Patient controlled analgesia and intramuscular injections: a comparisons of patient pain experiences and postoperative outcomes.

Abstract

Despite relatively widespread use of various forms of patient controlled analgesia (PCA), there remain conflicting results in the literature as to the efficacy of PCA. This study was conducted to assess the efficacy and postoperative outcomes of intravenous PCA compared to intramuscular (IM) injections in 73 patients who received major abdominal surgery. These patients were randomly selected and randomly assigned preoperatively to receiving IM or PCA modes of analgesia postoperatively. The following factors were compared: amount of pain; amount of analgesia use; degree of patient satisfaction with pain control both while on parenteral analgesia and after switching to oral; length of time to first ambulation; and length of stay in hospital. Results of the study did not demonstrate a statistically significant difference in any of these, using a P-value of 0.01. The PCA patients took an average of 4.5 hours longer than the IM patients to ambulate postoperatively and the IM patients received at least three times as much antiemetic (P = 0.001). Locus of control was not found to be a major factor in satisfaction or pain levels. Subsequent meta-analyses have also failed to yield significant differences between IM and PCA groups except in patient satisfaction. It is recommended that expansion of PCA programmes with abdominal surgery patients be considered only in cases where there is fiscal advantage or where patient satisfaction can be a driving force.