In patients suffering from major burns, outline the possible physiologic derangements and their underlying mechanisms that could contribute to problems of oxygenation and ventilation.
Answer and interpretation
a) List the differential diagnoses for his weakness.
Can affect 4 anatomic areas of the respiratory tract:
- Supraglottal, tracheobronchial, and pulmonary parenchymal, and chest/abdominal wall.
Loss of airway patency due to mucosal oedema
Loss of airway reflexes due to coma (e.g. blast Traumatic brain injury, intoxications such as carbon monoxide,)
Bronchospasm resulting from inhaled irritants
Mucosal oedema and endobronchial sloughing causing small airway occlusion, leading to intrapulmonary shunting.
- Pulmonary Parenchymal
Pulmonary (alveolar) oedema and collapse leading to decreased compliance, and further intrapulmonary shunting.
Loss of tracheobronchial epithelium and airway ciliary clearance contributing to tracheobronchitis and pneumonia.
Barotrauma, ARDS, pleural effusions, Ventilator associated pneumonia, TRALI and tracheobronchitis may all result from Intensive Care resuscitation, and treatments of the above.
Circumferential full thickness burns of the chest and abdomen may cause reduced static compliance resulting in restrictive ventilator defect, made worse by large volumes of oedema with fluid resuscitation and capillary leak.
Toxic inhalation of carbon monoxide (CO) resulting in a left shift of the ODC and oxygen transport capacity (Carboxy Hb) and decreased cellular oxidative processes.
Other toxic gases NH3, HCL – pulmonary oedema,mucosal irritation and ALI
CN- poisoning, cellular hypoxia
Increased metabolic requirements may overwhelm a respiratory system already impaired by all the above.
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.