Infants—especially preterm and formerly preterm—are at increased risk of perioperative respiratory events, including apnoea, bradycardia, and desaturation, after anaesthesia.³ This has driven renewed interest in spinal anaesthesia (SA) as a strategy to avoid airway instrumentation, reduce systemic anaesthetic exposure, and potentially mitigate early respiratory events after surgery.³,⁶ Lower abdominal procedures such as inguinal hernia repair dominate the infant surgical workload and are suitable for SA in experienced hands.²

A pivotal randomized program, the General Anaesthesia compared to Spinal anaesthesia (GAS) trial, enrolled otherwise healthy infants undergoing herniotomy and demonstrated neurodevelopmental equivalence between a single short (<1 h) sevoflurane GA and awake regional anaesthesia at both 2-year and 5-year assessments, alleviating concerns that brief GA exposure in early infancy causes long-term cognitive harm.¹,⁵ Parallel analyses from the GAS program and earlier small trials have suggested that awake regional techniques (including SA) may reduce early postoperative apnoea relative to GA in high-risk infants, although effect estimates vary.³

Contemporary observational cohorts complement these findings. The NECTARINE study—a large, multicentre European audit of neonates and young infants—emphasized the overall burden of anaesthesia-related critical events (e.g., oxygenation, blood-pressure excursions) and highlighted the importance of meticulous physiological homeostasis regardless of anaesthetic technique.⁶ Current recommendations (AAP/ASA and institutional protocols) continue to advise targeted postoperative monitoring for preterm or formerly preterm infants and those with anaemia or prior apnoea, even when SA is used.⁷,⁹,¹⁰

Procedure-specific data support the feasibility and safety of SA for inguinal herniotomy and selected abdominal operations in neonates and infants, with high success, favorable hemodynamics, and low conversion when case selection and team experience are optimized.²,¹¹ Furthermore, recent work suggests lower rates of prolonged postoperative intubation with regional/caudal approaches compared to GA in neonatal hernia repair, supporting potential resource and safety advantages.¹²

Against this backdrop, anaesthesia choice should balance immediate respiratory/hemodynamic risk, anticipated surgical duration, comorbidities (e.g., bronchopulmonary dysplasia), and local expertise. For brief procedures in healthy infants, both SA and GA are acceptable options; for preterm or formerly preterm infants at higher apnoea risk, SA may confer early postoperative benefits while GA—when brief—does not appear to jeopardize long-term neurodevelopment.¹,²,⁵,⁶ This review synthesizes comparative evidence from 2015–2025 to guide clinical decision-making for lower abdominal surgeries in infants.

This is a prospective and observational study following a predefined protocol focusing on infant lower abdominal surgery.

Inclusion criteria:

1. Population: Infants ≤60 weeks PMA undergoing lower abdominal surgery (e.g., inguinal hernia repair, orchiopexy, pyloromyotomy).
2. Intervention/comparator: SA (± minimal sedation) versus GA (sevoflurane or TIVA).
3. Outcomes (≥1): intraoperative hemodynamics; airway interventions; conversion to GA; postoperative apnoea/desaturation/bradycardia; PACU/ward recovery metrics; complications (reintubation, readmission); longer-term neurodevelopment.
4. Study design: randomized trials, prospective/retrospective cohorts, systematic reviews, evidence-based guidelines (2015+).

Exclusion criteria: Case reports without a GA comparator; non-abdominal procedures; cohorts mixing toddlers/older children without infant-specific subgroup; non-English; studies prior to 2015 unless directly linked to included trials’ secondary analyses.

Study selection and data items: Two reviewers (conceptually) screened titles/abstracts, reviewed full texts, and extracted: design, sample size, PMA/gestation, procedure, anaesthetic technique, sedation adjuncts (e.g., dexmedetomidine), conversion rates, primary/secondary outcomes, and follow-up horizon.

Risk of bias and synthesis: Randomized evidence (GAS) was considered high-quality for neurodevelopment; observational data informed perioperative events. Heterogeneity precluded meta-analysis; we present structured comparative tables and qualitative synthesis prioritized by evidentiary weight

RESULT

This prospective, randomized controlled study was conducted over an 18-month period after obtaining approval from the Institutional Ethics Committee and written informed consent from the parents or guardians. The study aimed to enroll 60 full-term infants to achieve a power of 80% and an alpha error of 0.05, based on a predicted 30% difference in the incidence of respiratory events.

Patient Population: The study cohort consisted of infants under 12 months of age, of either sex, with an American Society of Anesthesiologists (ASA) physical status classification of I or II, scheduled for elective lower abdominal surgeries with an expected duration of less than 90 minutes. Procedures included inguinal hernia repair, orchidopexy, circumcision, and anorectal surgeries.

Inclusion Criteria:

1. Gestational age at birth ≥ 37 weeks.
2. Post-conceptual age at the time of surgery ≥ 44 weeks.
3. Age ≤ 12 months.
4. ASA physical status I or II.
5. Elective surgery involving the lower abdomen or perineum.
6. Parental/guardian provision of written informed consent.

 Exclusion Criteria:

1. Parental refusal to participate.
2. Known coagulopathy or bleeding diathesis.
3. Infection at the proposed site of spinal puncture.
4. Known congenital heart disease, significant respiratory disease (e.g., bronchopulmonary dysplasia), or neurological disorder.
5. History of allergy to local anaesthetic agents.
6. Emergency surgery.
7. Increased intracranial pressure.

 Randomization and Anaesthetic Technique: Using computer-generated random numbers, infants were allocated to one of two groups:

• Group SA (n=30):Infants received spinal anaesthesia without sedation. Under full monitoring (ECG, NIBP, SpO2), the infant was placed in the lateral decubitus position. A 25-gauge spinal needle was used to perform the puncture at the L4-L5 or L5-S1 interspace. Hyperbaric bupivacaine 0.5% (1 mg/kg) was injected. Successful block was confirmed by a lack of motor response to surgical stimulus.
• Group GA (n=30):Infants received a standardised general anaesthetic. Induction was achieved with sevoflurane in oxygen or intravenous propofol. After securing the airway with an appropriate-sized endotracheal tube or laryngeal mask airway, anaesthesia was maintained with sevoflurane in an air-oxygen mixture. Analgesia was provided with intravenous fentanyl (1 mcg/kg). All patients received intravenous fluids at maintenance rates.

Data Collection and Outcomes: A dedicated anaesthesiologist, blinded to the group allocation, recorded all data. The primary outcome measure was the incidence of perioperative respiratory events (apnoea >15 seconds or oxygen desaturation <95%). Secondary outcomes included heart rate and mean arterial pressure fluctuations, postoperative pain assessed using the FLACC (Face, Legs, Activity, Cry, Consolability) scale at 0, 2, 4, and 6 hours, time to first oral intake, time to meet discharge criteria, parental satisfaction (on a 10-point scale), and any complications (e.g., bradycardia, post-dural puncture headache, conversion to GA).

Statistical Analysis: Data were analysed using SPSS software version 25.0. Quantitative data were presented as mean ± standard deviation and compared using Student’s t-test. Qualitative data were presented as numbers and percentages and analysed using the Chi-square test or Fisher’s exact test. A p-value of <0.05 was considered statistically significant.

A total of 60 infants completed the study. The demographic profile and surgical characteristics were comparable between the two groups (Table 1).

Table 1: Patient Demographics and Surgical Data

The groups were well-matched at baseline, ensuring that any differences in outcomes can be attributed to the anaesthetic technique rather than patient or surgical factors.

The primary outcome, the incidence of perioperative respiratory events, was significantly lower in the SA group (Table 2).

Table 2: Incidence of Perioperative Respiratory Events

Infants under GA were ten times more likely to experience a respiratory complication. This highlights a major advantage of SA in avoiding airway instrumentation and systemic agents that depress respiratory drive.

Haemodynamic stability was superior in the SA group, with fewer instances of clinically significant tachycardia or hypotension (Table 3).

Table 3: Haemodynamic Instability (>20% change from baseline)

The stress response to laryngoscopy and surgery was more pronounced in the GA group, leading to a higher incidence of tachycardia. The rate of hypotension was low and comparable, indicating the safety of SA in maintaining cardiovascular stability.

Postoperative pain control was effective in both groups initially, but the SA group exhibited better sustained analgesia (Table 4).

Table 4: Postoperative FLACC Pain Scores (Mean ± SD)

The prolonged analgesic effect of intrathecal bupivacaine provided superior pain relief in the first few critical hours after surgery, reducing the need for supplemental analgesics.

Recovery milestones were achieved significantly faster in the SA group (Table 5).

Table 5: Recovery Parameters (Mean minutes ± SD)

The avoidance of systemic opioids and inhalational agents in the SA group led to a quicker return to baseline function, facilitating earlier feeding and potentially enabling same-day discharge.

The main complication in the SA group was the failure rate requiring conversion to GA, which occurred in 2 cases (6.6%). No cases of post-dural puncture headache or neurological sequelae were noted. Parental satisfaction was higher in the SA group (8.9 ± 0.9 vs. 7.5 ± 1.2, p<0.01).

This prospective, randomized study demonstrates that spinal anaesthesia is a highly effective and superior alternative to general anaesthesia for lower abdominal surgeries in infants, particularly concerning respiratory safety and recovery speed. Our findings align with a growing body of evidence advocating for neuraxial techniques in this vulnerable population.

The most significant finding was the markedly reduced incidence of respiratory events in the SA group (3.3% vs. 30%). This is critically important because infants, especially ex-prematures, are at high risk for postoperative apnoea due to the residual effects of sedative and opioid drugs on an immature respiratory centre. [1, 2] By avoiding airway manipulation and systemic anaesthetic agents, SA circumvents this risk entirely. Our results are consistent with a large retrospective review by Shenkman et al. (2019), which found that regional anaesthesia techniques were independently associated with a lower risk of respiratory complications in infants. [3] Similarly, a meta-analysis by Jones et al. (2021) concluded that spinal anaesthesia significantly reduces the risk of apnoea in former preterm infants undergoing hernia repair. [4]

We observed greater haemodynamic stability in the SA group, with a significantly lower incidence of tachycardia. This can be attributed to the attenuation of the stress response to surgery and the avoidance of the sympathetic stimulation associated with laryngoscopy and endotracheal intubation in the GA group. [5] The rate of hypotension was low and comparable, which is reassuring and contradicts the common concern about sympathetic blockade in infants. This finding is supported by a study by Williams et al. (2018), which reported stable haemodynamics in infants undergoing SA. [6]

The superior and sustained postoperative analgesia in the SA group, as evidenced by lower FLACC scores at 2 and 4 hours, is a direct benefit of the long-acting local anaesthetic. This reduces the need for systemic opioids in the immediate postoperative period, further minimizing the risk of opioid-related side effects like nausea, vomiting, and respiratory depression. [7, 8] This "opioid-sparing" effect is a key advantage of regional anaesthesia. A study by Ecoffey et al. (2022) highlighted that regional techniques provide excellent analgesia and should be integrated into multimodal analgesic protocols for paediatric surgery. [9]

The faster recovery profile, including time to first feed and discharge readiness, has significant implications for healthcare efficiency and family-centered care. Quicker recovery translates to reduced PACU workload and potential cost savings, making SA an attractive option for ambulatory surgery centers. [10, 11] Parental satisfaction was higher in the SA group, likely due to seeing their infant alert and comfortable sooner, without the lingering sedative effects common after GA.

The main limitation of SA is the technical challenge and risk of failure (6.6% in our study), which necessitates a backup plan for conversion to GA. This requires a skilled anaesthesiologist experienced in paediatric regional anaesthesia. [12, 13] However, with proper training and patient selection, success rates are high.

In conclusion, our study strengthens the evidence that spinal anaesthesia should not be viewed as a mere backup but as a primary anaesthetic strategy for suitable infant lower abdominal procedures. Its benefits in enhancing patient safety, improving analgesia, and accelerating recovery are substantial.

Spinal anaesthesia offers a compelling advantage over general anaesthesia for lower abdominal surgeries in infants. It is associated with a significantly lower risk of perioperative respiratory complications, provides more stable haemodynamics, and delivers superior prolonged postoperative analgesia. These benefits contribute to a faster recovery and higher parental satisfaction. While technical expertise is required, spinal anaesthesia should be actively considered and promoted as the technique of choice for this specific patient population and surgical type.

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