Two-rescuer CPR should be performed with one rescuer positioned at the chest area and the other positioned beside the victim's head. The rescuers should be on opposite sides of the victim to ease position changes when one rescuer gets tired. Changes should be made on cue without interrupting the rhythm.

The victim's condition must be monitored to assess the effectiveness of the rescue effort. The person ventilating the patient assumes the responsibility for monitoring pulse and breathing. To assess the effectiveness of the partner's chest compressions, the rescuer should check the pulse during compressions. To determine if the victim has resumed spontaneous breathing and circulation, chest compressions must be stopped for 5 seconds at the end of the first minute (20 cycles) and every few minutes thereafter.

NOTE: Although it has fallen out to favor with some agencies, two-person CPR remains a viable method of resuscitation.

CPR for Children and Infants
CPR for children (1 to 8 years old) is similar to that for adults. The primary differences are that the heel of only one hand is used to apply chest compressions, and ventilations are increased to a rate of 20 breaths per minute (once every 3 seconds). Chest compressions are performed on the lower half of the sternum (between the nipple line and the notch). The chest should be depressed approximately one-third to one-half (about 1 to 1 1/2 inches) the total depth of the chest.

For infants (under 1 year old), CPR is performed with the infant supine on a hard, flat surface. The hard surface may be the rescuer's hand or arm, although using the arm to support the infant during CPR enables the rescuer to transport the infant more easily while continuing CPR. See figure 4-16. Once the infant is positioned on a hard surface, the airway should be opened using the head tilt-chin lift or jaw-thrust maneuver. Both maneuvers, however, must be performed very carefully and gently to prevent hyperextension of the infant's neck. Pulselessness is determined by palpating the brachial artery (fig. 4-17). If the infant has no pulse and is not breathing, CPR must be started immediately.

To perform CPR on an infant, place your mouth over the infant's nose and mouth, creating a seal. Give two slow breaths (1 to 1 1/2 seconds per breath) to the infant, pausing after the first breath to take a breath. Pausing to take a breath after the first breath of each pair of breaths maximizes oxygen content and

Figure 4-16.-Infant supported on rescuer's arm, and proper placement of fingers for chest compressions.

minimizes carbon dioxide concentration in the delivered breaths. Perform chest compressions by using two fingers to depress the middle of the sternum approximately 1/2 to 1 inch. See figures 4-16 and 4-18 for proper finger positioning for chest compressions.

For both infants and children, the compression rate should be at least 100 compressions per minute. Compressions must be coordinated with ventilations at a 5-to-1 ratio. The victim should be reassessed after 20 cycles of compressions and ventilations (approximately 1 minute) and every few minutes thereafter for any sign of resumption of spontaneous breathing and pulse. If the child or infant resumes effective breathing, place the victim in the recovery position.

SHOCK

LEARNING OBJECTIVE: Recognize the signs and symptoms of shock, and determine treatment by the type of shock presented.

Shock is the collapse of the cardiovascular system, characterized by circulatory deficiency and the depression of vital functions. There are several types of shock:

Hypovolemic shock-caused by the loss of blood and other body fluids.

Neurogenic shock-caused by the failure of the nervous system to control the diameter of blood vessels.

Cardiogenic shock-caused by the heart failing to pump blood adequately to all vital parts of the body.
Septic shock-caused by the presence of severe infection.

Anaphylactic shock-caused by a life-threatening reaction of the body to a substance to which a patient is extremely allergic.

Multiple types of shock may be present in varying degrees in the same patient at the same time. The most frequently encountered and most important type for the Hospital Corpsman to understand is hemorrhagic shock, a type of hypovolemic shock which will be discussed later in this chapter.

Shock should be expected in all cases of major injury, including gross hemorrhage, abdominal or chest wounds, crash or blast injuries, extensive large-muscle damage (particularly of the extremities), major fractures, traumatic amputations, or head injuries, or in burns involving more than 10 percent of the body surface area.