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Investigation into Deep Breathing through Measurement of Ventilatory Parameters and Observation of Breathing Patterns
Published on: September 16, 2019
Evaluation of a method for isocapnic hyperventilation: a clinical pilot trial
K Hallén1, P Jildenstål1, O Stenqvist1
1Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, The Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
Acta Anaesthesiologica Scandinavica
|October 17, 2017
Summary
Isocapnic hyperventilation (IHV) safely shortens emergence time from sevoflurane anesthesia by maintaining normal CO2 levels. This method allows for rapid extubation and recovery of post-operative cognition in ENT surgery patients.
Area of Science:
- Anesthesiology
- Respiratory Physiology
Background:
- Isocapnic hyperventilation (IHV) is a technique to shorten extubation time after inhalation anesthesia.
- It utilizes hyperventilation (HV) while maintaining normal carbon dioxide (CO2) levels.
- This study evaluated a CO2 delivery (DCO2) method during IHV in patients undergoing long-duration sevoflurane anesthesia.
Purpose of the Study:
- To evaluate the utility of a CO2 delivery technique to achieve isocapnia during HV.
- To assess the safety and efficacy of IHV in reducing emergence time from sevoflurane anesthesia.
- To monitor arterial blood gases and post-operative cognitive function.
Main Methods:
- Fifteen adult patients undergoing major ear-nose-throat (ENT) surgery were included.
- Mechanical HV was initiated post-surgery, with simultaneous CO2 delivery based on a nomogram.
- Time to extubation, eye opening, CO2 levels (inspired, expired, arterial), and cognitive function were recorded.
Main Results:
- A CO2 delivery rate of 285 ± 45 ml/min maintained stable isocapnia during HV.
- Extubation time averaged 11.3 ± 1.8 minutes after long-duration sevoflurane anesthesia.
- Arterial CO2 and expired CO2 remained normal, and 85% of patients showed return to baseline cognition within 60 minutes.
Conclusions:
- The CO2 delivery nomogram for IHV was validated in this patient cohort.
- IHV facilitated safe and rapid extubation following long-term sevoflurane anesthesia.
- The technique demonstrated no adverse effects on blood gases or post-operative cognition, potentially decreasing emergence time.
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