In an adult who received an appropriate dose of neostigmine with glycopyrrolate for rocuronium or vecuronium‑induced neuromuscular blockade but still has inadequate spontaneous ventilation or a train‑of‑four ratio <0.9, can sugammadex be administered as rescue?

Rescue Sugammadex After Failed Neostigmine Reversal

Yes, sugammadex can and should be administered as rescue therapy when neostigmine fails to adequately reverse rocuronium- or vecuronium-induced neuromuscular blockade, provided quantitative monitoring confirms inadequate reversal (TOF ratio <0.9) and the patient received an aminosteroidal neuromuscular blocker. 1

Critical Prerequisites Before Rescue Sugammadex

Before administering rescue sugammadex, you must confirm:

• Quantitative TOF monitoring demonstrates TOF ratio remains <0.9 despite adequate time for neostigmine to work (typically 10-20 minutes after administration) 1, 2
• The original neuromuscular blocker was rocuronium or vecuronium (aminosteroidal agents), not atracurium or cisatracurium (benzylisoquinoline agents), as sugammadex is completely ineffective against benzylisoquinoline compounds 3
• Adequate neostigmine dosing was given (0.04 mg/kg with anticholinergic) when at least 4 TOF responses were present 1, 2

Rescue Sugammadex Dosing Algorithm

The dose of rescue sugammadex depends on the current depth of residual blockade at the time of rescue administration:

• TOF ratio ≈ 0.5 (very moderate blockade): 0.22 mg/kg achieves TOF ≥0.9 in <5 minutes 1
• 4 TOF responses present (moderate blockade): 1.0-2.0 mg/kg achieves TOF ≥0.9 in <5 minutes 1
• 2 TOF responses present: ≥2.0 mg/kg minimum 1
• Deep blockade (PTC 1-2, no TOF): 4.0 mg/kg achieves reversal in 2-5 minutes 1

Calculate all sugammadex doses based on ideal body weight, not actual body weight. 1

Why Neostigmine May Fail

Understanding why neostigmine failed helps prevent future occurrences:

• Premature administration: Neostigmine given when <4 TOF responses were present is ineffective and should never have been administered 1, 2
• Ceiling effect: Neostigmine has limited efficacy at deeper levels of blockade and cannot reverse profound neuromuscular blockade 2, 4
• Paradoxical weakness: If neostigmine was given when TOF ratio was already >0.9, it may actually impair neuromuscular transmission 2
• Inadequate time: Neostigmine requires 10-20 minutes to achieve full effect; premature assessment may misidentify "failure" 1, 2

Mandatory Post-Rescue Monitoring

After administering rescue sugammadex:

• Continue quantitative TOF monitoring until sustained TOF ratio ≥0.9 is confirmed 1
• Monitor for recurarization: Inadequate sugammadex dosing can lead to reoccurrence of blockade, particularly in patients with renal impairment 1
• Expected recovery time: Sugammadex typically achieves TOF ≥0.9 within 1.5-3 minutes for moderate blockade 5, 6

Special Population Considerations

Severe renal impairment (CrCl <30 mL/min):

• Sugammadex efficacy is decreased but still superior to neostigmine 1, 7
• In patients with severe renal impairment, sugammadex 2 mg/kg achieved TOF ≥0.9 in 3.5 minutes versus 14.8 minutes with neostigmine 7
• Ensure prolonged monitoring in this population due to decreased drug clearance 1

Elderly patients:

• Sugammadex efficacy is modestly decreased (mean recovery time increased by approximately 1.6 minutes) but remains highly effective 5

Critical Pitfalls to Avoid

• Do not use sugammadex if the original blocker was atracurium or cisatracurium – it will be completely ineffective as sugammadex only encapsulates aminosteroidal agents 3
• Do not underdose sugammadex based on the depth of blockade present at the time of rescue administration; this leads to recurarization 1
• Do not discontinue monitoring after apparent reversal; late recurarization can occur with inadequate dosing 1
• Do not assume neostigmine "failed" if insufficient time has elapsed (<10-20 minutes) 1, 2

Clinical Superiority of Sugammadex

When aminosteroidal agents are used, sugammadex demonstrates clear advantages:

• 84% reduction in bradycardia compared to neostigmine (RR 0.16; NNTB = 14) 1
• 60% reduction in residual paralysis signs (RR 0.40; NNTB = 13) 1
• Lower risk of postoperative pulmonary complications compared to neostigmine 1
• More predictable reversal in critically ill patients with unpredictable drug metabolism 1