patient-controlled analgesia

{{short description|Administration of pain relief medication by a patient}}

{{Infobox interventions

| Name = Patient-controlled analgesia

| Image = PCA-01.JPG

| Caption = A patient-controlled analgesia infusion pump, configured for epidural administration of fentanyl and bupivacaine for postoperative analgesia

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| MeshID = D016058

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Patient-controlled analgesia (PCA{{cite journal | vauthors = Karanikolas M, Aretha D, Kiekkas P, Monantera G, Tsolakis I, Filos KS | title = Case report. Intravenous fentanyl patient-controlled analgesia for perioperative treatment of neuropathic/ischaemic pain in haemodialysis patients: a case series | journal = Journal of Clinical Pharmacy and Therapeutics | volume = 35 | issue = 5 | pages = 603–608 | date = October 2010 | pmid = 20831684 | doi = 10.1111/j.1365-2710.2009.01114.x | s2cid = 205331535 | doi-access = free }}) is any method of allowing a person in pain to administer their own pain relief.{{cite book | vauthors = Jewell CS, Chambers JQ, Chearney LA, Romaine DS, Levy CB |title=The Facts on File encyclopedia of health and medicine |publisher=Facts on File |location=New York |year=2007 |isbn=978-0-8160-6063-4 |url=https://archive.org/details/factsonfileencyc0000unse }} 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.{{cite book |title=Patient controlled analgesia for adults |year=2010 |publisher=Thomson Healthcare, Inc}} Providers must always observe the first administration of any PCA medication which has not already been administered by the provider to respond to allergic reactions.

Routes of administration

=Oral=

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.{{Citation needed|date=October 2009}}

=Intravenous=

Image:PCA-02.JPG administration of morphine for postoperative analgesia]]

In a hospital setting, an intravenous PCA (IV PCA) refers to an electronically controlled infusion pump that delivers an amount of analgesic when the patient presses a button.{{cite book | vauthors = Sarg M, Altman R, Gross AD |title=The cancer dictionary |publisher=Facts on File |location=New York |year=2007 |isbn=978-0-8160-6412-0 }} IV 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 IV PCAs.{{Cite book | vauthors = Loeser JD, Bonica JJ, Butler SH, Chapman CR | year=2001 | title=Bonica's Management of Pain | edition=3rd | publisher=Lippincott Williams & Wilkins | place=Philadelphia, PA | isbn=978-0-683-30462-6 | page=772}}{{cite book | vauthors = Glanze WD, Anderson K, Anderson LE |title=Mosby's medical, nursing, & allied health dictionary |publisher=Mosby |location=St. Louis |year=1998 |isbn=978-0-8151-4800-5 |url= https://archive.org/details/mosbysmedicalnur00ande }} It is important for caregivers to monitor patients for the first two to twenty-four hours to ensure they are using the device properly.{{cite book | vauthors = Taber CW, Venes D |title=Taber's encyclopedic medical dictionary |publisher=F a Davis Co |year=2009 |pages=108–9 |isbn=978-0-8036-1559-5}}

With an IV PCA the patient is protected from overdose by the caregiver programming the PCA to deliver a dose at frequent 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). The inability of an obtunded patient to push the button is also considered an inherent safety feature of PCA.{{cite book | vauthors = Ray N, Schmidt P, Ottestad E | date = 2017 | chapter = Management of acute postoperative pain. | veditors = Longnecker DE, Mackey SC, Newman MF, Sandberg WS, Zapol WM | title = Anesthesiology | edition = 3rd | publisher = McGraw Hill | chapter-url = https://accessanesthesiology.mhmedical.com/content.aspx?bookid=2152§ionid=164239256 | isbn = 978-0-07-184881-7 }}

=Epidural=

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.

=Inhaled=

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.{{cite journal | vauthors = Babl FE, Jamison SR, Spicer M, Bernard S | title = Inhaled methoxyflurane as a prehospital analgesic in children | journal = Emergency Medicine Australasia | volume = 18 | issue = 4 | pages = 404–410 | date = August 2006 | pmid = 16842312 | doi = 10.1111/j.1742-6723.2006.00874.x | s2cid = 1619160 }} 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.{{cite journal | vauthors = Babl F, Barnett P, Palmer G, Oakley E, Davidson A | title = A pilot study of inhaled methoxyflurane for procedural analgesia in children | journal = Pediatric Anesthesia | volume = 17 | issue = 2 | pages = 148–153 | date = February 2007 | pmid = 17238886 | doi = 10.1111/j.1460-9592.2006.02037.x | s2cid = 30105092 }} 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.

=Nasal=

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.{{cite journal | vauthors = Miaskowski C | title = Patient-controlled modalities for acute postoperative pain management | journal = Journal of PeriAnesthesia Nursing | volume = 20 | issue = 4 | pages = 255–267 | date = August 2005 | pmid = 16102706 | doi = 10.1016/j.jopan.2005.05.005 }}

=Transdermal=

Transdermal PCA using iontophoretic technology are also available. The most advanced ones are used for administration of opioids such as fentanyl. An adhesive is applied to the intact hairless skin, while a small electric current allows the ionized drug to cross the stratum corneum to deliver the analgesic dose upon the device being triggered by the patient.

Advantages and disadvantages

Advantages of 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.{{cite book| vauthors = Beers M |title=The Merck Manual of Diagnostics and Therapy |url= https://archive.org/details/merckmanual18the00mar |url-access=registration |edition=18th |year=2006 |publisher=Merck Research Laboratories |chapter=Injurie |isbn=978-0-911910-18-6 }}

Disadvantages include the possibility that a patient will use the pain medication non-medically, self-administering the narcotic for its euphoric properties even though the patient's pain is sufficiently controlled. If a PCA device is not programmed properly for the patient this can result in an under-dose or overdose in a medicine.{{cite encyclopedia |encyclopedia=Clinical Reference Systems |year=2010 |publisher=McKesson Health Solutions |volume=10 |title=Patient-controlled analgesia system (PCA)}} The system may also be inappropriate for certain individuals, for example patients with 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.

History

The PCA pump was developed and introduced by Philip H. Sechzer in the late 1960s and described in 1971.{{cite news |url=https://query.nytimes.com/gst/fullpage.html?res=9C07E5DB1138F937A35753C1A9629C8B63&n=Top/Reference/Times%20Topics/Subjects/D/Deaths%20(Obituaries) |title=Philip H. Sechzer, 90, Expert On Pain and How to Ease It | vauthors = Pearce J |date=2004-10-04 |newspaper=The New York Times |access-date=2010-11-22}}

References

{{Reflist|colwidth=30em|refs=

{{cite journal | vauthors = Dragon A, Goldstein I | title = Methoxyflurane: preliminary report on analgesic and mood-modifying properties in dentistry | journal = Journal of the American Dental Association | volume = 75 | issue = 5 | pages = 1176–1181 | date = November 1967 | pmid = 5233333 | doi = 10.14219/jada.archive.1967.0358 }}

{{cite journal | vauthors = Firn S | title = Methoxyflurane analgesia for burns dressings and other painful ward procedures in children | journal = British Journal of Anaesthesia | volume = 44 | issue = 5 | pages = 517–522 | date = May 1972 | pmid = 5044082 | doi = 10.1093/bja/44.5.517 | doi-access = free }}

{{cite journal | vauthors = Grindlay J, Babl FE | title = Review article: Efficacy and safety of methoxyflurane analgesia in the emergency department and prehospital setting | journal = Emergency Medicine Australasia | volume = 21 | issue = 1 | pages = 4–11 | date = February 2009 | pmid = 19254307 | doi = 10.1111/j.1742-6723.2009.01153.x | s2cid = 40158248 | doi-access = free }}

{{cite journal | vauthors = Josephson CA, Schwartz W | title = The Cardiff inhaler and penthrane. A method of sedation-analgesia in routine dentistry | journal = The Journal of the Dental Association of South Africa | volume = 29 | issue = 2 | pages = 77–80 | date = February 1974 | pmid = 4534883 }}

{{cite journal | vauthors = Major V, Rosen M, Mushin WW | title = Methoxyflurane as an obstetric analgesic: a comparison with trichloroethylene | journal = British Medical Journal | volume = 2 | issue = 5529 | pages = 1554–1561 | date = December 1966 | pmid = 5926260 | pmc = 1944957 | doi = 10.1136/bmj.2.5529.1554 }}

{{cite journal | vauthors = Packer KJ, Titel JH | title = Methoxyflurane analgesia for burns dressings: experience with the analgizer | journal = British Journal of Anaesthesia | volume = 41 | issue = 12 | pages = 1080–1085 | date = December 1969 | pmid = 4903969 | doi = 10.1093/bja/41.12.1080 | citeseerx = 10.1.1.1028.6601 }}

{{cite web|author=National Prescribing Service|title=Methoxyflurane (Penthrox) for analgesia (doctor's bag listing)|work=NPS RADAR|publisher=National Prescribing Service, Department of Health and Ageing|location=Canberra, Australia|year=2010|url=http://www.nps.org.au/__data/assets/pdf_file/0008/87866/OKA7754_NPS_RADAR_Methoxyflurane_V3.pdf|access-date=2010-11-21|author-link=National Prescribing Service}}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}

{{cite journal | vauthors = Romagnoli A, Busque L, Power DJ | title = The "analgizer" in a general hospital: a preliminary report | journal = Canadian Anaesthetists' Society Journal | volume = 17 | issue = 3 | pages = 275–278 | date = May 1970 | pmid = 5512851 | doi = 10.1007/BF03004607 | doi-access = free }}

{{cite web |title=Analgizer: Inhaler for supervised self-administration of inhalation anesthesia| vauthors = Wexler RE |publisher= Abbott Laboratories|location=Abbott Park, Illinois|year=1968|url=http://www.trademarkia.com/analgizer-72302697.html|access-date=2010-11-21}}

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