* Sharp: The sharp pain in her knee made it impossible to walk. (Describes intensity)
* Severe: The severe weather caused widespread damage. (Describes severity)
* Intense: The intense heat made it difficult to breathe. (Describes intensity)
* Critical: The patient's condition is critical and requires immediate surgery. (Describes urgency)
* Urgent: The situation is urgent and requires immediate action. (Describes urgency)
* Keen: She had a keen sense of smell, easily detecting the faint scent of smoke. (Describes sensitivity)
* Poignant: The poignant story of their love brought tears to her eyes. (Describes emotional impact)
Remember that the best synonym for "acute" will depend on the specific context of your sentence.