Jerome H. Modell

Pulmonary aspiration: effects of volume and pH in the rat

To evaluate the effect of volume of aspirates with different pHs on mortality associated with pulmonary aspiration, hydrochloric acid solutions were injected into the tracheas of 336 Sprague-Dawley rats. The rats were divided randomly into 33 groups, were observed for 96 hr after aspiration, and wer

Drowning: update 2009.

Over the past four decades, we have learned considerably more about the pathophysiology and treatment of drowning. This, coupled with increased emphasis in improvement in water safety and resuscitation, has produced a threefold decrease in the number of deaths, indexed to population, from drowning in the United States yearly. This review presents the current status of our knowledge of the epidemiology, the pathophysiology of drowning and its treatment, updates the definitions of drowning and the drowning process, and makes suggestions for further improvement in water safety.

Physiologic effects of near drowning with chlorinated fresh water, distilled water and isotonic saline

The clinical picture and biochemical changes reported in human victims of near-drowning is considerably different from those reported in dogs subsequent to total immersion in fresh water. To gain further insight into this apparent discrepancy and to study the differences in the pathophysiological response of animals to drowning in chlorinated fresh water compared to unchlorinated fresh water and isotonic saline solution, a group of experiments was undertaken. The changes in cardiovascular dynamics, blood constituents and serum electrolytes observed in this study were transient, frequently limited to the arterial samples; these spontaneously reverted to normal in the thirteen animals who survived the experiment. Ten to sixty minutes post-immersion the three groups studied were indistinguishable. Conversely, acute asphyxia with arterial hypoxemia and metabolic acidosis which persisted throughout the experiment was seen in all animals. The presence of chlorine in distilled water did not significantly alter the response to aspiration.

Effects of Volume of Aspirated Fluid During Chlorinated Fresh Water Drowning

Cardiovascular and biochemical changes were studied in the dog following aspiration of 1 ml. to 35 ml. of chlorinated distilled water per pound body weight. Survival rate was inversely proportional to the quantity of fluid aspirated. Ventricular fibrillation was common in animals who aspirated at least 20 ml. of water per pound but not observed with 10 ml. or less per pound. Three minutes following aspiration, the degree of change in blood volume, plasma hemoglobin, serum sodium, chloride, calcium, and potassium were dependent upon the quantity of water aspirated. Within one hour postaspiration, however, serum electrolytes returned to normal in surviving animals. Asphyxia was present acutely as evidenced by an increase in PaCO2 and decrease in pH, Pa and base excess. The latter changes were not as transient as changes in the electrolytes, and significant hypoxemia was still present at the conclusion of the experiment in all but one animal.

The Effects of Fluid Volume in Seawater Drowning

Excerpt The effect of drowning by total immersion in seawater on the serum electrolytes, blood constituents, and cardiovascular system of dogs was reported by Swann and Spafford (1). In their exper...

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.

NEAR-DROWNING: CORRELATION OF LEVEL OF CONSCIOUSNESS AND SURVIVAL

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 percent survived with apparently normal brain function, two per cent survived with impaired brain function and 11 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 significantly 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 surviving children in the series suffered residual brain damage. 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.RésuméLes auteurs ont revu les dossiers de 121 patients traités dans les hôpitaux universitaires de Miami et de Gainesville après avoir survécu à la noyade. Les 57 adultes et les 64 enfants que comprenait cette série ont été classifiés en trois groupes selon leur état de conscience à ľarrivée à la salle ďurgence. Un premier groupe comprenait les 61 patients qui étaient conscients et orientés à ľarrivée. Un second groupe était formé des 31 patients décrits à ľarrivée comme obnubilés (semi-comateux, confus, agités), alors que les 29 malades admis en coma ont été groupés dans un troisième groupe.Quatre-vingt-sept pour cent des patients ont survécu sans séquelles neurologiques, 2 pour cent avec atteinte neurologique et 11 pour cent des patients sont décédés. Le taux de survie de ceux qui étaient conscients à ľarrivée était significativement plus élevé que celui des patients obnubilés ou comateux. De même, le taux de survie s’est avéré plus élevé chez les malades obnubilés à ľarrivée que chez ceux qui étaient en coma.Aucun des adultes survivants n’a présenté de complications neurologiques alors que trois survivants chez les enfants ont présenté des séquelles neurologiques permanentes. Ľévolu-tion des sept adultes et des quatre enfants décédés sans amélioration de ľactivité cérébrale aurait-elle pu être modifiée par des techniques de protection cérébrale? Les auteurs ne peuvent répondre à cette question à partir de leur série.

Effects of Ventilatory Patterns on Arterial Oxygenation after Near-drowning in Sea Water

Forty-three dogs were anesthetized and subjected to aspiration of 22 ml/kg of sea water. After 5 minutes, fluid was drained from the lungs by gravity; 33.1 ± 5.9 ml/kg were recovered. Thirty-four dogs were apneic at this time and were treated with intermittent positive-pressure ventilation with a self-inflating bag. Forty-five minutes later, the 40 animals that survived were divided into four equal groups; one group breathed spontaneously and served as a control, the second was treated with IPPV, the third breathed spontaneously against 10 cm H2O PEEP, and the fourth received IPPV plus PEEP (i.e., CPPV). Arterial oxygen tensions of the animals in both groups with PEEP significantly increased during the 75-minute treatment period. By 48 hours two more dogs had died; however, Pa2s had returned to normal in the 38 that survived, regardless of me mode of treatment It is concluded that gravity drainage and immediate mechanical ventilation of victims who aspirate large quantities of sea water are important, since 40 of the 43 animals were resuscitated after being submerged for 5–10 minutes. Blood-gas data showed that positive end-expiratory pressure, with or without mechanical ventilation, significantly increased PaO2 after aspiration of sea water, suggesting that it is indicated in the treatment of sea-water near-drowning victims. Two case reports of human victims of near-drowning in sea water which support the animal studies are presented.

What is the incidence and significance of "dry-lungs" in bodies found in water?

Background:Drowning without aspiration of liquid, generally attributed to death from asphyxia while submerged and in laryngospasm, has been reported to occur in approximately 10% to 15% of drowning victims. Objectives:The occurrence of “dry-drowning” recently has been questioned and the hypothesis developed that “dry-lungs” in bodies found dead in the water could conceal more natural deaths than previously recognized. Methods:Based on 578 selected adult victims who presumably drowned, we analyzed the correlation between the cases with a low combined lung/pleura liquid weight (< 1000 g and < 750 g) and a wide set of individual, circumstantial, and postmortem (PM) variables, using multivariate logistic regression analysis. Victims with lung weight < 1000 g were screened for long-QT syndrome (LQTS) founder mutations in KCNQ1 and KCNH2 genes. Results:Of the 578 victims, 120 (20.7%) had a lung weight of < 1000 g, and 22 of these (3.8%) of < 750 g. Multivariate analysis showed a significant correlation for women (P < 0.001), for women aged 65 years or older (P < 0.001), and for men with prolonged PM submersion time (P < 0.001). “Normal” lungs were found in only 8 (1.4%) victims. Low-weight (< 1000 g), overdistended lungs with no sign of liquid penetration were seen in 11 (1.9%). No LQTS founder mutations were detected. Conclusions:The actual incidence of death of persons found in water who have normal lungs or do not have penetration of liquid into their airways, based on our study, is much lower (below 2%) than currently assumed.

Distribution and retention of fluorocarbon in mice and dogs after injection or liquid ventilation

Abstract Three groups of mice (strain ICR) were injected with either fluorocarbons FX-80, Caroxin-D, or with isotonic saline. The growth rates among these groups were not statistically different at 48 weeks. Seventeen to 19 months after the fluorocarbons were injected sc or ip, mice were sacrificed and the concentration of fluorocarbon in various tissues was determined by gas chromatography. In a second experiment, the lungs of dogs were ventilated with Caroxin-D fluorocarbon for 1 hr, after which they were reconverted to breathing gas. Twenty to 23 months later they were sacrificed, and the concentration of fluorocarbon in various tissues was determined. Except for the source of introduction of the fluorocarbon (the lung in dogs, which contained approximately 160 mg of fluorocarbon/100 g of tissue), other tissues in both dogs and mice contained minute quantities of fluorocarbon (approximately 0.1 mg/100 g). The highest concentration of fluorocarbon was found in fat.