# General Anesthesia Using Laryngeal Mask Airway Ventilation With Low-Dose Neuromuscular Blockade Is Safe and Effective for Patients Undergoing Hip Arthroscopy

## TL;DR

Using a laryngeal mask airway with low-dose muscle relaxants is a safe and effective method for general anesthesia during hip arthroscopy.

## Contribution

Demonstrates the safety and efficacy of LMA ventilation with low-dose neuromuscular blockade for hip arthroscopy without endotracheal intubation.

## Key findings

- No patients experienced pulmonary aspiration or anesthesia complications.
- Only 1.8% of cases required conversion to endotracheal intubation due to LMA issues.
- ASA classification was not associated with the need for conversion to ETT.

## Abstract

To investigate safety and efficacy of a general anesthesia protocol using laryngeal mask airway (LMA) ventilation without endotracheal intubation (ETT) in the setting of a low dosage of neuromuscular blockade (NMBA) for patients undergoing hip arthroscopy.

Patients who underwent hip arthroscopy for femoroacetabular impingement syndrome at a single institution from 2014 to 2024 were retrospectively analyzed. Those who underwent hip arthroscopy for non-femoroacetabular impingement syndrome indications and those with a concomitant periacetabular osteotomy were excluded. General anesthesia was administered with propofol and sevoflurane, with LMA ventilation. A low-dose (10-50 mg) NMBA agent (rocuronium) was given before hip distraction. The primary outcome of interest was pulmonary aspiration. Secondary outcomes of interest included conversion to ETT and operating room time.

This study included 1,169 cases (49.8% female) with mean age 37.8 years (± 11.0) and body mass index 24.4 (± 3.9). In total, 64.0% were American Society of Anesthesiologists (ASA) class I, 34.8% class II, and 1.2% class III. In 24 cases, patients underwent ETT without attempting LMA as a result of preoperative aspiration risk factors. Of the 1,145 cases that underwent LMA with NMBA, mean dose of rocuronium given was 20.4 mg, and no patients experienced pulmonary aspiration or anesthesia complications. Twenty-one cases (1.8%) required conversion to ETT as the result of poor LMA fit or ventilation leakage. ASA class was not associated with LMA-to-ETT conversion (P = .77). Mean airway manipulation time was 6.0 minutes (± 6.4), mean procedure duration was 100.3 minutes (± 48.7), and mean procedure end to airway removal time- 5.0 minutes (± 5.0). No surgical complications related to hip distraction or traction force occurred.

Administration of general anesthesia using LMA ventilation with a low dosage of neuromuscular blockade is safe and effective for patients undergoing hip arthroscopy. The rate of conversion to endotracheal intubation was low and showed no association with ASA classification.

Level IV, retrospective therapeutic case series.