Basic and Clinical Sciences (BCSE) 2025 – 400 Free Practice Questions to Pass the Exam

In patients with respiratory failure, increasing the dead space in the lungs can indeed worsen both hypoxemia and hypercapnia. Dead space refers to areas of the lungs where air is present, but gas exchange does not occur; this includes the conducting zones of the respiratory system and damaged alveoli. When dead space increases, less of the inhaled air effectively participates in oxygenating the blood or removing carbon dioxide.

As a result, even if a patient is taking in a normal volume of air, a larger portion of that air is not contributing to gas exchange, thus leading to lower oxygen levels (hypoxemia) and elevated levels of carbon dioxide (hypercapnia) in the bloodstream. This can exacerbate the underlying issues of respiratory failure, making it more difficult for the patient to maintain adequate oxygenation and ventilation. The interconnected nature of these gas exchange processes highlights why increased dead space is particularly detrimental in the context of respiratory failure.