a) If respiratory tract irritation is present, it may be useful to monitor pulmonary function tests.

a) If respiratory tract irritation is present, monitor arterial blood gases and chest x-ray.

a) Similar to studies where sucralfate was used in alkali caustic injury, strictures were not prevented, although nearly complete gastric mucosal healing occurred after 2 weeks. The patient received a gastrojejunostomy for pyloric stricture 6 weeks postingestion (Mittal et al, 1989).

1) Mild (grade I) - may have oral feedings first day
2) Moderate (grade II) - may have liquids after 48 to 72 hours
3) Severe (grade III) - jejunostomy tube feedings after 48 to 72 hours

a) Twenty-one esophagograms obtained at least 21 days following ingestion showed stricture formation. Edema and esophageal mucosal ulcerations radiologically appeared as blurring or contour irregularities along the esophageal margins.

a) Strictures, perforation, or both developed only in patients with Grade 2b (superficial localized ulceration, friability, blisters, and circumferential ulceration) and Grade 3 (multiple and deep ulcerations and areas of extensive necrosis) burns (Zargar et al, 1989). No complications relating to the endoscopic procedure were reported in this series.

a) One 3-year-old child developed esophageal stricture 2 years after the acid ingestion in a prospective study of 41 patients. This child had a normal barium study at one year after ingestion (Zargar et al, 1989).

a) REFERENCES: Gaudreault et al, 1983; Symbas et al, 1983; Crain et al, 1984; (Schild, 1985; Moazam et al, 1987; Sugawa & Lucas, 1989; Previtera et al, 1990; Zargar et al, 1991; Vergauwen et al, 1991; Gorman et al, 1992; Nuutinen et al, 1994)

a) Advancing across the cricopharynx under direct vision
b) Gently advancing with minimal air insufflation
c) Never retroverting or retroflexing the endoscope
d) Using a pediatric flexible endoscope
e) Using extreme caution in advancing beyond burn lesion areas
f) Most authors recommend endoscopy within the first 24 hours of injury, not advancing the endoscope beyond areas of severe esophageal burns, and avoiding endoscopy during the subacute phase of healing when tissue slough increases the risk of perforation (5 to 15 days after ingestion) (Zargar et al, 1991).

a) Several scales for grading caustic injury exist. The likelihood of complications such as strictures, obstruction, bleeding and perforation is related to the severity of the initial burn (Zargar et al, 1991):
b) Grade 0 - Normal examination
c) Grade 1 - Edema and hyperemia of the mucosa; strictures unlikely.
d) Grade 2A - Friability, hemorrhages, erosions, blisters, whitish membranes, exudates and superficial ulcerations; strictures unlikely.
e) Grade 2B - Grade 2A plus deep discreet or circumferential ulceration; strictures may develop.
f) Grade 3A - Multiple ulcerations and small scattered areas of necrosis; strictures are common, complications such as perforation, fistula formation, or gastrointestinal bleeding may occur.
g) Grade 3B - Extensive necrosis through visceral wall; strictures are common, complications such as perforation, fistula formation, or gastrointestinal bleeding are more likely than with 3A.

a) STUDY - In a retrospective study of patients with extensive transmural gastroesophageal necrosis after caustic ingestion, all 4 patients treated in the conventional manner (endoscopy, steroids, antibiotics, and repeated evaluation for the occurrence of esophagogastric necrosis and perforation) died, while all 3 patients treated with early laparotomy and immediate esophagogastric resection survived (Estrera et al, 1986).
b) Wu & Lai (1993) reported the results of emergency surgical resection of the alimentary tract in 28 patients who had extensive corrosive injuries due to the ingestion of acids or other caustics. Operative mortality was most frequently associated with sepsis. Non-fatal bleeding, infections, biliary or bronchial fistulas were other noted complications. Morbidity and mortality were related to the severity of the damage and the extent of surgery required.

a) ANIMAL
b) HUMAN

a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)

a) These recommendations apply to patients with MINOR chemical burns (FIRST DEGREE; SECOND DEGREE: less than 15% body surface area in adults; less than 10% body surface area in children; THIRD DEGREE: less than 2% body surface area). Consultation with a clinician experienced in burn therapy or a burn unit should be obtained if larger area or more severe burns are present. Neutralizing agents should NOT be used.

a) After initial flushing with large volumes of water to remove any residual chemical material, clean wounds with a mild disinfectant soap and water.
b) DEVITALIZED SKIN: Loose, nonviable tissue should be removed by gentle cleansing with surgical soap or formal skin debridement (Moylan, 1980; Haynes, 1981). Intravenous analgesia may be required (Roberts, 1988).
c) BLISTERS: Removal and debridement of closed blisters is controversial. Current consensus is that intact blisters prevent pain and dehydration, promote healing, and allow motion; therefore, blisters should be left intact until they rupture spontaneously or healing is well underway, unless they are extremely large or inhibit motion (Roberts, 1988; Carvajal & Stewart, 1987).

a) TOPICAL ANTIBIOTICS: Prophylactic topical antibiotic therapy with silver sulfadiazine is recommended for all burns except superficial partial thickness (first-degree) burns (Roberts, 1988). For first-degree burns bacitracin may be used, but effectiveness is not documented (Roberts, 1988).
b) SYSTEMIC ANTIBIOTICS: Systemic antibiotics are generally not indicated unless infection is present or the burn involves the hands, feet, or perineum.
c) WOUND DRESSING:
d) DRESSING CHANGES:
e) Analgesics such as acetaminophen with codeine may be used for pain relief if needed.

a) The patient's tetanus immunization status should be determined. Tetanus toxoid 0.5 milliliter intramuscularly or other indicated tetanus prophylaxis should be administered if required.

a) Rewarming of a localized area should only be considered if the risk of refreezing is unlikely. Avoid rubbing the frozen area which may cause further damage to the area (Grieve et al, 2011; Hallam et al, 2010).

a) Do not institute rewarming unless complete rewarming can be assured; refreezing thawed tissue increases tissue damage. Place affected area in a water bath with a temperature of 40 to 42 degrees Celsius for 15 to 30 minutes until thawing is complete. The bath should be large enough to permit complete immersion of the injured part, avoiding contact with the sides of the bath. A whirlpool bath would be ideal. Some authors suggest a mild antibacterial (ie, chlorhexidine, hexachlorophene or povidone-iodine) be added to the bath water. Tissues should be thoroughly rewarmed and pliable; the skin will appear a red-purple color (Grieve et al, 2011; Hallam et al, 2010; Murphy et al, 2000).
b) Correct systemic hypothermia which can cause cold diuresis due to suppression of antidiuretic hormone; consider IV fluids (Grieve et al, 2011).
c) Rewarming may be associated with increasing acute pain, requiring narcotic analgesics.
d) For severe frostbite, clinical trials have shown that pentoxifylline, a phosphodiesterase inhibitor, can enhance tissue viability by increasing blood flow and reducing platelet activity (Hallam et al, 2010).

a) Digits should be separated by sterile absorbent cotton; no constrictive dressings should be used. Protective dressings should be changed twice per day.
b) Perform twice daily hydrotherapy for 30 to 45 minutes in warm water at 40 degrees Celsius. This helps debride devitalized tissue and maintain range of motion. Keep the area warm and dry between treatments (Hallam et al, 2010; Murphy et al, 2000).
c) The injured extremities should be elevated and should not be allowed to bear weight.
d) In patients at risk for infection of necrotic tissue, prophylactic antibiotics and tetanus toxoid have been recommended by some authors (Hallam et al, 2010; Murphy et al, 2000).
e) Non-tense clear blisters should be left intact due to the risk of infection; tense or hemorrhagic blisters may be carefully aspirated in a setting where aseptic technique is provided (Hallam et al, 2010).
f) Further surgical debridement should be delayed until mummification demarcation has occurred (60 to 90 days). Spontaneous amputation may occur.
g) Analgesics may be required during the rewarming phase; however, patients with severe pain should be evaluated for vasospasm.
h) IMAGING: Arteriography and noninvasive vascular techniques (e.g., plain radiography, laser Doppler studies, digital plethysmography, infrared thermography, isotope scanning), have been useful in evaluating the extent of vasospasm after thawing and assessing whether debridement is needed (Hallam et al, 2010). In cases of severe frostbite, Technetium 99 (triple phase scanning) and MRI angiography have been shown to be the most useful to assess injury and determine the extent or need for surgical debridement (Hallam et al, 2010).
i) TOPICAL THERAPY: Topical aloe vera may decrease tissue destruction and should be applied every 6 hours (Murphy et al, 2000).
j) IBUPROFEN THERAPY: Ibuprofen, a thromboxane inhibitor, may help limit inflammatory damage and reduce tissue loss (Grieve et al, 2011; Murphy et al, 2000). DOSE: 400 mg orally every 12 hours is recommended (Hallam et al, 2010).
k) THROMBOLYTIC THERAPY: Thrombolysis (intra-arterial or intravenous thrombolytic agents) may be beneficial in those patients at risk to lose a digit or a limb, if done within the first 24 hours of exposure. The use of tissue plasminogen activator (t-PA) to clear microvascular thromboses can restore arterial blood flow, but should be accompanied by close monitoring including angiography or technetium scanning to evaluate the injury and to evaluate the effects of t-PA administration. Potential risk of the procedure includes significant tissue edema that can lead to a rise in interstitial pressures resulting in compartment syndrome (Grieve et al, 2011).
l) CONTROVERSIAL: Adjunct pharmacological agents (ie, heparin, vasodilators, prostacyclins, prostaglandin synthetase inhibitors, dextran) are controversial and not routinely recommended. The role of hyperbaric oxygen therapy, sympathectomy remains unclear (Grieve et al, 2011).
m) CHRONIC PAIN: Vasomotor dysfunction can produce chronic pain. Amitriptyline has been used in some patients; some patients may need a referral for pain management. Inability to tolerate the cold (in the affected area) has been observed following a single episode of frostbite (Hallam et al, 2010).
n) MORBIDITIES: Frostbite can produce localized osteoporosis and possible bone loss following a severe case. These events may take a year or more to develop. Children may be at greater risk to develop more severe events (ie, early arthritis) (Hallam et al, 2010).

a) 30 mg/m(3)