Morfina: revisão sistemática acerca das vias de administração do fármaco em pacientes com dor pós-histerectomizadas

Abstract

Hysterectomy is one of the most performed surgeries in women after the fertile period, in which the removal of the uterus is performed, and it can be total or partial. As for the causes that lead to the indication of this procedure, uterine bleeding secondary to uterine leiomyomatosis stands out. The pain complaints of post-hysterectomized women are related to several factors, from the way the surgical procedure was performed to their biopsychosocial aspects. Among the pharmacological therapies for pain relief, morphine, an opioid drug widely used to control moderate and severe pain, can be administered mostly intravenously and orally. Thus, the objective of this systematic review is to analyze the influence of the routes of morphine administration in hysterectomized women with postoperative pain. The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews database under No. CRD42022357183. The search for the studies was performed in the Pubmed, Scopus, Lilacs, Web of Science, and Embase databases. Studies with hysterectomized women with postoperative pain, in which morphine was used, published until August 2022 that answered the guiding question were included: is the use of parenteral morphine more effective in controlling postoperative pain and reducing adverse effects in hysterectomized patients compared to oral administration? Letters/comments to the editor, editorials, review articles, and animal studies, as well as in languages other than English/Spanish/Portuguese were excluded. The risk of bias was measured by the Cochrane Risk and Bias Checklist (ROB 2) for randomized clinical trials. A total of 864 articles were identified for reading of titles and abstracts. After this step, 10 articles were selected to be read in full, and of these, one study was included, which was in their references, through manual search. All steps were performed by two independent researchers and discrepancies were resolved in consensus with other researchers. Data such as the main characteristics of the included studies, treatment characteristics, and outcome characteristics were extracted from the included study. The results suggest that patients who treated pain with the patient-controlled analgesia method after abdominal hysterectomy should start a conventional intermittent dosing regimen, and a continuous infusion should be used only if pain relief remains ineffective during analgesic treatment. Postoperative pain control in patients who underwent hysterectomy appears to be palpable through the use of opioid drugs, specifically morphine, when used intravenously. The results obtained lead to questioning, about the widely accepted idea that, patients make sufficient demands of analgesic drugs to maintain a blood concentration above the minimum effective concentration of the drug.