COMPARISON OF THE EFFECTS OF QUADRATUS LUMBORUM BLOCK AND ILIOINGUINAL-ILIOHYPOGASTRIC NERVE BLOCK ON INTRAOPERATIVE OPIOID CONSUMPTION GUIDED BY NOCICEPTION INDEX, POSTOPERATIVE ACUTE PAIN, AND CHRONIC PAIN IN LAPAROSCOPIC INGUINAL HERNIA REPAIR

The lifetime incidence of inguinal hernia is 27% in men and 3% in women. The primary treatment is surgical intervention. Postoperative pain is defined as acute pain that begins with surgical trauma and gradually decreases with tissue healing. As with all surgical procedures, the treatment and control of pain following inguinal hernia repair are of great importance. Adequate pain control enables faster recovery, reduces thromboembolic complications through early mobilization, decreases pulmonary complications by preventing restrictions in respiratory movements, sputum expectoration, and cough reflex, minimizes metabolic and endocrine stress responses, preserves cognitive functions, reduces the risk of chronic pain development, and shortens the duration of hospital stay. Preventing acute postoperative pain will also reduce the probability of chronic pain development.

In anesthetized patients, accurate pain assessment is crucial for the anesthesiologist to adjust analgesic drug levels. While adequate analgesic levels are critical to prevent unexpected movements, cardiovascular complications resulting from sympathetic reactions, and the development of pain memory, limiting dosage to the minimum effective level is desirable to avoid opioid-induced hyperalgesia, drug side effects, and to achieve shorter perioperative durations.

It is suggested that intraoperative hemodynamic and stress responses, as well as postoperative chronic pain syndromes, are primarily caused by the poor control of nociceptive conditions. Techniques have been developed for more effective monitoring of the analgesia component of anesthesia to guide the administration of analgesics in order to provide an appropriate balance of nociception and antinociception. Nociception monitoring can be achieved through "central nervous system-based," "autonomic nervous system-based," and "spinal reflex-based" monitors. Autonomic nervous system-based monitors include pupillometry, the Analgesia Nociception Index (ANI), the Surgical Pleth Index, the Nociception Level Index, and skin conductance monitors.

The Analgesia Nociception Index (ANI) monitor is derived from heart rate variability, ranging from 0 (maximal nociception) to 100 (maximal analgesia) to reflect the analgesia/nociception balance during general anesthesia, and it detects changes in sympathovagal balance caused by surgical stimuli in the heart rhythm. Higher ANI values represent higher parasympathetic activity and likely less pain. Pain monitors not only help us avoid unnecessary opioid consumption but also assist in reducing opioid-related side effects such as nausea-vomiting, urinary retention, opioid-induced hyperalgesia, and physical dependence.

The incidence of chronic postoperative pain in patients undergoing inguinal hernia repair has been observed to be approximately 22.3% at the 3rd month. Chronic pain development affects the patients' mood and daily living activities. Although there are many mechanisms in the pathology of chronic pain formation after inguinal hernia surgery, research has shown that the preemptive blockade of the iliohypogastric-ilioinguinal nerves is effective in reducing the incidence of postoperative acute and chronic pain.