An Alarm for Monitoring CPAP

Carter, B; Clare, D.; Hochmann, M; Osborne, A. D.; Fraser, Thomas R

doi:10.1177/0310057x9302100214

Cited by 2 publications

(2 citation statements)

References 8 publications

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“…However, when the leakage flow becomes higher-this happens when the prongs are completely dislodged-the pressure within the ventilator circuit will decrease even when the expiratory valve is completely closed. The machine will detect the problem and alert the staff by activating an alarm [7] so that the nasal prongs can be repositioned only with a short interruption of the respiratory support. This occurs as long as the applied flow is within the flow range at the areas under the curves in Fig.…”

Section: Discussionmentioning

confidence: 99%

Danger of low pressure alarm failure in preterm infants on continuous positive airway pressure

et al. 2009

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In certain settings of conventional continuous positive airway pressure (CPAP) application, the ventilator may not be able to detect dislodgement of the prongs. This occurs especially in settings with high flow and small prongs. We investigated the relation between ventilator flows, size of the nasal prongs, and pressure generated within the ventilator circuit due to the flow resistance of the prongs. We studied a Baby-flow CPAP connected to a Babylog 8000plus ventilator. Five prongs of increasing size (x-small, small, medium, large, x-large) and one nose mask were connected to the CPAP in turn. Starting at 30 lpm, the flow was reduced in 2 lpm steps. The dynamic pressure caused by the flow resistance of the prongs within the ventilator circuit was recorded. For all devices, we observed a correlation between the reduction of the flow and the reduction in pressure within the ventilator circuit. However, the flow resistance of the x-small prongs generated the highest dynamic pressure (30 mbar at 22 lpm) within the ventilator circuit while the mask gave rise to the lowest pressure (9 mbar at 30 lpm). The pressure value generated with x-small prongs at low flow rate was observed at high flow rate with x-large prongs or with a mask. We conclude that in settings with high flow rates, low CPAP levels, and small prongs, the resistance of the prongs will create enough dynamic pressure within the ventilator circuit to permit the ventilator to compensate a large leakage flow by closing the expiratory valve. Thus, in case of dislodgement of the prongs, the pressure within the ventilator circuit will not decrease below the alarm level, and the machine will not be able to generate an alarm.

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Section: Discussionmentioning

confidence: 99%

Danger of low pressure alarm failure in preterm infants on continuous positive airway pressure

et al. 2009

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“…Indeed, patients with SAHS who also have COPD, respiratory muscle weakness, low CO 2 response, or who are receiving depressant drugs may present reduced response to a rise in CO 2 concentration and decreased arousability and, therefore, they could be more exposed to the risk of rebreathing associated to CPAP failure. Tak-ing into account that home CPAP is applied to an increasing number of patients during the whole night for a very long period, 3 we wonder whether the inclusion of alarms 10 or safety valves (Fig 4) to avoid this risk is advisable.…”

Section: Discussionmentioning

confidence: 99%