mike winters - don’t forget a and b!

Don’t ForgetA & B!

Michael Winters, MD FACEP FAAEMAssociate Professor of Emergency Medicine and Medicine

Co-Director, Combined EM/IM/Critical Care ProgramUniversity of Maryland School of Medicine

Twitter: @critcareguys

June 25, 1987

> 500,000

✓ High-Quality CPR

✓ Early Defibrillation

Resuscitation

✓ High-Quality CPR

✓ Early Defibrillation

✓ Ventilation

✓ Post-Arrest Care

Resuscitation

Resuscitation Pearls

• Intra-Arrest

- “Death by hyperventilation”

• Post-Arrest

- Target normocapnia

- Target normoxia

June 25, 1987

June 25, 2015

CCR

• Primary cardiac arrest

CCR

• Primary cardiac arrest

- Most common cause of OHCA

- Most often due to ventricular arrhythmias

- Breathing normal / near normal

- Arterial oxygen saturation is near normal

• 30,381 patients in Sweden

• 30-day survival

✓ CPR: 10.5%

✓ No CPR: 4%

Hasselqvist-Ax I, et al. NEJM 2015

• 520 patients

• Survival to DC

✓ Compression only: 14.6%

✓ Standard CPR: 10.4%

Hallstrom A, et al. NEJM 2000

• 4068 patients

• Favorable neurologic outcome at 30 days

✓ Compression only: 6.2%

✓ Standard CPR: 3.1%

SOS-KANTO Study Group. Lancet 2007

Bystanders…

✓ Compressions only

✓ No ventilation

EMS…

• Oxygenation

• Advanced Airway

• Ventilation

Oxygenation

• Current convention is to oxygenate at 100%

• Animal studies demonstrate worse outcome

• No human studies have compared 100% with titrated levels during CPR

Passive Oxygenation

• Retrospective analysis of adult OHCA

• 1019 patients

• Passive oxygenation compared with BVM

Bobrow BJ, et al. Ann Emerg Med 2009

• Neurologically intact survival to hospital DC

- Passive oxygenation: 39%

- BVM: 25.8%

- Only in witnessed v.fib / v.tach arrests

Bobrow BJ, et al. Ann Emerg Med 2009

Passive Oxygenation

• Allows constant delivery of compressions during early phases of arrest

Passive Oxygenation

• Allows constant delivery of compressions during early phases of arrest

• Not sufficient in advanced stages of arrest

- Chest resistance higher

- Lung compliance significantly decreased

Lower Success Rates

109 seconds!

> 30%

Interrupted Compressions

Advanced Airway

VS

Advanced Airway

• SGA - Limitations

✓ Laryngospasm present in early stages of arrest

✓ High peak pressures needed to overcome spasm

✓ May exceed maximal seal pressure of SGA

✓ May cause significant leak (> 20%)

Advanced Airway

• SGA - Limitations

✓ Ineffective in providing ventilation in patients with low lung compliance, high rigidity

✓ Carotid artery compression?

Advanced Airway

• ETI vs. SGA

- Wang, et al. Resuscitation 2012

- Tanabe, et al. J Emerg Med 2013

- McMullan, et al. Resuscitation 2014

- Benoit, et al. Resuscitation 2015

Confounding by Indication

Death by Hyperventilation!

Ventilation

• Low survival for OHCA may be result of uncontrolled ventilation

Ventilation

• Hyperventilation

✓ Increases intrathoracic pressure

✓ Decreases venous return

✓ Decreases cardiac output

✓ Decrease CPP

✓ Increased ICP

Intra-Arrest A & B✓ Passive oxygenation in early phases

✓ One size does NOT fit all

✓ Best airway / technique

- Patient factors

- Time-point during resuscitation

- Skill of rescuer

Intra-Arrest A & B

• Control ventilations!

Post-Arrest Goals1. Optimize neurologic resuscitation

2. Prevent secondary injury

Post-Arrest Goals

• A comprehensive approach:

✓ Optimize oxygenation & ventilation

✓ Optimize hemodynamics

✓ Targeted temperature management

✓ Emergent PCI

Mechanical Ventilation

• Pulmonary dysfunction common

- Trauma from CPR

- Hydrostatic pulmonary edema

- Non-cardiogenic edema

- Aspiration

• Patients have regional V/Q mismatch

• Post-ROSC VILI

✓ Greater cerebral hemodynamic instability

✓ Increased cerebral inflammation, oxidative stress

✓ Triggers hippocampal apoptosis


Gonzalez-Lopez A, et al. Am J Respir Crit Care Med 2013Polglase GR, et al. PLoS One 2012


• Tidal Volume

✓ Patients at high risk of ARDS

✓ Use lung protective strategy

✓ 6 - 8 ml/kg PBW

Peberdy MA, et al. Circulation 2010

• After ROSC

✓ Cerebral hyperperfusion (up to 30 min)

✓ Subsequent period of significantly reduced CBF

✓ Cerebral vascular responsiveness to CO2 intact


• CO2

- Potent regulator of cerebrovascular tone

- Hypocapnia

✓ Vasoconstriction

✓ Decreases CBF

✓ Increases intrathoracic pressure


• CO2

- Potent regulator of cerebrovascular tone

- Hypercapnia

✓ Vasodilation

✓ Elevates ICP


✓ 69% experienced pathologic values for PaCO2 after OHCA

Roberts, et al. Circulation 2013

• Observational cohort from ANZICS-APD

• 16,542 patients

✓ Hypocapnia group had trend toward higher in-hospital mortality

Schneider AG, et al. Resuscitation 2013

• Respiratory Rate

✓ Target “normocapnia”

✓ PaCO2 40-45 mm Hg

✓ PetCO2 35-40 mm Hg


• Oxygenation

- Optimal level remains unknown

- Common to place on 100% FiO2

- Hypoxemia has lethal effects


• Hyperoxemia

- May also have significant negative effects

- A precursor for reactive oxygen species

- Metabolic dysfunction

- Neurologic degeneration


• Meta-analysis of 14 observational trials

• 49,951 patients

• Examine effects of hyperoxia on outcomes of post-ROSC patients

Wang CH, et al. Resuscitation 2014

✓ Hyperoxia significantly associated with in-hospital mortality

Wang CH, et al. Resuscitation 2014

• Retrospective analysis of CA database

• 184 patients from University of Pittsburgh

• Association between PaO2 over first 24 hours after cardiac arrest

Elmer J, et al. Intensive Care Med 2015

• 36% exposed to severe hyperoxia

• For every hour of exposure to severe hyperoxia, survival to hospital DC decreased

Elmer J, et al. Intensive Care Med 2015

✓ Highest hyperoxemic values associated with treatment in prehospital phase and ED

Nelskyla, et al. Scand J Trauma Resusc Emerg Med 2013

• Oxygenation

✓ Avoid hypoxia and hyperoxia

✓ Adjust FiO2 to achieve SpO2 > 94%

✓ Maintain PaO2 ≈ 100 mm Hg


Intra-Arrest A & B✓ Passive oxygenation in early phases

✓ One size does NOT fit all

✓ Best airway / technique

- Patient factors

- Time-point during resuscitation

- Skill of rescuer

Intra-Arrest A & B

• Control ventilations!

Post-Arrest Breathing

• Tidal Volume

✓ Patients at high risk of ARDS

✓ Use lung protective strategy

✓ 6 - 8 ml/kg PBW

Peberdy MA, et al. Circulation 2010

• Respiratory Rate

✓ Target “normocapnia”

✓ PaCO2 40-45 mm Hg

✓ PetCO2 35-40 mm Hg


• Oxygenation

✓ Avoid hypoxia and hyperoxia

✓ Adjust FiO2 to achieve SpO2 > 94%

✓ Maintain PaO2 ≈ 100 mm Hg


Thank You!

[email protected]

@critcareguys

mailto:[email protected]

Passive Oxygenation

• Chest compressions and recoil generates passive airflow while applying NRB mask

• Vt > dead space → air moves into lungs

• Vt < dead space → turbulent mixing of air can lead to molecular diffusion

• 95 patients

• Boussignac tube vs. intermittent PPV

• % of ROSC / survival to admission same

Saissy JM, et al. Anesthesiology 2000

• 1042 patients

• ETI + MV versus Boussignac tube

• No difference in outcome; less complications

Bertrand C, et al. Intensive Care Med 2006

• Secondary analysis of ROC PRIMED trial

• Non-traumatic OHCA receiving ETI or SGA

• Survival to hospital DC with satisfactory neurologic outcome

Wang HE, et al. Resuscitation 2012

• 10,455 patients

- ETI: 8,487

- SGA: 1,968


• Nationwide, population-based study

• OHCA database in Japan

Tanabe S, et al. J Emerg Med 2013

• 318,141 patients

- ETI: 16,054

- LMA: 34,125

- Esophageal obturator: 88,069


• Secondary analysis of CARES Registry

• Compared outcomes of OHCA patients with ETI, SGA, or no airway

McMullan J, et al. Resuscitation 2014

• 10,691 patients

- ETI: 5,591

- SGA: 3,110

- No airway: 1,929


✓ Approximately 45% of patients experienced hypocapnia or hypercapnia

Falkenbach P, et al. Resuscitation 2009

• Prospective, nationwide, population-based

• OHCA database in Japan

Hasegawa, et al. JAMA 2013


- 367,837 had BVM

- 281,522 had advanced airway

• 41,972 ETI

• 239,550 SGA


• Neurologically favorable survival

- Lower for ETI and SGA


Advanced Airway

• SGA vs. BVM

✓ Similar ABG values

✓ Less regurgitation (3.5% vs. 12%)

Advanced Airway

• SGA vs. ETI

✓ Greater insertion success rates

✓ Less time to insertion

✓ Ventilation parameters

• 10,455 patients

• Survival to hospital DC with satisfactory neurologic outcome

- ETI: 4.7%

- SGA: 3.9%



• Neurologically favorable 1-month survival

- ETI: 1.14%

- LMA: 0.98%

- Esophageal obturator: 1.04%


• 10,691 patients

• Neurologically intact survival

- ETI: 5.4%

- SGA: 5.2%

- No airway: 18.6%


• ETI vs. SGA

- ETI

✓ Higher sustained ROSC

✓ Higher survival to hospital DC

✓ Higher hospital DC with good neurologic outcome


• 10 observational studies

- 34,533 patients with ETI

- 41,116 patients with SGA

Benoit JL, et al. Resuscitation 2015

• ETI patients

- Higher odds of ROSC (OR 1.28)

- Higher odds of survival to hospital admission

- Higher odds of neurologically intact survival

Benoit JL, et al. Resuscitation 2015

• 6,326 patients

✓ Higher in-hospital mortality in hyperoxemic group

Kilgannon JH, et al. JAMA 2010

mike winters - don’t forget a and b!

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