Abstract:
Metabolic alkalosis is a common acid-base imbalance frequently observed in intensive care unit (ICU) patients and is associated with increased mortality. Post-hypercarbia alkalosis (PHA) is a type of metabolic alkalosis caused by sustained high serum bicarbonate levels following a rapid resolution of hypoventilation in patients with chronic hypercapnia due to prolonged respiratory disturbance. Common causes of chronic hypercapnia include chronic obstructive pulmonary disease (COPD), central nervous system disorders, neuromuscular disorders, and narcotic abuse. Rapid correction of hypercapnia through hyperventilation leads to a swift normalization of pCO2, which lacks renal compensation, consequently causing an increase in plasma HCO3- levels and severe metabolic alkalosis. Most of PHA occurs in the ICU setting requiring mechanical ventilation and can progress severe alkalemia due to secondary mineralocorticoid excess from volume depletion or decreased HCO3- excretion from decreased glomerular filtration rate and increased proximal tubular reabsorption. PHA is associated with increased ICU stay, ventilator dependency, and mortality. Acetazolamide, a carbonic anhydrase inhibitor, has been utilized for managing PHA by inducing alkaline diuresis and reducing tubular reabsorption of bicarbonate. While acetazolamide effectively improves alkalemia, its impact on hard outcomes may be limited by factors such as patient complexity, co-administered medications, and underlying conditions contributing to alkalosis.
摘要:
代谢性碱中毒是在重症监护病房(ICU)患者中经常观察到的常见酸碱失衡,并与死亡率增加有关。高碳酸血症后碱中毒(PHA)是一种代谢性碱中毒,由长期呼吸障碍导致的慢性高碳酸血症患者的通气不足迅速解决后持续的高血清碳酸氢盐水平引起。慢性高碳酸血症的常见原因包括慢性阻塞性肺疾病(COPD),中枢神经系统疾病,神经肌肉疾病,和麻醉品滥用。通过过度换气快速校正高碳酸血症导致pCO2迅速正常化,缺乏肾脏补偿,因此导致血浆HCO3-水平升高和严重的代谢性碱中毒。大多数PHA发生在需要机械通气的ICU环境中,并且由于容量消耗引起的继发性盐皮质激素过量或肾小球滤过率降低和近端肾小管重吸收增加引起的HCO3-排泄减少,因此可以发展为严重的碱性血症。PHA与ICU住院时间增加有关,呼吸机依赖性,和死亡率。乙酰唑胺,碳酸酐酶抑制剂,已用于通过诱导碱性利尿和减少碳酸氢盐的肾小管重吸收来管理PHA。虽然乙酰唑胺有效改善碱性血症,它对硬结果的影响可能受到患者复杂性等因素的限制,共同管理的药物,和导致碱中毒的潜在条件。