NEAR-DROWNING: CORRELATION OF LEVEL OF AND SURVIVAL

J.H. MOOELL, S.A. GRAVES AND E.J. KUCK

ABSrRAC'~ This paper reports a retrospective review of 121 cases of near-drowning treated at university hospitals in Miami and Gainesville. The series included 57 adults and 64 children who were classified into three categories, Category A (Awake), Category B (Blunted) and Category C (Comatose), based on their level of consciousness on arrival at the primary hospital. Results based on the total 121 patients showed 87 per cent survived with apparently normal brain function, two per cent survived with impaired brain function and I I per cent died. The survival rate of all patients who were awake when they entered the hospital was significantly greater than that of both those who were admitted with blunted consciousness (p = 0.05) and those who were comatose when admitted (p < 0.0001). Further, the group whose members had blunted consciousness had a significanlly greater number of normal survivors than the group whose members were comatose on admission (p < 0.002). All treated adults survived without permanent neurological damage and only three surviv- ing children in the series suffered residual . Whether the course of the seven patients, three adults and four children, who died without return of brain function, would have been altered by deliberate attempts to preserve the brain is a matter of speculation.

DURING l-HE PAST FEW YEARS, some reports have accident was notoriously unreliable in regard to emphasized the incidence of severe neurological duration of submersion and exact details of re- sequelae after near-drowning."z The reported in- suscitation, we elected to categorize our patients cidence of persons who survive a near-drowning according to their levels of consciousness, re- episode but suffer incapacitating brain damage corded when they reached the emergency room varies from 0 to 21 per cent. ~-s At least one au- of the first hospital to receive them. The thor' reporting a high incidence of brain damage categories follow: questions whether all near-drowning victims Group A (awake). These patients were de- should be resuscitated; others have introduced scribed as awake and oriented when they reached intensive therapy aimed primarily at brain pre- the emergency room. Many of these patients had servation. 2 received cardiopulmonary at the To identify which patients are most susceptible scene of the accident because ofapnoea and sus- to residual brain damage or death after near- pected cardiac arrest. drowning and therefore, perhaps, to give guid- Group B (blunted). These patients suffered ance to the clinician, we developed, in conjunc- from what we have termed a blunted conscious- tion with Dr. Alan Conn of Toronto, a method of ness, indentified by such descriptions as lethar- categorizing near-drowning victims. gic, semi-comatose, combative, agitated, dis- oriented, and confused. METHODS Group C (comatose). These patients were de- The charts of 121 patients treated for near- scribed as comatose at the time they arrived at the drowning between 1963 and 1979 at the Univer- hospital. sity of Miami School of and the Univer- In no case were attempts made to treat any sity of Florida College of Medicine were re- patient pharmacologically for brain insult. In viewed retrospectively.* Since information ob- general, therapy centered around intensive pul- tained from persons who were at the scene of the monary care, cardiovascular support, and fluid replacement as required. 4'6'7 J.H. Modell, M.D., S.A. Graves, M.D., and Groups A, B and C were compared with each E.J. Kuck, Departments of and other, as were the adults and children in each , University of Florida College of Medicine, Box .I-254, J. Hillis Miller Health Center, Gainesville, group, by the Fisher exact test. Florida 32610, U.S.A. Reprint requests to J.H. Modell, M.D. RESULTS * University of Miami, July 1963-July 1973; Univer- sity of Florida, July 1969-October 1979. Ninety-one of Group A. Sixty-one patients, 27 adults (age these patients have been reported previously. 4 34.7 _+ 2.9 years) and 34 children (age 6.5 -I- 0.8 211 Canad. Anaesth. Soc. J., vol. 27, no. 3, May 1980 212 CANADIAN ANAESTHETISTS" SOCIETY JOURNAL

TABLE I OUTCOME OF NEAR-DROWNED ADULTS AND CHILDREN ACCORDING TO THEIR LEVEL OF CONSCIOUSNESS WHEN ADMITTED TO THE EMERGENCYROOM

Adults Children Total

Severe Severe Severe Normal Brain Normal Brain Normal Brain Level of Survival Deficit Death Survival Deficit Death Survival Deficit Death consciousness on admission n % n 70 n % n % n % n % n 7, n ~ n %

Awake 27 100 0 0 0 0 34 100 0 0 0 0 61 100 0 0 O 0 Blunted 17 89 0 0 2 I 1 11 92 0 0 I 8 28 90 0 0 3 10 Comatose 8 73 0 0 3 27 8 44 3 17 7 39 16 55 3 10 I0 34 Total 52 91 0 0 5 9 53 83 3 5 8 13 105 87 3 2 13 11 years, mean _ SEM), were awake and oriented child died. The arterial oxygen tension was found when admitted to the emergency room. All of to be 2.66 kPa (20 torr) and the child died while these patients survived with normal brain func- the sample was being analyzed. tion, as assessed by clinical examination and Group C. Twenty-nine patients were comatose comparison of the level of the individual's activ- on arrival at the hospital. Of the 11 adults (age ity before and after the accident (Table I). 37.9 + 4.6 years), eight (73 per cent) survived Group B. Nineteen adults (age 31.5 _ 3.9 with apparently normal brain function and three years) and 12 children (age 5.6 + 1.2 years) were patients died. The 18 children (age 6.6 + 1.2 described as having a blunted consciousness years) were not as fortunate; only eight (44 pet" when admitted to the emergency room. Seven- cent) survived with apparently normal brain teen of the adults (89 per cent) and 11 of the function, seven (39 per cent) died and three (17 children (92 per cent) made completely unevent- per cent) lived with incapacitating brain damage ful recoveries without residual neurological (Table I). While these figures suggest that the deficit (Table I). Two adults and one child died; normal survival rate may be lower for children these three patients deserve special mention. than for adults, the difference between them is Both adults were scuba diving when their acci- not statistically significant (p -- 0.1). Of the ten dents occurred - one at 70 feet below the surface, patients who died, seven (three adults and four the other at 60 feet. Both patients required car- children) never regained consciousness; the re- diopulmonary resuscitation at the scene of the maining three died of severe pulmonary insuffi- accident and on admission to the hospital were ciency. thought to have suffered hyperbarism as well as severe pulmonary aspiration. The lack of a Statistical Comparison of The Groups hyperbaric chamber of sufficient size and sophis- When the adults were analyzed separately, the tication to permit intensive care precluded re- percentages of survivors with normal brain func- compression of the two divers. Each had exten- tion in Group A and in Group B did not differ sive subcutaneous emphysema and bilateral statistically (p > 0.15). Likewise, the percentages pneumothoraces, which prevented effective ap- of survivors in Group B and'in Group C did not plication of high levels of positive end-expiratory differ (p -- 0.2). However, when the percentage of pressure. Both divers subsequently died of se- adult survivors who were awake when admitted vere pulmonary insufficiency. The mental status to the hospital was compared to the percentage of these patients appeared appropriate before of normal survivors who were comatose when they died. The death of the child occurred very they entered the hospital, the survival rate of early in the study, when the importance of inten- Group A is significantly greater than that of sive pulmonary therapy was poorly appreciated Group C (p < 0.02). and before positive end-expiratory pressure When the children were analyzed separately, therapy was introduced. This child was treated the survival rates of Groups A and B did not ultraconservatively with an oxygen tent and, differ (p > 0.25). However, the percentages of since equipment for evaluation of arterial blood normal survivors were significantly greater gas tensions was not readily available in that hos- both in Group A and in Group B than in Group pital at the time, measurements of blood gases C (p < 0.00l). were not obtained until immediately before the When adults and children were combined, of MODELL, el at.: NEAR-DROWNING 213 the 121 total patients treated, 87 percent survived our 1976 series who had fixed dilated pupils on with apparently normal brain function, two per admission to the emergency room died. 4 Since cent survived with impaired brain function and 11 that time we have treated a patient who was com- per cent died (Table I). The survival rate of all atose, with fixed dilated pupils when admitted to patients who were awake when they entered the the hospital, but who made a normal recovery. hospital was significantly greater than that of both Since 100 per cent of our patients who were those who were admitted with blunted con- awake and 90 per cent of those who had blunted sciousness (p = 0.05) and those who were com- consciousness when they reached the emergency atose when admitted (p < 0.0001). Further, the room survived with normal brain function, and group whose members had blunted conscious- since the three in Group B who died were pulmo- ness had a significantly greater number of normal nary deaths, we believe that patients in categories survivors than the group whose members were A and B should be treated with intensive pulmo- comatose on admission (p < 0.002). nary and cardiovascular support, but that tech- niques for brain protection such as barbiturate- DISCUSSION induced and hypothermia are unnecessary and may increasethe hazards to the patient. The recent literature varies from extremely In our previous report we suggested that the optimistic to pessimistic regarding the outcome use of steroids and prophylactic does of normal brain function for patients resuscitated not improve the survival rate. 4 Our subsequent after near-drowning, t'3 Also, some persons ad- experience with the last 30 cases in which these vocate aggressive attempts to preserve brain drugs were not used after the patients arrived at function. 2 Therefore, we felt that a review of our our hospital substantiates that previous sugges- data was important to seek factors that might help tion. Further, since that time Wynne et al. s have us to predict which patients would survive nor- demonstrated that the use ofcorticosteroids after mally with intensive therapy aimed primarily at aspiration of food-stuff may actually hinder nor- pulmonary and cardiovascular support. mal pulmonary healing. Therefore, we can com- In interviewing first responders, we frequently fortably state that steroids are not indicated for found extreme disparity in the history reported patients in Groups A and B. Some clinicians when more than one rescuer was involved. Thus, might argue with this conclusion for patients with the duration of submersion reported by the res- blunted consciousness; however, since none of cuer may be unreliable. Some persons have sug- our patients with blunted consciousness suffered gested that long submersion times in warm water neurological damage, we believe that withholding are not compatible with return of satisfactory steroids from this group is justified. brain function. Interestingly, one of our patients The patients who are comatose when they was submerged in a freshwater pool for ten min- enter the hospital present a more complicated utes by the clock. She initially was resuscitated picture. None of our patients have been treated with cardiopulmonary resuscitation and ap- with barbiturate-induced coma or deliberate proximately 24 hours later was able to respond hypothermia in an attempt to preserve brain appropriately to spoken commands and to com- function. Many of these patients, however, have municate on paper (vocal communication was not been deliberately hyperventilated to produce res- possible because of ). Unfor- piratory alkalosis and thus to decrease cerebral tunately, 84 hours later, that patient (Group C) blood flow and, potentially, to decrease cerebral died of extensive pulmonary destruction. oedema. Also, many have been treated with cor- Likewise, we have not found the initial mea- ticosteroids, since some persons think these surements of arterial pH and blood gas tensions drugs are helpful in such situations. 9 Though we to be of absolute prognostic value. We have did not use methods such as barbiturate coma to treated a patient with a pHa of 6.90 on admission preserve brain function, all adults we treated sur- and another with a Pao2of2.26 kPa (17 torr) while vived without permanent neurological damage being mechanically ventilated with 100 per cent and only three surviving children in our series oxygen, and both survived with normal brain suffered residual brain damage. Whether the function. On the other hand, one patient with an course of the seven patients (three adults and four initial pHa of 7.43 and a Paoz of 12 kPa (90torr) children) who died without return of normal brain (FIoz 0.3) suffered permanent brain damage and function would have been altered by deliberate another patient with an initial pHa of 7.41 died. attempts to preserve the brain is a matter of We have reported previously that all patients in speculation. A similar study was done by Connet 214 CANADIAN ANAESTHETISTS' SOCIETY JOURNAL al, j~ in Toronto where H.Y.P.E.R. therapy citative therapy administered at the scene of the aimed at brain preservation was used for 26 of 39 accident is paramount to the ultimate outcome of patients. When one compares the children in the near-drowned victim. Patients whose level of Group C of our study with those of Conn's work, consciousness is either awake or blunted when the overall data for survival, deaths, and residual admitted to the hospital should be treated with brain damage are virtually identical in both intensive pulmonary and cardiovascular support series. ~0 This leads one to question whether such but, since these patients do not suffer brain dam- therapy is necessary. We believe that there may be age, extraordinary attempts at brain preservation some differences between these two series that are unnecessary. The need for intensive therapy are not apparent from the statistics alone. Corm aimed at brain preservation for patients who are et al. were able to divide their patients in Cate- still comatose when admitted to the hospital re- gory C into three sub-groups, but we were quires further study, unable to do this retrospectively. Since their sur- vival data in sub-groups C. 1 (decorticate) and C.2 ACKNOWLEDGEMENTS (decerebrate) were significantly better than in sub-group C.3 (flaccid), it is possible that the The authors thank B.C. Ruiz, N, Davis and L. distribution of patients may have been different in Carroll for their assistance in the preparation of the two series. Thus we cannot be precise in our this manuscript. comparisons of normal survival rates with and without H.Y,P.E.R. therapy between these in- REFERENCES stitutions. If the case distribution between sub- groups is identical in the two series it would sug- 1. PETERSEN, B. Morbidity of childhood near- gest that H.Y.P.E.R. therapy is unnecessary. If drowning. Pediatrics 59:364-370 (1977). 2. CONN," A. W., EDMONDS, J.F. & BARKER, G.A. one series were skewed regarding the number of Near-drowning in cold fresh water: current treat- patients in sub-groups C. I, C.2 or C.3, completely ment regimen. Canad. Anaeslh. Soc. J, 25; 259-265 different conclusions might be reached. This sug- (1978). gests the need for an inter-institutional prospec- 3. FEARN, J.H., BART, R.D., JR. & YAMAOKA, R. Neurologie sequelae after childhood near- tive study in comparable circumstances. drowning: a total population study from Hawaii. It should be noted that if we treat one additional Pediatrics 64:187-191 (1979). adult and one child in Group C, and if the adult 4. MODELL, J.H., GRAVES, S.A. & KETOVER, A. lives and child dies or is brain damaged, the per- Clinical course of 91 consecutive near-drowning victims. Chest 70:231-238 (1976). centages of normal survivals between these two 5. PEARt~,J.H., NIXON, J. & W~LKEY.1. Freshwater groups would differ significantly at the p = 0.05 drowning and near-drowning accidents involving level. This difference would then require an ex- children: a five-year total population study. Med. planation. One consideration is that the heart of Journal of Australia 2:942-946 (1976). the child might be resuscitated after much longer 6. MODELL, J.H. Drowning and near-drowning, in disorders of the respiratory tract in children. Eds. periods of arrest and hypoxia than that of the Kendig, E.L., Jr. and Chernik, V., Saunders (1977) adult. However, the child's brain may not toler- pp. 498-510. ate cerebral hypoxia for the same length of time. 7. MODELL, J.H. Biology of drowning. Ann. Rev. This possibility may be important when one Med. 29:I-8 (1978). compares drowning statistics between institu- 8. WYr~NE,J.W., REYNOLDS, J.C., HOOD, C.I., AU- ZgaACH, D. & ONDRASlCK, J. Steroid lherapy for tions. It is important to ensure that the age of pneumonitis induced in rabbits by aspiration of patients, the caliber of emergency medical ser- foodstuff. Anesthesiology 51:11-19 (1979). vices available at the scene of the accident and 9. FXSHMAN,R.A. Brain edema. New Engl. J. Med. the ability of the institution to provide intensive 293:706-711 (1975). 10. CONN, A.W., MONTES, J.E., BARKER, G.A. & care are similar if comparisons of survival statis- EnMONr~S, J.F., Cerebral salvage in near- tics are to be valid. drowning following neurological classification by We believe that the quality of the initial resus- triage. Can. Anaes. Soc. Jour. 27: 201-209(1980).

RI~SUMf- Les auteurs ont revu les dossiers de 121 patients trait~.s dans les hrpitaux universitaires de Miami et de Gainesville apr~s avoir survdcu fi la noyade. Les 57 adultes et les 64 enfants que comprenait cette srrie ont 6t6 classifi6s en trois groupes scion leur ~tat de conscience I'arriv/:e b. la salle d'urgence. Un premier groupe comprenait les 61 patients qui ~taient MODELL, ,el al.: NEAR-DROWNING 215 conscients et orientes ~. l'arriv6e. Un second groupe 6tait form~ des 31 patients d6crits b. l'arriv6e comme obnubil6s (semi-comateux, confus, agit6s), alors que les 29 malades admis en coma ont 6t6 group6s dans un troisibme groupe. Quatre-vingt-sept pour cent des patients ont surv6cu sans s6quelles neurologiques, 2 pour cent avec atteinte neurologique et I I pour cent des patients sont d~c6d6s. Le taux de survie de ceux qui 6taient conscients fi I'arriv~e 6tait significativement plus 61ev6 que celui des patients obnubil6s ou comateux. De m~me, le taux de survie s'est av6r6 plus 61ev6 chez les malades obnubil6s h l'arriv~e que chez ceux qui 6talent en coma. Aucun des adultes survivants n'a pr6sent6 de complications neurologiques alors que trois survivants chez les enfants ont pr6sent6 des s~quelles neurologiques permanentes. L'6volu- tion des sept adultes et des quatre enfants dec6d6s sans am61ioration de l'activiff: c,~r6brale aurait-elle pu 6ire modifi6e par des techniques de protection c6r6brale? Les auteurs ne peuvent r6pondre ~ eette question b, partir de leur s~rie.