The Safe Limits of Mechanical Factors in the Apnea Testing for the Diagnosis of Brain Death

Olguner, Çimen; Koca, Uğur; Akan, Mert; Karcı, Ayşe; Elar, Zahi̇de

doi:10.1620/tjem.211.115

Cited by 5 publications

(9 citation statements)

References 13 publications

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“…Our results differ from those of Olguner et al, who used a 2.3-L anesthesia bag as a lung model 14 and performed the apnea test with ETTs of 7.0 to 8.0 mm inner diameter, ICs of 8 to 14 French, and flows of 6, 8, and 10 L/min. 14 Olguner et al calculated the IC/ETT ratio by dividing the ETT inner diameter by the IC outer diameter, 14 which is the inverse of the traditional ratio calculation.…”

Section: What This Paper Contributes To Our Knowledgecontrasting

confidence: 99%

“…Third, Olguner tested only 3 ETT sizes, whereas we tested 9 ETT sizes. 14 Our data suggest that as the IC/ETT ratio increases, the pressures and volumes also increase. Lang and Heckmann stated that barotrauma may be prevented during the apnea test by limiting the oxygen flow, using an appropriate IC/ETT ratio, and not advancing the IC past the ETT tip.…”

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 60%

“…14 Olguner et al calculated the IC/ETT ratio by dividing the ETT inner diameter by the IC outer diameter, 14 which is the inverse of the traditional ratio calculation. [11][12][13] Olguner concluded that ETT/IC ratio of Ͻ 1.75 was significantly different and associated with higher pressure in their lung model than diameter-based ETT/IC ratios Ͼ 1.75.…”

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 99%

“…[11][12][13] Olguner concluded that ETT/IC ratio of Ͻ 1.75 was significantly different and associated with higher pressure in their lung model than diameter-based ETT/IC ratios Ͼ 1.75. 14 We converted our IC/ETT ratios to ETT/IC ratios to compare our findings to those of Olguner et al…”

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 99%

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Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Henry

Marshall

2013

Respir Care

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BACKGROUND:The apnea test is used to determine the absence of respiratory drive when determining brain death. Current guidelines for performing the apnea test do not specify the size of insufflation catheter (IC) to use with each endotracheal tube (ETT) size, despite case reports describing procedure-related complications with the use of various IC sizes. We studied the effect of the ratio of IC outer diameter to ETT inner diameter on the pressure and volume generated within the lungs during the apnea test. METHODS: We tested ETTs with inner diameters of 6.0 -10.0 mm, IC outer diameters of 10 -16 French, and oxygen-supply tubing, at oxygen flows of 6 -15 L/min, in an intubation manikin connected to a test lung. RESULTS: The multivariate analysis of variance method identified significant differences in the pressures and volumes during the apnea test (P < .001), and the Tukey method identified significant differences in the pressures and volumes associated with IC/ETT ratios > 0.7 and < 0.7 (P < .05). CONCLUSIONS: An IC with an outer diameter < 70% of the ETT inner diameter, at 6 L/min, may prevent inappropriate lung pressure and volume during the apnea test. This recommendation, coupled with current American Academy of Neurology guidelines for the determination of brain death, may reduce the risk of procedure-related complications.

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Section: What This Paper Contributes To Our Knowledgecontrasting

confidence: 99%

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 60%

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 99%

Section: What This Paper Contributes To Our Knowledgementioning

confidence: 99%

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Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Henry

Marshall

2013

Respir Care

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“…Typical performance of this test involves the use of an oxygen catheter for apneic oxygenation of the patient’s lungs to avoid possible hypoxia during the procedure. This technique of apneic oxygenation has some limitations 6 , 7 but in most cases is an effective tool for sufficient oxygenation of the patient. However, there are some patients with severe respiratory disturbances and suspicion of brain death, for whom typical performance of the apneic test is difficult to complete because of quick desaturation and rapid deterioration without effective ventilation.…”

Section: Introductionmentioning

confidence: 99%

Boussignac CPAP system for brain death confirmation with apneic test in case of acute lung injury/adult respiratory distress syndrome – series of cases

Wieczorek¹,

Gaszyński²

2015

TCRM

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IntroductionThere are some patients with severe respiratory disturbances like adult respiratory distress syndrome (ARDS) and suspicion of brain death, for whom typical performance of the apneic test is difficult to complete because of quick desaturation and rapid deterioration without effective ventilation. To avoid failure of brain death confirmation and possible loss of organ donation another approach to apneic test is needed. We present two cases of patients with clinical symptoms of brain death, with lung pathology (acute lung injury, ARDS, lung embolism and lung infection), in whom apneic tests for recognizing brain death were difficult to perform. During typical performance of apneic test involving the use of oxygen catheter for apneic oxygenation we observed severe desaturation with growing hypotension and hemodynamic destabilization. But with the use of Boussignac CPAP system all necessary tests were successfully completed, confirming the patient’s brain death, which gave us the opportunity to perform procedures for organ donation. The main reason of apneic test difficulties was severe gas exchange disturbances secondary to ARDS. Thus lack of positive end expiratory pressure during classical performance of apneic test leads to quick desaturation and rapid hemodynamic deterioration, limiting the observation period below dedicated at least 10-minute interval.ConclusionThe Boussignac CPAP system may be an effective tool for performing transparent apneic test in case of serious respiratory disturbances, especially in the form of acute lung injury or ARDS.

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Apnea Testing for the Determination of Brain Death: A Systematic Scoping Review

2020

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Apnea is one of the three cardinal findings in brain death (BD). Apnea testing (AT) is physiologically and practically complex. We sought to review described modifications of AT, safety and complication rates, monitoring techniques, performance of AT on extracorporeal membrane oxygenation (ECMO), and other relevant considerations regarding AT. We conducted a systematic scoping review to answer these questions by searching the literature on AT in English language available in PubMed or EMBASE since 1980. Pediatric or animal studies were excluded. A total of 87 articles matched our inclusion criteria and were qualitatively synthesized in this review. A large body of the literature on AT since its inception addresses a variety of modifications, monitoring techniques, complication rates, ways to perform AT on ECMO, and other considerations such as variability in protocols, lack of uniform awareness, and legal considerations. Only some modifications are widely used, especially methods to maintain oxygenation, and most are not standardized or endorsed by brain death guidelines. Future updates to AT protocols and strive for unification of such protocols are desirable.

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The Safe Limits of Mechanical Factors in the Apnea Testing for the Diagnosis of Brain Death

Cited by 5 publications

References 13 publications

Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Boussignac CPAP system for brain death confirmation with apneic test in case of acute lung injury/adult respiratory distress syndrome – series of cases

Apnea Testing for the Determination of Brain Death: A Systematic Scoping Review

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The Safe Limits of Mechanical Factors in the Apnea Testing for the Diagnosis of Brain Death

Cited by 5 publications

References 13 publications

Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Apnea Testing: The Effects of Insufflation Catheter Size and Flow on Pressure and Volume in a Test Lung

Boussignac CPAP system for brain death confirmation with apneic test in case of acute lung injury/adult respiratory distress syndrome&nbsp;&ndash;&nbsp;series of cases

Apnea Testing for the Determination of Brain Death: A Systematic Scoping Review

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Boussignac CPAP system for brain death confirmation with apneic test in case of acute lung injury/adult respiratory distress syndrome – series of cases