A Better Standard to Assess the Performance of Portable Suction Devices: Time-Averaged Air Flow Rate

Introduction: Portable suction devices are important tools in airway management, yet evaluating their performance and adherence to standards presents challenges. This study explores the inadequacies of ISO 10079-1 and proposes a shift from instantaneous maximum air flow rate metric to time-averaged air flow rate metric for more accurate assessment. The focus is on the importance of effective suction in prehospital care, especially in scenarios like combat and civilian emergencies. Methods: Four portable suction devices (AMBU RES-QUE, LAERDAL VVAC, LAERDAL LCSU4, and SSCOR QUICKDRAW) were tested for air flow rate, liquid flow rate, and vacuum pressure. The study introduced the concept of time-averaged air flow rate as a more relevant metric than instantaneous maximum air flow rate. Statistical analyses, including Pearson correlation and regression methods, were employed to evaluate the relationship between instantaneous maximum and time-averaged air flow rates and their impact on liquid flow rate. Results: The AMBU RES-QUE showed 15.7 ± 0.4 L/min instantaneous and 2.3 ± 0.1 L/min time-averaged air flow rate; VVAC had 29.1 ± 5.4 L/min instantaneous and 6.0 ± 1.1 L/min time averaged; LCSU4, 21.8 ± 0.2 L/min instantaneous and 19.8 ± 0.4 L/min time averaged; and SSCOR QUICKDRAW, 11.3 ± 0.1 L/min instantaneous and 10.3 ± 0.1 L/min time-averaged. Water liquid flow rates (L/min) were 2.1 ± 0.1 (AMBU), 2.9 ± 0.2 (VVAC), 7.0 ± 0.1 (LCSU4), and 5.4 ± 0.0 (SSCOR); with ISO vomit simulant, they were 2.0 ± 0.3, 2.1 ± 0.4, 3.1 ± 0.4, and 2.2 ± 0.0, respectively. Time-averaged air flow rate correlated strongly with liquid flow rate (r = 0.97, R² = 0.93), whereas instantaneous maximum air flow rate correlated poorly (r = − 0.15, R² = 0.02). Discussion: The findings challenge the common reliance on instantaneous maximum air flow rate as a performance indicator. Instantaneous maximum air flow rate may mislead users about a device’s effectiveness, especially in long-term applications. Time-averaged air flow rate shows improved prediction of liquid flow rate. The study also identifies backflow issues in a manual suction device, emphasizing potential risks and the need for further exploration. Conclusion: The study advocates for a shift in standards, proposing the inclusion of time-averaged air flow rate in ISO requirements. This change aligns with the patient-centric focus, providing a more accurate representation of a device’s performance in real-world scenarios. Additionally, the identification of backflow in manual devices raises concerns, urging further investigation into its clinical significance and potential risks.