Title: Mild Hypercapnia or Normocapnia after Out-of-Hospital Cardiac Arrest<br/>Author: William Teeter<br/><a href='http://umem.org/profiles/faculty/2286/'>[Click to email author]</a><hr/><p>
<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;"><span style="color: rgb(77, 77, 77); font-variant-ligatures: common-ligatures;">Targeted Therapeutic Mild Hypercapnia after Resuscitated Cardiac Arrest (TAME)</span></span></span></p>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;"><strong>Current guidelines recommend normocapnia for out-of-hospital cardiac arrest (OHCA), the TAME Study asked is mild hypercapnia better?</strong></span></span></p>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Smaller previous studies have shown some benefits for hypercapnia including some improved outcomes:</span></span>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Increased likelihood of discharge home and better 12 month neurologic outcomes</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">The TAME study enrolled adults with OHCA with presumed cardiac or unknown cause within 3 hours of ROSC who were unconcious</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Unwitnessed, asystolic, hypothermic, pregnant, or ICH patients were excluded.</span></span>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">ECMO and Severe COPD patients on home O2 also excluded</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Randomization to either 24 hours of PaCO2:</span></span>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Intervention arm: 50-55 mmHg</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Control: 35-45 mmHg</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Strong design with strong methodology, adequate power, and good protocol adherence (>65% of measurements in group limitations) </span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Protocol violations in 8% of hypercapnia and 3% of normocapnia groups</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Missing primary outcome data in 7% of patients.</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Note: concurrent TTM trial (TTM2) was allowed to cross-enroll. Addressed with adequate statistical methodology</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;"><strong style="margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; font-optical-sizing: inherit; font-kerning: inherit; font-feature-settings: inherit; font-variation-settings: inherit; vertical-align: baseline;">Primary outcome (Favorable neurological outcome (GOSE ≥ 5)</strong></span></span>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">43.5% (mild hypercapnia) vs 44.6% (normocapnia)</span></span>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">ARR 0.98 (95% CI 0.87 to 1.11)</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;"><strong style="margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; font-optical-sizing: inherit; font-kerning: inherit; font-feature-settings: inherit; font-variation-settings: inherit; vertical-align: baseline;">Secondary outcomes</strong>: no differences</span></span></li>
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<span style="font-size:12px;"><span style="font-family:times new roman,times,serif;">Conclusion: "<span style="color: rgb(77, 77, 77); font-variant-ligatures: common-ligatures;">In patients with coma who were resuscitated after out-of-hospital cardiac arrest, targeted mild hypercapnia did not lead to better neurologic outcomes at 6 months than targeted normocapnia."</span></span></span></p>
<fieldset><legend>References</legend>
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https://www.nejm.org/doi/full/10.1056/NEJMoa2214552</p>
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https://clinicaltrials.gov/study/NCT03114033</p>
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https://www.thebottomline.org.uk/blog/ebm/tame/</p>
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