Patient-Controlled Analgesia (Encyclopedia of Surgery)
Patient-controlled analgesia (PCA) is a means for the patient to self-administer analgesics (pain medications) intravenously by using a computerized pump, which introduces specific doses into an intravenous line.
The purpose of PCA is improved pain control. The patient receives immediate delivery of pain medication without the need for a nurse to administer it. The patient controls when the medication is given. More importantly, PCA uses more frequent but smaller doses of medication, and thus provides more even levels of medication within the patient's body. Syringe-injected pain management by a nurse requires larger doses of medication given less frequently. Larger doses peak shortly after administration, often causing undesirable side effects such as nausea and difficulty in breathing. Their pain-suppressing effects also often wear off before the next dose is scheduled.
PCA uses a computerized pump, which is controlled by the patient through a hand-held button that is connected to the machine. The pump usually delivers medications in small regular doses, and it can be programmed to issue a large initial dose and...
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Patient-Controlled Analgesia (Encyclopedia of Nursing & Allied Health)
Patient-controlled analgesia (PCA) is a system of providing pain medication that allows the patient to self-administer synthetic, opium-like pain-relievers (opioids) on an "as-needed" basis, but only within the limit of a maximum dose every eight (or 12) hours. A pump-type device delivers the medicine into the veins (intravenously, the commonest of the three methods), under the skin (subcutaneously), or between the dura mater and the skull (epidurally). A health care provider programs the device both with the specific dosage to deliver at each request made by the patient and with the total permitted during the time for which the device is set (commonly eight hours, sometimes 12, especially if the health-care providers are working 12-hour shifts). Some of these devices are very sophisticated and even monitor themselves and ring an alarm-bell if there is an indication that they might be malfunctioning.
The purpose of PCA is improved pain control. PCA allows for immediate delivery of pain medication without the delay that would occur if a nurse, busy with many other patients on the floor, must answer the patient's buzzer or other signal. (It is not as needed if the patient has a full-time, private-duty nurse in the room every minute.) PCA also allows more frequent but smaller doses and thus a more even level of the pain-killer in the patient's body. The busy nurse must administer larger doses at one time. Unfortunately, these larger doses peak shortly after administration, often causing undesirable side-effects such as nausea and difficulty in breathing. Their effect often wears off before the next dose is scheduled.
Using such a pump requires an understanding of how to work it and the physical strength to do so (usually by pressing a button). Therefore, PCA should not be offered to patients who are confused, unresponsive, or paralyzed. Patients with neurologic disease or head injuries in whom narcotics would mask neurologic changes are not eligible for PCA. Patients with poor kidney or lung function are usually not good candidates for PCA, unless they are monitored very closely.
PCA may be used by children as young as seven years old. It has proven safe and successful in such children in the control of postoperative pain, sickle-cell pain, and pain associated with bone-marrow transplantation.
Whenever opium-like pain-killers are administered to the elderly patient, the health care professional must keep several things in mind: older adults may be more susceptible to side effects of narcotics because their heart, liver, and kidneys work less well than when they were younger. The elderly may also clear the narcotic out of their system more slowly. If the pump's timing device is calibrated for the typical younger person's rate of eliminating the drug, the elderly patient, who still has much of an earlier dose in the bloodstream, could accidentally receive an overdose. The health care provider should calculate the doses more conservatively for such elderly patients.
PCA uses a computerized pump that delivers a drug in small doses controlled by the patient. The same pump may also be programmed to deliver a large initial dose, or a steady, even flow of pain medications. The large initial dose or the steady flow is, of course, not patient-controlled analgesic at all, but the same pump can deliver the drug in these two ways when it is not advisable for the patient to control the medication.
The patient presses a button when medication is desired. When this button is pressed, some sound (usually a beep) is heard, indicating that the pump is working properly and that the button was pressed correctly. The nurse should instruct the patient to call a health care provider if the pump doesn't beep (or if its alarm sounds). The pain-killers most commonly used in PCA pumps are morphine and meperidine (Demerol). The pump delivers the medication through a plastic tube (the line) and a needle.
The pump may be set to deliver a larger initial dose of the drug (for example, 2 mg of morphine delivered one time only). The health care provider sets the pump to deliver a specified dose on demand with a lock-out time (for example, 1 mg of morphine on demand, but not more frequently than one dose every six minutes). If the patient presses the button before six minutes have elapsed, the pump will not administer the medication. It also generates a record which the health personnel can read to discover that the patient has indeed been pushing the button more frequently than every six minutes. An around-the-clock, even dose may also be set. The practitioner sets an total limit for an hour (or other period) that takes into account the initial dose, the demand doses, and the around-the-clock doses. The pump's computerized controls calculate all these amounts nicely, make a record of the requests it received, of the requests it refused, and even keep inventory and warn the staff when the supply of the drug is getting low.
Here is an example of how a nurse might program the pump. A patient has a prescription for a maximum of 11 mg of morphine an hour. The nurse sets the machine to deliver 1 mg at the beginning of the hour, and 1 mg on demand with a six-minute lock-out. There are 10 six-minute periods in an hour, so the patient could request and receive 10 mg. If he or she pressed the button every three minutes for a total of 20 times, the machine would deliver the same 1 mg every six minutes for the same total of 10 mg as if the patient had conscientiously cooperated with the prescription. The patient who pushed the button only three times for a total of 3 mg would probably be congratulated by the health professionals for being well on the way to recovery and therefore not needing as much pain medication. The nurse might program the machine to give an initial 2 mg, to give 3 additional mg at a steady rate throughout the hour (one twentieth of a mg every minute). That would use up 5 of the patient's 11 mg. That in turn leaves 6 mg on demand throughout the hour. There are six 10-minute periods in one hour, so the lock-out time would be 10 minutes.
When preparing to initiate PCA, the nurse must assess the patient to determine that PCA is indeed applicable in this case. and must then set the total dose and the timings as prescribed by the physician. The small amount of drug prescribed (3,000 doses of 10 mg each weigh less than 1 oz total) would not be sufficient to keep the plastic tube (the line) and the needle through which the drug moves from the pump into patient from clogging and the contents from coagulating. Therefore, the drug must be administered in a solution that will flush out the tube and needle (a flush solution), keep them open, and permit rapid administration The flush solution may also be used if the patient has a reaction to the opioid, to keep the line open for administration of other medication. For example, a patient may have a bad reaction to the pain-killing drug and thus need counteractive medication in a great hurry. The flush solution can also help keep the patient from becoming dehydrated. Likewise, many pain-killers prescribed (such as morphine sulfate) are solid crystals at room temperature, and hence would have to be dissolved in some fluid in any event.
When entering the settings into the system, the nurse must pay close attention to the physician's orders to ensure that the correct medication is used (there are different pain-killing drugs), that the concentration of the drug in the flushing solution is correct, that the dose of the drug itself is correct, that lock-out time is appropriate, and that the total hourly limit is properly entered into the pump's computerized controls. To eliminate the risk of incorrect programming, many institutions have adopted policies that require verification by an RN witness for all programming. That is, everything must be checked by a second nurse, and both must sign the written record.
Another important aspect of PCA is patient education. The settings on the PCA pump must be explained to patients so that they understand how and when medications will be available. The nurse should observe the patients as they first start using the button, should ensure that the equipment is functioning properly, and that the patients understand their role in the process and are carrying it out correctly.
While using PCA, patients should be assessed frequently to ensure that they are not being excessively sedated, that they are breathing enough, that the control of their pain remains effective, and that no dangerous side-effects to the medication arise. The nurse must also check regularly to see that the line and needle delivering the drug in the flush solution remain open and thus to enure that the medication is really getting into the patients, not merely into the line, as programmed.
Problems that may occur with PCA include allergic reactions to the medications and adverse side-effects such as nausea, a dangerous drop in the rate and effectiveness of breathing, and excessive sedation. The device
Analgesia medicine that relieves pain.
Basal infusionn around-the-clock, or continuous, even dose of a medication. It is one possible setting on a PCA pump.
Bolus large, one-time-only initial dose of medication. A bolus is usually given only when PCA is initiated, but it may also be given if pain is uncontrolled with the basal and on-demand settings.
Demand dose dose of pain-killer that is given when the patient requests it by pressing a button which activates a pump.
Lock-out timehe minimum amount of time (usually expressed in minutes) after one dose of pain-medication on demand is given before the patient is allowed to receive the next dose on demand.
Opiate drug which contains opium or an alkaloid derived from opium.
Opioid synthetic drug resembling opium or alkaloids of opium.
Respiratory depressionecreased rate (number of breaths per minute) and depth (how much air is inhaled with each breath) of breathing It is an undesired side-effect of many opioids. It leads to insufficient oxygen in the body. It can be very severe, even leading to death.
Sedation side-effect of many opioids that can range from a feeling of slight tiredness to semi-consciousness.
must be monitored frequently to prevent tampering by the patient or family. Many patients would love to change that 10-mg-an-hour maximum to 100. Even sophisticated devices that monitor themselves and sound an alarm when there are indications of something wrong should be checked, since no such machine is perfect. Ineffective pain control must be assessed to determine whether the problem stems from inadequate dosage or from inability, or unwillingness, of the patient to obey the rules.
The goal of patient-controlled analgesia is pain control enhanced by a more stable and constant level of the pain-killer in the patient's body than the peaks and valleys often found in the presence of the drug in the body when a nurse administers, for example, only one dose in one hour. PCA also gives the patient some control in an unfamiliar and uncomfortable situation where so much else depends on the actions of others. When administered properly, and with watchful assessment by health care providers, PCA can be a safe alternative to traditional methods of relieving pain.
Interestingly enough, studies have shown that when patients control their pain-killing medication, most of them use less pain medication overall than similar patients who have nurse-administered pain-killers.
Health care team roles
The nurse has a great responsibility with PCA, first of all to ensure that the pump is set and filled correctly and that the tube or line delivering the medication remains open. While PCA is in use, the nurse has an ongoing responsibility to assess the patient's level of pain, to monitor the patient's vital signs, and to check for any indications that the system is not working properly, or that the dose and settings may be inappropriate for the patient.
Patient education is an extremely important part of PCA. The patient must be taught about the different settings on the PCA pump. Most pumps lock so that patients and family members cannot tamper with them. However, patients may need to be reminded that the settings programed have been determined by their physician to be safe for them and that altering those settings may result in complications. A large, unauthorized overdose could result in death. On the other hand, patients who fear that the pump may give them an overdose should be reassured by information about the lock-out and hour limit settings.
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Potter, Patricia A., and Anne G. Perry. Fundamentals of Nursing Concepts, Process, and Practice. 4th ed. St. Louis: Mosby, 1997.
Eade, Diane M., R.N. "Patient-controlled Analgesialiminating Errors." Nursing Management 28, no. 6 (June 1997): 380.
Ellis, Jacqueline A., R.N., Ph.D.; Renee Blouin. R.N., B.Sc.N.; and Jean Lockett, R.N. "Patient-Controlled Analgesia: Optimizing the Experience." Clinical Nursing Research 8, no. 3 (August 1999): 28394.
American Association of Nurse Anesthetists/AANA. 222 South Prospect Avenue, Park Ridge, IL 60068-4001. (847) 692-7050. Fax: (847) 692-6968. . <<a href="http://www.aana.com">http://www.aana.com>.
American Society of Anesthesiologists/ASA. 520 North Northwest Highway, Park Ridge, IL 60068-2573. (847) 825-5586. Fax: (847) 825-1692. .
American Society of PeriAnesthesia Nurses/ASPAN. 10 Melrose Avenue, Suite 110, Cherry Hill, NJ 08003-3696. (877) 737-9696 (toll-free). Fax: (856) 616-9601. . <<a href="http://www.aspan.org">http://www.aspan.org>.
The National Hospice and Palliative Care Organization/NHPCO. 1700 Diagonal Road, Suite 300, Alexandria, VA 22314. (703) 837-1500. .
Jennifer Lee Losey, R.N.