Critical Care Medicine-Pulmonary Disorders>>>>>Respiratory Diagnostic Modalities and Monitoring
Question 10#

A 59-year-old male with history of COPD is admitted to the ICU for pneumonia and hypoxic respiratory failure. Four hours after admission, the patient continues to be in severe respiratory distress with O2 saturation of 85% on BiPAP (10 cm H2O IPAP, 5 cm H2O EPAP, and FiO2 100%). You decided to intubate the patient, and immediately after rapidsequence intubation, the patient oxygen saturation decreases to 78% with blood pressure 110/65 mm Hg and heart rate 95 bpm. Ventilator settings were tidal volume 6 mL/kg, respiratory rate 14 breaths/min, FiO2 100%, and PEEP 5 cm H2O. The ventilator is alarming for peak air pressure of 45 cm H2O with plateau pressure of 40 cm H2O. You next perform a point-of-care ultrasound of the lungs, and it shows an absence of pleural sliding on the left lung with positive A-lines and positive pulse sign on the left lung.

Which of the following is the MOST appropriate next step in management?

A. Perform left tube thoracostomy
B. Perform left needle thoracostomy
C. Start the patient on cisatracurium infusion
D. Adjust endotracheal tube

Correct Answer is D

Comment:

Correct Answer: D

Lung sliding sign is a created by the movement of visceral pleura on parietal pleura. The presence of lung sliding suggests that visceral and parietal pleurae are opposing, which excludes pneumothorax. The absence of lung sliding alone, however, does not diagnose pneumothorax. It has to be accompanied by the presence of lung point and absence of B-lines and lung pulse.

B-lines originate from visceral pleura, and their presence indicates that parietal and visceral pleurae are in contact and excludes pneumothorax. Lung pulse was described by Lichtenstein et al. as a sign of mainstem intubation. A completely atelectatic lung transmits the rhythmic movement of the heart to the pleura. An opposed parietal and visceral pleurae are required to transfer the heart pulses; hence, the presence of lung pulse excludes pneumothorax.

Neuromuscular blockade can help patient-ventilator synchrony. However, this is not the reason for this patient’s acute hypoxemia.

References:

  1. Lichtenstein DA, Lascols N Prin S Mezière G. The “lung pulse”: an early ultrasound sign of complete atelectasis. Intensive Care Med. 2003;29(12):2187-2192. doi:10.1007/s00134-003-1930-9.
  2. Volpicelli G. Sonographic diagnosis of pneumothorax. Intensive Care Med. 2011;37(2):224-232.
  3. Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38:577-591.
  4. Lichtenstein DA. BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill. Chest. 2015;147(6):1659-1670.