European Journal of Cardiovascular Medicine

Children have been among the earliest recipients of anesthetic techniques since the initial clinical use of surgical anesthesia (1). Securing and maintaining a patent airway remains central to pediatric anesthesia, and endotracheal intubation continues to be regarded as the gold-standard method because it facilitates controlled positive pressure ventilation, minimizes the risk of gastric insufflation, and provides reliable protection against pulmonary aspiration (2). Despite these advantages, endotracheal intubation is associated with significant limitations, including hemodynamic stimulation during laryngoscopy, increased sympathetic response, risk of failed intubation, and potential trauma to teeth, tongue, soft tissues, and other oropharyngeal structures (3). These concerns are particularly important in pediatric patients, where anatomical differences, limited airway reserve, and higher oxygen consumption predispose to rapid desaturation and increased procedural risk.

The development of supraglottic airway devices was a pivotal advancement in airway management. The first such device, the Laryngeal Mask Airway (LMA), was designed in 1981 by Dr. Archie Brain at the Royal London Hospital as a modification of the Goldman dental mask (4). It offered an effective alternative to intubation by providing an interface that could be placed without laryngoscopy while still permitting adequate ventilation. The paediatric Classic LMA (CLMA), though widely used, forms a relatively less efficient seal around the glottis. This may permit gas leakage into the stomach, predisposing to gastric distension, regurgitation, and potential aspiration in vulnerable patients (5). Because of these limitations, the CLMA is considered less reliable when higher airway pressures are required, such as during controlled ventilation or in situations of reduced pulmonary compliance.

To improve seal integrity and reduce aspiration risks, the ProSeal LMA (PLMA) was introduced by Brain in 2000.⁴ The PLMA incorporates a second lumen the gastric drainage tube placed parallel to the airway tube, allowing venting of gastric contents and reducing gastric insufflation during ventilation (5). This channel also enables passage of a gastric tube and helps detect incorrect positioning of the PLMA by confirming access to the esophagus. The paediatric PLMA shares these functional advantages but differs structurally from the adult version as it lacks the dorsal cuff, and is available in sizes 1, 1.5, 2, and 2.5.

Correct positioning of the PLMA is crucial for an optimal seal and effective ventilation. However, improper placement may occur due to folding of the cuff at its distal tip, leading to air leaks, inadequate ventilation, or the need for multiple insertion attempts. Traditional insertion techniques, such as finger-guided or introducer-tool-assisted placement, have variable success, especially in smaller paediatric airways (6). Alternative insertion techniques have been evaluated to improve success rates. Bougie-directed insertion has demonstrated superior first-attempt success rates and better placement quality in both adult⁷ and paediatric⁸ patients. Suction catheters, which are readily available in operating theatres, can serve as practical substitutes for bougies. Additionally, their placement under direct visualization may reduce post-insertion difficulties associated with introducing a gastric tube through the PLMA drainage channel.

Given these considerations, this study was undertaken to compare introducer-tool-assisted insertion with suction-catheter-guided insertion of the PLMA in paediatric patients. The study evaluates not only ease of insertion and first-attempt success rates but also the quality of airway seal, adequacy of ventilation, hemodynamic responses, and perioperative complications. By exploring whether suction catheter guidance offers measurable advantages over conventional methods, the study aims to identify a technique that can improve airway safety, reduce insertion-related trauma, and enhance overall efficiency in pediatric airway management.

This prospective, randomized, single-blind clinical study was conducted at the Bapuji Child Health Institute attached to JJM Medical College, Davangere, Karnataka. A total of 64 patients were enrolled, with 32 patients in each group. The study was conducted over 12 months from December 2022 to November 2023. Paediatric patients aged 1–10 years, belonging to ASA physical status I and II, scheduled for elective surgical procedures under general anaesthesia were included.

Randomization was performed using computer-generated random allocation tables, and subjects were assigned through sealed envelopes into:

• Group A: Introducer-tool-guided PLMA™ insertion
• Group B: Suction-catheter-guided PLMA™ insertion

Inclusion Criteria

• Weight 5–30 kg
• ASA Physical Status I or II
• Mouth opening > two finger breadths

Exclusion Criteria

• Known or predicted difficult airway, or risk of aspiration
• Significant systemic comorbidities, recent or active respiratory infection
• Head and neck surgeries
• Surgeries requiring prone positioning

Pre-Anaesthetic Preparation

All patients underwent routine pre-anaesthetic evaluation. The procedure was explained to parents or attendants, and written informed consent was obtained.

• Syrup Promethazine 0.3 mg/kg was administered the night before surgery.
• Standard fasting guidelines were followed.
• IV cannulation and maintenance fluids were initiated as per protocol.

Upon arrival in the pre-induction area, patients received:

• Glycopyrrolate 10 mcg/kg IV
• Fentanyl 2 mcg/kg IV

Anaesthesia was induced via inhalation with sevoflurane (up to 8% in oxygen) following 3 minutes of pre-oxygenation until apnoea and loss of jaw response permitted airway manipulation.

Device Selection

Table A: Device Selection Based on Body Weight

*Romsons Suction Catheter (Plain GS2006)

Insertion Technique

Group A: Introducer-Tool-Guided Insertion

PLMA™ was inserted using an introducer tool without laryngoscopy. After placement, a lubricated suction catheter was passed through the gastric drainage tube. Correct positioning was confirmed by aspirating gastric contents or by injecting air while auscultating the epigastrium.

Group B: Suction-Catheter-Guided Insertion

A suction catheter was preloaded through the PLMA™ drainage tube. Under gentle direct laryngoscopy, the distal catheter tip was inserted approximately 5 cm into the esophagus. The PLMA™ was then railroaded into position over the catheter, which was subsequently advanced deeper into the esophagus.

General Procedure

• The neck was kept in moderate extension during insertion.
• The PLMA™ cuff was fully deflated prior to insertion and inflated after placement until effective ventilation was achieved.
• Effective ventilation was confirmed by chest rise, bilateral air entry, and square-wave capnographic tracing.
• A maximum of three attempts was allowed; failure prompted conversion to endotracheal intubation and exclusion.

Cuff pressure was maintained below 60 cmH₂O using a digital cuff pressure monitor (Mallinckrodt Medical). Anaesthesia was maintained using Jackson-Rees modification of Ayre’s T-Piece. Device removal occurred once extubation criteria were met.

Criteria for Failed Insertion

Failure was defined as any of the following:

1. Inability to advance device into pharynx
2. Malposition (ineffective seal or failed suction catheter passage despite placement)
3. Ineffective ventilation (no ETCO₂ trace, ETCO₂ >45 mmHg, or expired tidal volume <8 mL/kg)

Suprasternal notch maneuver was performed when tip folding was suspected.

Outcome Measures

Primary Variables

• Ease of insertion (time and number of attempts)
• First, second, and third attempt success rates
• Efficacy of airway seal
• Episodes of desaturation (SpO₂ <90%) or other intraoperative complications

Secondary Variables

• Heart rate and blood pressure changes before, during, and after insertion
• Blood staining on catheter, laryngoscope, or PLMA™ on removal
• Trauma to mouth, lips, or tongue
• Postoperative airway morbidity assessed at 18–24 hours (sore throat, dysphagia, dysphonia)

Table B: Airway Seal Grading

Time to establish effective airway was measured from device insertion at incisors to confirmation via chest rise and air entry.

Statistical Analysis

Data were coded and analyzed using SPSS Version 21.0. Chi-square test was used for categorical variables including demographic data, number of attempts, airway seal, and complications. Independent t-test was applied to insertion time, haemodynamic variables, and oxygen saturation. A p-value <0.05 was considered statistically significant.

Table 1: Baseline Demographic and Clinical Characteristics of Study Groups

Both groups were comparable with respect to baseline demographic and clinical characteristics. The distribution of sex was similar between the groups, with males constituting 62.5% in Group A and 65.6% in Group B. Most patients belonged to ASA physical status I (98.4% overall), with only one child in Group B classified as ASA II. Cardiovascular and respiratory assessments revealed no abnormalities in any patient across both groups. The mean age and weight of participants were comparable between the groups (Age: 5.59 ± 2.11 years in Group A vs 5.19 ± 1.96 years in Group B; Weight: 16.34 ± 5.18 kg vs 15.59 ± 4.91 kg), with no statistically significant differences (p > 0.05). Overall, the baseline characteristics indicate that both groups were well matched prior to intervention (Table 1).

Figure 1: Comparison of Number of Attempts Between Groups

The Figure 1 compares the number of insertion attempts required in both study groups. Group B (suction-catheter–guided) achieved a 100% first-attempt success rate, with no cases requiring a second attempt. In contrast, Group A (introducer-tool–guided) had a lower first-attempt success rate (90.6%), with 9.4% of patients requiring a second attempt. This suggests that suction-catheter guidance enables smoother insertion and reduces procedural difficulty compared to the conventional method.

Table 2: Comparison of Duration of Insertion of PLMA (DOI-PLMA)

Independent sample t-test- *p < 0.05 statistically significant; p > 0.05 non-significant (NS)

The time required for successful placement of the ProSeal™ LMA differed significantly between the two techniques. The mean duration of insertion was shorter in the introducer-tool group (18.25 ± 5.83 seconds) compared to the suction-catheter guided group (23.47 ± 1.90 seconds). This difference was statistically significant (p < 0.001), indicating that the introducer tool provided faster initial placement. However, the clinical relevance of this time difference may be influenced by other factors such as ease of alignment, reduced malposition, and additional time required for subsequent gastric tube placement in the introducer-tool technique (Table 2).

Figure 2: Comparison of Efficacy of Airway Seal (EAS)

The figure 2 illustrates the distribution of airway seal efficacy between the two study groups. In Group A (introducer-tool guided insertion), 75% of children achieved a good airway seal while 25% demonstrated an average seal. In contrast, Group B (suction-catheter guided insertion) showed a markedly higher proportion of good seals at 96.9%, with only 3.1% categorized as average. This suggests that suction catheter–guided ProSeal™ LMA insertion provides a more effective seal compared to the conventional introducer-tool method, likely due to better alignment of the device with the glottic and oesophageal inlet. Improved sealing may help reduce leak, enhance ventilation efficiency, and minimize risk of gastric insufflation.

Figure 3: Comparison of Reasons for Difficult PLMA™ Insertion

The figure 3 compares reasons for difficulty encountered during ProSeal™ LMA insertion between the two groups. Most insertions in both groups were completed without difficulty (90.6% in Group A vs 96.9% in Group B). In Group A, the main issue encountered was tip folding or malposition (9.4%), whereas no such occurrences were observed in Group B. Conversely, suction catheter kinking was reported only in Group B (3.1%), and did not occur in Group A. These findings indicate that suction catheter–guided insertion reduces malposition-related difficulties, while minor issues such as catheter kinking may occur due to instrumentation rather than device alignment.

Figure 4: Comparison of SpO₂ (%) at Different Stages

The figure 4 compares perioperative oxygen saturation trends between the two groups across key procedural stages. Both groups maintained consistently high SpO₂ values throughout the procedure, indicating adequate oxygenation and effective ventilation with either technique. SpO₂ levels were comparable at induction and during PLMA insertion, with values approaching 100% in both groups. Minor fluctuations were observed thereafter, with Group B showing slightly higher saturation at a few time points (2nd and 3rd minute), whereas Group A demonstrated small transient dips at the 3rd minute and at extubation. These variations were not clinically significant, and no episode of desaturation occurred in either group. Overall, both insertion techniques maintained stable oxygenation profiles without compromising respiratory safety.

Table 3: Complications, Duration of Suction Catheter Insertion, and Reasons for Difficulty

The table 3 shows intraoperative complications, time required for suction catheter insertion, and causes of difficulty encountered during insertion. Most patients in both groups had no complications, though minor events such as suction blood staining and sore throat were slightly more frequent in Group A. The suction catheter insertion time was recorded only in Group A (mean 16.84 ± 4.16 seconds) because catheter placement was pre-loaded during insertion in Group B, making a separate measurement unnecessary. Difficulty in catheter insertion occurred only in Group A, where 9.4% required external assistance and 3.1% encountered insertion failure. Group B had no insertion-related difficulties, likely due to improved alignment and reduced maneuvering requirements with the pre-loaded approach.

Figure 5: Comparison of Heart Rate Between Groups at Different Time Intervals

The figure 5 demonstrates heart rate trends at predefined perioperative stages in both study groups. Baseline heart rates were comparable between Group A and Group B, with a mild rise noted during induction and a peak around the 2nd minute following PLMA insertion in both groups, reflecting the sympathetic response to airway manipulation. Beyond this point, heart rates gradually declined toward pre-induction values. Although Group A showed slightly higher variation at extubation, the overall patterns between groups remained similar throughout the procedure. The differences observed at various stages were statistically insignificant, indicating that neither insertion method produced clinically meaningful hemodynamic alterations.

Figure 6: Comparison of Systolic Blood Pressure (SBP) Between Groups at Different Time Intervals

The figure 6 shows systolic blood pressure trends at various perioperative stages for both groups. Baseline SBP values were comparable, with a gradual rise following induction and peaking at the 2nd minute after PLMA insertion in both groups, reflecting transient sympathetic stimulation. Group A consistently showed slightly higher SBP values than Group B during most intraoperative time points, though the differences remained small and statistically insignificant. Both groups demonstrated a fall in SBP by the 10th minute, returning close to baseline levels. At extubation, a mild rise was seen in both groups, consistent with airway stimulation.

Figure 7: Comparison of Diastolic Blood Pressure (DBP) Between Groups at Different Time Intervals

The figure 7 shows trends in diastolic blood pressure across various perioperative stages in both groups. Baseline DBP values were similar, with a small rise observed after induction and peaking around the 2nd minute following PLMA insertion in both groups. Group B consistently demonstrated slightly higher DBP values than Group A throughout most stages, though the magnitude of difference remained small and statistically insignificant. A gradual decline in DBP was noted toward the 10th minute, consistent with stabilization following airway manipulation, followed by a mild rise at extubation due to sympathetic stimulation. Overall, both techniques maintained stable diastolic pressures without clinically relevant hemodynamic fluctuations, suggesting that neither method adversely affects cardiovascular stability in paediatric patients

This study compared suction-catheter-guided and introducer-tool-guided PLMA™ insertion in 64 paediatric patients aged 1–10 years (ASA I–II), with both groups comparable in baseline demographic characteristics. PLMA™ offers advantages in paediatric airway management due to reduced sympathetic responses, minimal risk of laryngospasm and bronchospasm, and the presence of a drain tube that minimises gastric insufflation, reduces aspiration risk, and permits easy gastric tube placement. These findings are consistent with Lopez Gill M et al. (7), who reported higher oropharyngeal leak pressures and lower rates of gastric insufflation with PLMA™ compared to CLMA™ in children, despite similar ease of insertion.

Multiple insertion techniques for PLMA™ have been described, including digital, introducer-tool, rotational, GEB-guided, fibreoptic-guided, and suction-catheter-guided approaches. Adult studies suggest that SC guidance improves first-attempt success and airway seal efficiency (8). However, paediatric evidence remains limited. The SC provides adequate rigidity to guide the distal cuff accurately into the oesophagus, unlike flexible paediatric orogastric tubes that tend to kink, making the technique particularly useful in smaller airways.

In the present study, first-attempt success was higher with SC guidance (100%) compared to the introducer tool (90.6%), while overall success after two attempts was 100% in both groups. Similar trends were observed in studies by Brimacombe J et al (9) who reported 100% success with GEB compared to 84–88% with introducer-tool or digital techniques, and Garcia Aguado et al.¹³, who found SC guidance more successful. Teoh CY et al (10) found comparable success between IT and GEB in children and recommended GEB as a backup technique when IT fails.

The SC-guided group required fewer insertion attempts, whereas repeated attempts in the IT group were mainly associated with distal cuff folding a finding consistent with earlier reports identifying impaction at the oropharynx and incorrect cuff direction as common causes of failed placement. Although SC guidance required a slightly longer insertion time (23.47 ± 1.90 sec vs. 18.25 ± 5.83 sec), the difference was clinically insignificant and prevented later difficulty in gastric tube placement. Comparable observations were reported by Garcia Aguado et al (11).

Airway seal was superior in the SC group (96.9% good seal) compared to the IT group (75%), likely due to improved alignment of the cuff with the glottis and oesophageal opening. Previous studies reported higher leak pressures with guided techniques, such as 30.63 ± 4.71 mmHg with GEB versus 23.13 ± 3.69 mmHg with digital insertion (12). In this study, tip folding detected by the suprasternal notch test occurred in 9.4% of IT cases.

Both groups exhibited stable haemodynamics, with no significant desaturation or laryngospasm during insertion. Slightly higher sympathetic responses in the IT group may be attributed to direct stimulation from the rigid introducer tool. These findings correlate with observations by Lopez Gill M et al (7) and Brimacombe J et al (9).

Gastric tube insertion after PLMA™ placement in the IT group required additional time and manoeuvres such as neck flexion or extension, likely due to poor alignment of the drain tube with the oesophagus. Earlier studies have shown lubrication failure to be a major cause of insertion difficulty (13). In contrast, the SC-guided technique avoided these issues by pre-positioning the catheter before airway placement.

Trauma was minimal in both groups, though blood staining occurred only in the IT group. Postoperative sore throat was also slightly higher among IT-guided patients (6.3% vs. 3.1%). These findings align with Brimacombe et al (9) and Garcia Aguado et al (11), who reported increased trauma in techniques requiring greater manipulation or repeated attempts.

Beyond insertion success, SC guidance offers practical benefits including reduced risk of distal cuff folding, passive protection against regurgitation, ease of repositioning, and the advantage of routine laryngoscopy allowing identification of unexpected airway pathology. Alternative guided methods include gastric-tube-assisted insertion and fibreoptic-guided techniques (14), though these may be limited by cost, technical complexity, or catheter flexibility. A hybrid device combining rigidity of SC with guidance properties of GEB has been proposed for future development.

Suction-catheter-guided PLMA™ insertion demonstrated clear advantages over the introducer-tool technique in paediatric patients. It achieved a higher first-attempt success rate, required fewer attempts overall, ensured a more effective airway seal, and resulted in fewer insertion-related difficulties and reduced trauma. Although insertion time was marginally longer, the delay was clinically insignificant and allowed easier subsequent gastric tube placement. Haemodynamic responses and postoperative outcomes were comparable in both techniques.

SC-guided insertion can therefore be recommended as a reliable method for routine PLMA™ placement and may serve as an effective alternative technique when conventional insertion methods fail, particularly when proper anatomical alignment and high airway seal are required.

A limitation of this study is the lack of blinding during intraoperative assessment, which may introduce observer bias. Additionally, although laryngoscopy was gentle, it may still induce mild sympathetic responses in some patients, though this was not clinically significant.

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