Application of continuous monitoring of intracranial pressure and brain oxygen partial pressure in the treatment of patients with severe craniocerebral injury

Abstract

To investigate the effects of continuous monitoring intracranial pressure (ICP) and brain oxygen partial pressure (PbtO2) on the prognosis of patients with severe craniocerebral injury. A prospective randomized controlled trial was conducted. Seventy patients with severe craniocerebral injury with a Glasgow coma score (GCS) 4-8 admitted to the neurosurgical intensive care unit (NICU) of the People's Hospital of Inner Mongolia Autonomous Region from January 2017 to May 2020 were enrolled, and they were divided into ICP monitoring group and ICP+PbtO2 monitoring group by random number table. Patients in ICP monitoring group received ICP monitoring and were given traditional treatment of controlling ICP and cerebral perfusion pressure (CPP), the therapeutic target was ICP < 20 mmHg (1 mmHg = 0.133 kPa) and CPP > 60 mmHg. Patients in ICP+PbtO2 monitoring group were given ICP and PbtO2 monitoring at the same time, and oxygen flow was adjusted on the basis of controlling ICP and CPP to maintain the PbtO2 > 20 mmHg, and the therapeutic target of ICP and CPP was the same as the ICP monitoring group. ICP and PbtO2 values were recorded during monitoring in the two groups, the results of CPP, GCS and arterial blood gas analysis were recorded, and the prognosis at 3 months and 6 months after injury was compared by Glasgow outcome scale (GOS) score between the two groups. GOS score > 3 was considered as good prognosis. Kaplan-Meier survival curve was drawn, and the 3-month and 6-month cumulative survival rates of the two groups were analyzed. Linear regression analysis was used to further evaluate the relationship between PbtO2 and GOS score. Finally, a total of 70 patients with severe craniocerebral injury were enrolled in the analysis, 34 patients received ICP combined with PbtO2 monitoring and guided therapy, and 36 patients received ICP monitoring alone. The average ICP of ICP+PbtO2 monitoring group was significantly lower than that of ICP monitoring group (mmHg: 13.4±3.2 vs. 18.2±8.3, P < 0.01). Although the CPP in both groups was great than 60 mmHg, the average CPP of ICP+PbtO2 monitoring group was significantly higher than that of ICP monitoring group (mmHg: 82.1±10.5 vs. 74.5±11.6, P < 0.01). No significant difference was found in average GCS score or arterial partial pressure of carbon dioxide (PaCO2) between the ICP+PbtO2 monitoring group and ICP monitoring group [GCS score: 5.3±2.3 vs. 5.2±2.2, PaCO2 (mmHg): 33.5±4.8 vs. 32.6±5.2, both P > 0.05]. The average arterial partial pressure of oxygen (PaO2) of ICP+PbtO2 monitoring group was obviously higher than that of ICP monitoring group (mmHg: 228.4±93.6 vs. 167.3±81.2, P < 0.01). Compared with the ICP monitoring group, the good outcome rates of 3 months and 6 months after injury in the ICP+PbtO2 monitoring group were significantly higher (3 months: 67.6% vs. 38.9%, 6 months: 70.6% vs. 41.7%, both P < 0.05). Kaplan-Meier survival curve showed that the 3-month and 6-month cumulative survival rates of ICP+PbtO2 monitoring group were significantly higher than those of ICP monitoring group (3 months: 85.3% vs. 61.1%, Log-Rank test: χ2 = 5.171, P = 0.023; 6 months: 79.4% vs. 55.6%, Log-Rank test: χ2 = 4.511, P = 0.034). Linear regression analysis showed that PbtO2 was significantly correlated with GOS score at 3 months and 6 months after injury in patients with severe craniocerebral injury (r values were 0.951 and 0.933, both P < 0.01). PbtO2 compared with ICP monitoring guiding therapy is valuable in improving the prognosis of patients with severe craniocerebral injury. It can improve the prognosis at 3-6 months after injury.