Prioritization of Cerebral Deoxygenation in Severe Traumatic Brain Injury and Mortality Benefit.

Severe traumatic brain injury with a decrease in cerebral oximetry is associated with multiple impaired systemic microcirculations, more morbidities, and a higher mortality rate. When using the brain as an index organ, interventions to improve brain oxygen delivery may have systemic benefits for these patients.

We conducted a prospective interventional study. Data from all 80 severe traumatic brain injury patients were randomized to either perioperative cerebral regional oxygen saturation (rSO2) monitoring with an intervention protocol to prevent cerebral desaturation (intervention, n = 40), or underwent blinded rSO2 monitoring (control, n = 40). Predefined clinical outcomes were assessed by a blinded observer. 40 were retrieved on April 1, 2021 to February 28, 2024. Data collection comprised of patients' demographic data, treatment process, and outcomes of treatment was implemented in the intensive care unit. The pre-intervention included all consecutive severe traumatic brain injury patients admitted as participants. After ethic approval in all methods and obtaining written informed consent from the legal relatives, severe traumatic brain injury patients were enrolled on the basis of inclusion criteria of age ≥ 20 years, Patients were recruited from the preoperative clinic in cases of neurosurgery with agreement. Upon arrival in the emergency department, the randomization envelope was opened, and patients were assigned into either active treatment (intervention) or usual care (control) groups with cerebral oximetry monitoring using NIRS bilaterally (Root; Prime Medical Corporation, MASIMO, USA). After cleansing the adjacent skin area with alcohol, an adhesive optode pad was placed over each frontal to temporal area. Resting baseline rSO2 values were obtained after waiting at least 1 minute after the placement of the sensors. Once values had stabilized, the screen was electronically blinded, and the time monitoring and baseline parameters were recorded by taking the data frequency of 1 minute, 3 minutes after the start recording. For the intervention group, an alarm threshold at 55% of the resting baseline rSO2 value was established. Continuous rSO2 values were stored on a floppy disk with a 15-second update for the duration of the perioperative period. With the application of the scalp dressing and before leaving the ICU, monitoring was discontinued, and optodes were removed after discharge from the ICU for 10 days.

For all severe traumatic brain injury patients, the best clinical practices aim at maintaining hemoglobin (Hb) levels greater than 7 g/dl, blood glucose within the institutional normal range of 80-180 mg/dl, and mean arterial pressure (MAP) of 65 mmHg in the intensive care unit. In the intervention group, a prioritized management protocol was used to maintain rSO2 values at or above 55% of the baseline threshold. With a decrease in rSO2, the patient's head position was checked to ensure that it had not been rotated or kinked, and the face was observed to detect plethora. If PaCO2 or end-tidal CO2 was below 40 mmHg during positive pressure ventilation, ventilation was reduced to achieve PaCO2 ≥ 40 mmHg. If MAP was \< 65 mmHg, 40 μg increments of intravenous norepinephrine were administered to achieve an MAP ≥ 65 mmHg. If the cardiac index was \< 2.0 L/m2/min, administration of dobutamine increased to 2.5 L/m2/min. In patients with persistent rSO2 below the treatment threshold, FiO2 was increased. If Hb was below 7 g/dl, a red blood cell transfusion was administered immediately. Cerebral oximetry monitoring was continued after discharge from the intensive care unit for 10 days. To maintain participant blindness, no study group identifiers were included with the patient or in the patients' charts. For neurosurgical intensive care unit postoperatively, all patients were transferred to an autonomous, protocol-given, "closed" neuro-intensive care unit under the exclusion care of an intensive care unit intensivist without direct reference to the attending neurosurgeons or anesthesiologists. Criteria for discharge from the intensive care unit comprised (1) hemodynamic stability defined as absence of vasopressor or inotropic drugs, removal of arterial and pulmonary artery or central venous catheters, and absence of cardiac arrhythmias; (2) post-extubation respiratory parameter adequacy with maintenance of pulse oximetry (SpO2) \> 95% with supplemental O2 below 5 L/min; (3) level of consciousness appropriate sufficient to protect their airway; and (4) good kidney function (urinary output ≥ 0.5 mL/kg/hr). Data on ICU admission and discharge times, and use of a vasopressor were obtained from the intensive care unit database.

The sample size was based upon a projected near infrared spectroscopy (NIRS)-derived tissue oxygenation published in Annual Intensive Care 2012 about the correlation between near infrared spectroscopy (NIRS) in anesthesia and intensive care and brain tissue oxygenation and major organ function. As a priority assumption, we hypothesized that a 50% reduction in the incidence of overall complications would be associated with active NIRS cerebral oximetry. Accepting a p-value \< 0.05 for statistical significance and a β error of 0.2, we determined that 40 patients in each group were required for this study. The randomization method was done by blinded envelopes assigning treatment allocation and placing them in computer-generated random order, which were written in order to sequentially identify each subject that registered in this protocol and was disclosed in the neurosurgical ICU. Cerebral deoxygenation means a reduction in saturation below 55% of baseline for 1 minute or longer. To minimize the probability of patients reaching these levels, interventions to improve cerebral oxygenation were administered when rSO2 decreased to \< 55% of baseline for \> 15 s. Mean and minimum values of rSO2. Categorical values are presented as numbers (percentage) and were analyzed using contingency table analysis, Fisher's exact test, χ2, and Wilcoxon's rank sum tests as appropriate. Continuous variables are presented as mean ± SD using an unpaired t-test or ANOVA for analysis, with a p-value \< 0.05 required for statistical significance.

80 patients in the ICU were monitored for invasive arterial blood pressure, peripheral O2 saturation (SpO2), and electrocardiograms. Sedative and paralysis agents were given; keep the Richmond Agitation Sedation Scale (RASS) less than -3 and the Bispectral Index (BIS) 40-60 monitoring based on bedside intensivist judgment, including fentanyl, propofol, midazolam, and cisatracurium. Patients were mechanically ventilated using a volume-control ventilation mode with a tidal volume of 8 ml/kg, a respiratory rate adjusted to maintain normocapnia, an inspired oxygen fraction adjusted to maintain SpO2 above 95%, and an inspiratory/expiratory ratio of 1:2. The inclusion criteria were age more than 20 years old, Severe traumatic brain injury defined as Glasgow coma scale \< 8, and the exclusion criteria were patients who had a pregnancy, an infection at the forehead, a status epilepticus, a history of drug addiction, and Severe traumatic brain injury combination with metabolic causes.

Eligibility Criteria:
Inclusion Criteria:

* age more than 20 years old
* severe traumatic brain injury defined as Glasgow coma scale \< 8

Exclusion Criteria:

* pregnancy
* infection at the forehead
* status epilepticus
* history of drug addiction
* severe traumatic brain injury combination with metabolic causes