Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland.
Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Park Road, Grafton, Auckland, New Zealand.
J Physiol. 2021 Apr;599(8):2323-2340. doi: 10.1113/JP281319. Epub 2021 Mar 10.
Five years after bilateral carotid body resection (bCBR) performed in four patients, the absence of the hypoxic ventilatory response persisted, suggesting no compensatory regrowth. Breathing hypoxic gas mixtures (15% and 12%) results in a lower (by ∼10%) minimal blood oxygen saturation ( ) in bCBR patients compared to heart failure subjects (CHF) with intact peripheral chemoreceptors. After bCBR, patients were characterized by a greater short-term variability in during mild hypoxia in comparison to the CHF group. The ventilatory response to hypercapnia was preserved following bCBR and was sufficient to maintain minimal at levels comparable to controls when combined with hypoxia. Bilateral CBR - a novel treatment modality for sympathetically mediated diseases - should be used with caution due to the risk of significant desaturation even during mild hypoxia equivalent to that experienced during long-haul air travel and high altitude.
Carotid body resection has been proposed as a novel treatment for sympathetically mediated diseases but the safety of bilateral carotid body resection (bCBR) for blood oxygenation during hypoxic stress (long-haul flights or high altitude) remains uncertain. Also unknown is whether central ventilatory drive is sufficient to maintain adequate oxygen saturation when exposed to hypercapnia with concomitant hypoxia. Thus, we administered: 15% O , 12% O , 5% CO /12% O and 5% CO /95% O to a group of four patients with congestive heart failure (65 ± 2.9 years) in whom bCBR was performed 5 years earlier. Ventilatory, haemodynamic and blood oxygen saturation ( ) responses were recorded non-invasively and compared to control groups with intact peripheral chemoreceptors (both healthy and heart failure patients). First, we confirmed that the ventilatory response to hypoxia was eliminated in patients with bCBR, although the increase in cardiac output was preserved. Second, administration of hypoxic gas mixtures resulted in a larger decrease in and greater short-term variability of the leading to a lower minimal for both hypoxia levels in the bCBR group compared to heart failure controls (82.5 ± 1.2% vs. 91.6 ± 2.3% for 15% O and 73.8 ± 4.0% vs. 83.7 ± 3.1% for 12% O ). Third, in bCBR patients the ventilatory response to hypercapnia was present and sufficient to maintain a minimal at a level comparable to heart failure controls following administration of 5% CO /12% O (88.7 ± 4.2% vs. 91.1 ± 2.8%). We conclude that bCBR carries a risk of significant oxygen desaturation even during mild hypoxia. Despite preservation of central chemosensitivity, future studies should focus on unilateral CBR or on pharmacological modulation of peripheral chemosensitivity.
在四名患者中进行双侧颈动脉体切除术（bCBR）五年后，缺氧通气反应仍然持续存在，表明没有代偿性再生。与完整外周化学感受器的心力衰竭患者（CHF）相比，bCBR 患者在呼吸 15%和 12%的低氧混合气体时，最低血氧饱和度（ ）降低了约 10%。与 CHF 组相比，bCBR 后患者在轻度低氧期间的 短期变异性更大。在 bCBR 后，对高碳酸血症的通气反应得以保留，并且当与低氧结合时，足以维持与对照组相当的最低 水平。由于即使在类似于长途飞行和高海拔地区经历的轻度低氧等效条件下，也存在显著的血氧饱和度下降的风险，因此，双侧 CBR-一种用于治疗交感神经介导疾病的新型治疗方法-应谨慎使用。
颈动脉体切除术已被提议作为一种治疗交感神经介导疾病的新方法，但双侧颈动脉体切除术（bCBR）在缺氧应激（长途飞行或高海拔）期间对血氧的安全性仍不确定。此外，当暴露于伴有低氧的高碳酸血症时，中枢通气驱动是否足以维持足够的氧饱和度也尚不清楚。因此，我们给一组患有充血性心力衰竭的患者（65±2.9 岁）施用了 15%的 O ，12%的 O ，5%的 CO /12%的 O 和 5%的 CO /95%的 O ，这四例患者五年前接受了 bCBR。非侵入性地记录了通气、血液动力学和血氧饱和度（ ）反应，并与具有完整外周化学感受器的对照组（健康对照组和心力衰竭对照组）进行了比较。首先，我们证实 bCBR 患者的低氧通气反应被消除，尽管心输出量的增加得到了保留。其次，低氧混合气的给药导致 下降更大， 的短期变异性更大，导致 bCBR 组的两个低氧水平的最小 均低于心力衰竭对照组（15%的 O 时为 82.5±1.2%，12%的 O 时为 91.6±2.3%；12%的 O 时为 73.8±4.0%，12%的 O 时为 83.7±3.1%）。第三，在 bCBR 患者中，高碳酸血症的通气反应存在，并且在给予 5%的 CO /12%的 O 后足以维持与心力衰竭对照组相当的最小 水平（88.7±4.2%，91.1±2.8%）。我们得出结论，即使在轻度低氧时，bCBR 也会导致显著的氧饱和度下降。尽管保留了中枢化学敏感性，但未来的研究应集中在单侧 CBR 或外周化学感受器的药物调节上。
