Certified Flight Registered Nurse (CFRN) 2025 – 400 Free Practice Questions to Pass the Exam

A leftward shift in the oxy-hemoglobin dissociation curve indicates an increased affinity of hemoglobin for oxygen. This means that hemoglobin holds onto oxygen more tightly and is less willing to release it to the tissues.

Several physiological factors can cause this leftward shift. For example, a decrease in carbon dioxide levels, a decrease in temperature, or an increase in pH (a condition known as alkalosis) will lead to this shift. When hemoglobin is in a state of higher affinity for oxygen, it will effectively bind oxygen in the lungs, but this can also make it more challenging for oxygen to be released to the tissues that need it.

Understanding this concept is critical because shifts in the curve can have significant implications for oxygen delivery in various clinical situations. For instance, in situations of hypoxia, maintaining an optimal shift can help ensure that tissues receive adequate oxygen despite lower overall levels in the bloodstream.