Overview of Patient-Controlled Analgesia

Effective postoperative and post-trauma pain management plays a critical role in shaping patient outcomes and preventing progression to chronic pain (2). Patient-Controlled Analgesia (PCA) is one method of pain management in which patients self-administer analgesics such as opioids or local anesthetics through the press of a button. In comparison to non-patient-controlled administration by nurses, PCA can reduce stress on both the patient and hospital staff. Additionally, patient-controlled analgesia allows medication to be dispensed with more attunement to the patient’s changing needs by eliminating a fixed dosing schedule (5). Indeed, patient-controlled analgesia enables patients to exercise more autonomy in their care and perhaps even experience less pain, potentially lowering the amounts of pain medications that patients require (4). One caveat is that PCA systems require some absolute limits to avoid dangerous levels of medication. 

Patient-controlled analgesia typically delivers medication intravenously, though epidural catheters and peripheral nerve catheters are also utilized (1). Several variables must be programmed to meet each patient’s needs effectively and safely. To begin, the initial loading dose is titrated up to the minimum effective concentration by nurses (5). Additionally, a specific demand dose is set to be dispensed each time the patient presses the button, and a lockout interval is put in place to prevent further administration of the drug within a certain time period after the button has been pressed to avoid overdosing. Finally, one-and-four-hour caps limit the amount of medicine that can be dispensed during those time intervals, further helping to prevent overdose (5). 

Due to the number of variables involved in patient-controlled analgesia, drawing broader conclusions around best practices from clinical studies and ensuring that patients benefit maximally can be difficult (4). Furthermore, PCA requires complex equipment and continuous training of both hospital staff and patients (4). Staff must assess whether patients are fit to self-administer their medication based on their cognitive and psychological states, as well as their respiration, sedation, and pain levels (5). 

Current clinical guidelines support the use of patient-controlled analgesia over conventional analgesia in many situations; however, the actual implementation of PCA is still relatively low (5). Recently, clinical research has been testing non-invasive, improved mechanisms of patient-controlled analgesia that may reduce some of the risks involved with conventional PCA methods. For example, sufentanil sublingual tablet systems (SSTS) use handheld devices that dispense a single tablet of sufentanil that the patient holds under their tongue (5). Another method, fentanyl iontophoretic transdermal systems (FITS), administer fentanyl through an electrical current into the skin (5). These non-invasive PCA methods may provide additional options for the management of acute postoperative pain, adding to the techniques that can be combined for effective multimodal analgesia (2).

References 

1. Bainbridge, Daniel et al. “Patient-controlled versus nurse-controlled analgesia after cardiac surgery–a meta-analysis.” Canadian journal of anaesthesia vol. 53,5 (2006): 492-9. doi:10.1007/BF03022623 
2. Deflandre, Eric, and Joseph Jaucot. “Patient-controlled analgesia: past, present and future.” Minerva anestesiologica vol. 82,8 (2016): 811-3. 
3. McNicol, ED et al. “Patient controlled opioid analgesia versus non‐patient controlled opioid analgesia for postoperative pain.” Cochrane Database of Systematic Reviews 2015, issue 6. art. no.: CD003348. doi: 10.1002/14651858.CD003348.pub3. 
4. Morlion, Bart et al. “Non-invasive patient-controlled analgesia in the management of acute postoperative pain in the hospital setting.” Current medical research and opinion vol. 34, 7 (2018): 1179-1186. doi:10.1080/03007995.2018.1462785 
5. Pastino, Alexander. and Akshay Lakra. “Patient Controlled Analgesia.” StatPearls, StatPearls Publishing, 19 July 2022. 
6. “Patient-Controlled Analgesia Pumps.” Johns Hopkins Medicine, https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/patientcontrolled-analgesia-pumps.