Cardiovascular Critical Care II
ii.
Cricoid pressure is the technique of applying pressure to the patient’s cricoid cartilage to push
the trachea posteriorly and compress the esophagus with the goal of preventing aspiration.
| (a) | May help in visualizing vocal cords during tracheal intubation. |
|---|---|
| (b) | Recommend against use for adult cardiac arrest because of possible delay or prevention of |
advanced airway, lack of protection from aspiration, and lack of mastery from “expert” and
nonexpert rescuers (Emerg Med Australas 2005;17:376-81; Br J Anaesth 1994;72:47-51).
iii.
If a foreign body airway obstruction (FBAO) occurs:
| (a) | Observe the patient with a mild FBAO. Mild FBAO is defined by a patient with a partial |
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airway obstruction that is still able to talk and has an effective cough.
| (b) | Signs of severe FBAO include a silent cough, stridor, or increasing respiratory difficulty. If |
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these occur, ask the patient, “Are you choking?” If the patient clutches their neck (universal
sign of choking) or nods without answering verbally, consider severe FBAO:
| (1) | Activate the emergency response system. |
|---|---|
| (2) | Administer abdominal thrusts to nonobese adults. |
| (3) | In adults with obesity or women in the late stage of pregnancy, administer chest thrusts. |
| (c) | If the patient becomes unresponsive: |
| (1) | Place on ground and begin CPR as chest compressions have been shown to |
generate higher airway pressure than abdominal thrusts (Resuscitation 2000;
44:105-8).
| (2) | Each time the airway is opened during CPR to provide a rescue breath, look for an |
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object in the patient’s mouth and, if found, remove it. If not found, continue giving the
rescue breaths (two total breaths), followed by 30 chest compressions.
| (3) | No studies have evaluated the routine use of the finger sweep to clear an airway in |
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the absence of visible airway obstruction. Case reports have shown some efficacy, but
harm has also been demonstrated in patients and rescuers. A finger sweep should not
be used in the absence of visible airway obstruction.
B - Rescue breaths
Primary purpose is to assist in maintaining oxygenation, with secondary purpose of eliminating
carbon dioxide (CO2).
ii.
Compressions should always be initiated first as the arterial oxygen content of blood remains
unchanged until CPR is initiated.
iii.
Optimal compression/ventilation ratio, inspired oxygen concentration, tidal volume, and RR
are yet to be determined.
iv.
Compression-only CPR without rescue breaths is recommended for nonmedical rescuers
for OHCA (see earlier text for more detail). Trained nonmedical rescuers are encouraged to
perform rescue breaths at a ratio of 30 compressions to 2 breaths. When the patient has an
advanced airway in place during CPR, rescuers no longer deliver cycles of 30 compressions and
2 breaths (i.e., they no longer interrupt compressions to deliver 2 breaths). Instead, the provider
may reasonably deliver 1 breath every 6 seconds (10 breaths/minute) using bag-mask ventilation
while continuous chest compressions are being performed (Circulation 2015;132(suppl 2):
S414-35).
| (a) | Low minute ventilation (low tidal volume and/or low RR) can maintain oxygenation and |
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ventilation during CPR as there is low oxygen uptake at the tissues and low CO2 production
(Circulation 1997; 95:1635-41).
| (b) | Give sufficient tidal volume to produce visible chest rise (Resuscitation 1996;31:231-4). |
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Excessive ventilation can increase intrathoracic pressure and decrease venous return as
well as cause gastric inflation, which can lead to aspiration, regurgitation, and decreased
257:512-5).