The hypothesis of this study is that preincisional scalp nerve block will reduce postoperative opioid use and surgical stress response compared to postincisional scalp nerve block in craniotomy surgery with general anesthesia.

Craniotomy is an effective treatment method for cerebral diseases and injuries, and postoperative pain is an important clinical problem. The most painful stages of craniotomy are the placement of a nail head and skin incision. Therefore, in these stages, it is necessary to increase the depth of anesthesia with additional analgesic administration to prevent hemodynamic responses such as tachycardia and hypertension. In patients with impaired cerebral autoregulation, a sudden increase in systemic blood pressure can cause a sudden increase in intracranial pressure, which accelerates intracranial hypertension. High oxygen consumption and catecholamine release caused by postoperative pain can lead to increased cerebral perfusion and increased intracranial pressure, which can predispose to intracranial hematoma. Effective postoperative pain management is important to prevent these systemic changes, improve rehabilitation, and improve long-term outcomes.

In addition, early postoperative pain management can prevent the development of central sensitization and chronic pain caused by surgical tissue damage.

In recent years, studies aimed at controlling postoperative pain starting from the preoperative period have brought the concept of preemptive analgesia to the agenda. Preemptive analgesia is applied before the painful stimulus in order to reduce the pain. Studies have suggested that surgical trauma causes an increase in nociceptive afferent transmission and causes changes in the excitation threshold in both peripheral and central neurons, and it is thought that postoperative pain can be controlled by preoperative blockade of this mechanism. Multimodal analgesia includes the use of single agents in postoperative pain control, especially the use of different pain control mechanisms to reduce the opioid dose, improve the analgesic effect and minimize the risk of side effects.

Scalp nerve block (SSB) is widely used to reduce hemodynamic response and incisional pain during craniotomy. Analgesia can be achieved by blocking the greater and lesser occipital nerves, supraorbital and supratrochlear nerves, zygomatico-temporal nerve, auriculo-temporal nerve and greater auricular nerve. SBB is combined with non-opioid drugs with different mechanisms of action to maximize the analgesic effect. Traumatic stimulation, such as surgery, acts on peripheral nerve pain receptors and produces nerve impulses that are transmitted to spinal dorsal horn neurons via Aδ and C fibers, and pain occurs after loading and integration. SSB can interrupt this pathway. Effective postoperative analgesia can reduce complications and mortality.

Inclusion Criteria:

• Age range 18-65
• ASA 1-3 score

Exclusion Criteria:

• Chronic hypertension
• Arrhythmia
• body mass index (BMI) over 40 kg/m2
• Bleeding diathesis
• Allergy
• Serious cardiovascular, pulmonary, renal and hepatic disease
• Local infection at the injection site
• Alcohol and substance abuse
• Neurological sequelae, mental retardation
• GCS under 15
• Patients admitted to the intensive care unit as intubated
• Pregnancy
• Those with a history of chronic pain
• Scalp infection
• Use of vozoactive drugs
• Patients with previous craniotomy
• Patients who do not accept

Patients who will undergo cranitomy with general anesthesia