Tidal Volumes in Pediatrics: What to Use and When

It had been a while. That’s usually how it goes in a small hospital. You can go months without seeing a pediatric patient who needs a ventilator. Most of the time we stabilize and ship. So when one finally shows up, there’s always that moment where you have to stop and think it through. That’s really the point of this post. Not to make it complicated, just to review the basics so when it happens you’re not guessing.

One of the first questions that comes up is the circuit. Can you use an adult circuit on a pediatric patient with a Hamilton? Technically, yes. But it’s not ideal. Adult circuits have more volume and more compliance, and with a small patient that can throw things off. If you have a pediatric circuit, use it. It’s more accurate and just makes things easier. If you don’t, then you use what you have and pay closer attention to what you’re seeing.

The next thing is setup, and this is where everything comes back to weight. Pediatrics is all weight-based. If you don’t have a weight, get one, even if it’s just an estimate. That one number drives everything you do on the ventilator.

Mode is where people start overthinking things. Pressure versus volume always comes up. A lot of people lean toward pressure control, especially with uncuffed tubes, because you’re going to have some leak and pressure handles that better. That’s generally a safe way to go if you don’t do this often. Modern ventilators like the Hamilton can handle volume modes pretty well too, but if you’re unsure, pressure control keeps things simple and predictable.

When it comes to volumes, you’re usually thinking in the range of about 6 to 8 mL per kilogram. If the lungs are stiff or you’re worried about lung protection, you can go lower, more like 4 to 6. The big mistake is trying to fix problems by giving bigger breaths. Kids don’t need big tidal volumes. That tends to cause more harm than good. If you’re using a pressure mode, including pressure support, you’re not setting a tidal volume directly, so you adjust the pressure until you’re seeing those target volumes. Watch what the patient is actually getting and make your changes based on that, not just the number you dial in.

Rate is where pediatrics really separates from adults. Kids need higher rates. If you use adult settings, you’re going to under-ventilate them. Infants are often in the 25 to 40 range, younger kids somewhere around 20 to 30, and older kids still higher than adults. If your CO₂ is off, you usually fix that with rate before you start pushing pressures or volumes too high.

PEEP is simple. Start around 5 and adjust based on oxygenation. Same thinking as adults. FiO₂, start high if you need to, then bring it down as soon as you can. That part doesn’t change.

Inspiratory time is something people forget, but it matters more in kids. Their lungs are faster, so inspiratory time is usually shorter, somewhere around half a second up to maybe 0.8. If the waveforms don’t look right, this is one of the first things to adjust.

The biggest thing, especially if you haven’t done this in a while, is to watch the patient. Not just the ventilator. Look at chest rise, how they’re interacting with the vent, whether they look comfortable, whether the numbers actually match what you’re seeing. The ventilator can look perfect and still be wrong.

Working in a small hospital also changes your mindset. You’re not trying to manage this patient long term. You’re stabilizing, avoiding harm, and buying time until transport gets there. That takes a lot of pressure off if you think about it that way. You don’t need perfect settings, you just need safe and effective ones.

So if you keep it simple, get a weight, choose a mode you’re comfortable with, stay in a reasonable range for volumes or pressures, set a higher rate than you would for an adult, and watch the patient, you’ll be fine. It might feel uncomfortable if it’s been a while, but the basics don’t change. And in pediatrics, doing the basics well goes a long way.

The 7.40 / 40 Club

If you work in respiratory therapy long enough, you start to notice another pattern.

It’s not wheezing.
It’s not shortness of breath.

It’s numbers.

Specifically: pH 7.40 and CO₂ 40.

Somewhere along the way, those two numbers became the holy grail. The center of the universe. The place where all patients are apparently supposed to live at all times, no matter what.

I once had a doctor joke with me—half joking, anyway—that the goal of BiPAP is simple:

“Get the pH to 7.40 and the CO₂ to 40.”

That’s it. Mission accomplished. Everyone go home.

And honestly, once you hear it, you can’t unsee it.

Patient comes in with a CO₂ of 42.

Forty-two.

Two points above perfection.

Next thing you know: “Let’s put them on BiPAP.”

Now, is the patient in distress?
Are they altered?
Are they tiring out?

Eh… details.

The number is 42.

And we all know what that means.

They must be guided—gently, heroically—back to 40.

Because clearly, the human body cannot function at 42. It’s a miracle they made it this far.

So on goes the mask.

Pressures get dialed in.
Alarms start beeping.
The patient gives you that look like, “Was I doing something wrong?”

And in the background, the ABG waits patiently… ready to reveal whether we’ve restored order to the universe.

A couple hours later:

CO₂: 40

And there it is. Balance has been restored. The stars align. The RT exhales. The doctor nods. The number is right where it belongs.

Never mind that the patient felt okay before. Never mind that they feel exactly the same now—just with a tight mask strapped to their face and a machine hissing beside them.

But the number?

Perfect.

Now, to be fair, BiPAP absolutely has its place. When someone is in real trouble—acidotic, tiring out, heading in the wrong direction—it can be a lifesaver. No argument there.

But sometimes… sometimes it feels like we’re not treating patients.

We’re treating decimals.

We’re chasing a version of “normal” that looks great on paper but doesn’t always match what’s happening in front of us.

Because here’s the truth most of us learn eventually:

Not every patient is supposed to be 7.40 and 40.

Some live at 45.
Some live at 50.
Some have been there for years and are doing just fine.

And that’s okay.

The body adapts. It compensates. It finds its own version of balance, even if it doesn’t match the textbook.

But every now and then, you’ll still hear it.

“CO₂ is a little high… maybe we should start BiPAP.”

And you can’t help but smile.

Because deep down, we all know what we’re really chasing.

Welcome to the 7.40 / 40 Club.

Finding the Right Controller Inhaler — What Works for Me

Right now, my daily inhaler is Breztri Aerosphere. I didn’t start there. Like a lot of people with asthma, I’ve been on just about everything over the years. My doctor originally put me on Trelegy Ellipta, which combines three medications—a steroid, a long-acting bronchodilator, and a muscarinic agent. On paper, it made sense, and to be fair, it worked well for controlling my symptoms.

The issue for me wasn’t effectiveness. It was the delivery. Trelegy is a dry powder inhaler, and every time I used it, I felt that blast of powder hit the back of my throat. Sometimes it made me cough, and other times it just felt like I wasn’t getting a full dose. It left me with the feeling that some of the medication wasn’t making it where it needed to go.

Eventually, I asked if I could switch to something different. By that point I was seeing a PA instead of my usual doctor, and she was fine writing a prescription for Breztri. The main difference is that Breztri is a mist inhaler with a propellant. That may not sound like a big deal, but it is. The mist feels smoother going in, and to me it seems like it gets deeper into the lungs. I don’t get that same throat hit, and I don’t feel the urge to cough after using it.

There is a trade-off. Since switching, I’ve noticed more side effects. I get a little jittery at times and have some mild tremors. It’s nothing I can’t tolerate, but it’s definitely more noticeable than what I experienced on Trelegy. My guess is that if more of the medication is reaching my lungs, more of it is also getting into my system, which may explain the difference.

Over time, I’ve also started to pay attention to which parts of these combination inhalers seem to help me the most. Breztri, like Trelegy, contains three types of medication. In theory, they all play a role. But based on my own experience, I’m not convinced they all affect me equally. I’ve used muscarinic drugs going back to atropine years ago and later Atrovent, and I never really noticed much benefit from those.

Steroids are a little harder to judge. I know they’re supposed to reduce inflammation, but I had an experience that made me question how much they help me on their own. When I was on Symbicort, I ended up relying on it more like a rescue inhaler than I should have. My insurance would only allow one inhaler a month, so I would run out during the last week. To get through that gap, my doctor prescribed Flovent. During those stretches when I was only using Flovent, my asthma got worse. The steroid alone didn’t seem to carry me the way the combination inhaler did.

That experience is what led me to believe that the long-acting bronchodilator is the most important part of the combination for me. Having that medication in my system consistently seems to keep my airways open and helps prevent symptoms before they start. I still use my rescue inhaler more often than guidelines recommend, but I also know my asthma is more severe than what’s written in my chart.

At this point, I’ve tried enough different inhalers to know that they all help in their own way. The differences come down to how they’re delivered, how they feel, and how your body responds to them. For me, Breztri works well because I prefer the mist delivery and feel like I’m getting a better dose into my lungs, even if it comes with a few more side effects.

The bigger takeaway is that the “right” inhaler isn’t always the one that looks best on paper. It’s the one you can use consistently and confidently, the one that fits your routine, and the one that actually helps you breathe easier day to day. Right now, for me, that’s Breztri.

Neonatal Airway Basics: ETT Size and Depth Made Simple

In my humble opinion, taking care of a neonate is often easier than taking care of a pediatric patient. That might sound backwards, but it comes down to experience. In a small town hospital like ours, we don’t see critically ill pediatric patients very often. We usually stabilize and ship any neonate or pediatric patient that requires ongoing support. Because of that, pediatrics can feel less familiar and a little more stressful when they do come in.

Neonates, on the other hand, follow a more predictable path in resuscitation. We start with the basics—positive pressure ventilation with a Neopuff. And really, if you are getting good chest rise, you already have an airway. Air is moving. That’s what matters. If the heart rate is improving and the chest is rising, you’re doing your job.

The newer NRP guidelines, I believe the 9th edition, lean toward intubating earlier than the 8th edition. I understand the reasoning, but I don’t always agree with rushing to intubate. If I’m getting good chest rise, I’m not in a hurry. I’ve said it before in those moments: we’re getting good chest rise, everything looks good here, go take care of whatever else you need to do before we intubate. That’s just common sense to me. There’s no reason to rush into intubation when you already have effective ventilation and the provider may have other priorities.

That mindset carries over to adults too. Good bagging goes a long way. There’s no need to fix something that isn’t broken.

Working in a small hospital also shapes how we practice. For years we were told not to intubate and to wait for the transport team. So we did. That might mean Neopuffing for a long time while waiting for the “baby buggy” to arrive from the larger hospital. And honestly, that’s fine. It’s often far easier and less stressful than rushing an intubation and managing a ventilator in a setting that doesn’t do it often.

That said, there are times when intubation is necessary. When ventilation isn’t effective and the baby isn’t improving, there’s no other option. When that moment comes, you need to be ready. That’s where knowing what size ETT to pick and where to secure it becomes important. That’s the purpose of the chart below—it gives you a quick, reliable starting point.

And one last thing that doesn’t get talked about enough is taping the tube. Getting the tube in is one thing, but keeping it in place is just as important. It’s a skill that should be practiced at least once a year, because when you need it, you don’t want to be figuring it out on the fly.

In the end, neonatal resuscitation is about staying calm, doing the basics well, and not rushing into things you don’t need to rush into. When intubation is needed, be ready. But until then, good ventilation solves a lot of problems.

Palbuterol — And Other Things Only RTs Understand

It’s been a while since I created my list of 101 faux versions of albuterol for our Real Physician’s Creed. So I decided to showcase a few more.

Doctors and nurses may be confused… but we know.

If you’ve been around long enough in respiratory care, you start to realize something. Not everything we do is about the medication. Not every treatment fixes what it’s supposed to fix. And sometimes, what actually helps isn’t written anywhere in the order set.

That’s where these come from.

They’re absurd on the surface—but like most good respiratory humor, there’s a little truth hiding underneath.

PALBUTEROL

The medicine may have no effect…
But the company of an RT will.

We’ve all been there.

Treatment ordered. You show up. You assess. You listen. You already know—this isn’t going to change much.

But you stay anyway.

You talk. You reassure. You adjust a pillow. You tweak the oxygen just enough. And somehow… things settle down.

Was it the treatment?

Maybe.

But probably not.

ALLBETEROL

I think that’s all she needs.

There’s a moment in certain rooms where you realize everything doesn’t need to be escalated.

Not every patient needs more machines. More pressure. More noise.

Sometimes they just need someone who knows what they’re looking at… and isn’t panicking.

KNOWBETTEROL

For when you already know… before anyone else does.

You walk in.

Before the chart loads. Before the vitals cycle. Before anyone finishes explaining.

You already have a pretty good idea what’s going on.

Experience does that.

DEEPBREATHEROL

Side effects may include hearing things that weren’t there before.

“Take a deep breath.”

And just like that… crackles, rhonchi, noises everywhere.

Funny how that works.

ORDEROL

Prescribed every four hours… whether it’s needed or not.

No explanation needed.

The Point (Sort Of)

I’ll explain the Real Physician’s Creed more in a future post.

But the short version is this:

It’s not about making fun of doctors. It’s about pointing out the absurdity we sometimes see in medicine… by being just as absurd.

Because if you’ve worked in a hospital long enough, you know—

Some of the most ridiculous things we joke about
aren’t that far from reality.

And sometimes the difference between chaos and calm
isn’t another order…

…it’s just the right person walking into the room.

Singulair: A Medication That Works for Me, Despite the Controversy

It’s honestly hard to write about Singulair.

Any time I’ve mentioned it in asthma groups, the conversation can turn quickly. People share heartbreaking stories about serious side effects, including suicide. Those stories matter, and they deserve to be heard. Losing a child is unimaginable, and I don’t take that lightly.

At the same time, those stories can make people afraid to try a medication that might actually help them. The concern around Singulair is real enough that it now carries a black box warning. But it’s also true that the research hasn’t clearly established a direct cause-and-effect link in every case. Like a lot of medications, it comes down to weighing risks and benefits.

All I can really do is speak from my own experience.

For me, Singulair has worked very well.

Before I started taking it, spring was rough every year. I was constantly sniffling and sneezing, and it felt like I was always trying to stay one step ahead of my symptoms. About 15 years ago, a doctor told me he didn’t think most people noticed much difference with it, so he suggested I could stop. I did, and for a couple of years I got by without it.

At the time, that was fine with me. It was still under patent back then and cost about a dollar a pill, so I wasn’t exactly eager to keep taking it.

Then one summer, my allergies hit hard again. I was going through Sudafed like crazy—probably a box a week—and still felt miserable. One night, I woke up feeling awful and realized I was out of everything. The only thing I had was an old Singulair tablet.

So I took it.

Within about 20 minutes, I felt noticeably better.

That was enough for me. I went back on it and haven’t stopped since.

I understand the concerns. I really do. But I also know what it’s done for me. What frustrates me is that some people who might benefit from this medication may never try it because the conversation around it has become so one-sided. Like anything in medicine, it should come down to an informed decision between a patient and their provider.

Dr. Creed: The Krebs Cycle Theory of Oxygen (2026 Edition)

Warning: What follows is top secret information recently leaked to me from one of the nation’s most prestigious pulmonologists at a highly respected teaching institution. Read at your own risk. This is not edited.

The following is an excerpt from a lecture given by Dr. Ven Tolin, MD, PhD, MBA, at some point in the recent past.

Warning: What follows is top secret information recently leaked to me from one of the nation’s most prestigious pulmonologists at a highly respected teaching institution. Read at your own risk. This is not edited.

The following is an excerpt from a lecture given by Dr. Ven Tolin, MD, PhD, MBA, at some point in the recent past.

Transcript:

---

<pre style="font-family: Courier New, monospace; font-size: 14px; line-height: 1.4;">

Read at your own risk. This is not edited.


The following is an excerpt from a lecture given by
Dr. Ven Tolin, MD, PhD, MBA,
at some point in the recent past.


                         T R A N S C R I P T

</pre>
It has come to our attention that respiratory therapists continue to express concern when physicians lower oxygen on patients who appear, at least on the surface, to require it.

This is understandable.

RTs are trained to focus on things like oxygen saturation, work of breathing, and basic human survival. However, what they often fail to grasp is the deeper biochemical strategy at play.

Today I will once again explain why reducing oxygen remains one of the most effective ways to manage elevated CO₂ levels.

It all comes down to the Krebs Cycle.

You may remember this from your early training, although it is unlikely you fully understood it. Oxygen is required for aerobic metabolism, and aerobic metabolism produces CO₂.

So if you think about it:

More oxygen leads to more metabolism.
More metabolism leads to more CO₂.

Therefore, if a patient has too much CO₂, the logical solution is simple:

          Lower the oxygen.

At this point, the RT may begin to object.

They may say things like, “The PaO₂ is 47,” or “The patient looks terrible,” or even “They need oxygen to survive.”

These are surface-level observations.

We must think deeper.

By lowering oxygen, we limit aerobic metabolism and therefore reduce the production of CO₂ at its source. In this way, we are not just treating numbers—we are solving the problem at the cellular level.

In fact, one could argue that the most effective way to eliminate CO₂ is to eliminate the conditions required to produce it.

RTs often struggle with this concept.

They may quietly increase the oxygen when you leave the room. They may document concerns. They may even attempt to explain physiology.

Remain calm.

You are the physician.

If necessary, place a note in the chart stating:

          "DO NOT INCREASE OXYGEN UNDER ANY CIRCUMSTANCES."

This usually restores order.


A word of caution: do not attempt to fully explain this theory to a respiratory therapist. Excessive exposure to advanced medical reasoning may result in confusion, frustration, or spontaneous eye rolling. In rare cases, it may cause the RT’s head to swell to dangerous proportions.

We do not want that.


In conclusion, while RTs may continue to rely on outdated concepts such as oxygenation, ventilation, and patient comfort, we as physicians must remain committed to higher-level thinking.

Remember:

          Not everything that appears necessary... actually is.



                         END TRANSCRIPT



Editor’s note (RT Cave, 2026):

Sometimes the best way to understand a bad idea...
is to take it seriously all the way to the end.

---

Editor’s note (RT Cave, 2026): Sometimes the best way to understand a bad idea… is to take it seriously all the way to the end.