Our study consists of a combination of regional blockade ('local' anesthesia) of the anterior and lateral chest wall in the form of a thin needle prick and the supply of local anesthetic drugs to the area of the relevant chest wall structures to exclude all stimuli, including pain from the operative site. A short-acting analgesic and sedative drug will be administered intravenously throughout the procedure - in a dose that allows the required contact between the patient and the anesthetist. If necessary, the dose of the drug may be increased to maintain pain comfort throughout the procedure.

The anesthetic team will be with the patient throughout the procedure to ensure comfort and safety.

The current study is a continuation of the 2021-2023 project, during which 16 patients were anesthetized using a combination of previously known regional (PSP +SSAP) blocks in the thoracic area for S-ICD implantation. PSP (pectoserratus plane) block, previously known in scientific nomenclature as (PECS II /DPP/ PNB II) is a block placed under the pectoralis minor muscle between the pectoralis anterior muscle or also under it in the area of the III/IV rib lateral to the midclavicular line. SSAP (superficial serratus anterior plane) block is formerly known as SABP block, which is a block placed at the height of the fifth intercostal in the medial/posterior axillary line between the anterior pterygoid muscle and the dorsal widest muscle.

In some cases, this allowed the procedure to be carried out due to patient burdens, relative contraindications and high risk of complications during general anesthesia. After studies related to the volume of local anesthetics administered as well as the concentration of their mixture, the optimal concentration of the substance used for regional blockade was chosen. This is a mixture of 0.125% ropivacaine solution with 0.25% lidocaine solution in a total volume of 60mL of administered solution.

Superficial parastenal intercostal plane block (SPIP) formerly known as TTP/ PIP/ PIFP/ SIP/ PSP which is an alternative combination in combination with SSAP is a block in which we deposit a local anesthetic in the parasternal line at the level of the 4th and 5th intercostal spaces between the internal intercostal muscle and the transverse thoracic muscle.

The purpose of the study is to determine whether SPIP+SSAP blockade is the optimal form of anesthesia for S-ICD implantation.

The patient, after qualifying by the cardiologist for S-ICD implantation, will undergo a standard anesthesiological qualification process with evaluation of basic demographic parameters, examination of body mass composition by bioimpedance, comorbidities, medications taken, determination of surgical risk according to the ASA scale ( American Society of Anesthesiology) in addition, the patient will be checked for any contraindications to the use of regional blockade as a method of anesthesia. After qualification, the patient will be asked to read the consent to participate in the study and sign the informed consent form.

Patients will receive standard premedication in the form of 1g of paracetamol and 150mg of pregabalin orally 30min before the procedure.

The subjects will be randomly divided into 2 groups - Group I will be patients administered PSP+SSAP anesthesia (consecutively 20+40ml of the mixture indicated above). Group II will be patients given SPIP+SSAP blockade ( consecutively 20+40ml of the mixture indicated above). It was tentatively planned to conduct the study on a group of 32 patients (16 in each of the two groups).

Anesthesiologists administering anesthesia prior to surgery receive an envelope with a randomly indicated method of anesthesia based on simple randomization determines the type of regional blockade used during the procedure). The subject will not know which study group he or she has been classified into. The operator performing the procedure will not be informed of the type of anesthesia performed -[randomization by double-blinding]. The operator performing the procedure will not be informed about the type of block performed in order to objectivize the extent and quality of the subject's anesthesia, which he will evaluate after the procedure according to a scale of subjective operator comfort created (EOA scale).

During the procedure, i.v. analgesia with the short-acting opioid remifentanil in the dose range of 0.025ug/kg/min to 0.1ug/kg/min will be administered as needed to control pain.

Increasing the dosage of the drug above these doses for pain control will be a disqualifying factor for the patient from further examination and the blockade will be considered ineffective which will be associated with receiving the lowest possible value on the operator's comfort scale. The use of i.v analgesics in the form of ketoprofen 100mg, metamizole 2.5g will also be allowed during the procedure.

During the procedure, the operator will be allowed to additionally administer local anesthesia to the area of the surgical field where severe pain is experienced. Infiltration of the surgical field with a solution of 1% lidocaine with epinephrine in a volume of no more than 40ml will then be performed If it is necessary to exceed the volume of local anesthesia, the patient will be disqualified from further examination. After the procedure, for the purpose of test defibrillation (checking the function of the implanted device), the patient will be put under short-term deeper sedation with propofol at a single dose of 1-3mg/kg/m.c. on one occasion.

During the procedure, in order to assess the patient's pain, NRS(numerical pain scale) or VAS(visual analog scale) scales will be checked every 15min. At the same intervals, the patient's level of sedation will be assessed using the RASS (Richmond agitation/sedation scale) and GCS (Glasgow level of consciousness) scales. Parameters such as SpO2 (hemoglobin oxygen saturation) NIBP( non-invasive blood pressure measurement) or HR (heart rate) will be monitored every 5min.

The NRS check in post-operative care will be done every 6h on the first day, the QoR-15 form (post-operative quality of life and improvement scale) will be given to the patient to fill in 24h after surgery.

Inclusion Criteria:

• patients aged 18-90 years requiring S-ICD implantation for cardiac indications,
• high risk of anesthesia (ASA II or higher), patients giving informed consent to participate in the study.

Exclusion Criteria:

• absolute contraindications to regional anesthesia such as generalized coagulation disorders, inflammation at the site of anesthesia, allergy to the drugs used for regional anesthesia
• lack of consent of the patient for the conducted procedure,
• inability to cooperate with the patient - such as severe mental retardation, unregulated mental illness with motor agitation, advanced neurodegenerative diseases such as Parkinson's disease/Alzheimer's,
• inability to give informed consent to participate in the study.

Anesthesiologists administering anesthesia prior to surgery receive an envelope with a randomly indicated method of anesthesia based on simple randomization determines the type of regional blockade used during the procedure). The subject will not know which study group he or she has been classified into. The operator performing the procedure will not be informed of the type of anesthesia performed -[randomization by double-blinding]. The operator performing the procedure will not be informed about the type of block performed in order to objectivize the extent and quality of the subject's anesthesia, which he will evaluate after the procedure according to a scale of subjective operator comfort created (EOA scale).