ⅣV2 Circulation December 13. 2005 Mouth-to- Mouth Rescue breathing period of I second and provide sufficient tidal volume to Mouth-to-mouth rescue breathing provides oxygen and ven- cause visible chest rise on to the victim. 28 To provide mouth-to-mouth rescue aths, open the victims airway, pinch the victims nose, The Bag-Mask Device create an airtight mouth-to-mouth seal. Give I breath A bag-mask device should have the following140 overI seco take a"regular"(not a deep)breath, and give inlet valve; either no pressure relief valve or a pressure relief a second rescue breath over I second(Class IIb). Taking valve that can be bypassed; standard 15-mm/22-mm fittings regular rather than a deep breath prevents you from getting an oxygen reservoir to allow delivery of high oxygen con dizzy or lightheaded. The most common cause of ventilation alve that cannot be difficulty is an improperly opened airway, 12 so if the obstructed by foreign material and will not jam with an victims chest does not rise with the first rescue breath, oxygen flow of 30 L/min; and the capability to function perform the head tilt-chin lift and give the second rescue satisfactorily under common environmental conditions and extremes of temperature Masks should be made of transparent material to allow Mouth-to-Barrier Device Breathing detection of regurgitation. They should be capable of creatin Despite its safety, 29 some healthcare providers30-132 and lay a tight seal on the face, covering both mouth and nose. Masks rescuers may hesitate to give mouth-to-mouth rescue breath should be fitted with an oxygen(insufflation) inlet, have a ing and prefer to use a barrier device Barrier devices may not standard 15-mm/22-mm connector, 141 and should be avail- reduce the risk of infection transmission, 29 and some may able in one adult and several pediatric sizes. increase resistance to air flow. 33. 134 If you use a barrier device, do not delay rescue breathing Bag-Mask ventilation Barrier devices are available in 2 types: face shields and Bag-mask ventilation is a challenging skill that requires face masks. Face shields are clear plastic or silicone sheets considerable practice for competency. 142 143 The lone rescuer that reduce direct contact between the victim and rescuer but using a bag-mask device should be able to simultaneously do not prevent contamination of the rescuer's side of the open the airway with a jaw lift, hold the mask tightly against shield 35-13 the patients face, and squeeze the bag. The rescuer must also A rescuer with a duty to respond should use a face shield watch to be sure the chest rises with each breath only as a substitute for mouth-to-mouth breathing. These Bag-mask ventilation is most effective when provided by 2 responders should switch to face mask or bag-mask ventila trained and experienced rescuers. One rescuer opens the tion as soon as possible. 137 Masks used for mouth-to-mask airway and seals the mask to the face while the other squeezes breathing should contain a 1-way valve that directs the the bag. Both rescuers watch for visible chest rise. 143-144 The rescuer should use an adult(I to 2 L) bag to deliver a exhaled air away from the rescuer, diverting the patient's tidal volume sufficient to achieve visible chest rise(Class Some masks include an oxygen inlet for administration of a). If the airway is open and there are no leaks(ie, there supplementary oxygen. When oxygen is available, healthcare a good seal between face and mask), this volume can be providers should provide it at a minimum flow rate of 10 to delivered by squee l-L adult bag about one half to two 12 L/min thirds of its volume or a 2-L adult bag about one-third its volume. As long as the patient does not have an advanced Mouth-to-Nose and Mouth-to. Stoma Ventilation airway in place, the rescuer(s) should deliver cycles of 30 Mouth-to-nose ventilation is recommended if it is impossible compressions and 2 breaths. The rescuer delivers the breaths to ventilate through the victims mouth(eg, the mouth is during pauses in compressions and delivers each breath over seriously injured, the mouth cannot be opened, the victim is I second( Class Ila) in water mouth-to-mouth seal is difficult to achieve The healthcare provider should use supplementary ( Class IIa). A case series suggests that mouth-to-nose venti-(02>40%, a minimum flow rate of 10 to 12 L/mi lation in adults is feasible, safe, and effective(LOE 5). 138 available. Ideally the bag should be attached to an Give mouth-to-stoma rescue breaths to a victim with reservoir to enable delivery of 100% oxygen tracheal stoma who requires rescue breathing. A reasonable Advanced airway devices such as the LMA45, 146 and the alternative is to create a tight seal over the stoma with a round sophageal-tracheal combitubel47-149 are currently within the pediatric face mask ( Class IIb). There is no published scope of BLS practice in a number of regions(with specific idence on the safety, effectiveness, or feasibility of mouth- authorization from medical control). These devices may to-stoma ventilation. One study of patients with laryngecto- provide acceptable alternatives to bag-mask devices for mies showed that a pediatric face mask created a better healthcare providers who are well trained and have sufficient peristomal seal than a standard ventilation bag(LOE 4). 139 experience to use them(Class IIb). It is not clear that these Ventilation With Bag and Mask devices are any more or less complicated to use than a bag Rescuers can provide bag-mask ventilation with room air or and mask: training is needed for safe and effective use of both oxygen. a bag-mask device provides positive-pressure ven- the bag-mask device and each of the advanced airways tilation without an advanced airway and therefore may Ventilation With an Advanced Airway produce gastric inflation and its complications (see above). When the victim has an advanced airway in place during When using a bag-mask device, deliver each breath over a CPR, 2 rescuers no longer deliver cycles of CPr (ie,Mouth-to-Mouth Rescue Breathing Mouth-to-mouth rescue breathing provides oxygen and ven￾tilation to the victim.128 To provide mouth-to-mouth rescue breaths, open the victim’s airway, pinch the victim’s nose, and create an airtight mouth-to-mouth seal. Give 1 breath over 1 second, take a “regular” (not a deep) breath, and give a second rescue breath over 1 second (Class IIb). Taking a regular rather than a deep breath prevents you from getting dizzy or lightheaded. The most common cause of ventilation difficulty is an improperly opened airway,112 so if the victim’s chest does not rise with the first rescue breath, perform the head tilt–chin lift and give the second rescue breath.120,121 Mouth-to–Barrier Device Breathing Despite its safety,129 some healthcare providers130–132 and lay rescuers may hesitate to give mouth-to-mouth rescue breath￾ing and prefer to use a barrier device. Barrier devices may not reduce the risk of infection transmission,129 and some may increase resistance to air flow.133,134 If you use a barrier device, do not delay rescue breathing. Barrier devices are available in 2 types: face shields and face masks. Face shields are clear plastic or silicone sheets that reduce direct contact between the victim and rescuer but do not prevent contamination of the rescuer’s side of the shield.135–137 A rescuer with a duty to respond should use a face shield only as a substitute for mouth-to-mouth breathing. These responders should switch to face mask or bag-mask ventila￾tion as soon as possible.137 Masks used for mouth-to-mask breathing should contain a 1-way valve that directs the rescuer’s breath into the patient while diverting the patient’s exhaled air away from the rescuer.137 Some masks include an oxygen inlet for administration of supplementary oxygen. When oxygen is available, healthcare providers should provide it at a minimum flow rate of 10 to 12 L/min. Mouth-to-Nose and Mouth-to-Stoma Ventilation Mouth-to-nose ventilation is recommended if it is impossible to ventilate through the victim’s mouth (eg, the mouth is seriously injured), the mouth cannot be opened, the victim is in water, or a mouth-to-mouth seal is difficult to achieve (Class IIa). A case series suggests that mouth-to-nose venti￾lation in adults is feasible, safe, and effective (LOE 5).138 Give mouth-to-stoma rescue breaths to a victim with a tracheal stoma who requires rescue breathing. A reasonable alternative is to create a tight seal over the stoma with a round pediatric face mask (Class IIb). There is no published evidence on the safety, effectiveness, or feasibility of mouth￾to-stoma ventilation. One study of patients with laryngecto￾mies showed that a pediatric face mask created a better peristomal seal than a standard ventilation bag (LOE 4).139 Ventilation With Bag and Mask Rescuers can provide bag-mask ventilation with room air or oxygen. A bag-mask device provides positive-pressure ven￾tilation without an advanced airway and therefore may produce gastric inflation and its complications (see above). When using a bag-mask device, deliver each breath over a period of 1 second and provide sufficient tidal volume to cause visible chest rise. The Bag-Mask Device A bag-mask device should have the following140: a nonjam inlet valve; either no pressure relief valve or a pressure relief valve that can be bypassed; standard 15-mm/22-mm fittings; an oxygen reservoir to allow delivery of high oxygen con￾centrations; a nonrebreathing outlet valve that cannot be obstructed by foreign material and will not jam with an oxygen flow of 30 L/min; and the capability to function satisfactorily under common environmental conditions and extremes of temperature. Masks should be made of transparent material to allow detection of regurgitation. They should be capable of creating a tight seal on the face, covering both mouth and nose. Masks should be fitted with an oxygen (insufflation) inlet, have a standard 15-mm/22-mm connector,141 and should be avail￾able in one adult and several pediatric sizes. Bag-Mask Ventilation Bag-mask ventilation is a challenging skill that requires considerable practice for competency.142,143 The lone rescuer using a bag-mask device should be able to simultaneously open the airway with a jaw lift, hold the mask tightly against the patient’s face, and squeeze the bag. The rescuer must also watch to be sure the chest rises with each breath. Bag-mask ventilation is most effective when provided by 2 trained and experienced rescuers. One rescuer opens the airway and seals the mask to the face while the other squeezes the bag. Both rescuers watch for visible chest rise.142–144 The rescuer should use an adult (1 to 2 L) bag to deliver a tidal volume sufficient to achieve visible chest rise (Class IIa). If the airway is open and there are no leaks (ie, there is a good seal between face and mask), this volume can be delivered by squeezing a 1-L adult bag about one half to two thirds of its volume or a 2-L adult bag about one-third its volume. As long as the patient does not have an advanced airway in place, the rescuer(s) should deliver cycles of 30 compressions and 2 breaths. The rescuer delivers the breaths during pauses in compressions and delivers each breath over 1 second (Class IIa). The healthcare provider should use supplementary oxygen (O2
40%, a minimum flow rate of 10 to 12 L/min) when available. Ideally the bag should be attached to an oxygen reservoir to enable delivery of 100% oxygen. Advanced airway devices such as the LMA145,146 and the esophageal-tracheal combitube147–149 are currently within the scope of BLS practice in a number of regions (with specific authorization from medical control). These devices may provide acceptable alternatives to bag-mask devices for healthcare providers who are well trained and have sufficient experience to use them (Class IIb). It is not clear that these devices are any more or less complicated to use than a bag and mask; training is needed for safe and effective use of both the bag-mask device and each of the advanced airways. Ventilation With an Advanced Airway When the victim has an advanced airway in place during CPR, 2 rescuers no longer deliver cycles of CPR (ie, IV-24 Circulation December 13, 2005