TRIPASS XR تري باس

 

Asymptomatic

- CXR, consider labs

(electrolytes, blood count)

- Evaluate primary vs secondary

drowning

- Evaluate for traumatic injury

mit to monitored bed Discharge home

Figure 64-2. Drown ing incidents diag nostic algorithm. CXR, chest x-ray; ICU, intensive care unit.

DISPOSITION

Patient condition will largely determine disposition. Poor

prognostic factors include:

• Submersion for > 10 minutes

• > 10 minutes before initiation of basic life support

measures in an apneic/pulseless patient

• >25 minutes of pulselessness

• Initial temperature <33°C (92°F)

• Initial Glasgow score <5

• Need for cardiopulmonary resuscitation in the ED

• Submersion in water colder than l 0°C (50°F)

• Initial arterial blood gas pH <7.1

� Admission

Admission is indicated for any symptomatic patient. Those

who are intubated, have persistently altered mental status,

are hypothermic, or require high-flow oxygen should be

admitted to an intensive care unit. Cardiac monitoring is

indicated for any patient with oxygen requirements or

changes on chest radiograph.

� Discharge

Patients who present asymptomatic and remain asymp ­

tomatic for at least 6 hours may be safely discharged home.

Discharged patients should be instructed to return for

development of difficulty breathing, fever, or mental status

changes.

DROWNING INCIDENTS

SUGGESTED READING

Causey, AL, Nichter, MA. Drowning. In: Tintinalli JE, Stapczynski

JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD. Tintinalli's

Emergency Medicine: A Comprehensive Study Guide. 7th ed.

New York, NY: McGraw-Hill, 201 1, pp. 137 1-1374.

Causey AL, Tilelli JA, Swanson ME. Predicting discharge in

uncomplicated near-drowning. Am J Emerg Med. 2000;1 8:9.

Layon AJ, Modell JH. Drowning: Update 2009. Anesthesiology.

2009;1 10:1390.

Papa L, Hoelle R, Idris A. Systematic review of definitions for

drowning incidents. Resuscitation. 2005;65:255.

Salomez F, Vincent JL. Drowning: A review of epidemiology,

pathophysiology, treatment and prevention. Resuscitation.

2004;63:26 1.

van Beeck EF, Branche CM, Szpilman D, Modell JH, Bierens JJ.

A new definition of drowning: Towards documentation and

prevention of a global public health problem. Bull World

Health Organ. 2005;83:853.

Envenomation

Patrick M. La n k, MD

Key Points

• In addition to any focused or antidotal therapy available, aggressive symptom-based supportive care is

important for all envenomations.

• Knowledge of local venomous species may be helpful,

although be aware that patients may have contact with

non local or exotic venomous animals.

INTRODUCTION

In 2010, there were more than 60,000 calls made to United

States Poison Centers related to bites and envenomations.

Although there are many venomous animal species in

North America, a majority of these calls involved insects

(including bees, wasps, hornets, and ants), arachnids

(including spiders and scorpions), and snakes. From information provided in the 20 10 Annual Report of the

American Association of Poison Control Centers' National

Poison Data System, there were a total of 5 fatalities related

to all bites or envenomations and approximately 2,500

instances of antivenin being given.

The clinical presentations of the various forms of

venom exposure vary greatly and are dependent on multiple factors including the species of the animal, the

amount of venom delivered, and potential baseline medi ­

cal problems in the envenomed patient. Patients presenting with an animal envenomation may therefore display a

variety of symptoms ranging from local reaction to a bite

or sting to generalized yet nonspecific effects (eg, vomiting, headache, hypertension) or toxin-specific findings

(eg, paralysis or coagulopathy) . This chapter focuses on

the presentation, evaluation, and treatment of 2 of the

most clinically relevant North American envenomations:

snakes and spiders.

• North American venomous bites are rarely unprovoked.

• Contact your local poison control center (1-800-222-1 222)

for assistance with diagnosing and managing all envenomations.

� Snakes

Venomous snakes found in North America are most easily

divided into their 2 families: Elapidae and Viperidae (subfamily Crotalinae). The majority of venomous snakebites

occurring yearly in North America are caused by snakes in

the Crotalinae subfamily, which includes rattlesnakes

(genus Crotalus), copperheads, and cottonmouths (genus

Agkistrodon). Less than 5o/o of venomous snakebites are

from the Elapidae family, which includes the coral snake.

Fewer still may be from bites by exotic, nonnative snakes

usually being kept as pets.

Venomous snakes found natively in North America are

generally nonpredatory to humans. Bites, therefore, take place

on provocation of the snake-either intentional or accidental.

These bites are typically located on extremities, but particu ­

larly troublesome cases have been reported in which venomous bites have involved the face, neck, or tongue. The vast

majority of venomous snakebites occur in young men, with

an appreciable association with alcohol intoxication. Children

are also at a higher risk for being bitten by a venomous snake.

There are a few characteristics that can help identify a

North American snake as being part of the Crotalinae subfamily. These snakes have vertical slit-like pupils, long

fangs, and a triangular head. This subfamily is also referred

to as "pit vipers" because they have heat-sensing pits

274

ENVENOMATION

Poisonous (pit vipers) Harmless

Nostri l

Figure 65-1. Differences between venomous pit vipers and nonvenomous

North American snakes.

located on their heads j ust behind the nostrils and in front

of the eyes (Figure 65- 1). Crotaline venom contains a combination of chemicals that cause primarily local tissue

damage and hematologic effects.

Elapidae native to North America are the coral snakes.

These snakes, found mostly in the Southeast United States

(particularly Florida and Texas), have a characteristic color

pattern that distinguishes them from the similar-appearing but

nonvenomous scarlet king or milk snake. People often remember this pattern difference by reciting the rhyme, "Red on yellow kills a fellow. Red on black, friend of Jack'' (Figure 65-2).

Elapid venom has a curare-like neurotoxic effect and is said to

be one of the most potent North American venoms. However,

multiple characteristics of the snake make clinically significant

bites from these snakes rare. They tend to reside in remote

unpopulated areas and even if confronted will attempt to flee

before biting. Unlike the crotalids, the elapids' fangs are short

and unlikely to penetrate thick clothing or shoes. After biting,