Neurally adjusted ventilatory assist preserves cerebral blood flow velocity in patients recovering from acute brain injury

Pressure-support compared with pressure-controlled ventilation mitigates lung and brain injury in experimental acute ischemic stroke in rats

BACKGROUND

We aimed to evaluate the pulmonary and cerebral effects of low-tidal volume ventilation in pressure-support (PSV) and pressure-controlled (PCV) modes at two PEEP levels in acute ischemic stroke (AIS).

METHODS

In this randomized experimental study, AIS was induced by thermocoagulation in 30 healthy male Wistar rats. After 24 h, AIS animals were randomly assigned to PSV or PCV with VT = 6 mL/kg and PEEP = 2 cmH2O (PSV-PEEP2 and PCV-PEEP2) or PEEP = 5 cmH2O (PSV-PEEP5 and PCV-PEEP5) for 2 h. Lung mechanics, arterial blood gases, and echocardiography were evaluated before and after the experiment. Lungs and brain tissue were removed for histologic and molecular biology analysis. The primary endpoint was diffuse alveolar damage (DAD) score; secondary endpoints included brain histology and brain and lung molecular biology markers.

RESULTS

In lungs, DAD was lower with PSV-PEEP5 than PCV-PEEP5 (p < 0.001); interleukin (IL)-1β was lower with PSV-PEEP2 than PCV-PEEP2 (p = 0.016) and PSV-PEEP5 than PCV-PEEP5 (p = 0.046); zonula occludens-1 (ZO-1) was lower in PCV-PEEP5 than PCV-PEEP2 (p = 0.042). In brain, necrosis, hemorrhage, neuropil edema, and CD45 + microglia were lower in PSV than PCV animals at PEEP = 2 cmH2O (p = 0.036, p = 0.025, p = 0.018, p = 0.011, respectively) and PEEP = 5 cmH2O (p = 0.003, p = 0.003, p = 0.007, p = 0.003, respectively); IL-1β was lower while ZO-1 was higher in PSV-PEEP2 than PCV-PEEP2 (p = 0.009, p = 0.007, respectively), suggesting blood-brain barrier integrity. Claudin-5 was higher in PSV-PEEP2 than PSV-PEEP5 (p = 0.036).

CONCLUSION

In experimental AIS, PSV compared with PCV reduced lung and brain injury. Lung ZO-1 reduced in PCV with PEEP = 2 versus PEEP = 5 cmH2O, while brain claudin-5 increased in PSV with PEEP = 2 versus PEEP = 5 cmH2O.

Effects of Transcranial Magnetic Stimulation Combined with Computer-Aided Cognitive Training on Cognitive Function of Children with Cerebral Palsy and Dysgnosia

Objective

This study is aimed at researching transcranial magnetic stimulation (TMS) effects combined with computer-aided cognitive training (CACT) on cognitive function of children suffering from cerebral palsy and dysgnosia.

Methods

From December 2019 to October 2021, 86 children with cerebral palsy and dysgnosia who were treated at our hospital were recruited and assigned into observation and control groups (n = 43, each) using the random number table technique. The observation group received TMS combined with CACT (TMS+CACT), whereas the control group received only TMS. Chinese Wechsler Young Children Scale of Intelligence (C-WYCSI) and Chinese-Wechsler Intelligence Scale for Children (C-WISC) were used to evaluate the intelligence level of the two groups; Gross Motor Function Measure-88 (GMFM-88) of Fudan Chinese version was employed for evaluating the gross motor function of the two groups; a comparison was drawn among the two groups for the cerebral hemodynamic parameters before and after the treatment.

Results

For young children, the verbal intelligence quotient (VIQ) scores at 6 and 12 weeks of treatment in the observation group were increased when compared to those in the control group (48.91 ± 3.70 vs. 47.32 ± 3.33, 54.25 ± 4.46 vs. 49.48 ± 3.36), and the observation group's performance intelligence quotient (PIQ) score at 12 weeks of treatment was higher as to that of the control group (65.38 ± 4.23 vs. 62.81 ± 4.74, all P < 0.05). For older age children, the observation group's VIQ and PIQ scores were greater than the control group's at 6 and 12 weeks of treatment, with statistical significance (63.80 ± 3.76 vs. 59.50 ± 5.32, 74.64 ± 12.04 vs. 65.08 ± 6.30; 63.91 ± 5.96 vs. 58.42 ± 3.70, 72.73 ± 5.06 vs. 66.42 ± 5.93; all P < 0.05). The GMFM-88 scale scores in both groups were increased after 6 and 12 weeks of treatment. After treatment for 12 weeks, the observation group's A-E scores were greater than those of the control group (all P < 0.05). The peak systolic velocity (V s), end-diastolic velocity (V d), and mean velocity (V m) at the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) in the observation group were dramatically increased than those in the control group (all P < 0.05) after 12 weeks of treatment.

Conclusion

TMS+CACT can effectively improve the intelligence level, cognitive ability, gross motor function, and cerebral blood flow of children suffering from cerebral palsy and intellectual disability.

Effects of Varying Levels of Inspiratory Assistance with Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist on Driving Pressure in Patients Recovering from Hypoxemic Respiratory Failure

Background

Driving pressure can be readily measured during assisted modes of ventilation such as pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA). The present prospective randomized crossover study aimed to assess the changes in driving pressure in response to variations in the level of assistance delivered by PSV vs NAVA.

Methods

16 intubated adult patients, recovering from hypoxemic acute respiratory failure (ARF) and undergoing assisted ventilation, were randomly subjected to six 30-min-lasting trials. At baseline, PSV (PSV100) was set with the same regulation present at patient enrollment. The corresponding level of NAVA (NAVA100) was set to match the same inspiratory peak of airway pressure obtained in PSV100. Therefore, the level of assistance was reduced and increased by 50% in both ventilatory modes (PSV50, NAVA50; PSV150, NAVA150). At the end of each trial, driving pressure obtained in response to four short (2–3 s) end-expiratory and end-inspiratory occlusions was analyzed.

Results

Driving pressure at PSV50 (6.6 [6.1–7.8] cmH₂O) was lower than that recorded at PSV100 (7.9 [7.2–9.1] cmH₂O, P = 0.005) and PSV150 (9.9 [9.1–13.2] cmH₂O, P < 0.0001). In NAVA, driving pressure at NAVA50 was reduced compared to NAVA150 (7.7 [5.1–8.1] cmH₂O vs 8.3 [6.4–11.4] cmH₂O, P = 0.013), whereas there were no changes between baseline and NAVA150 (8.5 [6.3–9.8] cmH₂O vs 8.3 [6.4–11.4] cmH₂O, P = 0.331, respectively). Driving pressure at PSV150 was higher than that observed in NAVA150 (P = 0.011).

Conclusions

NAVA delivers better lung-protective ventilation compared to PSV in hypoxemic ARF patients.

Trial registration number and date of registration

The present trial was prospectively registered at www.clinicatrials.gov (NCT03719365) on 24 October 2018