Intubating Asthmatic Patients

Ariella Cohen · December 9, 2022 · Airway, Respiratory / Pulm

Asthma is Greek for panting, which is a fitting translation for a patient that presents with a severe asthma exacerbation. We try to avoid intubating these patients because they are prone to compilations such as pneumothorax, mucus plugging, and increased morbidity and mortality.

However, there are specific situations when you may consider intubating an asthmatic patient. One reason is that your patient may not be improving despite maximal medical therapy, such as BIPAP, albuterol, ipratropium, magnesium, epinephrine/terbutaline, ketamine, etc. Another reason is that your patient may now be altered, and have worsening work of breathing, and vital sign abnormalities. Remember that a “silent chest” is a poor prognostic indicator; you may not hear wheezing because they are not moving any air.

If you choose to intubate, there are tricks to maximize your success and optimize your management of your patient on the vent.

Use a large ETT (8-9) because it reduces airflow resistance and can facilitate procedures later (such as bronchoscopy).
Ketamine is a useful induction agent because of its bronchodilatory effects. It may also be useful if you choose delayed sequence intubation.
High airway pressures can cause hypotension after intubation, so consider giving volume if there is a current or prior history of hypotension.
If hemodynamics are compromised consider giving an epinephrine drip. It is considered a systemic bronchodilator that can provide hemodynamic support as well as bronchodilation.
Keep a low respiratory rate when bagging or on the vent (6-8 breaths/min). Giving them time to exhale will decrease the chances of air trapping and pneumothorax. Another way to do this is to increase the I:E time (1:4 or 1:5).
If the vent is alarming, troubleshoot (DOPES mnemonic) but be suspicious for mucus plugs, pneumothorax, or breath stacking. If they are breath stacking, disconnect them from the vent and push on their chest to help them fully exhale.

A quick note about auto-PEEP and breath stacking: Auto-PEEP refers to trapping gas in the lungs during respiration. This occurs when one breath can’t be fully exhaled before the next inhalation. This trapped gas causes additional positive pressure, known as “auto-PEEP” in the chest which is typically higher than the PEEP set on the ventilator. This process predisposes patients to develop a pneumothorox.

Thanks for reading!

Ariella

POTD: Intubating the Pregnant Patient

Ariella Cohen · December 5, 2022 · Airway, Obstetrics / Gynecology

Intubating a pregnant woman is intimidating because you have two patients to consider. Physiologic changes in pregnancy can affect intubation so it is important to plan ahead.

Both ventilation and acid-base status change during pregnancy. As progesterone rises, there is an increase in tidal volume, which results in maternal respiratory alkalosis. This creates a gas gradient to allow for the transfer of CO2 from the fetus to the mom. This maternal hypocarbia causes uteroplacental vasoconstriction, which can cause fetal hypoperfusion and hypoxia. This creates a very delicate acid-base balance that is exacerbated by increased fetal oxygen consumption and CO2 production in the third trimester. In addition, the diaphragm is pushed up by the gravid uterus reducing the mother's functional residual capacity by 10-25%. As a result of these factors, pregnant patients have a shorter safe apnea time and can desaturate quickly.

Progesterone also decreases the tone of the lower esophageal sphincter. Combined with increased intraabdominal pressure from the gravid uterus, pregnant patients are at higher risk for aspiration. For these reasons, you should be careful with bagging and consider intubating in a semi-upright position. This position also has the benefit of taking some pressure off of the patient's chest and IVC.

Anticipate a difficult airway in pregnant patients. Failed intubation is 8x more likely than in the general population. Human placental growth hormone secreted in pregnancy increases blood flow to the upper airways. This results in edema and hyperemia of the airway, causing it to be smaller and more friable. For this reason, you should prepare a smaller caliber ETT. Rocuronium and succinylcholine have been studied with similar efficacy. Induction agents therefore depend on patient specific factors.

TLDR: 1. preoxygenate well due to shorter safe apnea time. 2. Consider a smaller ETT for a narrower and more friable airway. 3. Limit aspiration risks by decreasing bagging if possible 4. consider intubating patients in a semi-upright position.

Thanks for reading!

Ariella

References:

https://rebelem.com/respiratory-failure-and-airway-management-in-the-pregnant-patient/

https://www.nuemblog.com/blog/intubating-the-pregnant-patient

https://www.uptodate.com/contents/airway-management-for-the-pregnant-patient

The Double Set-up

Sabena Vaswani · February 22, 2022 · Airway, Trauma

Hi all,

This is going to be a short but important POTD!

I wanted to write about an airway set up technique, colloquially termed “The Double Set Up” that the trauma and northside teams used yesterday during a level 1 trauma.

Without giving any secrets away for a case that will likely be an M&M in the future, for some situational background, the patient was getting progressively hypoxic with vomitus covering the entire airway. It was hard to get visualization of the airway using the Glidescope. The airway options were clear: either tube via DL or crich.

The team smartly employed the double set up technique to secure the airway.

What does this term mean?

The double set up is when you have simultaneously set up for an orotracheal intubation and for a cricothyroidotomy. The EM/ anesthesia physician is at the head of the bed with the orotracheal airway equipment, while the surgeon is completely prepared for the crich with the scalpel in hand at the neck of the patient. The neck should already be prepped, and the landmarks should be identified.

When should we do the double set up?

Strayer has an amazing blog post about this (see below). Here are some indications where you might want to do the double set-up:

An unstable maxillofacial trauma patient
As a last ditch effort to secure the orotracheal tube after a failed attempt
Rapidly desaturating patient with challenging anatomical features / cannot be successfully bagged
Concern for an obstructed airway

If the intubator is ultimately unsuccessful, they indicate to the surgical airway physician to proceed. If the orotracheal intubator is successful, then the surgical airway physician can stop.

References: