A patient-controlled analgesia infusion pump, configured for epidural administration of fentanyl and bupivacaine for postoperative analgesia
Patient-controlled analgesia (PCA) is any method of allowing a person in pain to administer their own pain relief. The infusion is programmable by the prescriber. If it is programmed and functioning as intended, the machine is unlikely to deliver an overdose of medication.
 Routes of administration
The most common form of patient-controlled analgesia is self-administration of oral over-the-counter or prescription painkillers. For example, if a headache does not resolve with a small dose of an oral analgesic, more may be taken. As pain is a combination of tissue damage and emotional state, being in control means reducing the emotional component of pain.
In a hospital setting, a PCA refers to an electronically controlled infusion pump that delivers an amount of intravenous analgesic when the patient presses a button. PCA can be used for both acute and chronic pain patients. It is commonly used for post-operative pain management, and for end-stage cancer patients.
Narcotics are the most common analgesics administered through PCAs. It is important for caregivers to monitor patients for the first two to twenty four hours to ensure they are using the device properly.
With a PCA the patient is protected from overdose by the caregiver programming the PCA to deliver a dose at set intervals. If the patient presses the button sooner than the prescribed intake pressing the button does not operate the PCA. (The PCA can be set to emit a beep telling the patient a dose was NOT delivered). Dosage is also controlled when the patient is too sedated to press the button; preventing the patient from receiving needless doses and be safe from overdosing. The same would be the case for a narcotic lollipop, typically fentanyl.
Patient-controlled epidural analgesia (PCEA) is a related term describing the patient-controlled administration of analgesic medicine in the epidural space, by way of intermittent boluses or infusion pumps. This can be used by women in labour, terminally ill cancer patients or to manage post-operative pain.
In 1968, Robert Wexler of Abbott Laboratories developed the Analgizer, a disposable inhaler that allowed the self-administration of methoxyflurane vapor in air for analgesia. The Analgizer consisted of a polyethylene cylinder 5 inches long and 1 inch in diameter with a 1 inch long mouthpiece. The device contained a rolled wick of polypropylene felt which held 15 milliliters of methoxyflurane. Because of the simplicity of the Analgizer and the pharmacological characteristics of methoxyflurane, it was easy for patients to self-administer the drug and rapidly achieve a level of conscious analgesia which could be maintained and adjusted as necessary over a period of time lasting from a few minutes to several hours. The 15 milliliter supply of methoxyflurane would typically last for two to three hours, during which time the user would often be partly amnesic to the sense of pain; the device could be refilled if necessary. The Analgizer was found to be safe, effective, and simple to administer in obstetric patients during childbirth, as well as for patients with bone fractures and joint dislocations, and for dressing changes on burn patients. When used for labor analgesia, the Analgizer allows labor to progress normally and with no apparent adverse effect on Apgar scores. All vital signs remain normal in obstetric patients, newborns, and injured patients. The Analgizer was widely utilized for analgesia and sedation until the early 1970s, in a manner that foreshadowed the patient-controlled analgesia infusion pumps of today. The Analgizer inhaler was withdrawn in 1974, but use of methoxyflurane as a sedative and analgesic continues in Australia and New Zealand in the form of the Penthrox inhaler.
Patient Controlled Intranasal Analgesia (PCINA or Nasal PCA) refers to PCA devices in a Nasal spray form with inbuilt features to control the number of sprays that can be delivered in a fixed time period.
Transcutaneous delivery systems, including iontophoretic systems, are available. These are popular for administration of opioids such as fentanyl, or local anesthetics such as lidocaine. Iontocaine is one example of such a system.
 Advantages and disadvantages
Advantages Patient Controlled Analgesia include self-delivery of pain medication, faster alleviation of pain because the patient can address pain with medication, and dosage monitoring by medical staff (dosage can be increased or decreased depending on need). With a PCA the patient spends less time in pain and as a corollary to this, patients tend to use less medication than in cases in which medication is given according to a set schedule or on a timer.
Disadvantages include the possibility that a patient will abuse the narcotics, self-administering the pain medication to get high. If a PCA device is not programmed properly for the patient this can result in an under-dose or overdose in a medicine. The system may also be inappropriate for certain individuals, for example patients who suffer learning difficulties or confusion. Also, patients with poor manual dexterity may be unable to press the buttons as would those who are critically ill. PCA may not be appropriate for younger patients.
- Karanikolas M, Aretha D, Kiekkas P, Monantera G, Tsolakis I, Filos KS (October 2010). "Case report. Intravenous fentanyl patient-controlled analgesia for perioperative treatment of neuropathic/ischaemic pain in haemodialysis patients: a case series". J Clin Pharm Ther 35 (5): 603–8. doi:10.1111/j.1365-2710.2009.01114.x. PMID 20831684.
- Cathy S. Jewell; Chambers, James Q.; Chearney, Lee Ann; Romaine, Deborah S.; Candace B., PhD. Levy (2007). The Facts on File encyclopedia of health and medicine. New York: Facts on File. ISBN 0-8160-6063-0.
- Patient controlled analgesia for adults. Thomson Healthcare, Inc. 2010.
- Sarg, Michael; Altman, Roberta; Gross, Ann D (2007). The cancer dictionary. New York: Facts on File. ISBN 0-8160-6412-1.
- Beers, Mark (2006). "Injuries". The Merck Manual of Diagnostics and Therapy (18th ed.). Merck Research Laboratories.
- Loeser, John David; Bonica, John J.; Butler, Stephen H.; Chapman, C. Richard (2001). Bonica's Management of Pain (3 ed.). Philadelphia, PA: Lippincott Williams & Wilkins. p. 772. ISBN 0-683-30462-3.
- Glanze, Walter D.; Anderson, Kenneth; Anderson, Lois E. (1998). Mosby's medical, nursing, & allied health dictionary. St. Louis: Mosby. ISBN 0-8151-4800-3.
- Taber, Clarence Wilbur; Venes, Donald (2009). Taber's encyclopedic medical dictionary. F a Davis Co. pp. 108–9. ISBN 0-8036-1559-0.
- Wexler RE (1968). "Analgizer: Inhaler for supervised self-administration of inhalation anesthesia". Abbott Park, Illinois: Abbott Laboratories. Retrieved 2010-11-21.
- Romagnoli A, Busque L, Power DJ (1970). "The "analgizer" in a general hospital: a preliminary report". Canadian Journal of Anesthesia 17 (3): 275–8. doi:10.1007/BF03004607. PMID 5512851. Retrieved 2010-11-21.
- Packer KJ, Titel JH (1969). "Methoxyflurane analgesia for burns dressings: experience with the Analgizer (subscription required)". British Journal of Anaesthesia 41 (12): 1080–5. doi:10.1093/bja/41.12.1080. PMID 4903969.
- Major V, Rosen M, Mushin WW (1966). "Methoxyflurane as an obstetric analgesic: a comparison with trichloroethylene". BMJ 2 (5529): 1554–61. doi:10.1136/bmj.2.5529.1554. PMC 1944957. PMID 5926260.
- Dragon A, Goldstein I (1967). "Methoxyflurane: preliminary report on analgesic and mood modifying properties in dentistry (subscription required)". Journal of the American Dental Association 75 (5): 1176–81. PMID 5233333.
- Firn S (1972). "Methoxyflurane analgesia for burns dressings and other painful ward procedures in children (subscription required)". British Journal of Anaesthesia 44 (5): 517–22. doi:10.1093/bja/44.5.517. PMID 5044082.
- Josephson CA, Schwartz W (1974). "The Cardiff Inhaler and Penthrane. A method of sedation analgesia in routine dentistry". Journal of the Dental Association of South Africa 29 (2): 77–80. PMID 4534883.
- Babl F, Barnett P, Palmer G, Oakley E, Davidson A (2007). "A pilot study of inhaled methoxyflurane for procedural analgesia in children (subscription required)". Pediatric Anesthesia 17 (2): 148–53. doi:10.1111/j.1460-9592.2006.02037.x. PMID 17238886.
- Grindlay J, Babl FE (2009). "Efficacy and safety of methoxyflurane analgesia in the emergency department and prehospital setting". Emergency Medicine Australasia 21 (1): 4–11. doi:10.1111/j.1742-6723.2009.01153.x. PMID 19254307.
- Babl FE, Jamison SR, Spicer M, Bernard S (2006). "Inhaled methoxyflurane as a prehospital analgesic in children (subscription required)". Emergency Medicine Australasia 18 (4): 404–10. doi:10.1111/j.1742-6723.2006.00874.x. PMID 16842312.
- McLennan JV (2007). "Is methoxyflurane a suitable battlefield analgesic?". Journal of the Royal Army Medical Corps 153 (2): 111–3. PMID 17896540. Retrieved 2010-11-21.
- Medical Developments International Pty. Ltd. (2009). "PENTHROX (methoxyflurane) Inhalation: Product Information". Springvale, Victoria, Australia: Medical Developments International Limited. Retrieved 2010-11-21.
- National Prescribing Service (2010). "Methoxyflurane (Penthrox) for analgesia (doctor's bag listing)". NPS RADAR. Canberra, Australia: National Prescribing Service, Department of Health and Ageing. Retrieved 2010-11-21.
- Miaskowski C (August 2005). "Patient-controlled modalities for acute postoperative pain management". J. Perianesth. Nurs. 20 (4): 255–67. doi:10.1016/j.jopan.2005.05.005. PMID 16102706.
- "Patient-controlled analgesia system (PCA)". Clinical Reference Systems 10. McKesson Health Solutions. 2010.
- Pearce, Jeremy (2004-10-04). "Philip H. Sechzer, 90, Expert On Pain and How to Ease It". New York Times. Retrieved 2010-11-22.
 Further reading
- Crombie, JM (1876). "On the self-administration of chloroform". The Practitioner 16 (2): 97–101. ISSN 0032-6518. Retrieved 2010-11-23.
- Klieman RL, Lipman AG, Hare BD, MacDonald SD: A comparison of morphine administered by patient-controlled analgesia and regularly scheduled intramuscular injection in severe, postoperative pain. J Pain Sympt Manag 1988;3:15-22
- Sechzer, PH (1971). "Studies in pain with the analgesic-demand system". Anesthesia and Analgesia 50 (1): 1–10. doi:10.1213/00000539-197101000-00001. ISSN 0003-2999. PMID 5100236.
- Fast Fact and Concept #085: Epidural Analgesia, End of Life/Palliative Education Resource Center, Medical College of Wisconsin
- White PF: use of patient-controlled analgesia for the treatment of acute pain. JAMA 1988;259:242-247