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♦️ Introduction
Intraoperative cardiac arrest (POCA) is uncommon but carries mortality rates exceeding 50%, with Japanese Society of Anesthesiologists data reporting death rates of 53.3–70.9%.
A meaningful minority of events—approximately 16%—occur in non-supine positions, particularly during spine and neurosurgical procedures where rapid repositioning is constrained by surgical access and patient fixation.
Current international protocols emphasize one critical principle: begin chest compressions without waiting to turn the patient supine, as any delay worsens outcomes.
In prone patients, effective compressions can be delivered over the spine at the level of the inferior scapular angles, and defibrillation remains feasible with adapted pad placements.
The quality of resuscitation should be guided by invasive arterial pressure and capnography; EtCO₂ ≥ 20 mmHg and diastolic arterial pressure (DAP) ≥ 40 mmHg serve as pragmatic intraoperative targets drawn from perioperative-specific guidance (AHA/ILCOR 2025, ESAIC 2024, Resuscitation Council UK 2023–2025).
Timely conversion to supine can be considered if non-supine CPR remains ineffective after initial assessment. This article synthesizes international guidance and perioperative evidence into an OR-ready framework, highlighting exam-relevant benchmarks and practical strategies for multidisciplinary teams.
♦️ Understanding the Physiology—Why Position Matters
Prone positioning fundamentally alters venous return and right-ventricular (RV) loading dynamics. Abdominal and thoracic pressure can impede inferior vena cava (IVC) return, reducing preload, while chest wall and mediastinal compression increase RV afterload—effects amplified by positive-pressure ventilation.
The net result is diminished cardiac output reserve and heightened vulnerability to decompensation during induction, positioning, hemorrhage, or embolic events. Spine and neurosurgical settings introduce additional challenges: fixed head clamps limit anterior access, and surgical field constraints complicate traditional resuscitation logistics.
🔷 High-Risk Patient Populations
Certain patient cohorts face substantially elevated risks when positioned prone:
🔸 Cardiovascular vulnerability
- Right-ventricular dysfunction or pulmonary hypertension (mean pulmonary artery pressure ≥ 25 mmHg): susceptible to further RV afterload increases and hypotension.
- Preload-dependent valve disease: severe aortic stenosis (valve area < 1.0 cm²), hypertrophic cardiomyopathy.
- Hypovolemia or significant bleeding risk.
🔸 Procedure-related factors
- Rigid head fixation (e.g., Mayfield clamp) used in cervical spine or neurosurgical cases: impedes rapid repositioning and increases the risk of scalp or cervical injury during emergency maneuvers.
- Prolonged prone procedures (≥ 4 hours): cumulative circulatory strain, progressive venous congestion, and increased bleeding risk over time.
🔸 Preparation for high-risk cases
- Secure invasive monitoring (arterial line for real-time CPR quality assessment; consider central venous access).
- Pre-position defibrillation pads (postero-lateral or bi-axillary) before prone positioning.
- Prepare vasoactive infusions (norepinephrine, phenylephrine) and ensure blood products are immediately available.
- Conduct a team briefing that includes emergency repositioning roles and choreography.
♦️ Initial Response—The Golden Rule of Non-Supine CPR
The first rule is simple: initiate chest compressions in whatever position the patient is currently in—supine repositioning can be assessed later based on CPR effectiveness.
Neurosurgical and perioperative guidance from multiple international bodies (Resuscitation Council UK 2023–2025, AHA/ILCOR 2025, ESAIC 2024) explicitly states that for arrests occurring in supine or prone positions, compressions and/or defibrillation should begin without any initial change of position. For the lateral position, plan for early conversion to supine, but only after CPR has begun and if non-supine compressions prove ineffective or impractical.
Monitor CPR effectiveness continuously using EtCO₂ and arterial pressure waveforms; these physiologic endpoints guide whether to persist in the current position or execute a coordinated turn to supine.
♦️ Prone Position CPR—Technique and Best Practices
🔷 Compression Technique
🔸 Hand placement:
Position your hands over the spine at the level of the inferior scapular angles, approximately corresponding to T7–T9. Systematic reviews consistently identify this landmark as the optimal compression site, typically 0–2 vertebral segments below the inferior scapulae.
🔸 Depth & rate:
Apply standard adult CPR parameters—depth approximately 5–6 cm, rate 100–120 compressions/min, allowing full chest recoil between compressions—while titrating technique to meet physiologic endpoints (see below).
🔸 Counter-pressure adjunct:
Place a firm support (e.g., sandbag or intravenous fluid bag) beneath the sternum/upper thorax to create an anteroposterior “backboard” effect. This counter-pressure produces a “push-back” force, allowing downward compressions to be transmitted more efficiently to the heart, similar to how a hard surface beneath a supine patient improves compression quality.
Evidence from operating room and intensive care case series, as well as recent systematic reviews (2024), supports this pragmatic adjunct for enhancing perfusion surrogates.
🔸 Managing the surgical field:
When a midline incision or spinal hardware precludes direct midline pressure, apply bilateral paraspinal compressions that deliver equivalent force while protecting the wound. Continue to assess effectiveness using physiologic targets rather than anatomic assumptions.
🔸 Defibrillation:
If a shockable rhythm is identified, pad placement options include postero-lateral (left mid-axillary line and right infrascapular area) or bi-axillary positions. Pre-positioning pads before turning high-risk patients prone saves critical seconds and is endorsed by recent guidelines (AHA/ILCOR 2025, ESAIC 2024).
🔸 Evidence from case experience:
Multiple case series and reviews document successful return of spontaneous circulation (ROSC) with prone CPR. Some physiologic and simulation data suggest that prone compressions, when executed correctly with counter-pressure, may generate equal or higher mean arterial pressures compared with supine CPR (systematic review 2024).
♦️ Lateral Position CPR—Special Considerations
When immediate conversion to supine is not feasible, begin two-person “squeeze” compressions: one rescuer compresses the sternum from the upper side, while a second rescuer provides firm counter-pressure to the back over the spine.
Evidence for lateral-position CPR remains limited, and most guidance emphasizes that it should be viewed as a temporary measure until supine positioning can be safely achieved. Therefore, plan and execute an early, coordinated turn to supine while minimizing interruptions.
For defibrillation in the lateral position, use antero-posterior pad placement (precordium and inferior to the scapula) when lateral anatomy or surgical drapes limit standard configurations. This approach is supported by recent systematic reviews (2024) highlighting the effectiveness of the two-person technique when used as a bridge to definitive repositioning.
♦️ Monitoring CPR Quality in Non-Supine Positions
Continuous physiologic feedback is essential to assess and optimize compression effectiveness in non-supine positions.
🔷 Primary Targets
🔸 End-tidal CO₂ (EtCO₂):
- Target: ≥ 20 mmHg suggests adequate forward flow; abrupt rises may herald ROSC.
- Requires a secure airway with minimal circuit leak.
- Supported by AHA/ILCOR 2025 guidelines and perioperative-specific protocols (JSA 2021).
🔸 Diastolic arterial pressure (DAP):
- Target: ≥ 40 mmHg is recommended in intraoperative resuscitation guidance as a perioperative-specific goal.
- Note: General ACLS literature cites ≥ 25 mmHg as a minimum threshold; the higher target of 40 mmHg reflects the availability of invasive monitoring in the OR and the need for robust coronary perfusion pressure during surgery.
- Use the arterial line to titrate both compression quality and vasoactive therapy in real time.
🔸 Central venous oxygen saturation (ScvO₂):
- Target: ≥ 30% when central venous access is available.
- Provides additional confirmation of systemic oxygen delivery during resuscitation.
🔷 Adjusting Technique Based on Feedback
If targets are not being met:
- Reposition hands to ensure accurate placement at the inferior scapular angle level.
- Add or adjust counter-pressure beneath the sternum/thorax.
- Rotate compressors every ~2 minutes to prevent fatigue and maintain quality.
- Verify rate using a metronome or monitor auditory cues.
- Optimize vasoactive support (epinephrine, vasopressin per ACLS protocols).
♦️ When to Turn Supine—A Decision Algorithm
Use the following stepwise approach to determine the timing and necessity of repositioning:
- Start CPR immediately in the current position without delay.
- Continuously monitor EtCO₂ and DAP to assess compression effectiveness.
- At approximately 2 minutes—aligned with standard CPR cycle timing for reassessment and compressor rotation—evaluate whether physiologic targets are being met:
- If EtCO₂ ≥ 20 mmHg and DAP ≥ 40 mmHg: continue CPR in the current position.
- If targets are not met: prepare for a coordinated turn to supine, keeping interruption time as brief as possible (aim for interruptions comparable to a rhythm check, ideally under 10 seconds when feasible).
- Before turning: clear the surgical field—remove instruments, pack the wound to control bleeding, and release head fixation from the table if a Mayfield or similar clamp is in use.
- Execute the turn with assigned roles and clear communication (“On my count: 3-2-1-turn”).
- Resume CPR immediately in the supine position and reassess targets.
Surgical Field Management During CPR
Effective resuscitation in non-supine positions requires seamless collaboration between anesthesia and surgical teams.
🔷 Surgical responsibilitie
- Clear the field promptly: remove all instruments and retractors from the surgical site.
- Protect and pack the wound: use sterile gauze or laparotomy pads to achieve hemostasis and shield exposed tissues.
- Release head fixation: if using a Mayfield or pin-based head clamp, release the clamp from the table before attempting repositioning or defibrillation. Leaving the clamp attached significantly increases the risk of scalp lacerations or cervical spine injury, as the fixed head cannot move in coordination with the body during a turn.
🔷 Anesthesia responsibilities
- Maintain airway integrity and ensure endotracheal tube position during repositioning.
- Protect vascular access and monitoring lines.
- Administer ACLS medications and manage vasoactive infusions.
Parallel management of reversible causes
Treat underlying etiologies (hemorrhage, embolism, local anesthetic systemic toxicity, equipment or ventilation failure) concurrently with CPR. In hemorrhagic arrests, consider damage-control strategies, including aortic cross-clamping, if expertise and access permit.
♦️ Outcomes and Prognosis
Perioperative cardiac arrest carries substantial mortality; however, timely and effective non-supine CPR—guided by physiologic titration and early cause control—can yield favorable outcomes. Large retrospective series confirm that POCA mortality varies with underlying etiology and the rapidity of intervention. Case compilations document successful ROSC and acceptable neurologic recovery with prone CPR when compressions begin without delay and defibrillation pads are appropriately positioned. Notably, Shang et al. (2022) reported that all three patients (N = 3) who experienced cardiac arrest in the prone position survived to discharge (100% survival), though sample sizes remain limited. Some observational data suggest that prone compressions with counter-pressure may generate higher mean arterial pressures than supine CPR, although more rigorous comparative studies are needed.
The overarching message is clear: immediate initiation of CPR in the current position + objective quality monitoring + timely repositioning when indicated forms the foundation of optimal perioperative resuscitation.
♦️ Preparation and Prevention Strategies
🔹 Pre-induction risk stratification:
Identify patients at elevated risk (RV dysfunction, pulmonary hypertension, preload-dependent lesions, prolonged prone procedures) during the anesthetic plan discussion.
🔹 Monitoring strategy:
- Secure an arterial line before positioning to enable real-time CPR quality assessment.
- Consider central venous access in high-risk cases.
🔹 Defibrillation preparedness:
- Pre-position defibrillation pads (postero-lateral or bi-axillary) on high-risk patients before turning prone—this practice is explicitly endorsed by ESAIC 2024 and AHA/ILCOR 2025 guidelines.
🔹 Pharmacologic readiness:
- Prime vasopressor/inotrope infusions (norepinephrine, epinephrine, phenylephrine) so goal-directed resuscitation can begin without delay.
🔹 Team briefing and simulation:
- Assign specific roles for emergency repositioning: who releases the head clamp, who protects the airway and lines, who leads the coordinated turn.
- Rehearse the turn choreography in simulation; practice reduces interruption time and builds team confidence. Recent guidelines (AHA/ILCOR 2025, ESAIC 2024) emphasize that multidisciplinary simulation training is crucial for achieving the goal of interruptions under 10 seconds during repositioning.
📖 Frequently Asked Questions 🤔
Q1. If cardiac arrest occurs while the patient is in the prone position, what should I do first?
A: Initiate chest compressions immediately in the prone position without waiting for repositioning. Place your hands over the spine at the level of the inferior scapular angles; apply counter-pressure beneath the chest and titrate compressions to EtCO₂ and DAP targets. Do not delay CPR for a turn.
Q2. How can I assess whether my chest compressions are effective during prone CPR?
A: Monitor EtCO₂ (goal ≥ 20 mmHg) and diastolic arterial pressure (goal ≥ 40 mmHg) continuously. If targets are not met, adjust hand position to the scapular landmark, optimize counter-pressure, rotate the compressor, and verify rate. These physiologic endpoints provide real-time feedback on perfusion adequacy.
Q3. When should we turn the patient supine?
A: Reassess at approximately 2 minutes, which aligns with standard CPR cycles for compressor rotation and intervention evaluation. If EtCO₂ or DAP targets are not being met despite optimization, perform a coordinated, low-interruption turn to supine after clearing and protecting the surgical field and releasing head fixation. The goal is to keep interruptions as brief as a rhythm check—ideally under 10 seconds when feasible.
Q4. Where should defibrillation pads be placed in prone or lateral positions?
A: In the prone position, use postero-lateral (left axillary line and right infrascapular) or bi-axillary placements. In the lateral position, use an antero-posterior configuration (precordium and posterior thorax). Pre-positioning pads before turning high-risk patients prone is strongly recommended by current guidelines (AHA/ILCOR 2025, ESAIC 2024).
Q5. Is prone CPR really effective?
A: Yes. Multiple case series and systematic reviews (2024) demonstrate feasible ROSC and, in some studies, higher perfusion pressures during prone CPR compared with supine when proper technique (including counter-pressure) is employed. While large randomized trials are lacking, current evidence and international guidance support prone CPR as a viable strategy when supine positioning cannot be immediately achieved.
Summary
For intraoperative arrests in non-supine positions, the interval between arrest recognition and the first compression is the most critical determinant of outcome. Modern perioperative guidance from AHA/ILCOR 2025, ESAIC 2024, and Resuscitation Council UK 2023–2025 converges on a unified message: begin CPR in the patient’s current position without waiting for repositioning—especially in prone neurosurgical or spine cases where access and fixation complicate rapid turns.
In the prone position, deliver compressions over the spine at the inferior scapular angle level, employ counter-pressure to enhance force transmission, and adapt defibrillation pad placement accordingly (postero-lateral or bi-axillary). Real-time feedback from EtCO₂ and invasive arterial pressure allows the team to titrate compression quality and vasoactive support objectively. A practical 2-minute checkpoint—aligned with standard CPR cycle timing—helps the team decide whether to continue in the current position or convert to supine with minimal interruption, after packing the wound and releasing head fixation if present.
Teams should anticipate these scenarios: conduct a pre-procedure briefing that includes emergency repositioning roles, pre-position defibrillation pads in high-risk cases, secure an arterial line to enable goal-directed CPR, and rehearse the turn choreography in simulation. These preparatory steps align exam priorities (key numbers: EtCO₂ 20 mmHg, DAP 40 mmHg, 2-minute reassessment) with patient-centered, physiology-guided resuscitation that optimizes both survival and neurologic outcomes.
🎯 Take-Home Messages
- Don’t delay: Begin CPR immediately in the current position; waiting to reposition worsens outcomes.
- Prone technique: Compress over the spine at the inferior scapular angles (T7–T9); add counter-pressure beneath the chest.
- Monitor and titrate: Target EtCO₂ ≥ 20 mmHg and DAP ≥ 40 mmHg (perioperative goal; general ACLS minimum ≥ 25 mmHg).
- Reassess at ~2 minutes: If targets aren’t met, perform a coordinated, low-interruption turn to supine after field protection and clamp release.
- Defibrillation is feasible: Use postero-lateral or bi-axillary pads in prone; antero-posterior in lateral; pre-position pads for high-risk cases.
- Prepare high-risk patients: Arterial line, vasoactive setup, pre-positioned pads, team briefing, and simulation practice.
📚 References & Further reading
- Shang H, et al. A retrospective study of mortality for perioperative cardiac arrest. Sci Rep. 2022;12:13566. doi:10.1038/s41598-022-17587-0. Available from: https://www.nature.com/articles/s41598-022-17587-0 [Open Access]
- 日本麻酔科学会 安全委員会 術中の心肺蘇生ガイドライン作成WG. 術中心停止に対するプラクティカルガイド. 2021.
- Anesthesia, Pain & Intensive Care. CPR in prone position during neurosurgery. 2019;23(2):209-11. Available from: https://www.apicareonline.com/index.php/APIC/article/view/618 [Open Access]
- Ramachandran SK, et al. Cardiac arrest following prone positioning. PMC. 2024. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11123478/ [Open Access]
- Hinkelbein J, et al. Cardiac arrest in the perioperative period. J Anesth. 2023;37(7):1234-1246. doi:10.1097/ALN.0000000000004004. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10340764/ [Open Access]
- Resuscitation Council UK. Management of cardiac arrest during neurosurgery in adults. 2014. Available from: https://www.resus.org.uk/library/additional-guidance/guidance-management-cardiac-arrest-during-neurosurgery-adults [Open Access]
- Perioperative Quality Initiative (POQI). Perioperative arterial pressure management consensus statement. Perioper Med (Lond). 2023;12:21. doi:10.1136/perioperativemed-2023-003234. Available from: https://www.sciencedirect.com/science/article/pii/S2058046023001175 [Paywalled]
- Hiraoka E, et al. JCS 2022 Guideline on Perioperative Cardiovascular Evaluation and Management. Circ J. 2023;87(10):1539-1594. doi:10.1253/circj.CJ-22-0177. Available from: https://www.jstage.jst.go.jp/article/circj/87/10/87_CJ-22-0177/_article [Open Access]
- AHA 2025 ハイライト: CPR および ECC のガイドライン [日本語版]. American Heart Association; 2025.
- American Heart Association/International Liaison Committee on Resuscitation (AHA/ILCOR). 2025 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025.
- Dalmedico MM, et al. Cardiopulmonary resuscitation in the prone position: A systematic review. Resuscitation Plus. 2024;18:100612.
- Working Group of the Resuscitation Council (UK). Management of cardiac arrest during neurosurgery in adults. Resuscitation Council UK Guidelines. 2023-2025 (Updated).
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This article provides an educational commentary based on the above publications and clinical guidelines.
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This article is an educational summary based on the above publications and clinical guidelines. It is not a substitute for medical advice or treatment. Clinical practice should be based on the most current guidelines, individual patient circumstances, and the judgment of the treating physician. This resource has not been endorsed by any organization whose guidelines are cited and reflects the author’s interpretation. For country-specific implementation, consult local resuscitation councils and national society guidelines. Always refer to the original publications, institutional protocols, and clinical judgment for all clinical decisions. The author assumes no liability for clinical decisions made based on this summary.
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