When a barrier device is not available what technique of rescue breaths should be used

A Rescue Breathing

Initial rescue breathing during CPR should be provided through a mouth-to-mouth method, mouth-to-barrier device, or bag-mask ventilation (if available). Each rescue breath should be given over 1 second with a sufficient tidal volume to produce a visible chest rise. Two ventilations should be provided after every 30 compressions (30 : 2 compression-to-ventilation ratio). Trained lay rescuers or health care providers should initiate rescue breathing. An untrained lay rescuer should provide chest compressions only and not initiate rescue breathing. If a pulse is present, one rescue breath should be given every 6 seconds and the pulse rechecked every 2 minutes.

The airway should be opened by a head tilt–chin lift maneuver, unless a cervical spine injury is suspected. If a cervical spine injury is suspected, a jaw thrust should be performed with the head maintained in a midline position.

Fainting

The following action should be taken with a patient faints. Check their airway and breathing. If indicated, call 911 and begin rescue breathing and CPR (Chapter 45). Loosen tight clothing around their neck. Raise their feet, about 12 inches, above the level of their heart. If the person has vomited turn their head to the side to prevent chocking. Keep the person lying down for a minimum of 10 to 15 minutes in a cool and quiet area. If this is not possible, sit the person forward with their head between their knees.

▸ NONINVASIVE AIRWAY MANEUVERS

If the upper airway is obstructed, there are four basic noninvasive airway-opening maneuvers. All noninvasive airway maneuvers except tongue traction and the internal jaw lift can be conjoined with rescue breathing or bag-valve-mask assisted ventilation.

The most simple is the head tilt, chin lift. The heel of one of the rescuer's hands is pressed down on the victim's forehead, and the fingers of the other hand are placed under the chin to lift it up. The intended result is the sniffing position. Problems arise if the mouth is closed or soft tissues are folded inward because of the chin lift. In addition, downward pressure on the forehead tends to lift the eyebrows and open the eyelids, so measures may need to be taken to protect the eyes.

A second maneuver is the jaw thrust (Fig. 10-4A). Pressure is applied to the angle of the mandible to dislocate it upward while forcefully opening the mouth. This is painful, and the conscious or semiconscious victim will object by clamping down or writhing.

A third maneuver is the internal jaw lift (see Fig. 10-4B). The rescuer's thumb is inserted into the victim's mouth under the tongue, and the mandibular mentum (chin) is lifted, thus stretching out the soft tissues and opening the airway. This is the best maneuver for the unconscious victim with a shattered mandible. The internal jaw lift is dangerous to the rescuer if the victim is semiconscious and can bite.

A fourth noninvasive airway maneuver takes some practice but serves several purposes and is the best maneuver if done correctly. In this two-handed triple maneuver, the head is held between two hands to prevent lateral rotation and maintain neck control. The fourth and fifth fingers are hooked behind the angle of the mandible to dislocate the jaw upward, and the thumbs ensure that the mouth is maintained open (see Fig. 10-2). The third finger may be positioned over the facial artery as it comes around the mandible so that the pulse can be monitored at the same time. For greatest stability, the rescuer's elbows should rest on the same surface on which the victim is lying.

Airway

1.

CPR Microshield or pocket mask. These are compact, easy-to-use, clear, flexible barriers or masks with a one-way air valve for performing mouth-to-mouth rescue breathing; prevents physical contact with a victim's secretions.

Oral airways

Laryngeal mask airway (LMA Fastrach), designed to facilitate tracheal intubation with an endotracheal tube

Endotracheal tubes, assorted sizes, to use with LMA or blind nasotracheal intubations. (NOTE: some expeditions carry laryngoscopes, but they are heavy and bulky; lightweight plastic units are a good alternative.)

V-VAC or other portable suction device—bulky but effective

Medical oxygen tanks with regulators, nasal cannulas, and l00% nonrebreathing masks

Management

Immediate airway management and initiation of CPR are unequivocally the most effective interventions for the submersion victim (Table 138-1). Bystander cardiopulmonary resuscitation (CPR) has been shown to significantly affect patient survival, and even rescue breathing or cardiac compressions alone are superior to no intervention.37–39

All patients should be transported to the hospital for evaluation. Basic life support protocols and standard trauma protocols must be followed, including cervical spine immobilization when there is a history suggestive of an injury or suspicion of a traumatic mechanism.33 Wet clothing should be removed to minimize heat loss. Airway protection must be a high priority due to the high frequency of vomiting (up to 86%) with chest compressions.40 Early placement of a nasogastric tube to decompress the stomach will decrease the risk of vomiting in patients who have received rescue breaths. Early tracheal intubation is recommended for airway protection, to ensure removal of any foreign material from the airway, and to institute continuous positive airway pressure or positive end-expiratory pressure as needed for respiratory failure.40 Once the airway is controlled, hypoxia and acidosis are better tolerated than hypoxia and hypotension. Permissive hypercapnia is preferable to avoid hypotension secondary to high mean airway pressures, which impede preload.41

No literature specifically addresses the use of bronchodilators for wheezing in a submersion victim. A reasonable approach is a one-time trial of bronchodilator therapy, with repeated treatments for the patients who improve clinically. In patients with a history of reactive airways disease or asthma, bronchodilators should be considered beneficial despite a dearth of evidence to support this recommendation.

Pediatric submersion victims are frequently hypothermic upon arrival to the ED. Due to significant peripheral vasoconstriction, rectal temperature lags behind true core temperature.16,18 Jugular bulb temperature reflects body temperature, not true CNS temperature, but determining true CNS temperature is impossible without invasive monitoring.42 An exaggerated response to warming occurs, making hyperthermia after resuscitation common.43 When monitoring the hypothermic patient, the clinician should remember that pulse oximetry is not reliable under 27° C.44

“Afterdrop” is a phenomenon that occurs during rewarming when a patient experiences a drop in core temperature secondary to mobilization of cold blood from the peripheral circulation. Afterdrop has been associated with sudden death in otherwise intact hypothermia survivors.45 Care must be taken not to be overly aggressive during the rewarming process. Rewarming with forced air (Bair Hugger) can increase temperature at a safe rate of 1.7° C/hr.46 This method requires circulation to be effective. In cases of severe hypothermia or cardiac arrest, extracorporeal rewarming may be beneficial.11 This technique has been available outside the surgical suite since 1993.47 Extracorporeal rewarming has a 50% intact survival rate for adults with severe accidental nonsubmersion hypothermia but presents obvious logistic difficulties for ED care.48

Alternatively, therapeutic hypothermia is potentially beneficial and neuroprotective for submersion victims.49,50 The stipulation is that the hypothermia must occur within 7 minutes of hypoxemia to be beneficial.24 However, hypothermia can also decrease peripheral circulation and may inhibit adequate distribution of rescue medications. Caution must be exercised to not overmedicate based on lack of effect at time of administration in patients with compromised circulation or peripheral vasoconstriction.

Multiple secondary therapeutic interventions have been investigated. High-dose barbiturate therapy has been shown to help control intracranial pressure (ICP), but neither barbiturate therapy nor ICP monitoring appears to improve neurologic outcome.40,51 Prophylactic steroids and antibiotics have been studied extensively and do not increase the odds of survival52 (see Chapter 9, Cerebral Resuscitation).

Patients who are initially hypothermic must be continually monitored to gauge the success of intervention and to guard against hyperthermia. An initial decrease in temperature as a result of afterdrop is not uncommon and should not be equated with inadequate rewarming.45 During rewarming from profound hypothermia, care must be taken so that rewarming does not occur too quickly and precipitate arrhythmias. Overly rapid rewarming also leads to hypotension from peripheral vasodilation, hypoxemia, and sinus bradycardia.53

Aspiration, whether of gastric contents or from the body of water, is a risk in any patient with an altered level of consciousness (Table 138-2). Tachypnea secondary to the pulmonary effects of submersion and the possibility that some rescuers will perform the Heimlich maneuver increases the odds of an aspiration.

Awake, alert patients who are asymptomatic after 4 to 6 hours of observation may be safely discharged home.35,36 Historically, there have been reports of “secondary drowning” in otherwise normal-appearing patients, but similar cases have not been seen in subsequent research. Upon review, such cases were not clinically subtle or suitable for discharge.54

Patients who are clinically symptomatic after 6 hours require inpatient care in a monitored bed. The emergency physician should communicate early with pediatric intensivists and/or referral centers for children with persistent symptoms or severe initial condition to arrange for admission or transport to a capable facility. Bathtub drownings or other cases suspicious for nonaccidental injury or neglect should be evaluated in conjunction with social work and law enforcement in accordance with local protocols. As noted earlier, maintaining high concern for abuse and/or neglect is the key to identifying these cases.

When a patient has a clear traumatic mechanism of injury associated with submersion, surgical consultants should be involved in evaluation and management. Other subspecialty services should be consulted as needed for patients with identifiable predisposing factors such as seizures or arrhythmias. If possible, the emergency physician should contact the patients' primary care physician to identify any unknown history and to arrange for adequate follow-up or ongoing care of more severe patients. The primary care physician may also be helpful in assisting the family in making important decisions about termination of life support when neurologic devastation is apparent.

Consensus exists for poor prognostic signs and symptoms, yet it is important to acknowledge that there will be outlying cases that defy all predictions of survival despite meeting all poor prognostic criteria.55–57 These cases occur very rarely and must be weighed against the more frequent occurrence of survival with neurologic devastation.

There are no absolutely reliable indicators of intact survival with cold water submersions.58 Positive prognostic indicators include submersion time less than 10 minutes, no evidence of aspiration, and body core temperature less than 35° C.58 Younger age of the victim as a positive prognosticator is supported in some studies but not others.58–60 Hypothermia that is delayed 15 minutes does not have the same protective effect (only moderate disability) as immediate hypothermia.61 Severe acidosis, with a pH as low as 6.33, has been reported with full recovery, reinforcing the poor prognostic value of this particular test.62 Mean time to return of spontaneous circulation for hypothermic submersion patients requiring CPR upon arrival at the ED is 58 minutes.63 It seems prudent to continue resuscitation of the hypothermic patient from a cold water submersion for a total of at least 1 hour.

In the ED, outcome of patients who have spontaneous circulation without spontaneous respirations cannot be reliably predicted. Children may experience an unexpected full recovery following a prolonged vegetative state.64 Dilated pupils 6 hours after injury and seizures 24 hours after admission have been associate with poor outcome, but again, case reports with exceptions have been published.13,55,57,65 The Pediatric Risk of Mortality (PRISM) score is somewhat helpful, but often does not differentiate neurologically intact survival among patients with median scores.14,66,67 There is universally poor neurologic outcome for patients who were normothermic, pulseless, and apneic upon arrival in the ED, although some still recommend continued support for 24 hours.63 The prognosis for children requiring CPR regardless of etiology is poor, and patients requiring more than two doses of epinephrine or resuscitation longer than 20 minutes also have a very poor prognosis.39,68 All patients with spontaneous respirations on presentation to the ED recover, and reactive pupils support a good prognosis.13

Role of Continuous Chest Compressions or Chest-Compression-Only CPR

Several studies have found that survival of patients with OHCA who receive chest compression alone without mouth-to-mouth ventilations by bystanders are not statistically different from survival of such patients who receive chest compression plus so-called “rescue breathing.”40-42 Nevertheless, the technique of chest compressions without rescue breathing has not been recommended by the guidelines unless the bystander is unable or unwilling to perform mouth-to-mouth ventilation.9,24 The rational for this recommendation is that the guidelines’ authors evidently did not want lay individuals to have to decide if the patient has a cardiac arrest or a respiratory arrest. As will be noted later, this author thinks that this is not only possible but essential because many more individuals have OHCA and respiratory arrest. In Tucson, Ariz., it has been estimated that there are about 100 out-of-hospital cardiac arrests for every drowning death. In Seattle, the reported incidence of cardiac arrest to respiratory arrest is 20 to 1.42 In certain cultures, for example in those with a high incidence of drug abuse, the incidence is probably higher. In other cultures the incidence of respiratory to cardiac arrests is probably lower.

Studies by Kern and associates, in realistic swine models of OHCA, found that the provision of chest-compression-only CPR was more effective than the provision of standard 2:15 CPR, when each set of 15 chest compressions was interrupted for a realistic 16 seconds, to simulate the duration without chest compressions reported for a single rescuer to deliver the recommended “two quick breaths” and resume chest compressions.36 In 2007, similar findings were reported in humans.28 The survey of survivors (SOS) KANTO study reported that the overall survival of patients with OHCA was 2.2% for those who had not received bystander CPR when the EMS arrived, 4.2% for those who were receiving chest compressions plus mouth-to-mouth ventilation, and 6.2% for those receiving chest-compression-only by bystanders.28 More importantly, these investigators reported that in the subset of patients with the greatest chance of survival—those with witnessed arrest and a shockable ventricular arrhythmia upon arrival of the EMS personnel, the survival was nearly twice as great (11% versus 19%, P = 0.05) in those who had received bystander chest compression alone than in those who received chest compression plus mouth-to-mouth ventilation.28

Following the publication of this important study, the guidelines were not changed despite a call for urgent changes.43 The reason was that this observational study was done during a time when the recommended ventilation to chest compression ratio was still 2:15. The 2005 Guidelines of the American Heart Association (AHA), the European Resuscitation Council, and the International Liaison Committee for Resuscitation (ILCOR) changed their recommendations in the 2005 guidelines for ventilations to chest compression ratio to 2:30.9 The change in the 2005 guidelines from 2:15 to 2:30 was based in part on the findings of Abella and colleagues.44 In a prospective observational study of in-hospital cardiac arrest in three hospitals during 2000-2003, those patients who had a return of spontaneous circulation (ROSC) received a greater number of chest compressions per minute than those who did not. The average number of chest compressions per minute was 90 + 17 in those who had ROSC compared with 79 + 18 in those who did not have ROSC.44 In their analysis, it seemed that a compression rate of at least 89 compressions per minute was necessary for higher rates of ROSC. Of note is the fact that the survival of patients with in-hospital cardiac arrest in these three academic hospitals was so poor that it was not reported.44

Animal studies showed that ROSC was better with a 2:30 ventilation to compression ratio than with the previous standard of 2:15.45 Thus there was no long-term (24-hour) survival evidence that the change to the recommended 2:30 ventilation to compression ratio would improve survival. The recommendation was based on consensus.9 One could argue that observational studies in man were needed before guideline changes could be made. We argue that our swine models of OHCA, showing that continuous chest compressions were better than 2:15 when a realistic 16-second interruption was used to provide the two ventilations, predicted the results found in man.28,43

In subsequent studies using the same swine model of OHCA, Ewy and colleagues found that when simulated bystander resuscitation was initiated 4 to 6 minutes after the onset of VF arrest, and defibrillated after 12 minutes of VF, chest-compression-only CPR (CCC-CPR) resulted in a greater number of neurologically normal 24-hour survivors than did 2:30 ventilations to compressions.46 Neurologically normal survival was found in 16 of 24 (64%) of the swine who received continuous chest compression compared with 6 of 23 (26%) receiving two ventilations for every 30 chest compressions before defibrillation.46

Breathing

C.

If the child is not breathing or has only occasional gasps, give two rescue breaths at 1 second per breath, and continue to give one breath every 3 to 5 seconds. Equal chest rise is an absolute marker of effectiveness of rescue breathing. In infants, it is acceptable to use both mouth-to-mouth and mouth-to-nose techniques. In children, use only the mouth-to-mouth technique. Barrier devices have not reduced the risk for transmission of infection and may increase the resistance to flow. Although not encouraged, barrier devices are acceptable as long as there is not a time delay to rescue breathing.

Epidemiology

In the United States submersion accidents remain the second most common cause of injury and death in children 1 to 4 years of age. Children younger than 5 years have the highest drowning mortality rates. Annually, about 1100 drowning deaths occur in the United States in children younger than 19 years. Approximately 75% of these victims are children of the ages of 1 to 4 years. Just over one-half of these drowning deaths occur in residential pools. The distribution of submersion accidents by age follows a well-defined bimodal pattern. Children younger than age 5 years represent the first peak, which is followed by a second peak at ages 16 to 24 years.