Hemodynamic and Cerebral Effects Evaluation in Anesthesia

Recently, there has been an increase in the popularity of minimally invasive surgical techniques, including arthroscopic surgeries for shoulder procedures. Interscalene block is currently the gold standard technique for these surgeries, combined or not with general anesthesia. The last, when used in patients positioned in a beach chair can lead to serious hemodynamic and cerebral changes in the patients. Continuous non-invasive monitoring of the patient's cardiac output can provide data for better hemodynamics management compared to standard monitoring. Therefore, the aim of the study is to compare hemodynamic changes (cardiac output, blood pressure, heart rate, oxygen saturation) and intraoperative cerebral oxygenation using peripheral cerebral saturation monitoring with continuous measurement of cardiac output or standard hemodynamic between two anesthetic techniques for shoulder surgery: interscalene block with sedation versus interscalene block with general anesthesia. The groups will be evaluated as follows: group 1 general anesthesia plus interscalene brachial plexus block and group 2 sedation plus interscalene brachial plexus block. Additionally, each group will be subdivided into two more groups, one with continuous hemodynamic monitoring and the other with standard hemodynamic monitoring, that is, a total of 4 groups in the study. The analyzed variables will include gender, age, ASA, medications in use, comorbidities. Furthermore, duration of procedure and in the anesthetic recovery room, blood pressure, heart rate, cardiac output, peripheral oxygen saturation, cerebral oxygen saturation, BIS value, cardiac index, etCO2 will be evaluated. Besides, length of hospital stay, delirium, behavioral status and postoperative complication will also be assessed.

The study will be split in 4 groups, being group 1A general anesthesia plus interscalene brachial plexus block with continuos non-invasive monitoring, group 1B general anesthesia plus interscalene brachial plexus block with standard hemodynamic monitoring, group 2A sedation plus interscalene brachial plexus block with continuos non-invasive monitoring, gruop 2B sedation plus interscalene brachial plexus block with standard hemodynamic monitoring.

The standard hemodynamic monitoring includes blood pressure, heart rate, peripheral oxygen saturation, brain monitoring and cerebral oxygen saturation. The continuos non-invasive monitoring includes the standard monitoring plus cardiac output, cardiac index and hypotension predict index. These variables will be analyzed intraoperatively and compared between groups with the aim of demonstrating the benefit of continuous non-invasive monitoring.

In the postoperative will be evalueted delirium, lenght hospital stay, postoperative complication and pain. We will use the Richmond Agitation Sedation Scale (RASS), Confusion Assessment Method in the ICU, visual analogue pain scale and visual numeric pain scale for evaluation postoperative.

Eligibility Criteria:
Inclusion Criteria:

* Undergoing arthroscopic shoulder surgery in a beach chair position.

Exclusion Criteria:

* Emergency surgery
* Blood dyscrasia
* Refusal of the procedure
* Infection at the puncture site
* Allergy to the medication used
* Previous cerebrovascular disease
* History of orthostatic hypotension
* Pulmonary disease
* Chronic use of opioids
* Performance of arthroscopic surgeries on both shoulders
* Refusal to participate in the study
* Not to sign an informed consent form.