Respiration and Oxygenation

Respiration is the process of moving air in and out of the lungs, through inspiration and expiration. During inspiration, oxygen enters the lungs and crosses into the bloodstream, where it's delivered to tissues, a process known as oxygenation. Then, during expiration, carbon dioxide is expelled from the lungs. When measuring your patient's respiration and oxygenation, you'll follow the steps of the Clinical Judgment Measurement Model to guide clinical decisions about patient care.

First, let's review physiological regulation of respiration and oxygenation. Now, respiration is generally an involuntary process controlled by the respiratory center in the brainstem. Here, chemoreceptors in the medulla assess changes in the level of carbon dioxide and pH in cerebrospinal fluid. When CO2 increases and pH decreases, the chemoreceptors signal the respiratory center to increase the respiratory drive, which increases the rate and depth of breathing to eliminate excess CO2. Now, these central chemoreceptors work in concert with peripheral chemoreceptors located in the aortic arch and carotid arteries to regulate respiration.

Peripheral chemoreceptors are primarily sensitive to oxygen levels in the blood. When they detect low oxygen levels, they send a message to the respiratory center to increase the rate and depth of respirations, so more oxygen is inhaled. While respiration is predominantly passive, voluntary changes in respiration are controlled by the cerebral cortex like breaths during swimming or singing.

Alright, let's review how respiration delivers oxygen to the tissues of the body. During inspiration, oxygen enters the lungs and travels into the alveoli, where it diffuses into the pulmonary capillaries and binds to hemoglobin in red blood cells. From there, the red blood cells deliver oxygen to the body's tissues. Meanwhile, carbon dioxide diffuses across the capillaries into the alveoli where it is exhaled from the body.

Okay, so you'll measure your patient's respirations by counting the number of breaths per minute. If the respirations are faster than normal, it's called tachypnea; while if the respirations are slower than normal, it's called bradypnea. It's also important to look at the depth of breathing, and whether the breaths are regular or irregular, and to measure your patient's oxygen saturation, or the percentage of oxygen that's bound to hemoglobin in the blood using a pulse oximeter, to ensure enough oxygen is delivered to the tissues.

Now, when assessing your patient's respiration and oxygenation, you'll use the Clinical Judgment Measurement Model to gather and recognize important cues. These can include objective cues like the respiratory rate, rhythm, depth, and oxygen saturation. Additionally, you'll assess for subjective cues such as dyspnea, or difficulty breathing, as well as dizziness or lightheadedness due to decreased oxygen supply to the brain.

Importantly, you'll recognize other factors that can alter respiration and oxygenation. For example, pulmonary conditions like pneumonia and chronic obstructive pulmonary disease, or COPD, can increase the respiratory rate and cause dyspnea. Fever can also cause respiration to increase in order to meet an increased metabolic demand. On the other hand, opioids can depress the respiratory center in the brain and decrease the respiratory rate or even cause apnea, where no breathing occurs for several seconds.

Next, you'll analyze cues by linking them to your patient's history and clinical presentation. For instance, you'll consider whether tachypnea and sputum production are consistent with pneumonia; or if bradypnea and hypoxia are consistent with administration of opioids for pain management.

Next, you'll determine a priority hypothesis related to altered respirations and oxygenation such as apnea, dyspnea, or impaired breathing. You'll rank the hypotheses by determining if the findings are potentially life-threatening, like apnea; or an immediate concern, like dyspnea or impaired breathing. Based on this information, you'll generate solutions such as My patient's respirations and oxygen saturation will return to the expected range within one hour of treatment.

Okay, once you've generated solutions, you'll take action to implement them. For apnea, your actions can include initiating rescue breathing or assisting with establishing an artificial airway. For dyspnea and impaired breathing, you'll implement actions like positioning the head of the bed at 45 degrees or greater to facilitate chest expansion, providing oxygen, and administering medications to treat the underlying cause.

Lastly, you'll evaluate whether the expected outcome has been met by reassessing your patient's respirations and oxygen saturation to determine if their condition has improved, declined, or remains unchanged. If your patient's condition is unchanged or declining, you'll revise the plan of care accordingly and take additional actions to guide care.

Alright, as a quick recap . . . Respiration is the act of breathing, and oxygenation is the process in which oxygen is delivered to the tissues of the body. When assessing your patient's respirations and oxygenation, you will follow the steps of the Clinical Judgment Measurement Model to make clinical decisions about patient care by recognizing and analyzing cues, prioritizing hypotheses, generating solutions, taking action, and evaluating the patient response to interventions.