Supraglottic Airway in Resuscitation: How to Use the i-gel Correctly

Airway management during resuscitation poses challenges even for experienced emergency physicians. Endotracheal intubation was long considered the gold standard – but the evidence has shifted. Supraglottic airways (SGAs), particularly the i-gel, have established themselves as an equivalent, and in some settings even superior, alternative. The i-gel stands out with its cuffless construction made of thermoplastic elastomer, which conforms to the perilaryngeal anatomy, enables rapid insertion without cuff management, and can be safely placed even by less experienced providers. This article covers the correct use of the i-gel during resuscitation – from size selection to insertion technique and placement verification – and contextualizes the evidence compared to endotracheal intubation.

Why the i-gel During Resuscitation?

The AHA guidelines present supraglottic airways and endotracheal intubation as equivalent options during resuscitation by Advanced Life Support providers. This recommendation is based on several large randomized trials that failed to demonstrate a significant survival advantage of intubation over SGAs. At the same time, relevant advantages of supraglottic airways were identified:

• Faster placement: The i-gel can typically be inserted within 5–10 seconds – significantly faster than intubation, which can take 30 seconds or more even for experienced providers.
• Less interruption of chest compressions: Every second without compressions reduces coronary perfusion pressure. Rapid i-gel insertion minimizes this no-flow time.
• High first-pass success rate: Studies report first-pass success rates of over 80–90% for the i-gel, even among providers with limited airway experience.
• No cuff management: Unlike the Classic Laryngeal Mask Airway or the laryngeal tube, there is no need to inflate a cuff. The thermoplastic elastomer of the i-gel conforms to the anatomy through body heat and progressively improves its seal.
• Gastric access channel: The i-gel features an integrated drainage channel through which a gastric tube can be inserted – a relevant advantage in patients at risk of aspiration.

Among available SGAs, the i-gel has emerged as particularly well-suited for resuscitation, as it combines ease of use with a reliable seal and the option for gastric decompression.

Size Selection: The Right Size at a Glance

Selecting the correct size is critical for an adequate seal and avoidance of complications. The i-gel is available in various sizes for adults and children. Size selection is primarily based on body weight:

Adult Sizes

Size	Body Weight	Color Coding
3	30–60 kg	Yellow
4	50–90 kg	Green
5	90+ kg	Orange

Pediatric Sizes

Size	Body Weight	Color Coding
1	2–5 kg	Pink
1.5	5–12 kg	Blue
2	10–25 kg	Orange
2.5	25–35 kg	Purple

Practical Tips for Size Selection

• When weight ranges overlap: When in doubt, choose the larger size, as a size too small more frequently leads to leakage than one that is slightly too large.
• In a resuscitation situation, a set with at least two sizes (typically size 4 and 5 for adults) should always be readily available.
• Clinical estimation: If the weight is unknown, the size can also be estimated based on the patient's body habitus. Size 4 fits the majority of adult patients.

Insertion Technique: Step by Step

Correct insertion of the i-gel follows a standardized procedure. Important: During resuscitation, insertion should ideally occur during a brief pause in compressions or – with sufficient experience – without interrupting chest compressions.

Preparation

1. Select the size based on estimated body weight.
2. Open the packaging and leave the i-gel in the provided storage cradle – this also serves as a "cradle" for stable placement.
3. Apply lubricant: Apply a thin layer of water-based lubricant to the back (convex side) of the i-gel. Avoid the distal tip and the inside of the airway channel to prevent obstruction or aspiration of lubricant.
4. Ensure suction readiness: Suction should be immediately available.

Insertion

1. Head position: Unless cervical spine immobilization is required, bring the head into a neutral to slightly extended position (sniffing position). During resuscitation, this is often difficult – the i-gel also works in a neutral head position.
2. Open the mouth: With the non-dominant hand, pull the mandible forward and downward (chin-lift maneuver) to open the mouth.
3. Hold the i-gel: Grip the i-gel like a pen at the proximal bite block, with the flat side of the i-gel (with the airway channel) facing the patient's chin.
4. Insert: Align the tip of the i-gel toward the hard palate and advance it with a smooth, gliding motion along the palate downward and dorsally. Do not apply excessive pressure.
5. Final position: Advance the i-gel until a definite resistance is felt. The teeth (or alveolar ridge in edentulous patients) should rest on the integrated bite block. The i-gel should not be forced beyond this point.
6. Fixation: Secure the i-gel with tape or a dedicated holder. In a resuscitation situation, manual fixation or a simple strip of tape is initially sufficient.

Common Insertion Errors

• Too little lubricant: Leads to increased insertion resistance and potential mucosal injury.
• Too much force: With correct technique, the i-gel glides in with virtually no resistance. Forceful advancement suggests incorrect direction or a size that is too large.
• Epiglottis downfolding: The epiglottis can fold caudally during advancement. Correct alignment along the hard palate minimizes this risk.
• Wrong size: An i-gel that slides back out after insertion often indicates a size that is too small.

Placement Verification: Is the i-gel Positioned Correctly?

Immediate placement verification after insertion is mandatory. The following parameters must be checked:

Primary Placement Verification

• Capnography: Capnography (end-tidal CO₂, etCO₂) is the gold standard for verifying correct placement. During ongoing resuscitation, an etCO₂ signal is the most reliable indicator of ventilation through the airway. However, absent etCO₂ can also occur with correct placement if cardiac arrest is prolonged and there is no significant pulmonary blood flow.
• Chest excursions: Visible, symmetrical chest rise during ventilation indicates correct placement.
• Ventilation pressures: When mechanical ventilation is connected, ventilation pressures should be within the expected range (typically <20 cmH₂O for sufficient ventilation through an i-gel).
• Auscultation: Bilateral breath sounds, absence of epigastric insufflation sounds.

Secondary Signs

• Gastric insufflation: A distended abdomen during ventilation suggests malposition or inadequate seal. In this case: reposition or consider a size change.
• Leakage: An audible leak during ventilation can be resolved by slight repositioning, deeper advancement, or a size change. In the resuscitation setting, some degree of leakage is tolerable as long as adequate ventilation is ensured.

Continuous Capnography as a Monitoring Tool

Once the i-gel is placed, continuous capnography should run as standard monitoring. It serves not only for placement verification but also provides valuable information during resuscitation:

• etCO₂ < 10 mmHg: Indicates inadequate chest compressions (check quality!) or prolonged cardiac arrest.
• etCO₂ rise > 20 mmHg: May be an early sign of Return of Spontaneous Circulation (ROSC).
• Sudden etCO₂ drop: Consider airway dislocation, airway obstruction, or tension pneumothorax.

Ventilation via the i-gel During CPR

Once a supraglottic airway is correctly placed, the ventilation strategy changes fundamentally:

• Asynchronous ventilation: Chest compressions and ventilations are decoupled. Compressions continue uninterrupted at a rate of 100–120/min, and ventilation is delivered every 6 seconds (corresponding to 10 breaths/min).
• No more 30:2 rhythm: The synchronized cycles of 30 compressions and 2 ventilations are discontinued after successful SGA placement.
• Tidal volume: A tidal volume that produces a visible but not excessive chest rise should be targeted. Hyperventilation must be strictly avoided, as it reduces venous return to the heart and worsens survival rates.
• Gastric tube insertion: A gastric tube (maximum 12 Fr for size 3, 14 Fr for sizes 4 and 5) can be inserted through the gastric drainage channel of the i-gel. This reduces aspiration risk and improves ventilation conditions in the presence of gastric dilation.

Evidence: i-gel Versus Endotracheal Intubation

The discussion around the optimal airway during resuscitation is supported by high-quality evidence:

Key Studies

The AIRWAYS-2 trial (pragmatic cluster-randomized trial, UK, over 9,000 patients) compared the i-gel with endotracheal intubation during prehospital resuscitation. The result: No significant difference in neurological outcome at 30 days. Intubation showed a slightly higher initial placement success rate among experienced paramedics, but the overall clinical net effect was comparable.

The PART trial (USA, over 3,000 patients) compared the laryngeal tube with endotracheal intubation and actually found a survival advantage for the supraglottic airway – a result that further supported the SGA strategy, although the i-gel was not the device studied in this trial.

What the Guidelines Conclude

The AHA guidelines recommend that the choice of airway should depend on the experience and training level of the provider. In practical terms, this means:

• When intubation experience is limited (e.g., fewer than 10 intubations per year): Prefer SGAs.
• When intubation experience is high and insertion can be achieved without prolonged interruption of compressions: Intubation remains a good option.
• In any case: An airway that is placed quickly and safely and enables adequate ventilation is better than a "superior" airway whose placement compromises CPR quality.

Special Situations

In certain clinical scenarios, endotracheal intubation remains the preferred option:

• Massive aspiration risk (e.g., active vomiting, airway hemorrhage)
• Known difficult airway with contraindication for SGA
• Prolonged resuscitation with planned transfer and transport ventilation
• After ROSC: Evaluate whether endotracheal intubation for definitive airway management is appropriate

Troubleshooting: When Things Don't Work

Even the i-gel can present problems. Here are the most common scenarios and their solutions:

Problem	Possible Cause	Solution
No etCO₂ signal	Esophageal placement, dislocation, no pulmonary blood flow	Verify placement, reposition, consider size change
Significant leakage	Size too small, malposition	Use next larger i-gel size, advance deeper
High ventilation resistance	Airway obstruction, bronchospasm	Suction through airway channel, remove i-gel and inspect airway
Visible regurgitation	Aspiration imminent	Suction, insert gastric tube via drainage channel, consider intubation
Insertion not possible	Anatomical variation, trismus	Improve jaw opening, reduce size, consider alternative SGA or intubation

A fundamental principle: If an SGA attempt fails, no more than one additional attempt with the same or an alternative device should be made before switching to a different airway strategy. Prolonged, unsuccessful airway attempts cost lives.

Summary: Key Messages

• The i-gel is an evidence-based airway that is equivalent to endotracheal intubation during resuscitation.
• Size selection is based on body weight – when in doubt, choose the larger size.
• Insertion technique: gliding motion along the hard palate, no forcing.
• Placement verification primarily via capnography, secondarily via chest excursions and auscultation.
• After SGA placement: asynchronous ventilation at 10/min, compressions without interruption.
• Use continuous capnography as a monitoring tool for CPR quality and ROSC detection.

Hands-On Training

Correct insertion and management of supraglottic airways cannot be ensured through theoretical knowledge alone. The motor skills, the feel for the right insertion resistance, and troubleshooting when problems arise require hands-on practice on a simulator. In the ACLS courses offered by Simulation Tirol, you train airway management during resuscitation under realistic conditions – including correct i-gel insertion, placement verification with capnography, and integration into the ACLS algorithm. This way, you gain the confidence you need when it matters most.