Evaluation of the Ambu Cpap System

Venn, P.J.H.

doi:10.1093/bja/62.3.340

Cited by 5 publications

(7 citation statements)

References 10 publications

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“…This agrees with published data, and it was also found that they are somewhat position sensitive. 7 The Vital Signs valves showed less pressure alteration with flow, but some individual valves deviated noticeably from their nominal resistance value.…”

Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 93%

“…The Downs'-Vital Signs system The Downs' adjustable flow generator is an oxygen-driven jet venturi, with an adjustable oxygen bypass which serves to increase the oxygen concentration in the delivered gas. 7 It is designed to deliver total gas flows in the 25 to 100 l.min -1 range and can be connected through a suitable corrugated tube to a Vital Signs CPAP mask. The latter is a clear plastic mask with a large inflatable cushion to prevent pressure effects to the patient's face.…”

Section: The Auspap Systemmentioning

confidence: 99%

“…Although we did not test this feature, it is said to be very economical of fresh gases. 7 Calculating from the final delivered oxygen concentration, the total gas flow was 4.27 times the oxygen flow. As entrainment systems deliver a mix of dry oxygen and room air, there is probably sufficient water vapour in the delivered gases not to need humidification for use by mask.…”

Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 99%

“…Angle-oriented modifications are many and include various fixed angled modified blades, 1.2 adaptors and hinge blocks.3-6 A special laryngoscope 7 handle with adjustable angles has been described. found so usefuF in obstetric anaesthetic practice 2 ,4 and it also requires the use of the other hand to adjust angles.…”

Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 99%

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Tests of Six Continuous Flow CPAP Devices

Shehabi

Hillman

et al. 1991

Anaesth Intensive Care

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Six continuous flow CPAP devices were tested for pressure fluctuation and stability of inhaled oxygen concentration under conditions of simulated respiration. Four of the systems, the Ambu, Auspap, Downs'-Vital Signs and the Drager are commercially available and two, the Prince Henry (PHH) and the Prince of Wales (POW) systems were assembled from Bird respirator parts, which were available in the respective Intensive Care Units. All appeared to be clinically effective. The Ambu offers convenience and economy of gases, the Drager showed the least pressure fluctuations. Three of the four commercial systems lacked certain safety features which could more easily be added to the two non-commercial devices.

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Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 93%

Section: The Auspap Systemmentioning

confidence: 99%

Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 99%

Section: The Prince Of Wales Hospital (Pow) Systemmentioning

confidence: 99%

See 2 more Smart Citations

Tests of Six Continuous Flow CPAP Devices

Shehabi

Hillman

et al. 1991

Anaesth Intensive Care

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“…These fluctuations in Paw have to be prevented, to keep the CPAP level constant during the entire respiratory cycle, thus reducing the imposed work of breathing (WOB) [4], incidence of barotraumas [l, 51 and changes in heart rate variability [6]. Since the end of the 1970s, many researches emerged about expiratory valves [ 1,3], development of low-WOB CPAP systems [2,7,81 and evaluation of these and the commonly used CPAP systems in various situations [4, [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Closed-loop control of a continuous positive airway pressure device

Favre¹,

Jandre²,

Giannella-Neto³

Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.0

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During continuous positive airway pressure (CPAP) therapy, the airway pressure (Paw) should be maintained almost constant during the entire respiratory cycle to minimize the patient work of breathing (WOB). We developed a CPAP setup using a closed-loop control acting on a miniature proportional valve that regulates the Paw established by the CPAP device. Spontaneous breathing was simulated by mechanically ventilating one of the two compartments of a lung simulator that passively displaced the other compartment connected to the CPAP setup. Paw dropped only 0.23 hPa below the 5 hPa and 10 hPa CPAP levels used, at a peak inspiratory flow of approximately 0.59 11s. In the worst case, Paw was 2.4 hPa above 10 hPa CPAP level during about 0.135 s when peak expiratory flow achieved 1.1 Us, followed by a 0.33 hPa undershoot. WOB, visualized by plotted pressure x volume curves, was smaller using the closedloop control as compared to the open-loop CPAP device. The closed-loop control utilized in the present CPAP setup seems to be able to minimize the pressure variation and thus reduce the WOB during the use of CPAP therapy. KeywordsXPAP, closed-loop control, work of breathing.

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A new reservoir-based CPAP with low oxygen consumption: the Bag-CPAP

et al. 2023

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Background Several noninvasive ventilatory supports rely in their design on high oxygen consumption which may precipitate oxygen shortage, as experienced during the COVID-19 pandemic. In this bench-to-bedside study, we assessed the performance of a new continuous positive airway pressure (CPAP) device integrating a large reservoir (“Bag-CPAP”) designed to minimize oxygen consumption, and compared it with other CPAP devices. Methods First, a bench study compared the performances of Bag-CPAP and four CPAP devices with an intensive care unit ventilator. Two FiO2 targets (40–60% and 80–100%) at a predefined positive end expiratory pressure (PEEP) level between 5 and 10 cm H2O were tested and fraction of inspired oxygen (FiO2) and oxygen consumption were measured. Device-imposed work of breathing (WOB) was also evaluated. Second, an observational clinical study evaluated the new CPAP in 20 adult patients with acute respiratory failure in two hospitals in France. Actual FiO2, PEEP, peripheral oxygen saturation, respiratory rate, and dyspnea score were assessed. Results All six systems tested in the bench study reached the minimal FiO2 target of 40% and four reached at least 80% FiO2 while maintaining PEEP in the predefined range. Device-delivered FiO2/consumed oxygen ratio was the highest with the new reservoir-based CPAP irrespective of FiO2 target. WOB induced by the device was higher with Bag-CPAP. In the clinical study, Bag-CPAP was well tolerated and could reach high (> 90%) and moderate (> 50%) FiO2 with an oxygen flow rate of 15 [15–16] and 8 [7–9] L/min, respectively. Dyspnea score improved significantly after introduction of Bag-CPAP, and SpO2 increased. Conclusions In vitro, Bag-CPAP exhibited the highest oxygen saving properties albeit had increased WOB. It was well accepted clinically and reduced dyspnea. Bag-CPAP may be useful to treat patients with acute respiratory failure in the field, especially when facing constraints in oxygen delivery.

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Evaluation of the Ambu Cpap System

Cited by 5 publications

References 10 publications

Tests of Six Continuous Flow CPAP Devices

Tests of Six Continuous Flow CPAP Devices

Closed-loop control of a continuous positive airway pressure device

A new reservoir-based CPAP with low oxygen consumption: the Bag-CPAP

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