Nephrology Division, New York University Langone Health and Nephrology Section, NY Harbor VA Healthcare System.
Pulmonary, Critical Care and Sleep Medicine Division, University of Washington, and VA Puget Sound Healthcare System, Seattle, Washington, USA.
Curr Opin Nephrol Hypertens. 2021 Mar 1;30(2):223-230. doi: 10.1097/MNH.0000000000000687.
Respiratory acidosis is commonly present in patients with respiratory failure. The usual treatment of hypercapnia is to increase ventilation. During the recent surge of COVID-19, respiratory acidosis unresponsive to increased mechanical ventilatory support was common. Increasing mechanical ventilation comes at the expense of barotrauma and hemodynamic compromise from increasing positive end-expiratory pressures or minute ventilation. Treating acute respiratory acidemia with sodium bicarbonate remains controversial.
There are no randomized controlled trials of administration of sodium bicarbonate for respiratory acidemia. A recent review concluded that alkali therapy for mixed respiratory and metabolic acidosis might be useful but was based on the conflicting and not conclusive literature regarding metabolic acidosis. This strategy should not be extrapolated to treatment of respiratory acidemia. Low tidal volume ventilation in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) has beneficial effects associated with permissive hypercapnia. Whether the putative benefits will be negated by administration of alkali is not known. Hypercapnic acidosis is well tolerated, with few adverse effects as long as tissue perfusion and oxygenation are maintained.
There is a lack of clinical evidence that administration of sodium bicarbonate for respiratory acidosis has a net benefit; in fact, there are potential risks associated with it.
呼吸性酸中毒在呼吸衰竭患者中很常见。通常治疗高碳酸血症的方法是增加通气。在最近 COVID-19 的爆发中，对增加机械通气支持无反应的呼吸性酸中毒很常见。增加机械通气会增加正压呼气末压或分钟通气量带来的气压伤和血液动力学损伤。用碳酸氢钠治疗急性呼吸性酸中毒仍然存在争议。
目前尚无碳酸氢钠治疗呼吸性酸中毒的随机对照试验。最近的一篇综述得出结论，碱治疗混合性呼吸性和代谢性酸中毒可能是有用的，但这是基于代谢性酸中毒方面相互矛盾且没有结论性的文献。这一策略不应被推断用于治疗呼吸性酸中毒。急性肺损伤（ALI）和急性呼吸窘迫综合征（ARDS）中的低潮气量通气与允许性高碳酸血症相关的有益作用有关。是否碱的使用会否定这些益处尚不清楚。只要组织灌注和氧合得到维持，高碳酸性酸中毒就能很好地耐受，很少有不良反应。
目前缺乏临床证据表明，碳酸氢钠治疗呼吸性酸中毒有净获益；事实上，它可能存在潜在风险。
