An 88-year-old man is brought to the emergency department for slurred speech, altered level of consciousness, and left sided facial droop. The family reports that the patient was fine last night, but they noticed changes in behavior when he awoke in the morning. They thought that he might get better on his own, but then they noticed the slurred speech and facial droop. In the emergency department, the patient has a National Institute of Health Stroke Scale (NIHSS) score of 5. CT scan is ordered and is read as normal. Neurology consultation is obtained, and an ischemic stroke is suspected. The neurologist does not recommend giving tissue plasminogen factor (tPA).
Which of the following provides the best reason why tPA should NOT be given to this patient?
B) Giving tPA outside of the 4.5 hour time window can cause reperfusion hemorrhage.
In situations of ischemic stroke, tPA is one of the only pharmacologic agents that can help reverse neurologic damage. However, during the time of ischemia, damage to the vasculature can occur. When reperfusion occurs after administration of tPA, the blood vessels that were ischemic are weak and can hemorrhage. Additionally, tPA can augment the activation of endogenous matrix metalloproteases during the phase of inflammation. This results in breakdown of the extracellular matrix and a further weakening of the blood vessels.
Answer A: Giving tPA is not indicated in patients with a normal CT scan, is incorrect. Ischemia does not show up on CT scan until several hours after the event. It is actually preferable to have a normal CT scan, as this would indicate that the event happened more acutely, it confirms no bleeding is present, and the patient could potentially be a tPA candidate.
Answer C: Giving tPA outside of the 4.5 hour time window will not be effective in dissolving the clot, is incorrect. tPA is able to dissolve a clot outside of the time window of 4.5 hours.
Answer D: Giving tPA outside of the 4.5 hour time window will not be effective in salvaging neurons inside the core region of ischemia, is incorrect. The neurons within the core region of ischemia will likely not survive regardless of tPA treatment, so this is not a good reason to withhold treatment in this case. The use of tPA is effective in preventing further spread of neuronal death.
Answer E: Giving tPA to an 88-year-old man is contraindicated due to age, is incorrect. There are no contraindications to tPA due exclusively to age.
Key Learning Point
Giving tPA outside of the 4.5 hour time window can cause reperfusion hemorrhage.
