Immediate Management of Unilateral Absence of Breath Sounds

Initial Assessment and Recognition

The American Society of Anesthesiologists recommends immediately suspecting tension pneumothorax and preparing for needle decompression if the patient shows signs of respiratory distress, hemodynamic instability, or cardiac arrest, as this is a life-threatening emergency requiring intervention before imaging confirmation 1
The American Heart Association suggests checking for signs of inadequate ventilation immediately, including absent or inadequate chest movement, cyanosis, decreasing oxygen saturation, hemodynamic changes, changed mental status, or somnolence 1
The American Heart Association recommends assessing responsiveness and breathing pattern, and if the patient is unresponsive with no breathing or only gasping, assuming cardiac arrest and initiating CPR immediately 2, 3

The American Society of Anesthesiologists recommends performing immediate needle decompression if tension pneumothorax is suspected in unstable patients, without waiting for imaging confirmation 1
The American Heart Association suggests providing high-quality ventilation support, with 1 breath every 5-6 seconds, while monitoring for adequate chest rise in patients with a pulse but inadequate breathing 4, 5
The American Heart Association recommends initiating CPR if the patient is pulseless, with chest compressions at a rate of at least 100/min and a depth of at least 2 inches, minimizing interruptions and allowing complete chest recoil 3, 4

The American Society of Anesthesiologists notes that pneumothorax/tension pneumothorax is the most urgent consideration, especially with trauma history or mechanical ventilation 1
The American Heart Association suggests that complete lung collapse can result from mucus plugging, foreign body, or tumor obstruction 7, 8

The American Society of Anesthesiologists warns against delaying needle decompression in unstable patients to obtain imaging, as clinical diagnosis of tension pneumothorax is sufficient to proceed with life-saving intervention 1
The American Heart Association advises against assuming relief with oxygen rules out serious causes, and recommends continuing systematic evaluation even if initial oxygen improves symptoms 6
The American Heart Association recommends avoiding excessive ventilation in cardiac arrest patients, limiting to 1 breath every 6 seconds with advanced airway, to prevent impairing venous return and worsening outcomes 3