British Journal of Anaesthesia 1997; 79: 214–225 Immersion, near-drowning and drowning F. ST C. GOLDEN, M. J. TIPTON AND R. C. SCOTT “Drowning” is defined as “suffocation by submersion, especially in water” 66 ; it continues to be the third most common cause of accidental death in the general population and, for children in many countries, the second most common cause after road accidents. 75 In the USA, 40% of drowning victims are less than 4 yr old. 74 In Britain, the Office of Population Census reports that child deaths from this cause continue to be the third most common cause of accidental death after road accidents and burns. “Near-drowning” is defined as “survival, at least temporarily, after suffocation by submersion in water”. 65 We would challenge this definition as most dictionaries define “suffocation” as cessation of breathing leading to unconsciousness or death. However, pulmonary complications may follow aspiration of water without cessation of breathing or loss of consciousness. Thus “near-drowning” should be defined as “survival, at least temporarily, after aspiration of fluid into the lungs”. The importance of the distinction between the two definitions is that aspiration of fluid may lead to later pulmonary complications, even in those without a history of loss of consciousness, and thus care must be exercised in the management of all patients with a history of aspiration. Modell, Graves and Ketover reported 68 that in dogs, aspiration of as little as 2.2 ml/kg body weight produced a decrease in 2 O a P to approximately 8 kPa (60 mm Hg) within 3 min. Pulmonary surfactant is altered locally by water in the alveoli resulting in pulmonary shunting via either fluid-filled (salt water) or atelectatic (fresh water) alveoli. Pearn 78 stated that within minutes after inhalation of as little as 2.5 ml/kg body weight, the normal intrapulmonary shunt of approximately 10% may increase to as much as 75%. Even victims who are conscious, alert and outwardly clinically normal after a near-drowning incident may take several days to revert to pre-immersion values. 78 After aspiration of either fresh or salt water there may be delayed outpouring of fluid into the alveoli, secondary to pulmonary parenchymal damage with transuda- tion of protein rich fluid, so called “secondary (Br. J. Anaesth. 1997; 79: 214225). Key words Drowning. Hypothermia. Heart, cardiopulmonary bypass. Heart, resuscitation. Immersion. drowning”, 77 82 with consequent impairment of gas exchange. Orlowski 74 cited several cases who appeared normal on assessment in the emergency department, even with normal chest x-rays, but who developed fulminant pulmonary oedema as long as 12 h after the near-drowning incident. While statistics on the incidence of drowning deaths are available for most nations, there are no precise data for near-drowning incidents, although in the USA they are estimated to be 500–600 times more common than their fatal counterpart. 75 In Britain, a comprehensive hospital survey for the years 1988–1989 by Kemp and Sibert 53 of 330 drowning and near-drowning incidents in children reported 142 deaths and 188 survivors. One of the great tragedies of drowning or near- drowning is that the victims, frequently young, are generally in good health before the unexpected event which resulted in death or brain damage in a number of survivors. In recent years increased public aware- ness of the general principles of basic life support and cardiopulmonary resuscitation (CPR) has resulted in many more near-drowning victims arriving in hospital in a state capable of being resuscitated. The many contemporary reports in the literature of apparently hopeless cases being success- fully resuscitated, particularly after cold water submersion, 11 20–22 38 45 53 54 59 85 86 102 has led to protracted resuscitative efforts by hospital personnel. Drowning and near-drowning have been the subject of many reviews. 15 64 66 74 78 88 While resuscita- tion and the subsequent respiratory management of the near-drowning patient is now well established and largely non-controversial, the remaining major therapeutic challenge is limitation of brain damage in survivors with its associated consequent human and economic costs. Although the success stories tend to be reported, in the absence of full statistical information it is difficult to obtain an overall picture of the ratio of those who have been resuscitated and left with or without residual brain damage. The criteria used to identify those with a poor prognosis needs to be refined. Some centres, based on retrospective analysis, have reported their results of various treatment regimens with suggested predic- tive criteria for recovery without severe brain damage. 34 53 68 74 Regrettably, these criteria are often F. ST C. GOLDEN, MB, BCH, PHD, M. J. TIPTON, MSC, PHD, Robens Institute, University of Surrey, Guildford, Surrey GU2 5XH. SURGEON COMMANDER R. C. SCOTT, MB, BSC, BCH, FRCA, Royal Navy, RH Haslar, Gosport, Hants PO12 2AA.