Face mask or Laryngeal Mask during positive pressure ventilation for Term newborns: Is one preferable than the other?

Objective: Pulmonary aspiration of gastric contents occurs 20 –30% of the time during cardiopulmonary resuscitation (CPR) of cardiac arrest. This is due to loss of protective airway reflexes, pressure changes generated during CPR, and positive pressure ventilation (PPV). Even though the American Heart Association (AHA) has recommended the laryngeal mask airway (LMA) as an acceptable alternative airway for use by EMS personnel, concerns over the capacity of the device to protect from pulmonary aspiration remain. We sought to determine the incidence of aspiration after LMA placement, CPR and PPV. Methods: We conducted a prospective study on 16 consecutive post-experimental mixed-breed domestic swine of either sex (mean mass 25.7 ±1.4 kgs). A standard size-4 LMA was modified so that a vacuum catheter could be advanced into and past the LMA diaphragm. The LMA was placed into the hypopharynx and its position confirmed using End-tidal CO 2 and direct visualization of lung expansion. Fifteen milliliters of heparinized blood were instilled into the pharynx. After 5 PPVs with a mechanical ventilator, chest compressions were performed for 60s with asynchronous ventilations continuing at a rate of 12 per minute. After chest compressions, a suction catheter was inserted through the cuff and suction applied for approximately 1 minute. The catheter was removed and inspected for signs of blood. The LMA cuff was deflated and the LMA removed. The intima of the LMA diaphragm was inspected for signs of blood. In a validation cohort of 4 animals, the LMA was reinserted, a cricothyrotomy performed and 5 mL of blood instilled directly into the trachea. Results: There were 0/16 (95% CI=0 –17%) with a positive tests for the presence of blood in both the vacuum catheter and the intima of the LMA diaphragm. In the validation cohort, all four were positive for blood in both the vacuum catheter and the intima of the LMA diaphragm. Conclusions: In this simple model of regurgitation of after LMA placement, there was no sign of pulmonary aspiration, and no evidence that blood had passed beyond the seal created by the LMA cuff. Concerns over aspiration with LMA use may be unfounded. Future studies should determine the frequency of pulmonary aspiration after LMA placement in the clinical setting.

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Comparing positive pressure ventilation efficacy of a novel foot operated resuscitator with self-inflating bag and mask in a manikin model

BMJ Innovations ◽

10.1136/bmjinnov-2018-000309 ◽

2020 ◽

Vol 6 (2) ◽

pp. 48-54

Author(s):

Somashekhar Marutirao Nimbalkar ◽

Binoy Viresh Shah ◽

Amee Atulkumar Amin ◽

Vishwa Tushar Patel ◽

Ajay Gajanan Phatak

Keyword(s):

Neonatal Intensive Care ◽

Positive Pressure Ventilation ◽

Pressure Sensors ◽

Peak Inspiratory Pressure ◽

Comparative Trial ◽

Face Mask ◽

Target Range ◽

Positive Pressure ◽

Medical Systems ◽

Inspiratory Time

AimTo compare positive pressure ventilation efficacy of a novel foot operated resuscitator (FOR) during positive pressure ventilation with that of self-inflating bag and mask (SIBM) using a manikin model.MethodA comparative trial was conducted with 117 participants at a level III neonatal intensive care unit using Baby Anne (Laerdal Medical, Norway). Flow and pressure sensors were used to measure tidal volume propelled (Vp) and delivered (Vt). Each participant delivered 60 breaths, using each device targeting adequate chest-rise defined as that corresponding to a Vt of 15–21 mL. Vt, Peak Inspiratory Pressure (PIP), Leak Percentage (%), Inspiratory Time (Ti, millisecond) and other parameters were recorded using a PC (Dell, Windows V.10) on a custom application (LabView 2014 platform NI, USA). The proportion of breaths achieving target range Vt, other key ventilation parameters and their variability were compared between a generic CE approved bag and mask and a novel FOR (NeoBreathe, Phoenix Medical Systems, India).ResultUsing an SIBM, participants delivered a mean (SD) Vt of 17.52 (5.22) mL, achieving target range Vt in 46.99% of all breaths, with a mean (SD) face-mask leak per cent of 32.51% (22.25). Using the FOR, participants delivered a mean (SD) Vt of 18.31 (3.90), achieving target range Vt in 54.37% of all breaths and a mean (SD) face-mask leak per cent of 18.89% (14.45). Variability of Vt, PIP and leak per cent was significantly reduced with FOR.ConclusionFOR significantly reduced face-mask leak, significantly increased the proportion of breaths achieving Vt within optimal range and could offer a novel alternative to a SIBM.

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