One aspect of the present disclosure relates to a system for monitoring a diaphragmatic twitch response. The diaphragmatic twitch response can be used to determine a depth of neuromuscular blockade. The system includes a neural stimulation device to stimulate a phrenic nerve of a subject, which has the effect of stimulating the subject's diaphragm. The system also includes a monitor to detect the diaphragm's response to the stimulation. For example, the monitor can include a nasogastric tube with two distally positioned inflatable balloons. Each of the inflatable balloons is coupled to a sensor to measure a corresponding pressure (e.g., an esophageal pressure and a gastric pressure). The pressure differential between the esophagus above the diaphragm and the stomach below the diaphragm (also referred to as the transdiaphragmatic pressure) can be used as a measure of the diaphragmatic twitch response.
