scholarly journals Increased interhemispheric asymmetry of cerebral blood flow in comatose adult patients on extracorporeal membrane oxygenation

Author(s):  
Thomas W Johnson ◽  
Irfaan Dar ◽  
Kelly Donohue ◽  
Yama Y Xu ◽  
Esmeralda Santiago ◽  
...  

Extracorporeal membrane oxygenation (ECMO) is a mechanical circulatory support method that is associated with a high burden of neurologic injury, but neurologic examination and imaging of this population presents prohibitive medical and logistical challenges. Diffuse correlation spectroscopy (DCS) can measure relative cerebral blood flow (rBF) non-invasively at the bedside. In this study we observed interhemispheric differences in rBF in response to mean arterial pressure (MAP) changes in adult ECMO recipients. Thirteen patients were recruited (ages 21-78, 7 with cardiac arrest, 4 with acute heart failure, 2 with acute respiratory distress syndrome). They were dichotomized via Glasgow Coma Scale Motor score (GCS-M) into comatose (GCS-M ≤ 4; n=4) and non-comatose (GCS-M > 4; n=9) groups. Comatose patients had more interhemispheric rBF asymmetry (ASYM_rBF) vs. non-comatose patients over a range of MAP values, (29% [IQR 23-34%] vs. 11% [IQR 8-13%], p=0.009). ASYM_rBF in comatose patients resolved near a MAP range of 70-80 mm Hg, while rBF remained symmetric through a wider MAP range in non-comatose patients. Associations between post-oxygenator pCO2 or pH vs. ASYM_rBF individually did not meet significance, though the linear model slopes were different between comatose and non-comatose subgroups. Here we have demonstrated asymmetric cerebral autoregulation in comatose ECMO patients.

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Imad Khan ◽  
Thomas Johnson ◽  
Irfaan Dar ◽  
Kelly Donohue ◽  
Yan Xu ◽  
...  

Asymmetric cerebral perfusion can occur when extracorporeal membrane oxygenation (ECMO) flow competes with native cardiac circulation. It is unclear whether this phenomenon associates with brain injury. Diffuse correlation spectroscopy (DCS) provides continuous, laser-based, non-invasive, bedside monitoring of relative cerebral blood flow (rCBF). This study measured rCBF in ECMO patients via DCS to determine whether comatose patients experience asymmetric cerebral perfusion. Adults receiving ECMO for any indication were prospectively recruited from 12/2019-3/2021. Patients with prior neurologic injury, scalp/facial lacerations, and SARS-CoV-2 infection were excluded. DCS monitoring was performed daily during ECMO support with sensors placed on bilateral foreheads. Mean arterial pressure (MAP) was continuously recorded from the bedside monitor. The Glasgow Coma Scale (GCS) was assessed by clinical staff multiple times daily with sedation pauses, if possible, per standard of care. rCBF was calculated by comparing continuous cerebral blood flow (CBF) measurements to the daily median CBF, then averaged at each MAP value. Daily rCBF asymmetry was calculated by summing the absolute difference of rCBF between the two hemispheres at each MAP value, normalized for the total MAP range experienced by the patient that day. Twelve subjects were enrolled in this study (ages 21-78, 6 with cardiac arrest, 4 with acute heart failure, 2 with ARDS) and grouped by maximum GCS motor (GCS-M) score during ECMO, with 3 “comatose” subjects (GCS-M ≤ 4), and 9 “awake” subjects (GCS-M > 4). DCS was performed over 66 sessions with a mean duration of 131.83 ± 1.13 minutes. Comatose subjects exhibited more rCBF asymmetry than awake subjects (0.28 ± 0.06 mmHg-1 vs. 0.10 ± 0.001 mmHg-1, p=0.045). No difference in asymmetry was noted between patients with or without cardiac arrest. We found that comatose ECMO subjects exhibited higher inter-hemispheric rCBF asymmetry over a range of blood pressures than awake subjects. Though our comatose sample is small, further validation of this finding and its causes, such as cerebrovascular dysregulation, is warranted.


Perfusion ◽  
2021 ◽  
pp. 026765912110339
Author(s):  
Shek-yin Au ◽  
Ka-man Fong ◽  
Chun-Fung Sunny Tsang ◽  
Ka-Chun Alan Chan ◽  
Chi Yuen Wong ◽  
...  

Introduction: The intra-aortic balloon pump (IABP) and Impella are left ventricular unloading devices with peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) in place and later serve as bridging therapy when VA-ECMO is terminated. We aimed to determine the potential differences in clinical outcomes and rate of complications between the two combinations of mechanical circulatory support. Methods: This was a retrospective, single institutional cohort study conducted in the intensive care unit (ICU) of Queen Elizabeth Hospital, Hong Kong. Inclusion criteria included all patients aged ⩾18 years, who had VA-ECMO support, and who had left ventricular unloading by either IABP or Impella between January 1, 2018 and October 31, 2020. Patients <18 years old, with central VA-ECMO, who did not require left ventricular unloading, or who underwent surgical venting procedures were excluded. The primary outcome was ECMO duration. Secondary outcomes included length of stay (LOS) in the ICU, hospital LOS, mortality, and complication rate. Results: Fifty-two patients with ECMO + IABP and 14 patients with ECMO + Impella were recruited. No statistically significant difference was observed in terms of ECMO duration (2.5 vs 4.6 days, p = 0.147), ICU LOS (7.7 vs 10.8 days, p = 0.367), and hospital LOS (14.8 vs 16.5 days, p = 0.556) between the two groups. No statistically significant difference was observed in the ECMO, ICU, and hospital mortalities between the two groups. Specific complications related to the ECMO and Impella combination were also noted. Conclusions: Impella was not shown to offer a statistically significant clinical benefit compared with IABP in conjunction with ECMO. Clinicians should be aware of the specific complications of using Impella.


Author(s):  
Luis Octavio Tierradentro-García ◽  
Sandra Saade-Lemus ◽  
Colbey Freeman ◽  
Matthew Kirschen ◽  
Hao Huang ◽  
...  

Objective Hypoxic-ischemic encephalopathy (HIE) in infants can have long-term adverse neurodevelopmental effects and markedly reduce quality of life. Both the initial hypoperfusion and the subsequent rapid reperfusion can cause deleterious effects in brain tissue. Cerebral blood flow (CBF) assessment in newborns with HIE can help detect abnormalities in brain perfusion to guide therapy and prognosticate patient outcomes. Study Design The review will provide an overview of the pathophysiological implications of CBF derangements in neonatal HIE, current and emerging techniques for CBF quantification, and the potential to utilize CBF as a physiologic target in managing neonates with acute HIE. Conclusion The alterations of CBF in infants during hypoxia-ischemia have been studied by using different neuroimaging techniques, including nitrous oxide and xenon clearance, transcranial Doppler ultrasonography, contrast-enhanced ultrasound, arterial spin labeling MRI, 18F-FDG positron emission tomography, near-infrared spectroscopy (NIRS), functional NIRS, and diffuse correlation spectroscopy. Consensus is lacking regarding the clinical significance of CBF estimations detected by these different modalities. Heterogeneity in the imaging modality used, regional versus global estimations of CBF, time for the scan, and variables impacting brain perfusion and cohort clinical characteristics should be considered when translating the findings described in the literature to routine practice and implementation of therapeutic interventions. Key Points


2020 ◽  
Vol 21 (6) ◽  
pp. 1017-1022
Author(s):  
Shek Yin Au ◽  
Ka Man Fong ◽  
Kwong Shun Chan ◽  
Sai Kwong Yung ◽  
Rowlina Pui Wah Leung ◽  
...  

Veno-arterial extracorporeal membrane oxygenation is a form of mechanical circulatory support for patients with refractory decompensated heart failure. Blood is drawn from a large vein and pumped back to a large artery, usually a femoral artery through large bore catheters. When the heart recovers, the extracorporeal membrane oxygenation support can be terminated and the catheters are decannulated. The bleeding at the venous side can be controlled by prolonged compression; however, the arteriotomy wound needs to be repaired. Conventionally, the arteriotomy wounds require open vascular repair in the operating theater. The novel application of percutaneous vascular closure devices, which have been commonly used in vascular operations and percutaneous structural heart interventions, could be applied for closure of arteriotomy wounds at the bedside after extracorporeal membrane oxygenation support. The post-close ProGlide (Abbott Vascular) technique was shown to be safe and could potentially save time and manpower. The wounds are much smaller as compared with the conventional open repair and potentially, the chance of wound infection can be reduced. However, the success of percutaneous bedside closure requires careful prior planning and technique training. Backup plans with vascular surgeons’ standby are essential in case of failure of closure. Staffs in the extracorporeal membrane oxygenation centers need to be familiar with the preparation, the procedure as well as the device application technique for successful percutaneous closure. The long learning curve and the limited case load mean that such skills are best trained by simulation scenarios. This article described how this new technique and the team logistics can be trained by simulation.


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