What question did this study set out to answer?

To determine whether dyspnoea and cardiovascular reflex responses rely on mechanical respiratory muscle contraction or central chemoreceptor drive during complete paralysis in conscious humans.

October 1, 1993The Journal of PhysiologyOpen Access

Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans.

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Authors

SGSimon C. GandeviaUniversity of Delhi KKK. J. KillianMcMaster University DMDavid K. McKenzieUNSW Sydney

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Implication

Experimental physiological study demonstrates preserved dyspnoea during total neuromuscular blockade in conscious humans, suggesting central neural drive produces respiratory discomfort.

Key Points

To determine whether dyspnoea and cardiovascular reflex responses rely on mechanical respiratory muscle contraction or central chemoreceptor drive during complete paralysis in conscious humans.
Total neuromuscular blockade was induced in three conscious subjects (N=3) via intravenous atracurium (> 2.5 mg kg⁻¹ bolus, 5 mg kg⁻¹ h⁻¹ infusion) following nasotracheal intubation and mechanical ventilation.
Complete paralysis of the diaphragm and abductor hallucis was confirmed by the loss of compound muscle action potentials under supramaximal electrical nerve stimulation, with communication temporarily maintained using an isolated arm cuff.
Dyspnoea was evaluated using a 10-point Borg scale across rebreathing, rebreathing with added CO2, and breath holding, alongside assessments of attempted voluntary movements and transcranial electromagnetic stimulation.
Dyspnoea increased progressively with hypercapnia during total paralysis, with mean end-tidal CO2 reaching 46 mmHg during rebreathing, 42 mmHg during breath holding, and 52 mmHg during rebreathing with CO2, showing no significant difference compared to pre-paralysis control trials.
Breath-holding duration and end-tidal CO2 at the break point were unaltered by paralysis, demonstrating that respiratory discomfort persists in the complete absence of respiratory muscle contraction.
Attempted contractions of paralyzed muscles increased heart rate by 7–15 beats min⁻¹ and mean arterial pressure by 20–32 mmHg, while motor cortex transcranial stimulation generated illusory movement sensations.

Cite This Study

Gandevia et al. (1993) studied this question.

synapsesocial.com/papers/69d576a7c23ff40c2825df89 https://doi.org/10.1113/jphysiol.1993.sp019849

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Implication

Experimental physiological study demonstrates preserved dyspnoea during total neuromuscular blockade in conscious humans, suggesting central neural drive produces respiratory discomfort.

Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans.

Discussion

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Implication

Key Points

Cite This Study

Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans.

Discussion

Member takes

Implication

Key Points

Cite This Study

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