Background:
The incidence of reintubation in the post-anesthesia care unit (PACU) is a rare occurrence, between 0.15-0.45% of all general anesthetic cases. This case report is aimed to highlight the effectiveness of the less frequently used perioperative pulmonary risk assessments.
Case Description:
A 73 year old male with multiple co-morbidities including, a five-month old myocardial infarction with placement of drug-eluting stents, a cardiac apical thrombus and ejection fraction of 20%, and severe chronic obstruction pulmonary disease (COPD; on two liters of supplemental oxygen at home), suffered a mechanical fall at home and was brought to the emergency department (ED) for a left intra-trochanteric femur fracture. Orthopedic surgery determined his case to be urgent and needing close reduction and internal fixation with a short intramedullary nail.
The patient had an inconspicuous airway and lung exam, and given his co-morbidities, a revised cardiac risk index for the patient was performed (11% risk of a major cardiac event). However, it was stressed from the orthopedics team that the patient should not have a delay in surgery. The risks of general anesthesia were discussed with the patient, including his higher risk of intra- or post-operative cardiac complications. His case proceeded with one hour surgical time and an uneventful intraoperative course. At the end of the case, the patient was given a reversal agent while he was breathing spontaneously at volumes similar to pre-induction and he was extubated once the patient opened his eyes to command.
Within 30 minutes after extubation, the anesthesia team was called to evaluate the patient who could no longer follow commands and began taking shallower breaths. The patient did not receive any benzodiazepines, and only had minimal opioids with induction. When he did not respond to naltrexone, a repeat arterial blood gas showed the patient was suffering from hypercarbic respiratory failure requiring reintubation. He was then transferred to the intensive care unit for mechanical ventilation and successfully extubated the following day.
Discussion:
Given the rarity of reintubation, there has been few published literature to suggest risk factors (e.g., COPD, emergent cases, ASA class III or higher) associated with reintubation. However, this complication can lead to significant morbidity and mortality, including prolonged hospitalization, intensive care stay, and further negative respiratory outcomes (e.g., pneumonia, prolonged mechanical ventilation, tracheostomy).
Risk calculators are created to help patients make medical decisions based on their probability of suffering a complication. This patient received scores between 13-15% risk of having some type of pulmonary adverse event based on two known calculators, ARISCAT preoperative pulmonary index and a postoperative respiratory failure calculator by CHEST. Interestingly, these scores are higher than his risk of cardiac complications. Most preoperative assessments emphasize the importance of calculating cardiac risks in the preoperative period, with smaller stress on respiratory complications. Using these tools can help accentuate the importance of assessing pulmonary adverse events and when applied, can help prevent a negative outcome such as reintubation.
