Introduction The incidences of burns varies worldwide according to culture The majority of the burn in children are scaled & caused by accident with kettles, pans, hot drink and hot water. Among the adolescence the burns are usually caused by experiments with matches & flammable liquid Most electrical and chemical injuries occurs in adult Cold and radiation are also very rare cause of the burns.
Conditions Which Increase The Risk Of Burns In Adult Mental disease (Attempted suicide or assault) Epilepsy Alcohol or drug abuse These are the underlying factors in as many as 80% of pts with burn admitted to hospital in some population.
Prevention Of Burn Health promotion and appliance design have reduce the incidence of burns Regulation regarding flame retardant clothes & furniture The promotion of smoke alarm The almost universal use of cordless kettles and education to parents to keep their hot water thermostat at 600 Introducing of effective legislation
The Pathophysiology Of Burn By far the most common organ affected by the burn injury is skin. Burn can also damage the airway and lungs with life- threatening consequences Air-way injury occurs when face and neck are burned Respiratory system injury usually occurs if the person trapped in burning vehicle, house, car and aeroplane and forced to inhale the hot & poisonous gases
Injury To The Airway & Lungs Physical Burn Injury To Airway Above The Larynx: The hot gases can physically burn the nose, mouth, tongue, palate & larynx lining of these structure start to swell these may start to interfere with larynx and may complete block the airway if proper action not taken. Physical Burn Injury To Airway Below The Larynx: This is rare as heat exchange mechanism in supraglottic airway are usually able to absorb heat safely. Steam has large latent heat of evaporation & can cause thermal damage to lower airway respiratory epithelium become swell & detach from bronchial tree blockage of lower airway.
Symptoms Associated With Laryngeal Edema The symptoms of laryngeal edema are very late, are Change in voice Stridor Anxiety Difficulty in respiration After these symptoms intubation at this point is very difficult or even impossible. Because of this early intubation of suspected airway burn is treatment of choice.
Metabolic Poisoning Carbon monoxide is the most common poisonous gas that cause metabolic poisoning This is the usual cause of person being found with altered consciousness in enclosed fire space. Carbon monoxide block the transport of oxygen by binding to Hb, because it has 240 times greater affinity than oxygen. Level of carbon monoxide in the blood stream have importance, concentration above 10% are dangerous and should be treated with pure oxygen for more than 24 hours (conc. around 60% cause death) Hydrogen cyanide a toxin produce in house fire cause metabolic acidosis by interfering mitochondrial respiration
Inhalational Injury Minuet particle within thick smoke not filtered by upper airway & reach to lung parenchyma are responsible for the inhalational injury. These particle stick to the moist lung Intense reaction within alveoli chemical pneumonitis edema of alveolar sac decreasing gases exchange & often give rise to bacterial pneumonia. Bacterial pneumonia have significant effect on the mortality of burn pt
Mechanical Block On Rib Movement Burned skin is very thick and stiff and this can physically stop ribs movement in case of full- thickness burn across the chest.
Danger Of Smoke, Hot Gases & Steam Inhalation Inhaled hot gases can cause supraglottic airway burn and laryngeal edema. Inhaled steam can cause infraglottic burn and loss of respiratory epithelium Inhaled smoke particle can cause chemical alveoli and respiratory failure Metabolic poisoning caused by the inhaled carbon monoxide gas Metabolic acidosis caused by inhalation poisonous gas hydrogen cyanide Full thickness burn to the chest cause mechanical block of the rib movement