Effect of Increasing Blood Pressure on Brain Tissue Oxygenation in Adults After Severe Traumatic Brain Injury.

OBJECTIVES: To examine if increasing blood pressure improves brain tissue oxygenation (PbtO2) in adults with severe traumatic brain injury (TBI). DESIGN: Retrospective review of prospectively collected data. SETTING: Level-I trauma center teaching hospital. PATIENTS: Included patients greater than or equal to 18 years of age and with severe (admission Glasgow Coma Scale [GCS] score < 9) TBI who had advanced neuromonitoring (intracranial blood pressure [ICP], PbtO2, and cerebral autoregulation testing). INTERVENTIONS: The exposure was mean arterial pressure (MAP) augmentation with a vasopressor, and the primary outcome was a PbtO2 response. Cerebral hypoxia was defined as PbtO2 less than 20 mm Hg (low). MAIN RESULTS: MAP challenge test results conducted between ICU admission days 1-3 from 93 patients (median age 31; interquartile range [IQR], 24-44 yr), 69.9% male, White (n = 69, 74.2%), median head abbreviated injury score 5 (IQR 4-5), and median admission GCS 3 (IQR 3-5) were examined. Across all 93 tests, a MAP increase of 25.7% resulted in a 34.2% cerebral perfusion pressure (CPP) increase and 16.3% PbtO2 increase (no MAP or CPP correlation with PbtO2 [both R2 = 0.00]). MAP augmentation increased ICP when cerebral autoregulation was impaired (8.9% vs. 3.8%, p = 0.06). MAP augmentation resulted in four PbtO2 responses (normal and maintained [group 1: 58.5%], normal and deteriorated [group 2: 2.2%; average 45.2% PbtO2 decrease], low and improved [group 3: 12.8%; average 44% PbtO2 increase], and low and not improved [group 4: 25.8%]). The average end-tidal carbon dioxide (ETCO2) increase of 5.9% was associated with group 2 when cerebral autoregulation was impaired (p = 0.02). CONCLUSIONS: MAP augmentation after severe TBI resulted in four distinct PbtO2 response patterns, including PbtO2 improvement and cerebral hypoxia. Traditionally considered clinical factors were not significant, but cerebral autoregulation status and ICP responses may have moderated MAP and ETCO2 effects on PbtO2 response. Further study is needed to examine the role of MAP augmentation as a strategy to improve PbtO2 in some patients.

Perioperative Care and Outcomes of Patients with Brain Tumors Undergoing Elective Craniotomy: Experience from an Ethiopian Tertiary-Care Hospital.

OBJECTIVE: To describe patients, perioperative care, and outcomes undergoing supratentorial and infratentorial craniotomy for brain tumor resection in a tertiary-care hospital in Ethiopia. METHODS: A retrospective cohort study of patients consecutively admitted between January 1, 2021, and December 31, 2021, was performed. We characterized patients, perioperative care, and outcomes. RESULTS: The final sample comprised 153 patients; 144 (94%) were 18 years and over, females (n = 48, 55%) with primarily American Society of Anesthesiologists physical class II (n = 97, 63.4%) who underwent supratentorial (n = 114, 75%), or infratentorial (n = 39, 25%) tumor resection. Patients were routinely admitted (95%) to floor/wards before craniotomy; Inhaled anesthetic (isoflurane 88%/halothane 12%) was used for maintenance of general anesthesia. Propofol (n = 93, 61%), mannitol (n = 73, 48%), and cerebrospinal fluid drain (n = 28, 18%), were used to facilitate intraoperative brain relaxation, while the use of hyperventilation was rare (n = 1). The average estimated blood loss was 1040 ± 727 ml; 37 (24%) patients received tranexamic acid, and 57 (37%) received a blood transfusion. Factors associated with extubation were a) infratentorial tumor location: relative risk (RR) 0.45 (95% confidence interval [CI] 0.29-0.69), preoperative hydrocephalus: RR 0.51, (95% CI 0.34-0.79), shorter total anesthesia duration: 277.8 + 8.8 versus 426.77 + 13.1 minutes, P < 0.0001, lower estimated blood loss: 897 + 68 ml versus 1361.7 + 100 ml, P = 0.0002, and cerebrospinal fluid drainage to facilitate brain relaxation: RR 0.52, 95% CI 0.32-0.84). Approximately one in ten patients experienced postoperative obstructive hydrocephalus, surgical site infections, or pneumonia. CONCLUSIONS: These findings suggest that certain factors may impact patient outcomes following craniotomy for tumor resection. By identifying these factors, health care providers may be better equipped to develop individualized treatment plans and improve patient outcomes. Additionally, the study highlights the importance of postoperative monitoring and management to prevent complications.

Bacterial Brain Abscess and Life-Threatening Intracranial Hypertension Requiring Emergent Decompressive Craniectomy After SARS-CoV-2 Infection in a Healthy Adolescent.

Acute coronavirus 2 (SARS-CoV-2) infection usually results in mild symptoms, but secondary infections after SARS-CoV-2 infection can occur, particularly with comorbid conditions. We present the clinical course of a healthy adolescent with a brain abscess and life-threatening intracranial hypertension requiring emergent decompressive craniectomy after a SARS-CoV-2 infection. A 13-year-old healthy immunized male presented with invasive frontal, ethmoid, and maxillary sinusitis and symptoms of lethargy, nausea, headache, and photophobia due to a frontal brain abscess diagnosed three weeks after symptoms and 11 days of oral amoxicillin treatment. Coronavirus disease 2019 (COVID-19) reverse transcription-polymerase chain reaction (RT-PCR) was negative twice but then positive on amoxicillin day 11 (symptom day 21), when magnetic resonance imaging revealed a 2.5-cm right frontal brain abscess with a 10-mm midline shift. The patient underwent emergent craniotomy for right frontal epidural abscess washout and functional endoscopic sinus surgery with ethmoidectomy. On a postoperative day one, his neurological condition showed new right-sided pupillary dilation and decreased responsiveness. His vital signs showed bradycardia and systolic hypertension. He underwent an emergent decompressive craniectomy for signs of brain herniation. Bacterial PCR was positive for Streptococcus intermedius, for which he received intravenous vancomycin and metronidazole. He was discharged home on hospital day 14 without neurological sequelae and future bone flap replacement. Our case highlights the importance of timely recognition and treatment of brain abscess and brain herniation in patients with neurological symptoms after SARS-CoV-2 infection, even in otherwise healthy patients.