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Q1: What is the most likely cause of deterioration of GCS in this case?
Hypoxia is the most important preventable cause of obtunded sensorium in a trauma patient. It may manifest in the form of non-purposeful motor responses, and, therefore, is a strong indication for the need for definitive airway.1 Hypoxia and hypotension are to be ruled out before incriminating intracranial events or drugs (alcohol) as a cause of deterioration in GCS score.
Q2: What should be the next step?
Extubate the patient because the tube is blocked. Oxygenate him with mask, and establish a definitive airway once again.
The cuff of the endotracheal tube was immediately deflated and the patient was extubated. The oral cavity and pharynx were cleaned and he was put on an oxygen mask. He was reintubated with another endotracheal tube and ventilated. Immediately thereafter, a bottle of saline (500 ml) was infused over 15 minutes. After 30 minutes of reintubation his blood pressure improved to 105 mm Hg systolic. Two hours after reintubation and ventilation, his arterial blood gases were: oxygen tension 13.6 kPa, carbon dioxide tension 5.6 kPa, and pH 7.32. About five hours after admission his blood pressure was 110 mm Hg and GCS score improved to 4/10. By this time the fluid infusion was limited to 800 ml (since admission) in view of the head injury and lack of any apparent blood loss (internal/external).
Q3: What is the most probable cause of hypotension in this case?
In a trauma setting, hypoxia is the most important preventable cause of death. Myocardial contractility is reduced in the presence of hypoxia or acidosis.2 Correction of hypoxia and acidosis (respiratory) after reintubation and ventilation resulted in improvement in blood pressure. Only an 800 ml fluid infusion over five hours was needed to raise his blood pressure; this indicates that it was not hypovolaemia that was the main cause of the lower blood pressure.
Q4: What is the finding shown in fig 1 (see p 123)?
The tube is blocked with a blood clot.
Q5: What is the most likely explanation for the development of blockage of this endotracheal tube?
Aspirated blood would block the endotracheal tube. It is an important possibility in this case as the patient had epistaxis at the time of presentation to the district hospital. Endotracheal suctioning, during transfer, could have saved him from such a catastrophe.
Blocked or displaced endotracheal tubes are an important cause of hypoxia in trauma during transfer. Whenever a patient is shifted from one ward/hospital to other, one must ensure patency and correct positioning3 of the endotracheal tube. This can be easily accomplished by a trained paramedic.
It is not surprising that there is deterioration in the sensorium because of a blocked or displaced tube. What is surprising is the lack of awareness, and desire to take appropriate measures (pre-hospital trauma care), among the public, administrators, and medical professionals that hypoxia can kill very quickly. Aliet al reported much improved care after introduction of the pre-hospital trauma life support program (PHTLS), on the principles of Advanced Trauma Life Support.4 PHTLS has been shown to be effective when compared to care before introduction of PHTLS in, for example, the frequency of airway control (99.7% v 10%). Failure to monitor the endotracheal tube resulted in the lumen being compromised by blood clots, a preventable complication. The major clinical problem in this case is that it took three hours for the patient to arrive at a tertiary centre and the patient was not accompanied by medical or paramedical staff. Besides the medical lessons learnt from this case, an even more important message is for planners of medical care. They should be aware that tertiary care hospitals cannot treat patients effectively until and unless primary and secondary care is made effective. Good communication and a safe paramedical escort to a further referral centre is the key as trauma patients with a compromised airway cannot wait.
Hypoxia causing obtunded sensorium.