Effect of Intravenous Infusion of Lidocaine and Remifentanil Perioperatively in Patients Undergoing Mastectomy: a Prospective, Randomized, Double-blind Study

The opioid analgesics are commonly used in clinical practice for pain management in the perioperative period. However, many side effects are associated with its use, such as respiratory depression, nausea, vomiting, drowsiness, itching, urinary retention, constipation, hyperalgesia and impaired immune function. Therefore, alternative techniques and drugs have been used to replace their use. One is the intravenous infusion of lidocaine, a local anesthetic widely used in anesthetic practice. Studies show that the use of lidocaine during surgery significantly decreased postoperative pain. The mechanisms of analgesia this local anesthetic in surgical trauma may be blocking neuronal transmission in the lesion site alleviating neurogenic response, and anti-inflammatory systemic intrinsic activity. Intraoperative lidocaine promotes, besides analgesia, decreased consumption of both inhalational anesthetic and opioids; faster return of bowel movements; decreasing the production of interleukins and reduction of airway reactivity. This anesthetic also has significant anti-inflammatory properties, reduces cytokine release both in vitro and in vivo by inhibiting neutrophil activation. Besides there are few studies with use of intravenous lidocaine during the perioperative period, the intravenous injection of local anesthetic still arouses oddity among professionals; therefore, the investigators interest in the subject.

The patients underwent a prospective, randomized, double blind, in which the examiners responsible for intra and post operative will not know which group they were randomly allocated: Lidocaine group (n = 30) 3 mg / kg / h or Remifentanil group (n = 30) 0.1 mcg / kg / min.

In the clinical record, the following information will be emphasized: Blood pressure and heart rate intraoperative, perioperative side effects, quantify pain by Visual Analogue Scale (VAS) (ranging from 0 to 10 cm, zero being found when the patient is no pain and ten, with maximum or unbearable pain), Verbal Rating Scale (VRS), consisting of a list of phrases (no pain, mild pain, moderate pain, intense pain, maximum pain) and qualification of pain assessed by the amount of analgesics required postoperatively and the time to request them.

The results were analyzed statistically with the XLSTAT for Excel program using parametric and nonparametric tests, depending on the nature of the variables studied. Measures of central tendency (means) and dispersion (standard deviation) were used. The level of significance was set at < 0.05. The following tests were used: Mann-Whitney test for age, duration of anesthesia and surgery, time to first analgesic supplementation, total amount of analgesics, pain intensity; Student t-test for weight and height.