Drowning: The Problem of Nonfatal Submersion and the Unconscious Patient

Drowning: The Problem of Nonfatal Submersion and the Unconscious Patient JOHN M. CAHILL, M.D.*

The victim of a typical drowning accident becomes unconscious due to anoxia, goes into shock, and has cardiac arrest of some type. The entire episode resulting in death may take from four to ten minutes depending on the circumstances. Obviously the difference in time between a successful resuscitation or death may be a matter of a few seconds. If the victim has never lost consciousness, the problem is generally a minor one. Usually, however, consciousness has been lost and the situation must be considered serious even if the patient awakens rapidly. Relatively few doctors are faced with the treatment of serious but nonfatal submersion since in the majority of cases resuscitation is either rapidly successful and the patient goes home, or it fails and he is dead on arrival at the hospital. At this hospital only three to four cases per year are admitted for near drowning, while the number of those seen at the morgue is four to five times that number. The increased interest throughout the country in aquatic forms of recreation will undoubtedly result in a rise in the number of deaths from drowning above the present figure of about 7000 per year. At the same time, the public is better informed about the improved methods of resuscitation and a greater percentage of half-drowned patients may survive to reach the hospital. Physicians must be prepared to manage the emergency resuscitation of drowning victims at the scene of the accident. In addition, they must be cognizant of the somewhat unusual problems which may arise in cases of nonfatal submersion arriving at the hospital.

PATHOLOGY The pathology following death from drowning has been extensively studied and reported. Much of the material is related to problems of *Assistant Professor of Surgery, Boston University School of Medicine; Associate Director, Third Surgical Service, Boston City Hospital, Boston, Massachusetts

Surgical Clinics of North America- Vol. 48, No. 2, April, 1968.

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a medicolegal nature. However, a number of the findings have clinical implications and have provided the basis for experimental studies on the physiology of drowning. Pulmonary edema or something resembling it has been found in most of the victims. 6 • 14 Similar clinical findings have been reported not only immediately after submersion,6 • 17 but also recurring hours after the original episode. 6 • 11 • 17 Foreign material, both organic and inorganic, has been found on microscopic examination of the lungs, 6 • 14 and gastric aspirate is frequently present in the tracheobronchial tree. The possible effect of such material in the development of pulmonary complications is obvious. Distention of the stomach with gas and water has been a common pathologic finding 6 • 14 with clinical implications. Differences in the composition of the blood on the two sides of the heart depending on whether the victim drowned in fresh or salt water 6 • 14 have been a subject of great speculation and research interest. 13 • 18 Overdistention of areas of the lung is typical in drowned victims 6 • 8 • 14 and has led to some excellent studies of the effect of fresh and salt water on ventilatory mechanics and gas exchange. 2 • 3

EXPERIMENTAL DROWNING In an effort to explain some clinical impressions and pathologic findings, a great many experiments have been carried out on various aspects of the drowning syndrome. The pattern of drowning has been demonstrated by a number of investigators.!, 4 • 12 The entire process of apnea followed by dyspnea, loss of consciousness, convulsions, terminal apnea, and cardiac standstill or fibrillation usually takes about four minutes. Banting 1 observed vigorous swallowing following aspiration of even small amounts of water and called attention to the gastric distention and reflex vomiting which occurs frequently. He also noted that death could be caused by asphyxia alone prior to any aspiration at all, although in the majority of cases large amounts of fluid were aspirated. This confirms autopsy findings. The clinical impression and pathologic finding of pulmonary edema has been commonly reproduced in experimental models,'· 13 • 18 especially following immersion or flooding with sea water. The effect of aspirating sea water, fresh water, or saline has been studied by a number of investigators often from different viewpoints. In general, the expected effects of asphyxia are similar for all media. Blood Po 2 falls, Pco 2 rises, and pH falls during the early period of apnea or of aspiration. 13 • 18 Blood pressure and venous pressure were generally elevated in animals during this same period. After aspiration, blood pressure fell progressivelyY· 18 Venous pressure was slightly more elevated following fresh water aspiration than salt. 15 • 18 In Swann's studies 18 • 19 the aspiration of fresh water resulted in a fall in blood sodium and chloride and a rise in blood volume, while opposite changes were noted following sea water aspiration. The aspiration of saline on the other hand resulted in no essential change in blood chemistries. 13 Modell13 noted that after nonfatal aspiration of fresh water the changes in the blood electrolytes rapidly returned to normal. Flooding of one lung

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with different media while adequately ventilating the opposite side has been carried out to study the effect of aspiration of various media without asphyxiating the animal.9 Distilled water was absorbed rapidly while sea water initially drew fluid into the lung. Saline was absorbed slowly. The effects of aspiration on ventilatory mechanics have been studied by Colebatch. 2 He noted a marked fall in compliance and a variable rise in resistance to airflow following fresh and sea water aspiration. Positive pressure inflation caused compliance to improve following fresh water but had no effect following salt. In addition, the severe hypoxia noted following aspiration was found to be due to pulmonary venous admixture (shunt). When 100 per cent 0 2 was administered by intermittent positive pressure breathing (IPPB), the shunt was relieved. These same authors in a more recent paper 3 noted pulmonary hypertension following fresh water aspiration which was relieved by the administration of epinephrine, isoproterenol, or atropine. The interesting studies of Kylstra 10 on the survival time of animals breathing buffered saline under high oxygen pressures, as well as those of Modell, 13 may indicate that our swimming pools should be filled with a buffered saline solution in an effort to lessen the effects of aspiration if an accident should occur.

HUMAN DROWNING Medical impressions of the early events in human drowning are largely based on reports by untrained observers and assumptions made from experimental studies, combined with our present knowledge of the physiologic effect of asphyxia, shock, and cardiac arrest. The later problems if the patient survives to reach the hospital are somewhat better documented. Fuller 6 in 1962 presented an outstanding report on drowning and the post-immersion syndrome. He reviewed 3000 autopsies and presented 18 cases of delayed death from drowning and the cumulative findings in 50 nonfatal cases. The significant features in 1 7 cases of our own from 1960 to the present are included in Table 1. Reports from the site of the accident indicate that in the majority of cases of serious import the subjects are unconscious at the time of rescue. If they are not, recovery is universal, other things being equal. Victims are described variously as blue in color, frothing at the mouth, not breathing, distended, vomiting, in shock, and pulseless. The signs and symptoms vary over a wide range and undoubtedly depend upon the length of immersion, the type and amount of aspiration, the temperature of the water, whether the water was salt or fresh, and the overall general condition of the victim. The initial description of the patients on arrival at the hospital varied from alert to coma and cardiac arrest. Of 17 patients in our series 12 were fully conscious, three were semiconscious and two had dilated fixed pupils. Both those with dilated pupils and one of the conscious patients were in shock. Rales and some cyanosis were present in the majority. Vomiting was reported in six. Seven of 12 persons after

Table 1. Relevant Data for Series of 17 Cases of Near Drowning Seen at the Boston City Hospital (1960-1967)

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Belligerent. Possible mild CVA Suicide attempt. Intoxicated. Temp. 104° Temp. 92° on admission Bathtub accident. Twitching. ~ Dilantin Fixed dilated pupils. H Hypothermia, Antibiotics, Decadron, Thorazine. Temp. 78° Chronic lung disease. Moderate respiratory distress. H Antibiotics Temp. 94° Temp. 94° Fixed dilated pupils. ll Hypothermia, Antibiotics, Decadron, Thorazine. EEG abnormal at 7 days

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salt water immersion had positive x-ray findings but all x-rays were negative after the fresh water accidents. There was no difference in the hematocrits of fresh and salt water victims. Sodium and chloride levels were generally in the normal range, with a slight tendency toward high levels in salt water cases and a slightly low level in the one fresh water case in which they were measured. Four patients were hypothermic on admission. One patient 12 had a temperature of 78° and was in coma, shock, and had fixed dilated pupils. His accident occurred in icy sea water. The other patient in coma with fixed dilated pupils 17 had fallen into fresh water. This patient, age 4, had bloody urine and icteric serum. He had to be catheterized, however, to obtain the urine sample. There was otherwise no evidence of a renal problem. Some focal neurologic symptoms were present while he was in the hospital and his electroencephalogram was abnormal seven days after immersion. He was the only patient in our series with even a question of neurological sequelae following the drowning accident. All patients in this series recovered. The 18 cases of delayed death reported by Fuller 6 establish several important facts. Recovery of consciousness was followed by a fatal outcome in at least eight of the patients. Severe pulmonary edema was common. Gastric contents were found in the bronchial tree in six victims. Two of these expired immediately following a vomiting episode and one developed severe respiratory problems immediately after vomiting. Cerebral edema was noted in several at autopsy but severe brain damage was reported in only two and they never recovered consciousness at all. Both of these patients were decorticate until death 19 days after immersion. Two patients had clinical evidence of renal damage prior to death with findings suggestive of tubular necrosis. Two excellent individual case reports have appeared in the recent literature. The first is the report of Kvittingen 11 in 1963 of a case of survival after an estimated 22-minute submersion in icy fresh water. This patient initially required mouth-to-mouth respiration and external cardiac massage for two hours. The pupils were dilated and fixed for five days. Unconsciousness was present for a much longer period. Evidence of severe hemodilution and red cell breakdown was manifest. Attacks of "pulmonary edema" were recurrent for several days. The patient, however, recovered with what appeared to be relatively minor neurological problems. In a more recent case, Warden 20 was able to report the results of some sophisticated respiratory studies following resuscitation after a 7- to 10-minute submersion. Inability to oxygenate the blood and a marked fall in lung compliance in the absence of apparent pulmonary edema were the most striking features of this case. KEY Age Type of water Resuscitation

Years S = Salt F =Fresh

Age X-ray

M = Mouth to mouth Hct E = Extemal pressure WBC Condition at Hospital C = Conscious A =Alert Na, Cl, C0 2 , K SC = Semicoma U =Unconscious CV A

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+ =Positive N =Negative per cent Thousands Milliequivalents per liter = Cerebrovascular accident

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CAHILL

Some evidence of hemodilution was present. A pulmonary physiologic shunt on the order of 65 to 70 per cent of cardiac output was estimated. It was not relieved even by 100 per cent 0 2 under pressure. This is fairly definite evidence of an acute atelectasis and would indicate a more severe situation than that seen in the experimental study of Colebatch. 3 He was able to fully saturate his animals after aspiration with 100 per cent 0 2 and IPPB. Warden 20 postulated an early, severe, possibly nonbacterial pneumonitis as a cause of the pulmonary problem. His patient was normal three weeks after the accident.

MANAGEMENT The management of the drowning victim begins during or immediately after the rescue operation. The most urgent feature is to initiate ventilation. It is generally agreed that some form of the mouth-to-mouth positive pressure method is best. 8 • 16 Efforts to drain the lungs are not recommended but the upper airway should be cleared of any solid material. If pulse and heartbeat cannot be recognized, external cardiac massage should be instituted after a few seconds of ventilation and continued until a pulse is present or an electrocardiogram can be taken to determine whether arrest or fibrillation is the problem. Basically, therefore, the initial treatment is the same as for asphyxia or cardiac arrest from any cause. The state of consciousness at this point is of interest only as a guide to the success of treatment. If a diving accident was involved, an effort should be made to protect the spine during resuscitation. The presence of fixed, dilated pupils is not grounds for cessation of efforts following drowning and cardiac arrest until the equipment is available to indicate death with certainty. Obviously, if the submersion has been over 15 minutes, little hope is warranted unless the temperature of the water was near freezing. Kvittingen's 11 case represents an example of this situation. The decision of when to release a patient from observation if he recovers consciousness at the scene of the accident is of somewhat more practical importance. The attitude should be one of caution, no matter how well the patient appears. If the patient is conscious at the time of rescue and remains so, hospital admission is probably not required unless there are obvious medical problems. If consciousness has been lost, then hospital admission is mandatory no matter how well the patient may appear. Eight of Fuller's 6 patient's recovered consciousness but later died, one having refused hospital admission. When the patient arrives at the treatment center, the necessary measures have to be somewhat guided by the general condition of the patient. Under the best of circumstances, where no immediate treatment appears necessary a chest film should be taken and blood drawn for chemical analysis and if possible the determination of pH, Pco2 , and Po 2 • In the more serious cases if cardiac action is still not detectable, both massage and respiratory aid should be maintained and electrocardiographic monitoring carried out to determine whether fibrillation or asystole is present. The treatment of cardiac arrest and acute asphyxia is described in detail in other articles and only the unusual aspects of these problems will be mentioned here. Intracardiac epi-

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nephrine has been recommended 16 as an immediate measure for cardiac cases following drowning. This might be a questionable point. In cardiac emergencies unassociated with drowning, ventricular fibrillation is more common than asystole and epinephrine would not be indicated. If arrest is still present at the hospital, electrocardiography should precede the administration of any cardiac stimulants. From the respiratory standpoint, pulmonary edema or something like it appears to be the most frequent problem following drowning. Experimental data indicate that it is best treated by intermittent positive pressure breathing (IPPB) and oxygen. 2 • 13 If it is associated with a high pulmonary artery or venous pressure, then laboratory studies indicate that atropine, epinephrine or isoproterenol may also be of benefit. 3 In any case, recurrent attacks of pulmonary edema have been reported 6 • 11 and continued careful observation is necessary to prevent sudden death from this complication. As Warden 20 has pointed out, the incidence of true pulmonary edema may be overemphasized. It appears likely that often a diffuse pneumonitis may simulate edema or follow it so closely that a distinction cannot be made. Pneumonitis may well be due to foreign material in the water or frequently the aspiration of vomitus. Antibiotics may be given prophylactically in serious cases and, if the aspiration of gastric contents is suspected, steroids should be administered as well. Proper humidification of the inspired air, expectorants, bronchodilators, and IPPB may be of help in preventing severe lung complications. Suction of the stomach is advisable to prevent further vomiting and aspiration. Blood volume and electrolyte abnormalities should be appropriately treated. Hemoconcentration is clinically present more often than hemodilution even following fresh water drowning and is probably related to fluid loss from pulmonary edema and pneumonitis. Acidosis unrelated to high Pco 2 should be assumed to be present if cardiac arrest has occurred and should be treated with bicarbonate. If hemolysis is severe following fresh water drowning, exchange transfusion has been recommended to diminish renal damage. 11 Serious renal damage has been rarely reported thus far following near drowning, but a high free hemoglobin level in the presence of shock is a classical way to produce renal tubular necrosis experimentally. Neurological problems of a transient (Table 1, Case 17) and occasionally of a prolonged nature 5 • 11 may follow near drowning, but the sooner consciousness and reflex activity return, the more likely is the patient to recover. If, however, cardiac arrest has occurred and particularly if the loss of corneal and pupillary reflexes persists, measures should be taken to reduce cerebral edema and consequent brain damage. Hyperpyrexia may aggravate the problems. Hypothermia to 90° F. will reduce metabolic rate and brain swelling; chlorpromazine may be used to prevent shivering, and if pulmonary edema is not a problem mannitol diuresis may be beneficial. Although few reports of severe neurological defects following otherwise successful resuscitation from drowning can be found, such cases are not uncommon following cardiac arrest from other causes. Should improved on-the-scene treatment result in a greater number of patients arriving at the hospital following cardiac arrest due to drowning, then early preventive therapy for

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cerebral edema will be more frequently necessary to reduce complications. Both the literature 11 and our own experience make it clear, however, that dilated fixed pupils following drowning accidents are no indication for suspending efforts at resuscitation.

SUMMARY An increase can be expected both in the number of drowning accidents and in the number of half-drowned patients arriving at the hospital. Asphyxia, shock, and cardiac arrest are the major problems requiring emergency treatment. The amount of aspiration is a variable factor, but physicians should be aware of its possible effect on the lungs, circulation, and blood. Unexpected pulmonary emergencies are common in serious cases during early hospitalization and should be anticipated. Serious neurological problems have been rare in long-term survivors, despite an early picture which may appear hopeless.

REFERENCES 1. Banting, F. G., Hall, G. E., Janes, J. M., Leibel, B., and Lougheed, D. W.: Physiological studies in experimental drowning. Canad. Med. Assoc. J., 39:226-228, 1938.

2. Colebatch, H. J. H., and Halmagyi, D. F. J.: Lung mechanics and resuscitation after fluid aspiration. J. Appl. Physiol., 16:684-696, 1961. 3. Colebatch, H. J. H., and Halmagyi, D. F. J.: Reflex pulmonary hypertension of freshwater aspiration. J. Appl. Physiol., 18:179-185, 1963. 4. Coryllos, P. N.: Mechanical resuscitation in advanced forms of asphyxia. Surg. Gynec. Obstet., 66:698-722, 1938. 5. Courville, C. B.: Case studies in cerebral anoxia X. Effects of drowning on the brain observed after survival for six days. Bull. Los Angeles Neural. Soc., 20:189-192, 1955. 6. Fuller, R. H.: Drowning and the post immersion syndrome. A clinicopathologic study. Military Med., 128:22-36, 1963. 7. Halmagyi, D. F. J.: Lung changes and incidence of respiratory arrest in rats after aspiration of sea and fresh water. J. Appl. Physiol., 16:41-44, 1961. 8. Imburg, J., and Hartney, T. C.: Drowning and the treatment of non-fatal submersion. Pediatrics, 37:684-698, 1966. 9. Kylstra, J. A.: Lavage of the lung. Acta. Physiol. Pharmacal. Neerl. 7:163-221, 1958. 10. Kylstra, J. A., Tissing, M. 0., and VanDer Maen, A.: Of mice as fish. Trans. Amer. Soc. Artif. Int. Organs, 8:3 78-383, 1962. 11. Kvittingen, T. D., and N aess, A.: Recovery from drowning in fresh water. Brit. Med. J., 1:1315-1317, 1963. 12. Lougheed, D. W., Janes, J. M., and Hall, G. F.: Physiological studies in experimental asphyxia and drowning. Canad. Med. Assoc. J., 40:423-428, 1939. 13. Modell, J. H., Gaub, M., Moya, F., Vestal, B., and Swarz, H.: Physiologic effects of near

drowning with chlorinated fresh water, distilled water, and isotonic saline. Anesthesiology, 27:33-41, 1966. 14. Mortiz, A. R.: The Pathology of Trauma. Philadelphia, Lea and Febiger, 1942, pp. 168171. 15. Redding, J. S., Cozine, R. A., Voigt, G. C., and Safar, P.: Resuscitation from drowning. J.A.M.A., 178:1136-1139, 1961. 16. Redding, J. S.: Resuscitation and treatment following submersion. Pediatrics, 37:6()6668, 1966. 17. Saline, M., and Baum, G. L.: The submersion syndrome. Ann. Int. Med., 41:1134- I 13il. 1954. 18. Swann, H. G., and Bruger, M.: The cardiorespiratory and biochemical events during rapid anoxic death. VI. Fresh water and sea drowning. Texas Rep. Bioi. Med., 7:604618, 1949. 19. Swann, H. G.: Mechanism of circulatory failure in fresh and sea water drowning. Circulation Res., 4:241-244, 1956. 20. Warden, J. C.: Respiratory insufficiency following near-drowning in sea water. J.A.M.A., 201:209-212, 1967. 818 Harrison Avenue

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