Patient-controlled analgesia ( PCA) is a commonly used technique for postoperative analgesia. The following statement(s) is/are true for the use of PCA

b. The technique is not applicable in the semiconscious or uncooperative patient

c. PCA is as safe as conventional intramuscular administration of pain medication 

d. Excessive administration of narcotic medication can be limited by a lockout duration which controls administration of the narcotic

The technique of patient-controlled analgesia is based on investigations that small intravenous bolus doses of narcotic on demand can provide patients with improved pain relief at the same or less total narcotic dose. The system requires some degree of sophistication and a conscious patient who has been instructed in the technique. Numerous studies have demonstrated that PCA is as safe as conventional IM medication. The patient can be restricted from receiving excessive agents via setting a lockout interval duration of several minutes during which time a dose of narcotic cannot be successfully administered. In addition, limits to the total hourly dose can be set.