Reading Abnormal Ventilator Waveforms Part 3

SIMV: Respiratory therapist and anesthesia assistant Melody Bishop, RT, joins Nick (@pulmtoilet) to break down the history and physiology of synchronized intermittent mandatory ventilation (SIMV), how it has evolved, and why its combination of mandatory and spontaneous breaths can create unexpected challenges.Together, they explore the evidence against SIMV as a weaning strategy, its potential drawbacks in ARDS and complex ventilator cases, and why switching to SIMV isn't necessarily the solution to patient-ventilator dyssynchrony.From patient-triggered breaths and alarm settings to controlled ventilation, pressure support, and waveform interpretation, this episode challenges common ventilator practices Featured articles: Delayed WeaningSIMV 3x longer than daily SBTA Comparison of Four Methods of Weaning Patients from Mechanical VentilationComparison of three methods of gradual withdrawal from ventilatory support during weaning from mechanical ventilation - PubMedWOBAS SIMV RR is decreased,  WOB rises as RR through ALL breath typesEffect of Intermittent Mandatory Ventilation on Respiratory Drive and Timing | American Review of Respiratory DiseaseExternal Work Output and Force Generation during Synchronized Intermittent Mechanical Ventilation: Effect of Machine Assistance on Breathing Effort | American Review of Respiratory DiseasePSV better than SIMV for progressively loading the patient’s respiratory musclesComparative evaluation of diaphragmatic activity during pressure support ventilation and intermittent mandatory ventilation in animal model. | American Journal of Respiratory and Critical Care MedicineSIMV mandatory breaths do not offload the diaphragm.AnesthesiologyPediatric Critical Care MedicineAsynchronySIMV >10% Asynchrony index. High RR increases risk of asynchronyPatient-Ventilator Asynchrony in a Traumatically Injured Population | Respiratory CareSIMV higher dyssynchrony than Control Modes and PSVPediatric Critical Care MedicineSIMV increased risk of dyssynchrony when RR >10Patient-Ventilator Asynchrony in a Traumatically Injured Population | Respiratory CareSIMV increases the risk of reverse triggering esp. when RR close to spont. RR (50% of study patients and 30% incidence of causing breath stacking!)Frequency and Risk Factors for Reverse Triggering in Pediatric Acute Respiratory Distress Syndrome during Synchronized Intermittent Mandatory Ventilation - PMCSIMV changes neural breath timing and increases risk of asynchrony Prolonged Neural Expiratory Time Induced by Mechanical Ventilation in Infants | Pediatric Research

Here is my pre confernce recording of the talks I was giving at CHEST 2026!This is open access along with the slides but PLEASE consider subscribing to my patreon!!!! The monetary support allows me to keep this thing going !Claim a free month below !AttendingsCritical AccessCRNAAPPs, PharmD, and Rehab ServicesMedics/RNs/RTs/Flight CrewAll Trainees & First Responders

Former ICU nurse and palliative care APP Courtnee Stagner shares the words clinicians can use to help families face what’s happening, understand their options, and make decisions grounded in what the patient would want. An honest, practical conversation about ICU care, palliative care, and saying the hard things with compassion.

Everyone thinks ventilator waveforms are confusing, but when you understand the physiology you can dissect them much easier!!!In this lecutre, I go over core concepts in ventilator waveform physiology :💨 Flow occurs when there’s a pressure gradient.📈 Know what normal looks like → recognize when the patient–ventilator interaction changes.🧠 Waveforms show you how pressure, flow, and volume are interacting in real time.This is a shortened version of the whole lecture which could be found on my patreon along with the slides at https://patreon.com/Pulmtoilet?utm_medium=unknown&utm_source=join_link&utm_campaign=creatorshare_creator&utm_content=copyLinkClick below for a free month !AttendingsCritical AccessCRNAAPPs, PharmD, and Rehab ServicesMedics/RNs/RTs/Flight CrewAll Trainees & First Responders

In this episode, we move beyond normal waveforms and break down the abnormal patterns you’ll actually encounter at the bedside. Learn how changes in pressure, flow, and volume can reveal problems with resistance, compliance, flow delivery, air trapping--lets move beyond just sedating!!Full video and powerpoint on patreon!Click your job below for a free month!AttendingsCritical AccessCRNAAPPs, PharmD, and Rehab ServicesMedics/RNs/RTs/Flight CrewAll Trainees & First Responders

🫁 MAKE THE DRIVING PRESSURE < 15We all hear it: “Keep driving pressure <15.”Cool… HOW?There’s no driving pressure button on the ventilator.In this webinar, we break down the physiology and the practical bedside approach to actually lowering driving pressure—using tidal volume, PEEP, recruitment, compliance, ventilator modes, and waveform interpretation.The goal isn’t just to memorize DP <15. It’s to understand WHY the driving pressure is high and what you can actually do about it.🎥 Full webinar + slides available on Patreon:Patreon.com/cw/PulmtoiletClick the link for your specialty to sign up and get a free month!!!!!AttendingCRNAAPPs/PharmD/Rehab ServicesRTs/RNs/Medics/FlightAll Trainees and First RespondersCritical access healthcare workers

I go over 4 waveforms sent to me from followers! They quite bad so take a listen and let me know what you think! Only 2/4 are here-- go to my patreon (@pulmtoilet) for the full 4 waveforms and the accompanying PDF to download and annoate along!https://www.patreon.com/Pulmtoilet/posts/waveform-video-2-167832507?utm_medium=clipboard_copy&utm_source=copyLink&utm_campaign=postshare_creator&utm_content=join_link

Bridging the Gap in Critical Care EducationIn this episode, I sit down with Karen Battistoni, a CVICU educator from the Texas Medical Center, to discuss one of the biggest challenges in critical care: the gap between classroom education and bedside practice.We explore why many clinicians feel underprepared for complex ICU patients, how social media has become a powerful educational tool, and why teaching practical physiology matters. Karen also shares her perspective on fast-track cardiac surgery protocols, emphasizing that patient assessment and clinical judgment should always come before rigid protocol adherence.Finally, we discuss the importance of collaboration between nurses, respiratory therapists, and physicians, and how shared decision-making leads to better patient outcomes.Key takeaways:Practical education is essential for building ICU confidence.Protocols should support—not replace—clinical judgment.Teamwork is critical for delivering high-quality patient care.Whether you're a nurse, RT, APP, resident, fellow, or attending, this conversation offers practical insights you can apply at the bedside.

In this episode, I break down the same framework I teach in my Ventilator Dyssynchrony Bootcamp. Rather than memorizing a long list of named dyssynchronies, I focus on understanding what a normal breath should look like first. From there, we compare expectation to reality and systematically work through each phase of the breath—trigger, flow, cycle, and expiration—to identify where the patient and ventilator have fallen out of sync. This approach helps make waveform interpretation more intuitive, more reproducible, and ultimately more useful at the bedside for anyone caring for mechanically ventilated patients!

A clip of my webinar that I did on PRVC and why adaptive modes are generally bad in the ICU. Want full webinar? Email [email protected]