Emergency department intensive care units monitor acute respiratory failure patients with arterial blood gas analysis. Nurses monitor, manage, and support critically ill patients at the bedside, making their job the hardest. Purposive sampling selected 50 Nurses for a descriptive study. Critical Care Unit study. After examining ABG analysis literature and consulting nursing experts, the investigator created a questionnaire to measure staff nurses' understanding. Data gathering was ethically approved. Participants gave informed consent when the setting gave permission. ABG knowledge questionnaire and socio-demographic data were obtained. Results: 16% of staff nurses had low ABG analysis knowledge, 72% had average knowledge, and 12% had strong knowledge. Conclusions: Most nurses had average ABG Analysis expertise. Nurses need ABG analysis training.