TetraGraph® Level-of-Block Gauge™: Visual Clarity in Real-Time

The TetraGraph Level-of-Block Gauge simplifies data interpretation across all phases of neuromuscular block management, providing clinicians with a clear and actionable display. In this blog, we are reviewing the key elements of this intuitive feature. 

In modern anesthesia care, the ability to monitor neuromuscular block accurately and efficiently is essential. Next-generation TetraGraph introduces a powerful new feature: the Level-of-Block Gauge, a real-time visual display of a patient’s neuromuscular block status. Designed to align with American Society of Anesthesiologists (ASA)-defined block levels, this intuitive gauge helps clinicians make informed decisions with confidence throughout all phases of anesthesia.

The Level-of-Block Gauge eliminates the guesswork often associated with traditional twitch monitors. As the depth of neuromuscular block increases, the gauge’s needle moves clockwise. As recovery begins—either spontaneously or with a reversal agent—the needle moves counter-clockwise, offering a continuous and easy-to-interpret representation of patient status.

The Level-of-Block Gauge is designed to reflect clinically accepted neuromuscular block levels. Each position on the gauge corresponds to a specific range:

Acceptable Recovery – TOFr ≥ 90%

• Indicates full neuromuscular recovery
• TOFr number turns green after 2 consecutive readings greater than 90%, confirming reversal and extubation readiness

Minimal Block – TOFr 40–89%

• Partial recovery; patient is not yet fully reversed

Shallow Block – TOFr < 40%

Moderate Block – TOFc = 0–3

Deep Block – PTC = 1–20 

• PTC value turns pink to clearly show post-tetanic monitoring has begun

Complete Block – PTC = 0

• Complete block; no diaphragm movement

The Level-of-Block Gauge does more than visualize numbers—it can improve clinical outcomes by enhancing decision-making. With instant visual confirmation of depth of block, clinicians can time redosing, reversal, and extubation with precision.

• Visual reinforcement of key clinical thresholds
  o     Green = Go → Safe to extubate
  o     Pink = Post-tetanic → Deep block confirmed
• Aligned with guidelines for quantitative neuromuscular monitoring
• Helps to speeds up intraoperative decisions and handoffs

By translating quantitative EMG data into clear visual cues, the Level-of-Block Gauge empowers clinicians to manage neuromuscular block with greater safety, clarity, and efficiency.

Clarity changes everything, especially when seconds matter.