Patient-controlled analgesia
Encyclopedia
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.
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.
that delivers an amount of intravenous analgesic (usually an opioid) that is set by the patient. 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.
Narcotic
s 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.
, by way of intermittent bolus
es or infusion pumps. This can be used by women in labour, terminally ill cancer patients or to manage post-operative pain.
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 in length 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 fracture
s 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 score
s. 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
.
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.
in the late 1960s and described in 1971.
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
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.
Oral
The most common form of patient-controlled analgesia is self-administration of oral over-the-counterOver-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
or prescription
Prescription drug
A prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...
painkillers. For example, if a headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
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.
Intravenous
In a hospital setting, a PCA refers to an electronically controlled infusion pumpInfusion pump
An infusion pump infuses fluids, medication or nutrients into a patient's circulatory system. It is generally used intravenously, although subcutaneous, arterial and epidural infusions are occasionally used....
that delivers an amount of intravenous analgesic (usually an opioid) that is set by the patient. 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.
Narcotic
Narcotic
The term narcotic originally referred medically to any psychoactive compound with any sleep-inducing properties. In the United States of America it has since become associated with opioids, commonly morphine and heroin and their derivatives, such as hydrocodone. The term is, today, imprecisely...
s 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.
Epidural
Patient-controlled epidural analgesia (PCEA) is a related term describing the patient-controlled administration of analgesic medicine in the epidural spaceEpidural space
In the spine, the epidural space is the outermost part of the spinal canal. It is the space within the canal lying outside the dura mater...
, by way of intermittent bolus
Bolus (medicine)
In medicine, a bolus is the administration of a medication, drug or other compound that is given to raise its concentration in blood to an effective level...
es 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 LaboratoriesAbbott Laboratories
Abbott Laboratories is an American-based global, diversified pharmaceuticals and health care products company. It has 90,000 employees and operates in over 130 countries. The company headquarters are in Abbott Park, North Chicago, Illinois. The company was founded by Chicago physician, Dr....
developed the Analgizer, a disposable inhaler
Inhaler
An inhaler or puffer is a medical device used for delivering medication into the body via the lungs. It is mainly used in the treatment of asthma and Chronic Obstructive Pulmonary Disease . Zanamivir , used to treat influenza, must be administered via inhaler...
that allowed the self-administration of methoxyflurane
Methoxyflurane
Methoxyflurane is a halogenated ether that was in clinical use as an volatile inhalational anesthetic from its introduction by Joseph F. Artusio et al in 1960 until around 1974. It was first synthesized in the late 1940s by William T...
vapor
Vapor
A vapor or vapour is a substance in the gas phase at a temperature lower than its critical point....
in air for analgesia. The Analgizer consisted of a polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
cylinder 5 inches in length and 1 inch in diameter with a 1 inch long mouthpiece. The device contained a rolled wick
Candle wick
A candle wick is a string, cord, or wooden object that holds the flame of a candle. A candle wick works by capillary action, drawing the fuel to the flame. When the liquid fuel, typically melted candle wax, reaches the flame it then vaporizes and combusts. The candle wick influences how the...
of polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
felt
Felt
Felt is a non-woven cloth that is produced by matting, condensing and pressing woollen fibres. While some types of felt are very soft, some are tough enough to form construction materials. Felt can be of any colour, and made into any shape or size....
which held 15 milliliters of methoxyflurane. Because of the simplicity of the Analgizer and the pharmacological
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
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
Amnesia
Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...
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
Obstetrics
Obstetrics is the medical specialty dealing with the care of all women's reproductive tracts and their children during pregnancy , childbirth and the postnatal period...
patients during childbirth, as well as for patients with bone fracture
Bone fracture
A bone fracture is a medical condition in which there is a break in the continuity of the bone...
s and joint dislocations, and for dressing changes on burn
Burn
A burn is an injury to flesh caused by heat, electricity, chemicals, light, radiation, or friction.Burn may also refer to:*Combustion*Burn , type of watercourses so named in Scotland and north-eastern England...
patients. When used for labor analgesia, the Analgizer allows labor to progress normally and with no apparent adverse effect
Adverse effect
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
on Apgar score
Apgar score
The Apgar score was devised in 1952 by the eponymous Dr. Virginia Apgar as a simple and repeatable method to quickly and summarily assess the health of newborn children immediately after birth...
s. All vital signs
Vital signs
Vital signs are measures of various physiological statistics, often taken by health professionals, in order to assess the most basic body functions. Vital signs are an essential part of a case presentation. The act of taking vital signs normally entails recording body temperature, pulse rate ,...
remain normal in obstetric patients, newborns, and injured patients. The Analgizer was widely utilized for analgesia and sedation
Sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure...
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
Penthrox inhaler
The Penthrox inhaler, manufactured and marketed by Medical Developments International , is a hand-held inhaler device which can be used for the self-administration of methoxyflurane for analgesia .-Indications:...
.
Transcutaneous
Transcutaneous delivery systems, including iontophoreticIontophoresis
Iontophoresis is a technique using a small electric charge to deliver a medicine or other chemical through the skin. It is basically an injection without the needle...
systems, are available. These are popular for administration of opioids such as fentanyl, or local anesthetics such as lidocaine
Lidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
. Iontocaine
Iontocaine
Iontocaine, known by the brand name Numby, is a local anesthetic with vasoconstrictor, administered via iontophoresis through the skin. It can numb up to 10 mm of skin as quick as 10 minutes. It is a 2% lidocaine, 0.01 mg/ml epinephrine solution. It was manufactured by IOMED, Inc.Iontocaine was...
is one example of such a system.
Advantages and disadvantages
Advantages of the use of Patient Controlled Analgesia include the lack of waiting time for patients requiring pain medication before a caregiver can increase the dosage of medication. In this way, 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. Disadvantages include the possibility that the button can accidentally pressed, delivering an unneeded increase in the dosage of the medication. Many newer systems have mechanisms to prevent this. Also, if a PCA device is not programed properly for a patient it can result in an under-dose or overdose in a medicine.History
The PCA pump was developed and introduced by Philip H. SechzerPhilip H. Sechzer
Philip H. Sechzer was a pioneer in anesthesiology and pain management. He was the inventor of patient-controlled analgesia , now commonly used post-operatively...
in the late 1960s and described in 1971.
Further reading
- 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
- Fast Fact and Concept #085: Epidural Analgesia, End of Life/Palliative Education Resource Center, Medical College of WisconsinMedical College of WisconsinMedical College of Wisconsin is a private, freestanding medical school and graduate school located in Milwaukee, Wisconsin, United States. It was formerly affiliated with Marquette University....
- White PF: use of patient-controlled analgesia for the treatment of acute pain. JAMA 1988;259:242-247