Use of trans-nasal humidified rapid insufflation ventilatory exchange in a post-pneumonectomy patient undergoing injection laryngoplasty: a case report

INTRODUCTION

Loss of an entire lung produces profound and permanent alterations in respiratory physiology.¹ Post pneumonectomy patients have reduced functional residual capacity (FRC), diminished total lung capacity, increased pulmonary vascular resistance, mediastinal shift, and compensatory hyperinflation of the remaining lung.² Oxygen reserve during apnea is significantly reduced because FRC serves as the primary oxygen reservoir during periods of hypoventilation or apnea. In addition, the single lung must accommodate total cardiac output, increasing susceptibility to ventilation–perfusion mismatch and hypoxemia.³ Left recurrent laryngeal nerve palsy following thoracic malignancy is not uncommon; however, hoarseness as the dominant presenting symptom after tumor encasement is relatively rare and may precede overt respiratory compromise.⁴ Injection laryngoplasty requires optimal visualization of the glottis and minimal interference from airway devices.⁵ Traditional endotracheal intubation may obstruct the surgical field, while jet ventilation carries a risk of barotrauma in patients with a single lung. We report the successful use of THRIVE in such a high-risk physiological setting.

CASE REPORT

A 40yr old patient with a history of left pneumonectomy (Figure 1) performed for bronchogenic carcinoma presented with progressive hoarseness of voice. The tumor had previously encased the left recurrent laryngeal nerve, resulting in unilateral vocal cord paralysis. The patient reported vocal fatigue but denied dyspnea at rest or stridor. Exercise tolerance was mildly reduced compared with preoperative baseline. On examination, oxygen saturation on room air was 97%. Breath sounds were absent over the left hemithorax, with compensatory expansion of the right chest. Airway assessment was unremarkable. Flexible laryngoscopy confirmed immobility of the left vocal cord in the paramedian position. Preoperative evaluation revealed stable hemodynamics and acceptable baseline arterial blood oxygenation. Pulmonary function tests demonstrated restrictive physiology consistent with prior pneumonectomy. After multidisciplinary discussion, the patient was scheduled for injection laryngoplasty under general anesthesia. Considering the reduced pulmonary reserve and need for an unobstructed laryngeal view, THRIVE was selected as the primary oxygenation technique.

Diagnostic assessment

Unilateral vocal cord paralysis was confirmed using flexible laryngoscopy. The underlying cause was attributed to recurrent laryngeal nerve encasement by tumor during the previous disease course. No evidence of airway obstruction was present. The anticipated anesthetic concern centered on reduced oxygen reserve, rapid desaturation during apnea, and risk of ventilator-induced lung injury to the remaining lung. The patients’ blood work was unremarkable and was taken up for proposed procedure under ASA-II.

Therapeutic intervention

In the operating room, standard monitoring was instituted. A difficult airway cart, microlaryngeal tubes, and rigid bronchoscope were kept available as backup. THRIVE was initiated using a high-flow nasal oxygen delivery system with heated and humidified oxygen (Figure 2).⁶ Pre-oxygenation was commenced at 30 L/min and increased to 60 L/min with a fraction of inspired oxygen of 1.0. Intravenous induction was performed using propofol at 2 mg/kg and fentanyl as opioid at 2 mcg/kg, followed by administration of depolarizing neuromuscular blocking agent succinylcholine at 1 mg/kg. For maintenance of adequate depth propofol at 1 mg/kg/hr and dexmeditomidine bolus of 1mcg/kg over 10 minutes. Once adequate depth of anesthesia was achieved, laryngoscopy was performed without endotracheal intubation (Figure 3). THRIVE was continued at 60 L/min throughout the apneic period. The injection laryngoplasty was completed within approximately 20 minutes. Oxygen saturation remained between 98% and 100% during the procedure. Although end-tidal carbon dioxide could not be measured due to the absence of a closed circuit, the limited duration and stable hemodynamics supported acceptable ventilation-perfusion status. After completion of surgery, assisted mask ventilation was provided until spontaneous respiration resumed. The patient recovered uneventfully and was discharged after observation.

Follow-up and outcomes

Postoperatively, oxygen saturation remained stable on room air. There were no episodes of respiratory distress or desaturation. Voice quality improved significantly on follow-up examination. No delayed pulmonary complications were observed.

DISCUSSION

Post-pneumonectomy physiology fundamentally alters anesthetic planning. Removal of one lung reduces FRC by approximately 30-50%, significantly decreasing oxygen reserve. During apnea, oxygen continues to be absorbed into the bloodstream at a rate of approximately 200-250 mL/min, while carbon dioxide accumulates more slowly because of buffering and reduced alveolar excretion.⁷ In patients with intact lungs, the large FRC delays desaturation. In single-lung physiology, however, desaturation occurs rapidly once alveolar oxygen stores are depleted.⁸ Furthermore, positive pressure ventilation in post-pneumonectomy patients may increase pulmonary vascular resistance and impair right ventricular function. Over distension of the remaining lung risks volutrauma and barotrauma.⁹ The mediastinal shift and altered chest wall compliance further complicate ventilation strategies. THRIVE delivers heated, humidified oxygen at high flow rates, generating several physiological effects. First, apneic oxygenation maintains alveolar oxygen content through mass flow driven by the negative pressure gradient created by continuous oxygen uptake into the pulmonary circulation.¹⁰ Second, high flow rates wash out nasopharyngeal dead space, improving effective oxygen delivery. Third, flow-dependent positive airway pressure of approximately 3-7 cm H₂O may provide mild alveolar recruitment, partially compensating for reduced FRC. Finally, although carbon dioxide elimination during apnea is limited, high flow may facilitate some degree of diffusion-mediated CO₂ clearance. Compared with microlaryngeal tube intubation, THRIVE avoids obstruction of the surgical field and eliminates the need for intermittent removal of the tube.¹¹ In a single-lung patient, it also reduces exposure to positive pressure ventilation, potentially minimizing lung injury. Jet ventilation, while providing a tubeless field, introduces significant risk of barotrauma, air trapping, and pneumothorax-complications that would be catastrophic in a post-pneumonectomy setting.¹² Conventional low-flow apneic oxygenation lacks humidification, provides no meaningful PEEP effect, and may not sustain oxygenation for adequate duration in patients with reduced FRC.¹³ Despite its advantages, THRIVE has limitations. Progressive hypercapnia is inevitable during apnea, with carbon dioxide levels rising approximately 1-3 mmHg per minute. The technique is therefore best suited for short procedures <30 minutes duration.¹⁴ Continuous capnography is not feasible without airway instrumentation. Additionally, THRIVE depends on a patent upper airway and is contraindicated in cases of complete obstruction, in procedures involving airway lasers, high inspired oxygen concentrations increase fire risk. Alternative strategies could have included awake fiberoptic intubation with a small-caliber microlaryngeal tube, maintenance of spontaneous respiration under total intravenous anesthesia, or cautious use of high-frequency jet ventilation.¹⁵ However, each of these approaches carries specific disadvantages in the context of single-lung physiology and shared airway requirements. This case demonstrates that THRIVE can safely extend the apneic window and maintain oxygenation even in patients with markedly reduced pulmonary reserve, provided that procedure duration is limited and contingency plans are in place.

CONCLUSION

This case highlights the feasibility of using THRIVE as a primary oxygenation strategy in a post-pneumonectomy patient undergoing shared airway surgery. Despite reduced pulmonary reserve and an anticipated risk of rapid desaturation, THRIVE enabled effective maintenance of oxygenation while providing a completely unobstructed surgical field and avoiding the potential harms of positive pressure ventilation to the solitary lung. Careful patient selection, thorough preoperative assessment, strict limitation of apneic duration, and readiness with backup airway and ventilation strategies were critical to success. Although progressive hypercapnia and lack of continuous capnographic monitoring remain inherent limitations, this experience supports the role of THRIVE as a valuable alternative to conventional techniques in short-duration airway procedures, particularly in high-risk single-lung physiology where minimizing ventilatory stress is essential.

The patient reported satisfaction with the perioperative experience and significant improvement in voice quality without respiratory complications.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: Not required

REFERENCES

1. 1. Christodoulides N, Fitzmaurice GJ, Bukowska I, O’Rhaillaigh E, Toale C, Griffin M, et al. Post-pneumonectomy syndrome: a systematic review of the current evidence and treatment options. J Cardiothorac Surg. 2023;18:119.
2. 2. Physiologic consequences of pneumonectomy-Batirel-Shanghai Chest. Available at: https://shc.amegroups.org/article/view/6062/html. Accessed on 26 March 2026.
3. 3. Deslauriers J, Ugalde P, Miro S, Ferland S, Bergeron S, Lacasse Y, et al. Adjustments in cardiorespiratory function after pneumonectomy: Results of the pneumonectomy project. J Thorac Cardiovasc Surg. 2011;141(1):7-15.
4. 4. Gullung JL, Halstead LA. Recurrent laryngeal nerve paresis postpneumonectomy contralateral to site of surgery. Ann Thorac Surg. 2012;94(2):628-30.
5. 5. Injection Laryngoplasty for Vocal Fold Paralysis and Glottic Incompetence. Iowa Head and Neck Protocols-Carver College of Medicine. The University of Iowa. Available at: https://iowaprotocols.medicine.uiowa.edu/protocols/injection-laryngoplasty-vocal-fold-paralysis-and-glottic-incompetence. Accessed on 26 March 2026.
6. 6. Hackett S, Jones R, Kapila R. Anaesthesia for pneumonectomy. BJA Educ. 2019;19(9):297-304.
7. 7. Luzzi L, Tenconi S, Voltolini L, Paladini P, Ghiribelli C, Di Bisceglie M, et al. Long-term respiratory functional results after pneumonectomy. Eur J Cardiothorac Surg. 2008;34(1):164-8.
8. 8. Brown LM, Rannels SR, Rannels DE. Implications of post-pneumonectomy compensatory lung growth in pulmonary physiology and disease. Respir Res. 2001;2(6):340-7.
9. 9. Evaluation of Pulmonary Blood Flow, Right Atrium, Right Ventricle, and Pulmonary Artery in Patients After Pneumonectomy. Available at: https://www.mdpi.com/2077-0383/14/19/6793. Accessed on 26 March 2026.
10. 10. Lau J, Loizou P, Riffat F, Stokan M, Palme CE. The use of THRIVE in otolaryngology: our experiences in two Australian tertiary facilities. Aust J Otolaryngol. 2019;2:22.
11. 11. Jagannathan N. Use of THRIVE in children for head and neck procedures: why is it a useful technique? J Head Neck Anesth. 2020;4(1):e23.
12. 12. Jet Ventilation-an overview. ScienceDirect Topics. Available at: https://www.sciencedirect.com/topics/medicine-and-dentistry/jet-ventilation. Accessed on 26 March 2026.
13. 13. Mittimanj K, Jabanathan M, Chandrashekhar S, Tandon S. THRIVE: a different approach in microlaryngeal surgeries. Int J Otorhinolaryngol Head Neck Surg. 2022;8(8):672-6.
14. 14. ENT and Audiology News. The use of THRIVE in laryngology and phonosurgery. Available at: https://www.entandaudiologynews.com/development/spotlight-on-innovation/post/the-use-of-thrive-in-laryngology-and-phonosurgery. Accessed on 26 March 2026.
15. 15. Winerman I, Ezra S, Man A, Segal S. Limitations of jet ventilation through the laryngoscope. Can Anaesth Soc J. 1982;29(2):117-20.