Prevent complications after stroke

Dr M Pradeep | 10-June-2013

By Dr M Pradeep

Rapid diagnosis of stroke and initiation of treatment are important to maximize recovery, prevent recurrence of stroke and prevent complications.

Treatment of acute stroke patients in specialised stroke units correlated with lower mortality rate, reduced length of hospital stay and potentially reduced cost.

Development of a stroke team is advantageous to expedite emergency care which involves attention to protection of the airway, to avoid obstructions, hypoventilationand aspiration pneumonia. Mild hypothermia protects the brain from ischemic injury; mild hyperthermia worsens ischemic outcome. Prevention of pulmonary complications is necessary in the bed-riddenpatient. The mortality rate from pneumonia is as high as 15 percent to 25 percent in stroke patients. Aspiration was documented by video-fluroscopymodified Barium Swallow examination in more than a third of patients with brain stem strokes, in one-fourth with bilateral hemispheric strokes and one tenth of patients with unilateral hemispheric strokes.

If there is evidence of orpharyngealdysfunction, it is important to place a temporary enteral feeding tube to minimize the risk of aspiration.The next step is assessment of circulation. Evaluate BP and cardiac function. Cardiac monitoring is recommended for the first 24 to 48 hours after stroke. Concomitant cerebral and myocardial ischemia can occur in approximately three percent to 20 percent of cases.Ischemic stroke can be completed by a variety of cardiac arrhythmias.

In patients with stroke, the BP should be monitored frequently or even continuously for the first 48 to 72 hours. It is not unusual for the BP to be transiently elevated after a stroke. Optimal arterial pressures post stroke appears to range from 160 to 200 mm Hg for systolic BP and 70 to 110mm of Hg for Diastolic Bp. Lower or higher pressure are otherwise associated with an increased volume of stroke in CT scan four to seven days post stroke. It is important notto over treatblood pressure and cause hypotension. The most important objective is to maintain adequate cerebral blood flow in the presence of impaired auto regulation.

The American Heart Association guidelines suggest lowering the arterial blood pressure immediately post stroke only if the patient’s blood pressure is above 220/130 mm Hg and unless the patient is a candidate for thrombolytic therapy, in which case a target goal of less than 185/110 mm Hg is appropriate prior to thrombolysis.

NIHSS value of greater than 15 is an indicator of a large infarction.Once stability of the airway, breathing and circulation is determined and a focused neurological examination is performed to assess neurological stability, the patient should be sent immediately for a brain CT scan. This can point the way to treat the patient with TPA(Tissue Plasminogen Activator) or to avoid anticoagulant in patients with intracranial bleeds.

TPA is given either intravenously (IV)or Intra-arterially(IA). It is thrombolytic agent. IV TPA is given upto 4 .5 hours and IA TPA is given upto 6.5 hours after stroke. This is the golden period for the treatment of acute ischemic stroke. Treatment during this period enhances the chances of maximum recovery of the patient. In intra-arterial thrombolysis catheters are introduced into the cerebral artery involved in stroke in the brain and TPA is delivered directly onto the clot.Mechanical clot removal devices like Merci Retriever are also used in removing the clot from the brain.

Attention should be directed not only to treating stroke, but also to preventing complications. A variety of neurological and medical complications can occur after a stroke. During the first week after stroke, the most common cause of deterioration is development of brain edema. Brain edema begins to develop within the first several hours after stroke and reaches its peak within 72 to 120 hours. Those at greatest risk fordevelopment of cerebral edema are those with large infarctions often caused by large-artery occlusion.

Corticosteroids are not indicted for acute ischemic stroke. For cerebellar strokes with edema and herniation, posterior fossa decompression may be lifesaving.

In the second through the fourth weeks, pneumonia is the most common cause of non-neurological death. Many cases of pneumonia are caused by aspiration of food, saliva or regurgitated gastric secretion, or bacterial pathogens in saliva. Basal ganglia infarct seems to predispose patients to pneumonia because of frequent aspiration during sleep.

Other potential complications include seizures, cardiac arrhythmias, electrolyte disturbances, deep vein thrombosis, Decubitus ulcers and urosepsis.

Frequent neurological checks are necessary for early recognition of neurological changes associated with herniation, recurrent or progressive stroke or complications such as seizures.Anticonvulsant medications should be initiated if a seizure occurs.

Lower extremity deep vein thrombosis is common in stroke patients who are non-ambulant. This can be prevented by intermittent pneumatic compression of the lower extremities and by using Heparin preferably a LMWH (Low Molecular Weight Heparin). Prophylactic doses of heparin can be safely given to patients receiving Aspirin.

The patient’s nutritional status and fluid requirements should be assessed. Swallowing function should be assessed before intake of fluid or food is initiated.Patients who have significant oropharyngeal dysfunction require parenteral or tube feeding.

Preventing stroke recurrence

General measures include control of associated risk factors such as hypertension, hyperlipidemia and diabetes.  To stop cigarette smoking as well as use of anti-thrombotic agents (platelet anti-aggregants and anti-coagulants), anti-hypertensive agents and statin therapy,remains the mainstay of medical therapy for stroke prevention. A large proportion of strokes should be preventable by controlling BP, stopping cigarette smoking, treating cardiac rhythm abnormalities.

 If there is a significant carotid artery stenosis,it can be associated with an increased risk of stroke. The atherosclerotic lesion in the carotid arteries can be either stented or removed by endarterectomy to prevent stroke.Oral anticoagulants are used in patients with prosthetic cardiac valves and in atrial fibrillation to prevent strokes.

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