It is important for the healthcare professional to learn both one-rescuer and two-rescuer CPR. It has several advantages, not the least of which is that it's less tiring during long resuscitations. Additionally, you can utilize a device known as a bag-valve-mask to assist in ventilations. The following is the approved technique for two-rescuer CPR in the adult patient.

When a second rescuer becomes available, he or she should activate EMS if it is not already done. Then, one person is positioned at the patient's side and performs chest compressions. The other rescuer remains at the patient's head, maintains an open airway, monitors a carotid pulse for effectiveness of chest compressions and provides rescue breathing.

The compression rate for two-rescuer CPR is approximately 100/minute. The number of compressions performed remains at 15. The ratio of compression to breaths is 15:2, with a pause for ventilation until the airway is secured. Once this occurs i.e., the patient is intubated, compressions and ventilations are asynchronous. The rate of compression will remain approximately 100/minute and the ventilation rate becomes 10-12/minute (1 breath every 5 seconds).

When the person performing chest compressions becomes fatigued, a switch  should occur. With as little delay as possible, the rescuers should stop APR, switch positions. assess the ABC's and resume immediately, if needed. Stop only every several minutes to see if normal breathing, pulse or signs of circulation have returned.

Cardiac or respiratory arrest does not have to be primarily cardiac in origin. There are many situations which may lead to arrest that can require you to change your approach to CPR. Here we will discuss these special situations and how you can deal with them.

Stroke: We have discussed this in detail in the central nervous system module. To summarize, your general emergency therapy centers around airway management and oxygen therapy.

Hypothermia: Your protocol for resuscitation of the hypothermic patient is similar to that of a normal cardiac event. However, you must additionally rewarm the patient along with providing defibrillation, CPR and oxygen therapy. Hypothermic patients can easily slip into arrest during the rewarming process. Care should be taken not to cause unnecessary movement.

Near-Drowning: Safe access to your patient is your biggest concern in a near drowning. Exercise caution when rescuing someone from the water. Remember, asphyxiation is usually the underlying cause of respiratory arrest in this case. Cardiac arrest is  generally secondary to respiratory arrest.

Traumatic Arrest: Cardiac arrest secondary to trauma can be a grave situation. Because the underlying cause may be difficult or impossible to correct, you main management priorities still center on the ABC's. Correct uncontrolled bleeding right away. When opening the airway of a suspected trauma patient, use the jaw-thrust method to minimize cervical spine movement. Additionally, maintain in-line neck stabilization. Utilize a cervical collar and backboard to immobilize the patient. Defibrillation may be safely used on this patient, but is less effective due to underlying trauma.

Pregnancy: The use of CPR on expectant mothers is unique because of the difference in cardiac and respiratory function. During pregnancy, cardiac output can increase up to 50%. Heart rate and oxygen consumption also increase. These changes cause the pregnant woman to be more susceptible to and less tolerant of cardiac changes. Additionally, when flat on her back, the uterus can compress the major blood vessels of the lower body, resulting in a decrease in cardiac output. Some of the causes of cardiac arrest during pregnancy are pulmonary embolism, placental bleeding, abruption and complications during delivery. When cardiac arrest occurs in a pregnant woman, standard CPR procedures should be applied. If defibrillation is indicated it should be used without hesitation. Adjust pad placement as necessary, allowing for a shift in the location of the heart due to pregnancy. Also, during CPR, place a pillow under the right hip to help facilitate blood return to the heart. As always, high flow oxygen is indicated.

Asphyxiation: Suffocation or asphyxiation occurs most commonly when a gas other than oxygen is inhaled or during a near-drowning. Inhalation asphyxiation can occur during chemical spills, gas leaks or fires. In the home environment, carbon monoxide is a common cause. Whatever the reason, the result is not enough oxygen reaching the brain. This results in unresponsiveness, respiratory arrest and eventually cardiac arrest. After safely retrieving the patient, perform ABC's and rescue breathing. CPR may be necessary as well. High flow oxygen is also indicated to speed oxygen to the brain.

The use of the airway adjunct called a bag-valve-mask is one of the most useful tools for the healthcare professional. Designed to make the delivery of oxygen to a cardiac arrest patient easier and more efficient, once mastered, the BVM is an incredibly useful tool. When hooked up to high flow oxygen, the BVM is capable of delivering up to 100% oxygen during ventilations. The key to using this airway device is to manage the airway properly. Watch for aspiration of vomit and be prepared to clear or suction the airway as needed. Two rescuers are needed to adequately to operate the BVM. One rescuer to maintain a seal over the patient's face and the second rescuer to perform the ventilations.

The skills of rescue breathing and chest compressions (CPR) are critical for BLS healthcare professionals. By performing these skills in the prescribed manner, you can maintain the delivery of oxygen and nutrients to the brain and stabilize the cardiac arrest patient. Simply remember the ABCD's and let them guide you in the management of sudden cardiac arrest.

Forceful or excessive ventilation during CPR may cause gastric inflation, regurgitation or aspiration.

A tidal volume of 700-1000 ml should be delivered over 2 seconds until observing well-defined chest rise for mouth-to-mouth or mouth-to-mask ventilations.

When supplemental oxygen is available a tidal volume of 400600 ml can be delivered over 1-2 seconds until observing a chest rise for BVM use.

Cricoid pressure is helpful in preventing gastric inflation in the unresponsive patient but always requires the presence of a second rescuer.

Healthcare professionals perform a carotid pulse check while looking for signs of circulation (normal breathing, coughing or movement).

Utilize the recovery position for the management of patients who are unresponsive, but are breathing and have a pulse (unless spinal injury is suspected).