Modality/response* | Interpretation/management | Comments |
Intubating conditions | ||
TOFC 0 TOFR 0 | Adequate conditions likely | During onset of neuromuscular block, diaphragm and vocal cords become paralyzed prior to the adductor pollicis muscle. Diaphragm and vocal cords also recover prior to adductor pollicis. |
TOFC ≥1 TOFR ≥0 | Adequate conditions unlikely | Profound block is required for optimal intubating conditions. |
Intraoperative conditions | ||
TOFC 0, PTC 1 to 5 | Deep blockade; return of diaphragm movements possible, twitch may return in 5 to 15 minutes, may have twitch response at face with PNS | |
TOFC 1 to 3 | Moderate blockade; sufficient for most procedures | Deeper levels of block may be warranted in specific settings in which any unexpected movement must be avoided (eg, during delicate dissection under the microscope during craniotomy). |
TOFC 4 ± fade | Shallow or minimal block; additional NMBA may be needed | |
Management of recovery and reversal* | ||
TOFC 0, PTC 0 | Complete or profound blockade; wait or administer sugammadex 16 mg/kg IV |
|
TOFC 0, PTC 1 or 2 | Deep blockade; wait or administer sugammadex 4 mg/kg IV | |
TOFC 1 | Moderate blockade; wait or administer sugammadex 4 mg/kg IV | |
TOFC 2 or 3 | Moderate blockade; wait or administer sugammadex 2 mg/kg IV | |
TOFC 4 with fade TOFR <0.4 | Shallow blockade; wait or sugammadex 2 mg/kg IV or neostigmine 20 to 50 mcg/kg IV | |
TOFC 4 without fade TOFR 0.4 to 0.9 | Minimal blockade; wait or sugammadex 2 mg/kg IV or neostigmine 15 to 30 mcg/kg IV | |
TOFR ≥0.9 | Fully reversed; no need to administer reversal prior to extubation |
TOFC: train of four count; TOFR: train of four ratio; NMBA: neuromuscular blocking agent; PTC: post tetanic count; PNS: peripheral nerve stimulator.
* Train of four stimulation consists of four successive supramaximal stimuli using a peripheral nerve stimulator. After administration of a full dose of nondepolarizing NMBA, responses show fade, or progressively decreasing amplitude of the responses; with increasing block the number of responses to a train of four stimuli decreases. When the train of four count is zero, further information on the depth of block can be obtained by applying tetanic stimulation, followed by a series of single twitches for 20 seconds. The post tetanic count (PTC) refers to the number of twitches apparent in this series; increasing PTC correlates with less profound block.Do you want to add Medilib to your home screen?