A new definition of drowning: towards documentation and prevention of a global public health problem.

Drowning is a major global public health problem. Effective prevention of drowning requires programmes and policies that address known risk factors throughout the world. Surveillance, however, has been hampered by the lack of a uniform and internationally accepted definition that permits all relevant cases to be counted. To develop a new definition, an international consensus procedure was conducted. Experts in clinical medicine, injury epidemiology, prevention and rescue from all over the world participated in a series of "electronic" discussions and face-to-face workshops. The suitability of previous definitions and the major requirements of a new definition were intensely debated. The consensus was that the new definition should include both cases of fatal and nonfatal drowning. After considerable dialogue and debate, the following definition was adopted: "Drowning is the process of experiencing respiratory impairment from submersion/immersion in liquid." Drowning outcomes should be classified as: death, morbidity, and no morbidity. There was also consensus that the terms wet, dry, active, passive, silent, and secondary drowning should no longer be used. Thus a simple, comprehensive, and internationally accepted definition of drowning has been developed. Its use should support future activities in drowning surveillance worldwide, and lead to more reliable and comprehensive epidemiological information on this global, and frequently preventable, public health problem.

Subdural air collection: a likely source of radicular pain after lumbar epidural.

This case conference reports two cases of epidural anesthesia in which air was used to identify the epidural space during a loss-of-resistance placement technique. Both patients subsequently complained of severe pain and subdural air was demonstrated in case 1 by computed tomography and in case 2 by magnetic resonance imaging. The possible causes of the pain syndrome experienced by both patients are discussed.

Opioid overdose in a patient using a fentanyl patch during treatment with a warming blanket.

IMPLICATIONS: This case describes the narcotic overdose associated with the use of a fentanyl transdermal patch in a patient being rewarmed with an external warming blanket during surgery. The clinical manifestation and the presumed pharmacokinetic mechanism responsible for the fentanyl overdose are discussed.

Inadvertent severe hypercarbia associated with anesthesia machine malfunction in one cat and two dogs.

Severe acute hypercarbia occurred in a cat and 2 dogs as a result of anesthesia machine malfunction. In each case, the anesthesia machine had been checked by the anesthesia technician and clinician, and no problems were found. After it was noticed that the same machine had been used on each animal, further investigation revealed an expiration valve that was functional with large breaths or positive pressure ventilation but was not functional with small breaths with low peak inspiratory flow. Rebreathing of expired carbon dioxide occurred, and the patients subsequently became severely hypercarbic. Recovery from anesthesia was prolonged in 2 animals, and cardiac and respiratory arrest occurred in the third. Hypercarbia from rebreathing can be detected through the use of blood gas analysis or end-tidal carbon monoxide monitoring.

A morphologic study of long-term retention of fluorocarbon after liquid ventilation.

STUDY OBJECTIVES: To determine how long perfluorinated hydrocarbons remain in the lung after they are used for lung ventilation in dogs, and to determine if residual perfluorinated hydrocarbons cause structural alteration or an inflammatory reaction of the lung. DESIGN: Adult dogs were anesthetized and received ventilation with oxygenated perfluorinated hydrocarbon liquid. Morphologic studies of tissue from the lungs of these dogs were performed at intervals of a few minutes to 10 years after reconversion to breathing gas. SETTING: University College of Medicine. PARTICIPANTS: Adult mongrel and beagle dogs. INTERVENTIONS: Anesthetized adult dogs breathed oxygenated liquid fluorocarbons for 1 h and then were reconverted to breathing air. Three fluorocarbons, FX-80 (C(8)F(16)O; 3M Company; St. Paul, MN), Caroxin-D (C(10)F(22)O(2); P-1D; Allied Chemical Company; Morristown, NJ), and Caroxin-F (C(9)F(20)O; P-12F; Allied Chemical Company), were used. Morphologic studies of the lungs of these animals were performed immediately after restoration of air breathing and at intervals for up to 10 years. Not all animals were studied at each time interval. MEASUREMENTS AND RESULTS: A transient, acute inflammatory reaction was followed by a massive influx of macrophages, which were at first intra-alveolar and later interstitial, especially around vessels and bronchioles. Fluorocarbons remained in the lung in diminishing amounts for at least 5 years, as evidenced by persistent vacuolated macrophages in the alveoli, interstitium, and hilar lymph nodes; fluorocarbon was also detected in these tissues by chemical assays. In no case was there fibrosis or any other structural alteration associated with the residual fluorocarbon, which suggests that it was inert. At 10 years, no evidence of residual fluorocarbon was seen morphologically.

Drowning without aspiration: is this an appropriate diagnosis?

It has been reported that 10-15% of drowning victims do not aspirate water. We have revisited the original studies quoted to reach this conclusion and find it is without foundation. Sudden cardiac standstill is known to occur on land and, therefore, may also occur when the victim is in water. In the absence of the common finding of significant pulmonary edema in the victim's respiratory system, to conclude his or her death was caused by "drowning without aspiration" is unwise. All causes of sudden death that might occur in which respiration may not take place should receive serious consideration when examining bodies with such findings that are found in water.

Health care delivery systems, managed care, and the changing practice of medicine.

The declining ability of physicians to make independent decisions regarding patient care, the declining level of reimbursement paid for physician services, the increased availability and use of alternative medicine, increasingly strict governmental regulations, and new questions regarding graduate medical education are just a few of the changes that have confronted the health care industry in the last decade. Physicians must become proactive in all arenas where future health care policy will be determined. We must reestablish the physician as the patient's advocate, provide for independent physician judgment in the delivery of health care, and reestablish our dominant role in determining national health policy.

Pulmonary embolism: high-frequency jet ventilation offers advantages over conventional mechanical ventilation.

After injecting autologous muscle to induce massive pulmonary embolism, the effects of high-frequency jet ventilation (HFJV) were compared with those of controlled mechanical ventilation (CMV) in anesthetized, paralyzed dogs. HFJV better maintained both alveolar ventilation and oxygenation than did CMV. Moreover, PaO2, cardiac index, and oxygen delivery were greater with HFJV than with CMV when the two modes of ventilation were compared at the same PaCO2.

Near drowning.

Several conditions that contribute to drowning and near drowning must be considered in the treatment of near-drowned victims. Regardless of the cause, mechanical ventilation should begin as soon as possible and closed-chest cardiac massage should be administered when there is any question about the adequacy of cardiac output. After aspiration of either fresh or seawater, a large intrapulmonary physiologic shunt can occur, which requires aggressive mechanical ventilatory support to ensure adequate oxygenation and to return pulmonary function to normal. Near drowning is a multisystem disease and, while abnormalities of the lung and brain have been emphasized, definitive therapy must be tailored to each patient and must address all of the patient's needs.