Breathing and Swallowing: What you need to know
SLPs often talk about the "swallow" as if it’s an isolated event. But if the swallow is the lead singer, the respiratory system is the entire rhythm section, the stage, and the power supply.
It’s impossible to have one without the other.
When this relationship is harmonious, the patient does great. But when the respiratory system falters, it drags the swallow down with it. We can’t look at the swallow by itself. That would be like exercising only one side of your body. The better approach is to examine the entire system.
So, what does this look like?
Case Study
Meet Alan, a 72-year-old admitted with an acute exacerbation of COPD (I’ve changed the name and details of the case to protect the identity of the patient). When I walked into his room, he was sitting on the edge of the bed, conserving his own energy just to breathe. His Respiratory Rate (RR) was 32 breaths per minute, and he was on a High-Flow Nasal Cannula (HFNC) at 60 Liters per minute (LPM).
Alan was desperate for a drink of water. His clinical swallowing evaluation showed no overt coughing with applesauce or small amounts of liquids, but given his respiratory status, I knew he was teetering on the edge of decline.
What’s the first thing to look at?
1. The Respiratory Rate (RR)
A respiratory rate above 20 (tachypnea) is a massive red flag. For Alan, at an RR of 32, the coordination between breathing and swallowing is already compromised. When you’re breathing that fast, the "apneic window" (the brief pause in breathing during a swallow) becomes dangerously short.
The risk isn't just that he might aspirate; it’s that his lungs are already working overtime to fight respiratory disease. If he aspirates now, his "functional reserve" may be too low to handle even a small amount of additional contents in the lungs. We’re looking at the big picture here, right? Yes, swallowing is important, but what does dysfunctional swallowing mean for the overall system?
This matters for Alan: Because his systemic status is so fragile that even a "trace" aspiration could lead to a rapid decline.
2. The Pressure Factor (FiO2 and Flow)
Alan was on 60 LPM of airflow. Think of this sort of like a tornado in his throat. High-flow oxygen creates significant airway pressure to keep the airways and alveoli open. This is a double-edged sword. Keeping the airways open is great for breathing, but not so great for swallowing.
The result? An increased risk of blowing the bolus and its residue into the airway before, during, or after the swallow.
So, do we make him NPO? Change his diet consistency?
3 things we can do without messing around with the diet:
Instrumental study: We opted for an instrumental evaluation (FEES) rather than a bedside evaluation. In the ICU, even a small aspiration event can trigger a downward spiral, and we want to assess this risk firsthand while exploring strategies to improve his airway protection. Turns out for Alan, a chin tuck was helpful in protecting his airway.
Manage fatigue: We moved from three large meals to six "micro-meals." This reduced the work of breathing associated with eating and prevented fatigue-related aspiration.
Pacing and positioning: We utilized pursed-lip breathing between bites to reset his respiratory rhythm. We also focused on keeping him in an upright position to improve his breathing and improve his safety during meals.
As you can see, the most important part of Alan's care wasn't the texture of his food—it was training the staff and family. We educated them on the red flags (e.g., desaturation, respiratory distress) and the safety strategies we learned during the instrumental swallowing evaluation, as well as other basic safety precautions to keep in mind during meals (e.g., slow pacing, small bites/sips, upright positioning).
It’s All One System
Breathing affects swallowing, which affects breathing… which affects swallowing. This cycle is inseparable. The yin and yang of dysphagia management.
With this in mind, we must understand 3 key principles to properly manage swallowing in patients with cardiopulmonary issues:
Normal coordination of the breath-swallow cycle: Healthy individuals will inhale, exhale a bit, swallow, and then exhale some more. This cycle allows us to create subglottic pressure to propel the bolus and expel the bolus if it gets anywhere near the airway.
How disease disrupts that coordination: Many cardiopulmonary conditions (E.g., COPD, CHF) may increase the respiratory rate, causing persistent tachypnea at rest, which is exacerbated by activity (E.g., meals). A respiratory rate over 24 is considered tachypnea, and rates in the 30s and 40s may significantly increase the risk of aspiration.
How our interventions (such as oxygen support) alter the risk profile: BiPAP, CPAP, high-flow nasal cannula, and invasive mechanical ventilation increase pharyngeal and laryngeal pressure, increasing the risk of aspiration and choking. HFNC also delivers high levels of oxygen (up to 100%), which may indicate that a patient is not medically stable to eat and drink. Further, other masks that cover the mouth may not be appropriate for eating and drinking, as they require removing a vital source of oxygen flow to the patient when they need it most… during meals.
Conclusion
In the end, Alan got his water—not because we ignored the medical risks, but because we managed those “host variables” that made him most vulnerable. We must stop viewing the swallow as an isolated motor event and start seeing it as a critical branch of the respiratory system. By focusing on respiratory stability, managing fatigue with micro-meals, and ensuring upright positioning, we become less hyperfocused on the swallow itself and instead zoom out to manage the patient as a whole. SLPs can bring significant value to the (dinner) table by identifying when a patient's functional reserve is too low for a full meal and when—with the right support—it is safe to move forward. The answer isn’t always easy, but by asking the right questions, we can engage the interdisciplinary team and find the path that’s right for our patients.
