Nursing care of patients undergoing venous thrombolysis
Thrombolysis therapy is based on the use of intravenous drugs that can dissolve the blood clot (formed by platelets and fibrin and called thrombus) that is created within the cerebral arteries causing ischemic stroke.
Thrombolysis is performed, after a neurologist has made the diagnosis of ischemic stroke.
Treatment with r-tPA (Recombinant Tissue Plasminogen Activator) is initiated after all the contraindications to treatment are excluded, and after the neurologist obtains a written informed consent.
The r-tPA must be administered within 3 hours from the onset of symptoms for the treatment to be effective.
The dose of r-tPA is calculated as follows: 0.9 mg / kg (to a maximum of 90 mg), 10% of which should be administered as a bolus via a previously placed peripheral venous access.
A bladder catheter is positioned before starting the treatment, particular attention being paid not to cause any bleeding, because this could jeopardize the whole treatment process.
The drug r-tPA is supplied in 2 vials, one containing the solute (Alteplase), and the other one containing the solvent (water for injections).
After administering the bolus, the rt-PA is infused at a constant speed using a pump over a period of 60 min; during the infusion the patient’s neurological status is assessed every 15 minutes, and every 30 minutes in the following 6 hours, and finally every 60 minutes for 16 hours.
The infusion is stopped (if still in progress) and an emergency CAT scan of the brain is obtained if neurological deterioration, severe headache, acute hypertension, or nausea and vomiting occur.
The blood pressure is monitored every 15 minutes for the first 2 hours, every 30 minutes for the following 6 hours, and every 60 minutes for 16 hours. It is necessary that the systolic blood pressure does not exceed 180 mm / Hg and the diastolic blood pressure 100 mm / Hg; if these parameters are not within these limits, the physician orders a Labetalol bolus, which is administered slowly and repeated every 20 minutes; if its use is contraindicated (e.g. asthma, heart failure or serious impairment of cardiac conduction) sodium Nitroprusside is used.
It is essential not to give anticoagulants or antiplatelet agents for 24 hours. In the following days it is also important to avoid foods that influence the clotting mechanism; especially spinach, lettuce, broccoli, cabbage, cauliflower and vegetable oil are contraindicated.
After 12 or 24 hours, depending on the neurological evaluation, it is important to check a CT of the brain.
Although Thrombolysis is a noninvasive procedure, it is not free from risk; in fact, the risk of bleeding is so high that key vital parameters and neurological status require constant and continuous monitoring.
This kind of care can only take place in a department such as the Stroke Unit.
In fact the Stroke Unit is an “ad hoc” dedicated and specialized unit for acute management of strokes, under the responsibility of a neurologist, who has the authority to initiate thrombolysis.
A multidisciplinary team made of competent nursing staff and at least a physiotherapist, must be also part of this unit.
The nursing team of the Stroke Unit ensures constant care and is qualified to monitor the level of consciousness and neurological status of the patient through structured assessment scales; the most frequently used scale, supported by SPREAD (see bibliography reference for details) is the National Institutes of Health Stroke Scale (NIHSS), which requires from 5 to 8 minutes for its compilation.
The Stroke Unit is also equipped for monitoring arterial pressure, heart rate, electrocardiogram (ECG), peripheral oxygen saturation, and respiratory rate.
Attention must also be paid to the psychological aspects of patients undergoing Thrombolysis; the patient should be informed step by step of the procedures that are being performed, and above all must receive a valid psychological support from the competent nursing staff and the other members of the team.
SPREAD, Cerebral Stroke: Italian guidelines for prevention and treatment, V edition (updated 2007);
Marina Vanzetta, The neurological patient: assistance, relationship, education, Ed. Mac Graw Hill, ed. February 2007.
Stroke Unit Nurses, Poliambulanza Foundation, Brescia, Italy.