want to overlook a hypotensive period, which would require actively elevating BP and maybe emergency stenting. If an ischemic episode (leading to aphasia and hemiparesis) occurs just after the last clinical examination, although the next is routinely planned 4 hours later, it will certainly be missed. Clearly, this is a rare example and does not describe a standard patient on a stroke unit, but there are certainly more examples of subtypes of stroke for which “continuous” monitoring is needed. And there are even more examples if patients are included who suffer from intracranial bleeding or subarachnoid hemorrhage, who are prone to a variety of complications, particularly in the acute phase.
Obviously, clinical monitoring cannot be performed continuously, considering shortages of personnel and cost. However, technical monitoring with feedback and warning systems can. Basic physiological monitoring as recommended by EUSI may provide important information about the patient, because many clinical changes may be accompanied or even preceded by changes in physiological parameters. This is especially important when treatment options are available. For example, aphasic patients cannot complain about pain. However, pain leads to an increase in pulse rate and blood pressure, which may be followed by an increase in intracranial pressure (ICP). In other cases, the increase in blood pressure may be due to increasing ICP (referred to as Cushing-Kocher response) in patients who have had large strokes. Many stroke patients suffer from elevated blood pressure during the acute phase of stroke and some may need antihypertensive treatment.2 On the other hand, hypertensive treatment may be needed in some patients with unstable blood pressure.3 Patients with suspected cardioembolic stroke require continuous ECG monitoring to detect arrhythmia in order to start anticoagulation as early as possible. Acute stroke at the brain stem or large supratentorial strokes may cause insufficient breathing that can be detected by continuous monitoring of the respiration rate or arterial oxygen saturation. Pneumonia due to silent aspiration is frequently heralded by a temperature increase, which may be missed for hours without continuous monitoring. In all these examples, continuous monitoring will detect changes and will have direct therapeutic consequences.
Some argue that monitoring interferes with early mobilization. This is not necessarily true. Monitoring is mostly used in the very early course of the disease when, in most patients, extensive mobilization is not prescribed. Even so, the devices are not that bulky and can be removed during physiotherapy when the therapist is present and provides clinical monitoring. This is also true if prolonged monitoring is required. Monitoring can also be used in patients sitting in a chair.
In conclusion, stroke patients are monitored both clinically and technically. Because clinical monitoring cannot be performed continuously and stroke patients are prone to risk during the acute phase, continuous physiological monitoring is helpful in patient management. This is especially important in all patients with unknown but suspected cardioembolic cause of stroke; patients with labile blood pressure; patients who are prone to develop a second stroke, increasing ICP, or dysphagia; or patients at risk of breathing insufficiency, because monitoring may have therapeutic consequences. Basic technical monitoring comprises continuous ECG, blood pressure, respiration, oxygenation, and temperature. Stroke units have proven their positive effect on mortality, clinical outcome, and social re-integration, but the extent of clinical and physiological monitoring was not specified.4 The influence of intensive monitoring on clinical outcome has not formally been established either. Those of us using it, however, feel more comfortable in making decisions about patient management. Basic intensive monitoring may be costly. Therefore, it is time to study the effect of continuous intensive monitoring.
The opinions expressed in this editorial are not necessarily those of the editors or of the American Stroke Association.
Section Editors: Geoffrey A. Donnan, MD, FRACP, and Stephen M. Davis, MD, FRACEP
Rordorf G, Cramer S, Efird J, Schwamm L, Buonanno F, Koroshetz W. Pharmacological elevation of blood pressure in acute stroke: clinical effects and safety. Stroke. 1997; 28: 2133–2138.
Organised inpatient (stroke unit) care for stroke: stroke unit trialists’ collaboration. Cochrane Database Syst Rev. 2000; CD000197.