Plateau Pressure and Alveolar Pressure

Frank Lodacerto and Eric Acker describe plateau pressure, how to measure it, and its significance for alveolar injury.

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🧭 REBEL Rundown

🗝️ Key Points

💉 Hydrocortisone Saves Lives:
The 2023 Cape Cod Trial (NEJM) showed a clear mortality benefit and reduced need for intubation in severe CAP patients treated with hydrocortisone.
📊 Guidelines Are Catching Up:
The SCCM (2024) and ERS now recommend steroids for severe CAP, while ATS/IDSA updates are still pending.
🔥 Redefining “Severe”:
Patients requiring high FiO₂ (>50%), noninvasive or mechanical ventilation, or PSI >130 meet criteria for steroid therapy — even outside the ICU.
🍬 Main Risk = Hyperglycemia:
Elevated glucose was the most consistent adverse effect, but rates of GI bleed and secondary infection were not increased.
🧭 Early, Targeted Use Matters:
Start hydrocortisone within 24 hours of identifying severity — especially in patients with high CRP (>150) or strong inflammatory response.

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📝 Introduction

Corticosteroids have long sparked debate in the treatment of bacterial pneumonia — once viewed with skepticism, now increasingly supported by high-quality evidence. In this episode, Dr. Alex Chapa joins the REBEL Core Cast team to explore how the 2023 Cape Cod Trial (NEJM) reshaped practice and guideline recommendations for severe community-acquired pneumonia (CAP).

📖 Historical Context & Long-Standing Skepticism

For decades, the use of steroids in pneumonia was controversial.

- Early Use: Steroids entered practice in the 1940s and 50s for autoimmune inflammation, but there was immediate hesitation regarding secondary superinfections.
- Mixed Data: From the 1980s to the 2000s, small studies emerged on severe pneumonia and ARDS, but the data was inconsistent. Different trials used varying definitions of “severe” pneumonia and different C-reactive protein (CRP) cutoffs, making the data “spread” and easy to “cherry pick” to support or deny a benefit.
- Past Guidelines: This uncertainty was reflected in official guidelines:
  - 2007 (ATS/IDSA): The American Thoracic Society and the Infectious Diseases Society of America did not address the topic due to insufficient data.
  - 2019 (ATS/IDSA): Pre-COVID, the guidelines recommended against using corticosteroids in severe CAP. They acknowledged no benefit for non-severe pneumonia, but the data for severe pneumonia was considered too weak to endorse.
  - Pre-Trial Consensus: Prior to 2023, the consensus was to avoid steroids in non-severe pneumonia, while severe pneumonia remained a “gray area” with no treatment showing a clear mortality difference.

📜 The Landmark Cape Cod Trial (NEJM 2023)

The Cape Cod trial, published in the New England Journal of Medicine in 2023, reignited the discussion by providing robust, positive data.

Trial Design: Phase 3, multi-center, double-blind, randomized, controlled trial.
Intervention: 800 patients randomized to two groups, Hydrocortisone as a continuous infusion (200mg/day) versus a placebo infusion.
Taper: On day 4, clinicians would decide whether to continue the infusion or begin a taper based on clinical response.
Population: Patients with severe CAP, defined by meeting at least one of the following criteria:
- Pneumonia Severity Index (PSI) > 130.
- O2 by FiO2 ratio < 300.
- Need for mechanical or non-invasive ventilation (with PEEP ≥ 5).
- Need for high FiO2 (>50%) via non-rebreather or heated high flow.
Primary Outcomes: Death for any cause 6.2% (hydrocortisone) vs 11.9% (placebo)
Secondary outcomes:
- Death from any cause at 90 days 9.3% (hydrocortisone) vs 14.7% (placebo)
- Endotracheal intubation 18% (hydrocortisone) vs 29% (placebo)
- Hospital-acquired infections 9.8% (hydrocortisone) vs 11.1% (placebo)
- Gastrointestinal bleeding 2.3% (hydrocortisone) vs 3.3% (placebo)
- Vasopressor initiation by day 28 15.3% (hydrocortisone) vs 25.0% (placebo)
Key Findings: The trial demonstrated superiority for hydrocortisone

📋 Updated Guidelines & Current Practice

The Cape Cod trial, along with subsequent meta-analyses, has begun to change official recommendations.

Society of Critical Care Medicine (SCCM): In 2024, an SCCM expert panel, reviewing the Cape Cod trial and 18 others, strongly recommended corticosteroids for severe CAP. They concluded that steroids reduce mortality and the need for mechanical ventilation.
Meta-Analysis (Smit et al.): A 2024 meta-analysis in Lancet Respiratory confirmed the 30-day mortality benefit.
European Respiratory Society (ERS): The ERS has issued a recommendation to use steroids for severe pneumonia but still urges caution regarding side effects.
ATS/IDSA: As of the podcast recording, the ATS/IDSA had not yet updated their 2019 guidelines.

🛠️ Practical Application for Clinicians

Defining “Severe” CAP: The key is to identify patients who qualify as “severe”. This can be done using:

Scoring Tools: The PSI is the best validated tool for mortality but is cumbersome. Simpler tools like CURB-65 or SMART-COP are practical and acceptable for defining severity. 2023 meta-analysis from by Zaki et al showed both work well, but CURB-65 has better mortality prediction early on.
Cape Cod Criteria: Any patient meeting the trial’s inclusion criteria (e.g., high-flow O2, non-invasive ventilation) qualifies, regardless of location (ED, floor, or ICU).
Biomarkers: While not required, a CRP level was used in many studies. A CRP > 150 (Cape Cod) or > 204 (Smit meta-analysis) strongly indicates severe inflammation that would benefit from steroids.
Clinical Judgment: A patient who looks “sick,” has “soft” blood pressure, or has dense infiltrates and high oxygen needs (e.g., >50% FiO2 on high flow) is a candidate.

Adverse Effects:

Hyperglycemia: This was the most significant risk identified, with rates between 6-12%. This is a primary concern, especially in patient populations with high BMI.
GI Bleed & Secondary Infection: Fears of these side effects, which contributed to historical skepticism, were not borne out in the Cape Cod trial. The data does not support being overly concerned.
Other Side Effects: Mood changes, delirium, insomnia, and agitation in the elderly are known side effects of steroids that were not specifically addressed in the trial but remain clinical concerns.

🔄 Clinical Pathway for Steroids in Severe CAP

Review of Corticosteroids in Community-Acquired Pneumonia Cinical Pathway.

Unanswered Questions & Future Research

Possible remaining questions:

Biomarkers: Can we find a more precise CRP level to distinguish moderate from severe disease? Could other markers like ferritin or IL-6 be used?
Dosing & Tapering: How much immunomodulation is needed, and when is it truly safe to taper?
Gender Differences: Early data suggests females may respond better to steroids and experience fewer side effects. The question of female patients with severe CAP require less corticosteroids needs further exploration.

👉 Clinical Bottom Line

The current literature, spearheaded by the Cape Cod trial, now supports the use of corticosteroids in severe community-acquired pneumonia. The best evidence currently points to hydrocortisone, started early (within 24 hours) after severity is identified using a validated tool. While hyperglycemia is a risk, the previous fears of GI bleeding and secondary infections were not substantiated in recent, rigorous trials.

📚 References

Chapa-Rodriguez A, Abou-Elmagd T, O’Rear C, Narechania S.
Do patients with severe community-acquired bacterial pneumonia benefit from systemic corticosteroids?. Cleve Clin J Med. 2025;92(10):600-604.
PMID: 41033846
Dequin PF, Meziani F, Quenot JP, et al.
Hydrocortisone in Severe Community-Acquired Pneumonia. N Engl J Med. 2023;388(21):1931-1941.
PMID: 36942789
Chaudhuri D, Nei AM, Rochwerg B, et al.
2024 Focused Update: Guidelines on Use of Corticosteroids in Sepsis, Acute Respiratory Distress Syndrome, and Community-Acquired Pneumonia. Crit Care Med. 2024;52(5):e219-e233.
PMID: 38240492