Abstract 13737: Enhanced Prehospital End-Tidal CO2 Monitor Data Analysis for Intubated Severe Traumatic Brain Injury: Striking Findings From the EPIC Study

Background: Studies show that EMS patients are often inadvertently hyperventilated (HV), resulting in hypocapnia. In TBI, HV markedly increases mortality. We evaluated continuous prehospital ETCO2 data in intubated TBI patients. Methods: Analysis of monitor data files (Philips MRx™) from a sample of intubated TBI cases in the EPIC Study (NIH-R01NS071049). Results: Among hundreds of cases, graphical display of continuous ETCO2 from 3 subjects dramatically exemplified commonly-occurring inadvertent HV. Fig 1 shows unrecognized HV lasting nearly 15 min. Fig 2 reveals nearly 14 min of increasing ventilatory rate and progressively worsening hypocapnia. Fig 3 shows nearly 4 min of HV that ends abruptly with clear, sudden recognition and slowing of ventilatory rate that leads to restoration of normal ETCO2 in only a few breaths. The corresponding EMS patient care records (PCR) failed to document the presence, severity, and duration of HV. Conclusions: In a study emphasizing prevention of HV, subsequent evaluation of continuous ETCO2 data revealed many cases of unintentionally rapid manual ventilation and severe hypocapnia, often occurring for long periods. These findings, even in the face of explicit guideline-based training, demonstrate a clear need for routine access to continuous monitor data among intubated patients for quality improvement and in clinical studies. Review of PCRs does not reliably identify mismanagement of ventilation. Furthermore, these findings make it likely that real-time audiovisual feedback technology would improve ventilatory management by alerting providers to unidentified HV that results from the frequent distractions occurring during EMS care.

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Abstract 233: Prehospital End-Tidal CO2 Measurement in Non-Intubated Traumatic Brain Injury Patients: Concordance Between EMS Provider Documentation and Non-Invasive Monitor Data Tracking

Circulation ◽

10.1161/circ.138.suppl_2.233 ◽

2018 ◽

Vol 138 (Suppl_2) ◽

Author(s):

Octavio Perez ◽

Daniel W Spaite ◽

Eric Helfenbein ◽

Saeed Babaeizadeh ◽

Dawn B Jorgenson ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Study Objective ◽

Non Invasive ◽

Ventilation Setting ◽

Data Tracking ◽

End Tidal ◽

Post Hoc ◽

Monitor Data ◽

End Tidal Co2

Background: End-Tidal CO2 (ETCO2) monitoring is valuable in the management of traumatic brain injury (TBI). In intubated patients it helps prevent hyper/over-ventilation. In non-intubated patients, placing a sensor in the nares allows accurate monitoring of respiratory rate and has other promising uses (e.g. monitoring ETCO2 trends in worsening TBI, COPD, etc). Study Objective: To identify how accurately EMS providers document ETCO2, we compared the values recorded in EMS patient care records (PCR) to monitor data in non-intubated TBI patients. Methods: Cases from 6 EMS agencies reporting continuous monitor data (Philips MRx) in the EPIC Study (NIH 1R01NS071049) were evaluated (4/13-3/17). All ETCO2 data available for this post-hoc review were displayed and accessible to the EMS providers during care. Concordance was defined in two ways (for both highest and lowest ETCO2): ≤5 and ≤3 mmHg difference between the monitor data and PCR-documented values. Results: 106 cases were included [median age: 47 (range: 9-91), 66% male]. The figure shows concordance between PCR documentation and monitor data for both the lowest and highest recorded ETCO2 values. Conclusion: The highest PCR-recorded vs monitor ETCO2 values had excellent concordance for a difference ≤5 mmHg (85.9%) and it was good (76.4%) even when defined at the limits of instrument precision (≤3 for ETCO2 compared to actual pCO2). However, for lowest ETCO2, concordance was very poor (only 42.5% for ≤5). The failure to accurately document low ETCO2 in a “passive-ventilation” setting may also have significant implications for improving ventilatory care among intubated patients because identifying and correcting hypocapnia/hyperventilation in actively-ventilated cases is extraordinarily important. The low concordance rates may be due to the emphasis on discreet, intermittent vital sign documentation rather than ongoing identification and documentation of significant ETCO2 variation.

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Hyperventilation and seizures in an adolescent female

Monaldi Archives for Chest Disease ◽

10.4081/monaldi.2013.99 ◽

2015 ◽

Vol 79 (2) ◽

Author(s):

F. Nicosia ◽

L. Giordano ◽

L. Bonini ◽

L. Corda ◽

M. Bolzon ◽

...

Keyword(s):

Apnea Hypopnea Index ◽

Slow Recovery ◽

Night Time ◽

Qt Intervals ◽

The Face ◽

Loss Of Contact ◽

End Tidal ◽

End Tidal Co2 ◽

Recovery Of Consciousness

A 16 year-old girl was admitted after suffering from recurrent episodes of dyspnea and stridor, cyanosis, loss of contact, stiffening of all four limbs, clenching of the jaw and eye retroversion that lasted for a few seconds to a minute, followed by slow recovery of consciousness without any loss of sphincter control. These symptoms began at the age of 11 and worsened over time. Prolonged rate corrected QT intervals was observed with an ECG. Two cardio-respiratory monitorings were performed (one during daytime hours while the patient was awake, and one at night time while the patient slept). Daytime recordings showed 17 central apnoeas and 97 central hypopneas, with an apnea-hypopnea index (AHI) of 13.2 events/hour, that were associated with severe oxyhemoglobin desaturation. In contrast, night time recordings were normal (AHI=1.1 events/hour). The patient underwent diurnal monitoring of transcutaneous pCO2(PtcCO2), transcutaneous O2(PtcO2), SpO2 and end tidal CO2 (PETCO2), with simultaneous monitoring of regional cerebral oxymetry (rSO2) which showed values of PtcCO2 between 8 and 15 mmHg, suggesting several episodes of marked hyperventilation. Twenty-nine episodes of severe arterial desaturation (SpO2<50%) were registered, all after the same number of apnea events, with ascent of PtcO2 up to 28 mmHg at the end of apnea. During the final phase of apnea, the patient showed cyanosis, contact disturbance, grimaces, oral movements of rhyme, and, on three occasions, partial seizures. A mask was packaged and applied daytime to the face of the patient during episodes of hyperventilation to prevent, together with a psychiatric follow up, rapid falls of PaCO2 levels determining central apnoeas.

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Breathing responses of unanesthetized man and guinea pigs to increased transrespiratory pressure

Journal of Applied Physiology ◽

10.1152/jappl.1979.47.1.119 ◽

1979 ◽

Vol 47 (1) ◽

pp. 119-125 ◽

Cited By ~ 7

Author(s):

J. R. Gillespie ◽

E. Bruce ◽

J. Alexander ◽

J. Mead

Keyword(s):

Lung Volume ◽

Guinea Pigs ◽

The Body ◽

Low Frequencies ◽

Lung Inflation ◽

Arterial Pco2 ◽

The Face ◽

Mechanical Factors ◽

End Tidal ◽

End Tidal Co2

We compared the breathing responses of unanesthetized men and guinea pigs to externally imposed shifts in lung volume produced by steady pressures applied to the body surface while the mouth remained near atmospheric pressure. Lung inflation caused no consistent or significant changes either in frequency or end-tidal CO2 in the three men. In contrast, during lung inflation the guinea pigs breathed at low frequencies and smaller tidal volumes and showed consistent increases in arterial PCO2 lasting up to 10 min. The changes seen immediately on application of pressure, namely apneic periods followed by breathing in which inspiratory duration was shortened while expiratory duration was substantially increased, indicates that conscious guinea pigs have active inflation reflexes. We concluded that the reflex responses rather than mechanical factors probably account for the underventilation in the guinea pigs and that guinea pigs are not nearly as well equipped as is man to defend gas exchange in the face of nonmetabolic shifts in lung volume.

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Abstract 386: Prehospital Capnography in Non-Intubated Traumatic Brain Injury Patients: Association Between End-Tidal CO2 and Level of Consciousness

Circulation ◽

10.1161/circ.140.suppl_2.386 ◽

2019 ◽

Vol 140 (Suppl_2) ◽

Author(s):

Bruce J Barnhart ◽

Daniel W Spaite ◽

Eric Helfenbein ◽

Dawn Jorgenson ◽

Saeed Babaeizadeh ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Mental Status ◽

Study Objective ◽

Wilcoxon Rank Sum Test ◽

Significant Difference ◽

Level Of Consciousness ◽

End Tidal ◽

Monitor Data ◽

End Tidal Co2

Background: The EMS traumatic brain injury (TBI) guidelines encourage limiting prehospital intubation (ETI) to patients with profoundly depressed level of consciousness (LOC) and who cannot protect their airway or adequately ventilate without ETI. Thus, EMS providers may manage many TBI patients without intubating even when they have significant alterations in LOC. Monitoring End-Tidal CO2 by placing sensors in the nares (NC-CO2) of non-intubated patients may give providers valuable information about ventilatory status and trends. Study Objective: To evaluate the association between LOC and NC-CO2 in non-intubated TBI patients. Methods: Non-intubated cases from 6 EMS agencies reporting continuous monitor data (Philips MRx™) in the EPIC Study (NIH 1R01NS071049) were evaluated (4/13-3/17). Glasgow Coma Scale (GCS) was available from the EMS record in call cases. Comparisons in patient-level mean, median, lowest and highest NC-CO2 levels were made across GCS categories using clinically meaningful thresholds: <15, <12, <9, and 3. Statistics: Wilcoxon rank-sum test. Results: Included were 106 cases [median age: 47 (range: 9-91), 66% male]. The Table shows the NC-CO2 patterns and comparisons across the GCS categories. In no case was there a significant difference in NC-CO2 between the better vs. worse mental status cohort. Conclusion: We believe this is the first evaluation of the association between NC-CO2 and mental status in TBI. Patients that had significant (and even profound) decreases in LOC, but whom paramedics chose not to intubate, had remarkably similar NC-CO2 patterns compared to those with normal or near-normal mental status. This may support the overall approach of limiting ETI to those with airway/ventilatory compromise or impending hypoxia as there was no evidence of increasing NC-CO2, indicative of hypercapnia, in the non-intubated patients even when they had very depressed LOC.

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Cardiorespiratory Functioning in Youth with Persistent Post-Concussion Symptoms: A Pilot Study

Journal of Clinical Medicine ◽

10.3390/jcm10040561 ◽

2021 ◽

Vol 10 (4) ◽

pp. 561

Author(s):

Aliyah Snyder ◽

Christopher Sheridan ◽

Alexandra Tanner ◽

Kevin Bickart ◽

Molly Sullan ◽

...

Keyword(s):

Processing Speed ◽

Mean Value ◽

Exhaled Breath ◽

Post Injury ◽

The Past ◽

Neurobehavioral Outcomes ◽

End Tidal ◽

Relationship Of ◽

The Relationship ◽

End Tidal Co2

Dysregulation of the autonomic nervous system (ANS) may play an important role in the development and maintenance of persistent post-concussive symptoms (PPCS). Post-injury breathing dysfunction, which is influenced by the ANS, has not been well-studied in youth. This study evaluated cardiorespiratory functioning at baseline in youth patients with PPCS and examined the relationship of cardiorespiratory variables with neurobehavioral outcomes. Participants were between the ages of 13–25 in two groups: (1) Patients with PPCS (concussion within the past 2–16 months; n = 13) and (2) non-injured controls (n = 12). Capnometry was used to obtain end-tidal CO2 (EtCO2), oxygen saturation (SaO2), respiration rate (RR), and pulse rate (PR) at seated rest. PPCS participants exhibited a reduced mean value of EtCO2 in exhaled breath (M = 36.3 mmHg, SD = 2.86 mmHg) and an altered inter-correlation between EtCO2 and RR compared to controls. Neurobehavioral outcomes including depression, severity of self-reported concussion symptoms, cognitive catastrophizing, and psychomotor processing speed were correlated with cardiorespiratory variables when the groups were combined. Overall, results from this study suggest that breathing dynamics may be altered in youth with PPCS and that cardiorespiratory outcomes could be related to a dimension of neurobehavioral outcomes associated with poorer recovery from concussion.

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