scholarly journals Effects of Positive End-Expiratory Pressure on Lung Recruitment, Respiratory Mechanics, and Intracranial Pressure in Mechanically Ventilated Brain-Injured Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Robba ◽  
Lorenzo Ball ◽  
Stefano Nogas ◽  
Denise Battaglini ◽  
Antonio Messina ◽  
...  
Keyword(s):  
Brain Injury ◽  
Intracranial Pressure ◽  
Respiratory Mechanics ◽  
Lung Recruitment ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Brain Injured ◽  
Injured Patients ◽  
Lung Ct ◽  
Increased Icp

Background: The pathophysiological effects of positive end-expiratory pressure (PEEP) on respiratory mechanics, lung recruitment, and intracranial pressure (ICP) in acute brain-injured patients have not been completely elucidated. The primary aim of this study was to assess the effects of PEEP augmentation on respiratory mechanics, quantitative computed lung tomography (qCT) findings, and its relationship with ICP modifications. Secondary aims included the assessment of the correlations between different factors (respiratory mechanics and qCT features) with the changes of ICP and how these factors at baseline may predict ICP response after greater PEEP levels.Methods: A prospective, observational study included mechanically ventilated patients with acute brain injury requiring invasive ICP and who underwent two-PEEP levels lung CT scan. Respiratory system compliance (Crs), arterial partial pressure of carbon dioxide (PaCO2), mean arterial pressure (MAP), data from qCT and ICP were obtained at PEEP 5 and 15 cmH2O.Results: Sixteen examinations (double PEEP lung CT and neuromonitoring) in 15 patients were analyzed. The median age of the patients was 54 years (interquartile range, IQR = 39–65) and 53% were men. The median Glasgow Coma Scale (GCS) at intensive care unit (ICU) admission was 8 (IQR = 3–12). Median alveolar recruitment was 2.5% of total lung weight (−1.5 to 4.7). PEEP from 5 to 15 cmH2O increased ICP [median values from 14.0 (11.2–17.5) to 23.5 (19.5–26.8) mmHg, p < 0.001, respectively]. The amount of recruited lung tissue on CT was inversely correlated with the change (Δ) in ICP (rho = −0.78; p = 0.0006). Additionally, ΔCrs (rho = −0.77, p = 0.008), ΔPaCO2 (rho = 0.81, p = 0.0003), and ΔMAP (rho = −0.64, p = 0.009) were correlated with ΔICP. Baseline Crs was not predictive of ICP response to PEEP.Conclusions: The main factors associated with increased ICP after PEEP augmentation included reduced Crs, lower MAP and lung recruitment, and increased PaCO2, but none of these factors was able to predict, at baseline, ICP response to PEEP. To assess the potential benefits of increased PEEP in patients with acute brain injury, hemodynamic status, respiratory mechanics, and lung morphology should be taken into account.

Comparison of transorbital ultrasound measurements to predict intracranial pressure in brain-injured patients requiring external ventricular drainage

2021 ◽  
pp. 1-7
Author(s):  
Jin Young Youm ◽  
Jae Hoon Lee ◽  
Hyun Seok Park
Keyword(s):  
Intracranial Pressure ◽  
Dura Mater ◽  
Doppler Ultrasonography ◽  
External Ventricular Drainage ◽  
Repeated Measurements ◽  
Transverse Diameter ◽  
Ventricular Drainage ◽  
Brain Injured ◽  
Injured Patients ◽  
Increased Icp

OBJECTIVE The optic nerve sheath diameter (ONSD) excluding the dura mater (ONSDE; i.e., the subarachnoid diameter) and the ONSD including the dura mater (ONSDI) have been used differently in studies, but the predictive ability of these two different measurements of the ONSD as measured by invasive intracranial pressure (ICP) monitoring has never been compared. Additionally, studies on the prediction of ICP using central retinal artery (CRA) Doppler ultrasonography are scarce. The authors aimed to determine how the two different ONSD measurements, the ONSD/eyeball transverse diameter (ETD) ratio, and transorbital Doppler ultrasonography parameters are associated with ICP via external ventricular drainage (EVD). METHODS This prospective observational study included 50 patients with brain injury who underwent EVD between August 2019 and September 2020. The mean of three repeated measurements of the ONSDI and ONSDE was calculated to reduce artifact and off-axis measurements. ETD, an immutable value, was measured from the initial brain CT with a clear outline of the eyeball. Simultaneously, flow velocities in the CRA and posterior ciliary artery (PCA) were compared with the ICP. RESULTS The ONSDE, ONSDI, and ONSD/ETD ratio were significantly associated with ICP (p = 0.005, p < 0.001, and p < 0.001, respectively). The ONSD/ETD ratio showed the highest predictive power of increased ICP (area under the curve [AUC] 0.897). The ONSDI was correlated more with the ICP than was the ONSDE (AUC 0.855 vs 0.783). None of the Doppler ultrasonography parameters in the CRA and PCA were associated with ICP. CONCLUSIONS The ONSD/ETD ratio is a better predictor of increased ICP compared with the ONSDI or ONSDE in brain-injured patients with nonsevere ICP. The ONSDI may be more available for predicting the ICP than the ONSDE.

Intracranial Pressure Changes in Brain-injured Patients Requiring Positive End-Expiratory Pressure Ventilation

Neurosurgery ◽  
1981 ◽  
Vol 8 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Kim J. Burchiel ◽  
Timothy D. Steege ◽  
Allen R. Wyler
Keyword(s):  
Intracranial Pressure ◽  
Lung Compliance ◽  
Positive End Expiratory Pressure ◽  
Rapid Reduction ◽  
Intracranial Compliance ◽  
Brain Injured ◽  
Significant Change ◽  
Peep Ventilation ◽  
Pressure Changes ◽  
Injured Patients

Abstract In 16 patients with severe head injury and 2 patients with subarachnoid hemorrhage, positive end-expiratory pressure (PEEP) ventilation was required to maintain adequate oxygenation. The effects of PEEP on intracranial pressure (ICP) were evaluated with respect to the volume-pressure response (VPR), an indicator of intracranial compliance, and the static lung compliance (CL). Based on these parameters: (a) All 11 patients with a normal VPR (&lt;2 torr) had no significant change in ICP with PEEP therapy. (b) All 5 patients with an abnormal VPR and a normal CL (&gt;30 ml/cm H2O) had significantly increased ICP or decreased cerebral perfusion pressure while on PEEP. (c) Two patients with both an abnormal VPR and a decreased CL had no significant change in their ICP with PEEP. (d) Significant elevations of ICP were also seen in 4 patients with abnormal VPRs concurrent with the rapid reduction or withdrawal of PEEP ventilation. Thus, the VPR is an accurate predictor of the effects of PEEP on the ICP. In addition, however, decreased lung compliance may buffer these effects in patients who have decreased intracranial compliance. We propose that ICP monitoring and intracranial compliance determination are necessary in the management of brain-injured patients requiring PEEP ventilation.

scholarly journals Patient–ventilator asynchrony in acute brain-injured patients: a prospective observational study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xu-Ying Luo ◽  
Xuan He ◽  
Yi-Min Zhou ◽  
Yu-Mei Wang ◽  
Jing-Ran Chen ◽  
...  
Keyword(s):  
Prospective Observational Study ◽  
Esophageal Pressure ◽  
Respiratory Drive ◽  
Asynchrony Index ◽  
Mechanically Ventilated ◽  
Airway Occlusion ◽  
Brain Injured ◽  
Injured Patients ◽  
Duration Of Ventilation ◽  
Ventilated Patients

Abstract Background Patient–ventilator asynchrony is common in mechanically ventilated patients and may be related to adverse outcomes. Few studies have reported the occurrence of asynchrony in brain-injured patients. We aimed to investigate the prevalence, type and severity of patient–ventilator asynchrony in mechanically ventilated patients with brain injury. Methods This prospective observational study enrolled acute brain-injured patients undergoing mechanical ventilation. Esophageal pressure monitoring was established after enrollment. Flow, airway pressure, and esophageal pressure–time waveforms were recorded for a 15-min interval, four times daily for 3 days, for visually detecting asynchrony by offline analysis. At the end of each dataset recording, the respiratory drive was determined by the airway occlusion maneuver. The asynchrony index was calculated to represent the severity. The relationship between the prevalence and the severity of asynchrony with ventilatory modes and settings, respiratory drive, and analgesia and sedation were determined. Association of severe patient–ventilator asynchrony, which was defined as an asynchrony index  ≥ 10%, with clinical outcomes was analyzed. Results In 100 enrolled patients, a total of 1076 15-min waveform datasets covering 330,292 breaths were collected, in which 70,156 (38%) asynchronous breaths were detected. Asynchrony occurred in 96% of patients with the median (interquartile range) asynchrony index of 12.4% (4.3%–26.4%). The most prevalent type was ineffective triggering. No significant difference was found in either prevalence or asynchrony index among different classifications of brain injury (p > 0.05). The prevalence of asynchrony was significantly lower during pressure control/assist ventilation than during other ventilatory modes (p < 0.05). Compared to the datasets without asynchrony, the airway occlusion pressure was significantly lower in datasets with ineffective triggering (p < 0.001). The asynchrony index was significantly higher during the combined use of opioids and sedatives (p < 0.001). Significantly longer duration of ventilation and hospital length of stay after the inclusion were found in patients with severe ineffective triggering (p < 0.05). Conclusions Patient–ventilator asynchrony is common in brain-injured patients. The most prevalent type is ineffective triggering and its severity is likely related to a long duration of ventilation and hospital stay. Prevalence and severity of asynchrony are associated with ventilatory modes, respiratory drive and analgesia/sedation strategy, suggesting treatment adjustment in this particular population. Trial registration The study has been registered on 4 July 2017 in ClinicalTrials.gov (NCT03212482) (https://clinicaltrials.gov/ct2/show/NCT03212482).

scholarly journals The Expanding Role of Quantitative Pupillometry in the Evaluation and Management of Traumatic Brain Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Jason H. Boulter ◽  
Margaret M. Shields ◽  
Melissa R. Meister ◽  
Gregory Murtha ◽  
Brian P. Curry ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Brain Injuries ◽  
Ease Of Use ◽  
Brain Injured ◽  
The World ◽  
Injured Patients ◽  
Austere Environments ◽  
Active Investigation

Traumatic brain injury is a rapidly increasing source of morbidity and mortality across the world. As such, the evaluation and management of traumatic brain injuries ranging from mild to severe are under active investigation. Over the last two decades, quantitative pupillometry has been increasingly found to be useful in both the immediate evaluation and ongoing management of traumatic brain injured patients. Given these findings and the portability and ease of use of modern pupillometers, further adoption and deployment of quantitative pupillometers into the preclinical and hospital settings of both resource rich and medically austere environments.

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