Respiratory therapy involves treating, assessing and taking care of patients suffering from cardiopulmonary and breathing disorders. The patients could be of any age, from premature infants to neonates to the elderly with diseased lungs. Also, patients that suffer from lung ailments like emphysema, asthma or those in need of emergency care require the services of a respiratory therapist. Therefore, a respiratory therapist works closely with physicians and nurses to form a team. Respiratory therapists conduct diagnostic tests on their patients. They also evaluate them, monitor them, assess their progress and perform physical examinations on them. Respiratory therapists maintain the equipments in the respiratory unit and ensure that that function optimally. Smoke inhalation is the number one major cause of death related to fire accidents. It is estimated that about 2/3rds of deaths from fire accidents are smoke inhalational rather than burns injuries. Smoke inhalation occurs when products of combustion during fire are breathed in, causing severe pulmonary injury. According to Thompson et al, patients who had smoke inhalational injuries had a 50% mortality rate when compared with burns injury patients without inhalational injuries at 4.1%.
Consequently, upper airway obstruction results within the first 12 hours post inhalation injury. Secondly, there is a significant decrease in pulmonary compliance up to about 50%. Also, inhalational injury results in inactivation of surfactants, which results in profound ventilation-perfusion mismatch. The resulting hypoxemia and microvascular injury results in a clinical picture of adult respiratory distress syndrome.
Smoke inhalational injuries cause various respiratory complications , which are often challenging to the respiratory therapist and the respiratory care professionals. The problems range from resuscitation of the victims , endotracheal intubation, assistance with diagnostic bronchoscopies, airway maintenance, arterial blood gas monitor , chest physiotherapy, management of mechanical ventilator and avoiding nosocomial pneumonia.
Respiratory therapists play a major role in patient assessment, drug delivery through the respiratory tract, oxygen therapy, airway care, cardiopulmonary resuscitation, mechanical ventilation, transport of an unstable patient and ensuring their respiratory support. The degree of responsibility thrust upon respiratory therapists in managing these myriad challenges are huge. In some settings, the respiratory therapist functions as a member of a well integrated respiratory unit, whereas in some centres , the respiratory therapist leads the management of such cases.
In assessing the patient, the following are checked by the respiratory therapist; use of acessory muscles of respiration, ventilatory pattern, airway patency, vital capacity, pressure-volume loops, flow-volume loops,airway pressure,flow and volume waveforms, work of breathing, peak inspiratory and expiratory pressure, timed forced expiratory volume and maximum inspiratory pressure. To assess bedside ventilatory functions such as airway pressure flow, pressure volume, flow -volume loops and airway pressure flow, the Med-Science VenTrack is employed.
For effective management of a patient with inhalational injury, accurate and prompt diagnosis must be made, diagnosis is confirmed by investigations, the patient is continually monitored and assessed , appropriate management plans are instituted subsequently depending on the severity of the injury. Signs of inhalation injury are not always present at presentation, but stridor, tachypnea, cyanosis, wheezing and crackles are regarded as signs of established injury. To confirm the diagnosis, the following tests are carried out; asphyxiants (carboxyhaemoglobin and cyanide) are measured, chest radiography is done, arterial blood analysis, radionuclide scanning, direct airway viewing using bronchoscopy, nasopharyngoscopy or laryngoscopy and carrying out pulmonary function tests.
Arterial carboxyhaemoglobin levels are measured since carbon monoxide intoxication is a serious effect of smoke inhalation. Elevated carboxyhaemoglobin levels could also reveal that the patient had been exposed to toxic products like cyanide and mathemoglobin. Also, arterial blood-gas analysis yield useful information in this regard.
Chest X-rays are of low diagnostic values as they reveal little concerning inhalational injuries. Hpwever, they may be helpful in excluding other thoracic injuries.
Fibreoptic bronchoscopes and nasopharyngoscopes are used for direct airway visualization. Edematous supraglottisc structures and soot-colored , inflamed tracheobronchial tree is usually seen. Also, bronchoscopy could be therapeutic, when used to remove large amounts of inspissated secretions.
Pulmonary function tests using the spirometer and peak flow rate determination are carried out. Inspiratory and expiratory rates are reduced and there are abnormal patterns of flow-volume curves. The respiratory therapist charts the peak flow measurements serially, the results are useful in monitoring non-intubated patients.
Management involves maintaining the airway, use of mechanical ventilation for hypoventilatory failure, clearing the airway mechanically, ensuring tissue oxygenation and administering selected drugs.
Bronchial hygiene therapies are airway clearance techniques employed by the respiratory therapist in the management of inhalational injury patients. They include; therapeutic coughing which clears the airway of excess mucous and fibrin casts. The respiratory therapist often places his fingers in the sternal notch and massages gently in an inward circular motion. This is more applicable in obtund patients. Others include chest physiotherapy, airway suctioning and early ambulation.
Bronchodilators can be used when there is lower airway injury. Aerosolized sympatomimmetics are also used.
Racemic epinephrine is used. It is an aerosolized topical bronchodilator, vasoconstrictor and secretion bond breaker. It may be given 2-4 hourly once there is no tachycardia.
Mucolytic agents like N-acetylcysteine is also used. It is a strong mucolytic agent. Also, Heparin/N-acetylcysteine are used as scavengers for free oxygen radicals produced by activated alveolar macrophages.
The respiratory therapist mans the mechanical ventilator. He ensures proper functioning of the ventilator, sets the desired pattern of ventilation and adjusts the ventilator settings depending on patients response. He also applies non-invasive intermittent positive pressure ventilation in the emergency room using facemasks, nasal prongs and oxygen supply.
In conclusion, the respiratory therapist’s role in the management of smoke inhalational injuries cannot be overemphasised. They are involved in all the stages of management of this dangerous condition; from transporting unstable patients to providing advanced cardiac life support.
References
Mlcak et al (2007) Burns.Respiratory Management of Inhalation Injury.www.elsevier.com/locate/burns
Robert.M.Kacmarek (1991) American Association for Respiratory Care. The Role of the Respiratory Therapist in Emergency Care.
E. F. Haponik. (1991) American Association of Respiratory Care. Smoke Inhalation Injury:Some Priorities for Respiratory Care Prefessionals
