Modell, Jerome H. MD, DSc (Hon)
A recent review article, “Drowning: Update 2009,”1 reported that the death rate from drowning in the United States has decreased each decade since 1970, with 3.87 deaths per 100,000 population in 1970, 2.67 in 1980, 1.60 in 1990 and 1.24 in 2000.
Additionally, it was projected that when the US Census is taken again in 2010, there will be a further decrease in this mortality rate. A major factor in the decrease of the death rate from drowning was attributed to a far better understanding of the pathophysiology and treatment of drowning in 2009, as compared to prior years. Also important, however, is the implementation of standards that govern safe pool design and maintenance, enforcing those standards and properly instructing lifeguards in the latest methods of waterfront surveillance and resuscitation techniques.
To determine the opportunities that will further reduce needless drowning deaths, the case histories of 255 consecutive drowning victims where the episode ended up in litigation were reviewed. Admittedly this is a skewed population and should not be misinterpreted as a random sample. What follows is an analysis of those cases that occurred at swimming pools, particularly pointing out areas where needless deaths occurred due to lack of adherence to common sense standards and proper attentiveness to persons in the water.
Presentation of Data
This study covered 255 cases of people who drowned between 1998 and 2008. All but three persons in this study either died or suffered permanent, extensive residual hypoxic brain damage. Of the 255 drownings, 180 occurred in swimming pools. Ninety-seven of these pools had lifeguards in attendance. Eighty-three were public pools or pools in commercial enterprises without lifeguard supervision, or home pools. For the remaining 75 cases, 15 occurred in lakes, 15 in rivers or streams, 39 in the ocean and 6 at other miscellaneous locations.
Of the 180 victims of drowning in swimming pools, the initiation of their submersion episode was not observed, but, rather, the victim was found submerged and unresponsive in 123 cases. Of those who drowned in the 97 pools manned by lifeguards, in only 38 cases was the body discovered by a lifeguard, whereas 59 were discovered by bystanders. Further, of the 97 victims of drowning in lifeguard-manned pools, the body was retrieved by the lifeguards in only 67 cases and by someone else in 30 cases.
Basic cardiopulmonary resuscitation (CPR) was administered to 68 of these 97 victims by the lifeguards and to 29 victims by bystanders. Some reasons why CPR was administered by bystanders rather than lifeguards included: lifeguards ignored the request for help, lifeguards thought the victim was playing around or faking, lifeguards stood around and did nothing, lifeguards admitted they did not know how to administer CPR, lifeguards gave CPR incorrectly, lifeguards were socializing with others, lifeguards were tending to janitorial duties, or the lifeguards were otherwise not readily available. Current acceptable practice should require that lifeguards be certified in both lifesaving and basic cardiopulmonary resuscitation and they should be tested for continuing competence at regular intervals. Further, they should devote their entire attention to scanning the pool when they are on duty and to rescuing persons in trouble. While on lifeguard duty, they must not be distracted by other endeavors.
Of the 180 victims of drowning in swimming pools, the water in the pool was described as murky or cloudy in 18 cases, thus precluding anyone from readily visualizing the victim submerged in the pool. This significantly delayed retrieval of the body and initiating resuscitation attempts. Four victims were trapped under water by the suction created by drains with absent or defective covers on the drain pipes. For many others, simple rescue equipment such as Shepherd's hooks and life rings on a rope were not available, which compromised rescue attempts.
Inadequate or defective fencing surrounding the pool was implicated in 9 cases where young children entered the pool, unseen by an adult. This included both commercial pools and home pools. Eight additional victims succumbed to “shallow water blackout” secondary to holding their breath and swimming underwater after hyperventilating.
Seventy-two of these 180 patients were between 8 months and 8 years of age. In 23 of these cases it was documented that there was not adequate parental supervision at the pool.
Lessons to be Learned
Review of the 180 victims of drowning in pools clearly points out that the vast majority of these deaths could have been prevented if common sense and adherence to basic standards had been followed. Clearly, it is dangerous to swim in waters that are so cloudy that a person below the surface is not visible to observers at poolside. In that situation, if one does become submerged, it is extremely unlikely that they will be found and retrieved promptly so that they can be successfully resuscitated. Thus, if the pools were maintained properly, the 16 deaths that occurred in this series in cloudy or murky water should all have been preventable.
Common sense dictates that drain pipes, which create underwater suction, can trap a person and cause them to drown. Two of the 4 persons in our series were trapped by the arm, one by the hair and the fourth by suction to the temple area. Safety covers for pool drains are available that prevent build up of sufficient suction to trap a person and should be standard and fully operational on all pools.
Inadequate or defective fencing and gates around pools is a disaster waiting to happen because small children can gain access to the area and jump or fall into a pool when not attended constantly by a vigilant adult. Had proper effective fencing been present in all pools in this series, another 9 lives would have been saved.
“Shallow water blackout” is the clinical acronism used to describe what happens when one deliberately hyperventilates and then enters the water to see how long they can stay submerged or how far they can swim underwater. When a person hyperventilates, they blow off carbon dioxide, and they can then voluntarily hold their breath for a longer period of time. In this situation their arterial oxygen tension drops until they lose consciousness from cerebral hypoxia before they have a drive to breathe from increased carbon dioxide tension. Once they lose consciousness, they respond to a hypoxic drive to breathe and inhale water, thus initiating the drowning process.2,3 The general public needs to be educated as to the dangers of hyperventilation prior to becoming submerged in water and hyperventilation followed by breath holding needs to be actively discouraged. This would have saved an additional 8 lives in this series of patients.
Seventy-one of these victims were aged 8 months to 8 years, and for 23 of these cases it was determined that adequate parental supervision was not present at the time of their drowning episode. Clearly, it is unwise for a parent to leave their small children at a pool to be unsupervised or watched only by other children, siblings or busy lifeguards.
It is interesting to realize that in 123 of our 180 pool drowning victims, no one observed that the victims were in trouble until they were missing and found to be submerged and in a state of cardiac arrest. This suggests that the number of people who suffer from what was once called passive or silent drowning is much higher than originally thought.4 An alternative explanation is that they were not under constant surveillance and therefore, the initiation of their submersion episode was unwitnessed. Our analysis supports the latter conclusion.
Certainly, one would think that for the 97 pools manned by lifeguards, the submersion episode should have been seen by the lifeguards. The fact that only 40% of these victims were discovered by the lifeguard and 60% were discovered by other persons at the pool suggests that the lifeguards were not continuously scanning the pool as is required. Further, if the lifeguards had been scanning the pools at all times as is appropriate, the vast majority of these victims should have been spotted at the onset of submersion, not sometime later. If removed promptly at that time and treated as necessary, they should have survived.
In this series there were several instances where it could be documented that surveillance did not meet the standards. Many reasons for this were identified, which included, but were not limited to: insufficient numbers of lifeguards present for the number of pool patrons, lifeguards not at lifeguard stations but socializing with persons at poolside, lifeguards leaving their post without being relieved by another lifeguard, lifeguards performing other chores like cleaning restrooms or taking tickets while on duty, etc.
Also, once the victim was discovered, in only 67 cases did the lifeguard enter the water to retrieve the victim. The remaining 30 victims were retrieved by poolside patrons. Some of the reasons for not entering the water included the fact that some lifeguards were fully clothed rather than being in bathing suits; were physically incapacitated and unable to enter the water; were unable to speak or understand English and so could not communicate with the persons who discovered the body; were unsure that they could retrieve the victim without putting themselves at risk due to differences in size; and thought the victim was faking or “playing around” under water.
The hallmark of effective lifesaving is the uninterrupted scanning of the water continuously by alert lifesavers who are neither distracted nor fatigued. Current recommendations are that once a potential victim is observed to possibly be in trouble for 10 seconds, he/she should be retrieved from the water within 20 seconds and applicable therapy should be applied.5 Clearly, this was not followed in this group of patients. If these recommendations had been followed, the timely retrieval, rescue, and resuscitation rate would have been considerably higher than it was in this population.
Discussion and Recommendations
Although the improvement in decreasing the death rate from drowning in the United States has been impressive over the past four decades (greater than 300%), the data presented in this paper clearly emphasize that many remaining deaths are avoidable with little additional effort.
Significant improvements in pool standards have occurred, yet some pools suffer from inadequate maintenance. There is no excuse for submerged persons not to be visible from the surface of the pool because of dirty, murky, or cloudy water. The water in pools should be kept clear at all times, so the bottom of the pool is clearly visible. Further, chemical additives should be adjusted to control the pH of the water and minimize the potential of overgrowth of bacterial pathogens, fungi, and algae.
Hazardous conditions such as drain pipes capable of trapping persons underwater due to suction must be repaired and eliminated by use of improved design and preventive covers. Pool floors should not drop off suddenly but rather should be sloped and accurate depth indicators should be present. The floors must be kept clean and free of substances and growths that would make them slippery and hazardous to a nonswimmer.
Rescue equipment such as life rings and Shepherd's hooks should be clearly visible at the poolside. Emergency airway equipment including bag, valve, mask resuscitation apparatus, an oxygen source, portable suction, and automatic electrical defibrillators (AED) should be present at all public and commercial pools that are open to the public or available for a fee.
Protective fencing to avoid children accidently having access to or falling into the pool when not accompanied by a responsible adult should be present and in good repair for all pools where this exposure exists. Children, especially those who cannot swim or who have limited swimming ability, should not be permitted to enter a pool area without being actively supervised at all times by a responsible adult who can give them his or her undivided attention.
Lifeguards should be present in adequate numbers at all public and commercial pools that are open to the public. The lifeguards must be properly trained and certified both as a lifesaver and in the administration of basic cardiopulmonary resuscitation (CPR). When on guard duty, the lifeguard must not be assigned any other responsibilities. He/she must have constant surveillance of the pool and not be distracted or leave their post without being properly relieved. A regular refresher course to include basic cardiopulmonary resuscitation for lifeguards should be in place to test their continuing competence. They should be trained in water hazards and what things can initiate the drowning process. If a person is observed motionless or otherwise in trouble in the water, the lifeguard must initiate the retrieval and resuscitation efforts immediately and not rely on pool patrons or others to check on the victim, nor to retrieve him. Most of all, lifesavers must recognize the importance of their job and give it their undivided attention. They must accept their responsibility and always function to the best of their ability.
Calls for assistance from other rescue personnel and persons who have had resuscitation training should be made immediately by a second person. This may include others currently at the location and/or fire, police, emergency medical technicians (EMTs), paramedics, 911, etc. To do this, a functioning telephone must be readily accessible at poolside. As soon as properly trained medical or paramedical professionals are on the scene, advanced life support measures should be initiated and the victim should be transported to the nearest medical facility with emergency treatment capability. Life support procedures should be continued during transport.
How to provide for emergency resuscitation at home pools or small privately owned commercial pools without lifeguards in attendance remains a problem. Becoming certified in basic cardiopulmonary resuscitation is not that difficult even for lay persons, and if one accepts the responsibility of having a pool onsite, they should be willing to spend a few hours learning CPR, and should have a phone by the poolside from which they can easily call 911 for assistance. Also, it would be prudent to have an adult who can swim to serve as a dedicated observer at a home pool when others are in the water.
If attention had been paid to detail and the pool design and maintenance had been appropriate, many of these deaths from drowning in this population could have been avoided. Further, lifeguards who are properly trained, with the proper credentials, and who gave their full attention to surveillance of the pool and retrieving and resuscitating persons in trouble could have turned many of these tragic deaths into a survivable experience.
When lifeguards are vigilant in performing their duties, they can significantly reduce the incidence of death from drowning. Their mere presence, however, if they do not take their responsibilities seriously, can give pool patrons a false sense of security, and contribute to catastrophes.