Ventilator Autocycling and Delayed Recognition of Brain Death

Abstract

When brain-dead patients who are suitable organ donors are mistakenly identified as having cerebral activity, the diagnosis of brain death is delayed. This delay impacts resource utilization, impedes recovery and function of organs for donation, and adversely affects donor families, potential recipients of organs, and patient donors who may have testing and treatment that cannot be beneficial. Patients with catastrophic brain injury and absent cranial nerve function should undergo immediate formal apnea testing.

Ventilator autotriggering

“…Among 83 neurological and neurosurgical patients who met all clinical criteria for brain death, false triggering was found in a report in 4 patients (4.8%) [29]. In a later report, autotriggering was observed in 9 patients over a period of 15 months, representing an incidence of 10-12% extrapolated from an estimated collective of 50 patients who were declared to be brain dead each year [19]. In a retrospective evaluation of 672 cases (i. e. patients with absent brainstem reflexes except for spontaneous respiration on the mechanical ventilator), an algorithm designed to identify and correct VAT could have been used in 63 cases (9.4%) [13].…”

“…In a retrospective evaluation of 672 cases (i. e. patients with absent brainstem reflexes except for spontaneous respiration on the mechanical ventilator), an algorithm designed to identify and correct VAT could have been used in 63 cases (9.4%) [13]. It is emphasized that this phenomenon is likely to occur more frequently than estimated and it is believed that VAT may remain undetected in an unknown number of cases; indeed, this clinical scenario does not seem to be uncommon, as other clinical experiences show [19,29]. A factor for problems in the context with VAT could be the state of education and knowledge about this phenomenon.…”

Ventilator auto‐cycling from cardiogenic oscillations: case report and review of literature

“…Auto‐triggering or auto‐cycling is defined as a ventilator being triggered in the absence of patient effort, intrinsic respiratory drive or inspiratory muscle activity (Fenstermacher and Hong, ; Arbour, ; Kondili et al ., ). This may occur during an inappropriate setting of the trigger threshold, better defined when the sensitivity to trigger a controlled breath is too susceptible, so an unintended ventilation will be provided (Willatts and Drummond, ; Harboe et al ., ; Arbour, ; McGee and Mailloux, ). Both flow‐trigger and pressure‐trigger modes can be involved in ventilator auto‐triggering, depending on the preset sensitivity (Imanaka et al ., ; Nilsestuen and Hargett, ).…”

Confounding factors in brain death: Cardiogenic ventilator autotriggering and implications for organ transplantation

“…One form is potentially complex movement involving the head, trunk and/or extremities (Arbour, 2005;De Freitas et al, 2003;Saposnik et al, 2004;Wijdicks et al, 2010;Wijdicks, 2001) resulting from complex spinal reflexes and not related to residual brain/brainstem function. A second form is ''overbreathing'' the ventilator set rate that may be misinterpreted as intrinsic respiratory drive (Arbour, 2005(Arbour, , 2009McGee and Mailloux, 2011;Ng and Tan, 2001;Wijdicks et al, 2005Wijdicks et al, , 2010Wijdicks, 2001). Either may confuse clinicians and family members about whether brain death determination is appropriate.…”

“…It may lead to additional stress on family members from prolonging the ICU experience. It may also lead to loss of potentially transplantable organs (Arbour, 2005(Arbour, , 2009McGee and Mailloux, 2011). The focus of this review, analysis, two case illustrations and discussion is to explore physiology, risk factors, recognition, management and transplant implications for cardiogenic ventilator autotriggering in the brain-dead patient.…”