Utility of Pulse Oximetry Screening for Hepatopulmonary Syndrome in Low Resource Settings

Abstract

Listen

Translate article

Introduction: Hepatopulmonary syndrome (HPS) is present in up to 30% of patients with cirrhosis and increases mortality even after liver transplant. HPS and pulse oximetry utility have not been described in Guatemala. Methods: Patients from Hospital Roosevelt in Guatemala City with ultrasound confirmed cirrhosis and no cardiac or lung abnormalities were enrolled from the internal medicine inpatient services and the gastroenterology outpatient clinics. Baseline characteristics for both groups were recorded and all patients underwent proper diagnostic studies. Results: 54 patients were enrolled, of which 17 (32%) were diagnosed with HPS; the most common etiology for liver cirrhosis was chronic alcohol consumption, mean age of diagnosis was 50.4 ±11.8 years. Both groups were similar, differing only in that 6 patients (35%) in the HPS group presented with orthodeoxia compared to 1 patient (2%) in the Non-HPS group (p < 0.001). It was found that with a threshold value of standing SpO2 of ≤96% pulse oximetry had a sensitivity of 100% and specificity of 93% for detecting patients with a PaO2 of ≤60mmHg. Interestingly, in patients with arterial blood gas PaO2 values of ≤60mmHg a diagnosis of HPS could be made with a sensitivity of 94% and specificity of 94%. Conclusion: Pulse oximetry is a useful tool for screening patients with cirrhosis for HPS due to its wide availability and low cost. It has a high sensitivity and specificity for detecting hypoxemia, this is important in low resource settings as in primary care clinics in Guatemala, where access to specialized healthcare workers and technology is not readily available. As our study results show, a standing SpO2 value of ≤96% and arterial blood gas PaO2 value of < 60mmHg can be good indicators of presence of HPS when saline contrast echocardiogram is unavailable. This is the first study to report specificity and sensitivity estimates in a resource-limited practice for non-Caucasian patients at 1500m above sea level. This confirms once again the utility of oximetry as a vital sign, not widely applied in primary care settings. This study should raise awareness to primary health care providers in Guatemala of the relevance of HPS and the importance of early screening and prompt referral of these patients to specialized centers in or outside of the country. Early diagnosis is critical in regions where liver transplant programs are still not available, for appropriate symptomatic management of these patients.Table: Baseline characteristics.Table: Sensitivity and specificity values of standing pulse oximetry with a threshold value of SpO2 96% for detecting patients with a PaO2 of 60mmHg.Table: Sensitivity and Specificity values of PaO2 for detecting the presence of Hepatopulmonary Syndrome.