Hypoxemia in a patient with pulmonary arterial hypertension: getting to the heart of the matter

Inflammation and immunity in the pathogenesis of hypoxic pulmonary hypertension

Hypoxic pulmonary hypertension (HPH) is a complicated vascular disorder characterized by diverse mechanisms that lead to elevated blood pressure in pulmonary circulation. Recent evidence indicates that HPH is not simply a pathological syndrome but is instead a complex lesion of cellular metabolism, inflammation, and proliferation driven by the reprogramming of gene expression patterns. One of the key mechanisms underlying HPH is hypoxia, which drives immune/inflammation to mediate complex vascular homeostasis that collaboratively controls vascular remodeling in the lungs. This is caused by the prolonged infiltration of immune cells and an increase in several pro-inflammatory factors, which ultimately leads to immune dysregulation. Hypoxia has been associated with metabolic reprogramming, immunological dysregulation, and adverse pulmonary vascular remodeling in preclinical studies. Many animal models have been developed to mimic HPH; however, many of them do not accurately represent the human disease state and may not be suitable for testing new therapeutic strategies. The scientific understanding of HPH is rapidly evolving, and recent efforts have focused on understanding the complex interplay among hypoxia, inflammation, and cellular metabolism in the development of this disease. Through continued research and the development of more sophisticated animal models, it is hoped that we will be able to gain a deeper understanding of the underlying mechanisms of HPH and implement more effective therapies for this debilitating disease.

Pulmonary arterial hypertension unveils itself: a cancer-like progression - a case report

Background

Pulmonary arterial hypertension (PAH) is a rare disorder with a poor prognosis, characterized by progressive remodelling of the small pulmonary arteries that precede the clinical and haemodynamic manifestations of the disease. Thus, a prompt diagnosis and early intervention are crucial.

Case summary

A 39-year-old pregnant women presented with persistent severe hypoxaemia after the diagnosis of influenza B and an elective caesarean delivery at 33 weeks. Ten months after, an extensive and inconclusive investigation that included a lung biopsy, despite of a spontaneous improvement in oxygen saturation, clinical deterioration led to further testing, namely genetic screening. It revealed a fast-progressing case of hereditary PAH caused by BMRP2 mutation.

Discussion

This case highlights the challenges of a timely diagnosis of PAH and the importance of close clinical monitoring of patients at high risk of PAH. In addition, it emphasizes the fast development of severe haemodynamic changes associated with a BMPR2 mutation. The availability of a lung biopsy without signs of pulmonary vascular disease (PVD) and a right heart catheterization with mild pulmonary hypertension at the baseline assessment demonstrates that PVD can progress in a neoplastic-like manner in a matter of months.

Metastatic leiomyosarcoma presenting as a lung mass with left atrial extension: case report and anesthetic management

Introduction

Lung metastasis of leiomyosarcoma that protrudes into the left atrium is an extremely rare condition. Severe complications may occur that prominently increase the mortality during the perioperative period. Currently, the anesthetic management reports are limited and there is no generally acknowledged algorithm available.

Case presentation

A 67-year-old man presented with cough and dyspnea for 10 days. Workup revealed bilateral pulmonary effusion. Transthoracic echocardiography showed a large mass in the left atrium. Urgent surgical resection under cardiopulmonary bypass was performed. We focused on oxygenation improvement and cardiac function management by applying protective ventilation with low positive end expiratory pressure, low dose inotropic agents, and other methods to maintain stable homeostasis. Results of biopsy established a diagnosis of metastatic leiomyosarcoma.

Conclusion

We reported a case of metastatic leiomyosarcoma presenting as a lung mass with left atrial extension and anesthetic management during surgical resection. Treating acute heart failure and refractory hypoxemia was the key focus perioperatively.