Kumar Akshay, Advani Shailesh, Asim Kichloo, Mohamed Mohamed A, Wani Farah, Singh Jagmeet, Albosta Michael, Shiwalkar Nimisha, Keshavamurthy Suresh
Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, 100 Lothrop St, Pittsburgh, PA 15213 USA.
Department of Cardiothoracic Surgery, Medanta Hospital, Gurugram, India.
Indian J Thorac Cardiovasc Surg. 2022 Jul;38(Suppl 2):335-346. doi: 10.1007/s12055-021-01319-6. Epub 2022 Mar 14.
To synthesize the evidence for incidence, pathophysiology, etiology, and protocol-based management of hyperammonemia in lung transplant patients.
Elevated ammonia levels are toxic to the brain, and hyperammonemia results in a potentially fatal complication for lung transplant recipients. The hallmark of this condition is ammonia production being way out of proportion to the degree of liver derangement. While there are many hypotheses, the cause remains obscure.
A retrospective review of patients with hyperammonemia following lung transplantation was done to understand the pathophysiology, various treatment modalities, and its impact on patient mortality and morbidity. Studies in the English literature were identified through an electronic database search from PubMed/MEDLINE, Ovid Embase, Google Scholar, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Web of Science, and ClinicalTrials.gov until June 2020. No restriction of dates were used, and the search was up until June 2020.
Mortality among patients with hyperammonemia following lung transplantation is high. Multi-modal treatment approaches include avoiding nephrotoxic drugs, use of bowel decontamination, nitrogen scavengers, branched-chain amino acids, adjustment of immunosuppression, antibiotics like fluoroquinolones or azithromycin, and renal replacement therapy. However, there remains a scarcity of preoperative screening protocol for patients at risk of hyperammonemia as well evidence-based post-operative management guidelines. Intermittent hemodialysis, compared to continuous venovenous hemodialysis, provides better patient outcomes.
Early detection of patients at risk by appropriate screening, along with maintaining a high degree of suspicion for hyperammonemia and multi-modal treatment approach, is the key to successful patient outcomes. Further prospective observational studies would facilitate development of protocol-based treatment of this potentially fatal condition.
综合肺移植患者高氨血症的发病率、病理生理学、病因及基于方案的管理方面的证据。
氨水平升高对大脑有毒性，高氨血症会给肺移植受者带来潜在致命并发症。这种情况的标志是氨生成与肝脏紊乱程度严重不成比例。虽然有许多假说，但病因仍不明确。
对肺移植后发生高氨血症的患者进行回顾性研究，以了解其病理生理学、各种治疗方式及其对患者死亡率和发病率的影响。通过从PubMed/MEDLINE、Ovid Embase、谷歌学术、Cochrane系统评价数据库（CDSR）、Cochrane对照试验中心注册库（CENTRAL）、Scopus、科学网和ClinicalTrials.gov进行电子数据库检索，查找截至2020年6月的英文文献研究。未设置日期限制，检索截至2020年6月。
肺移植后高氨血症患者的死亡率很高。多模式治疗方法包括避免使用肾毒性药物、进行肠道去污、使用氮清除剂、支链氨基酸、调整免疫抑制、使用氟喹诺酮类或阿奇霉素等抗生素以及肾脏替代治疗。然而，对于有高氨血症风险的患者，术前筛查方案以及循证术后管理指南仍然匮乏。与连续性静脉-静脉血液透析相比，间歇性血液透析能为患者带来更好的预后。
通过适当筛查早期发现有风险的患者，同时对高氨血症保持高度怀疑并采用多模式治疗方法，是患者取得成功预后的关键。进一步的前瞻性观察性研究将有助于制定针对这种潜在致命疾病的基于方案的治疗方法。
