VOL: 102, ISSUE: 38, PAGE NO: 28
Phil Jevon, PGCE, BSc, RN, is resuscitation officer/clinical skills lead, Manor Hospital, WalsallVentilation and oxygenation during resuscitation help to preserve cerebral function. In hospital, at the very least...
Ventilation and oxygenation during resuscitation help to preserve cerebral function. In hospital, at the very least, a pocket mask should always be immediately available (Soar and Spearpoint, 2005). This article describes pocket-mask and bag-mask ventilation techniques.
Blood oxygen levels remain high in the first few minutes of a non-asphyxial cardiac arrest. This means ventilations are initially less important than chest compressions (Kern et al, 2002), so on confirmation of cardiac arrest, 30 chest compressions must be performed followed by two ventilations (30:2).
The pocket mask is transparent, enabling prompt detection of vomit or blood in the patient's airway. A one-way valve directs expired air away from the nurse.
Most masks have an oxygen connector for the attachment of supplementary oxygen (10L/min) (Resuscitation Council UK, 2000), so an inspired oxygen concentration of approximately 50% can be achieved. If there is no oxygen connector, supplementary oxygen can be added by placing oxygen tubing underneath one side of the mask and pressing down to achieve a seal (Nolan et al, 2005).
- Don gloves (if available).
- Kneel behind the patient's head with your knees shoulder-width apart (if you are alone kneel beside the patient level with the nose and mouth) (RCUK, 2001).
- Rest back to sit on the knees and adopt a low kneeling position.
- Bend forwards from the hips, leaning down towards the patient's face and resting your elbows on your legs to support your weight (RCUK, 2001).
- If available, attach oxygen to the connector on the mask at a rate of 10L/min (RCUK, 2000) (Fig 1). If there is no connector, place the oxygen tubing underneath one side of the mask and press down to achieve a seal (Fig 2) (Nolan et al, 2005).
- Apply the mask to the patient's face; press down with the thumbs and lift the chin into the mask by applying pressure behind the angles of the jaw.
- Take a breath and ventilate the patient with sufficient air to cause visible chest rise (Fig 3). Each ventilation should last one second.
- If the patient is on a bed or trolley (its height should have been adjusted so that the patient is level between the knee and mid-thigh of the nurse performing chest compressions): stand at the side facing the patient, level with the nose and mouth and bend forward from the hips to minimise flexion of the spine (Fig 4). You can also support your weight by resting your elbows on the bed and leaning your legs against the side of the bed frame (RCUK, 2001). If another nurse is performing chest compressions adopt a position at the top of the bed facing the patient.
The bag-mask (self-inflating bag) device allows the delivery of higher concentrations of oxygen. If an oxygen reservoir bag is attached, with an oxygen flow rate of 10L/min, an inspired oxygen concentration of approximately 85% can be achieved (Nolan et al, 2005).
When using a bag with a face mask, it can be difficult to achieve a seal, maintain an open airway and squeeze the bag alone (Alexander et al, 1993), so a two-person technique is recommended, one person to open the airway and ensure a good seal with the mask, while the other squeezes the bag (Nolan et al, 2005).
- Ensure the patient is supine.
- Move the bed away from the wall and remove the backrest if applicable. Ensure the brakes of the bed are on. The height of the bed should be adjusted so that the patient is level between the knee and mid-thigh of the nurse performing chest compressions (RCUK, 2001).
- Adopt a position at the top of the bed facing the patient, with the feet in a walk/stand position (RCUK, 2001).
- Select an appropriately sized mask - one that comfortably covers the mouth and nose but does not cover the eyes or override the chin.
- Ensure oxygen reservoir bag is attached and connect oxygen at a flow rate of 10L/min (Fig 5) (Nolan et al, 2005).
- First nurse: tilt the head back, apply the mask to the face, pressing down on it with the thumbs. Lift the chin into the mask by applying pressure behind the angles of the jaw. An open airway and an adequate face/mask seal should now be achieved. A pillow under the patient's head and shoulders can help to maintain this position.
- Second nurse (positioned beside the bed): squeeze the mask bag (not the oxygen reservoir bag) sufficiently to cause visible chest rise (Fig 6). Each ventilation should be delivered over one second.
- Observe for chest rise and fall. If the chest does not rise recheck the patency of the airway; slight readjustment may be all that is required.
All nurses who carry out clinical procedures must have received approved training, undertaken supervised practice and demonstrated competence in the clinical area. The onus is also on the individual to ensure that knowledge and skills are maintained from both a theoretical and a practical perspective. Nurses should also undertake this role in accordance with an organisation's protocols, policies and guidelines.