The size of the maintenance (PCA) dose is the primary determinant of the effectiveness of PCA.
Therefore, titration of the maintenance (PCA) dose, based on objective caregiver assessment of pain, is the cornerstone of PCA therapy.
Patient-controlled analgesia (PCA) is a method of providing analgesia using a computerized pump that allows patients to self-administer predetermined doses of opioids.
Continuous Infusion Examples: Patient utilizes 72 mg morphine over the preceding 12 hours Average hourly usage = 6 mg (72 mg 12 hours) Titration Titration of maintenance (PCA) dose is based on pain and sedation scores.
With the use of opioids, complete eradication of pain is often unattainable without an unacceptable incidence of serious side effects.
The default limit four-hour limit is 30 mls of the solution, so the concentration of the selected agent will determine the mcg or mg amount of opioid.
Although no four hour limit can be selected it is advisable to have a warning of high opioid use ensure repeated patient assessment. For acute pain, which is subject to rapid change, the continuous infusion rate should be approximately one-third of the average hourly usage. cancer, mucositis), up to two-thirds of the average hourly usage is appropriate.
The loading dose should be repeated every 5 -10 minutes (5 minutes for fentanyl) so that the effect of the dose is felt before the next dose is administered.
The size of the initial loading dose is influenced by: If the initial 3 to 4 loading doses are ineffective the loading dose can be increased by 25 to 50 % after an appropriate assessment of the patient.
The lockout interval (LOI) is a necessary safeguard to prevent patients from taking an additional dose before appreciating the effect of the preceding dose.
The refractory period limits the potential of the patient administering an inadvertent overdose due to the "stacking" of opioid doses.
Pain scores of With inadequate analgesia the initial step should be an appropriate loading dose followed by an increase in the size of the PCA dose.