Kanj, Amjad N

ABSTRACT Background: Although central venous oxygen saturation (ScvO2) has been used as an endpoint for the treatment of circulatory shock, its role in guiding the evaluation and treatment of patients with severe hypoxemia remains to be assessed. The aim of this study was to assess the incidence of low ScvO2 in a cohort of hypoxemic patients and the association of this finding with differences in clinical management and patient outcomes. Methods: Retrospective review of data from adult intensive care unit patients with hypoxemia who required invasive mechanical ventilation for over 24 h and had at least one ScvO2 measured within 6 h of a PaO2/FiO2 ratio <200. Results: Of 442 mechanically ventilated patients with severe hypoxemia, 249 (56%) had an ScvO2 <70%. When compared with patients with ScvO2 ≥70%, those with low ScvO2 had worse systemic oxygenation and hemodynamic parameters and were more likely to receive red blood cell transfusions (31.7% vs. 18.1%, P = 0.001), epinephrine (27.3% vs. 16.6%, P = 0.007), and inodilators. Outcomes such as median intensive care unit length of stay (7.5 vs. 8.3 days, P = 0.337) and hospital mortality (39.8% vs. 35.7%, P = 0.389) were not different between groups. When stratified by the central venous-to-arterial CO2 difference (∆PCO2), patients with a low ScvO2 and normal ∆PCO2 had lower median PaO2 and hemoglobin levels and received more red blood cell transfusions, whereas those with an increased ∆PCO2 had a lower pulse pressure and cardiac index and were more likely to receive epinephrine and milrinone. Conclusion: Low ScvO2 is frequently observed in mechanically ventilated patients with severe hypoxemia, and these patients receive different interventions. Clinicians often use therapies targeting systemic oxygen delivery to correct low ScvO2. Prospective research is needed to identify patients with severe hypoxemia that might benefit from interventions targeting systemic oxygen delivery.

Abstract Introduction Indigenous North Americans have the highest cigarette smoking prevalence among all racial and ethnic groups in the United States. We seek to identify effective components of smoking cessation interventions in Indigenous people in the United States associated with favorable cessation outcomes. Methods A review of literature studying smoking cessation interventions in Indigenous North Americans (American Indians and Alaska Natives) from January 2010 through August 2021 was completed. The primary objective of this study was to identify components of interventions associated with positive smoking cessation outcomes in Indigenous people. The studies identified were synthesized in a meta-narrative approach. Results Ten studies out of 608 titles were included (6 randomized trials, 2 single-arm studies, 1 cohort study, and 1 prospective observational study). Five categories of smoking cessation interventions were identified; phone or web-based tools, culturally-tailored interventions, the inclusion of Indigenous study personnel, pharmaceutical cessation aids, and behavioral health interventions. Phone and web tools, cultural tailoring, and inclusion of Indigenous personnel conditions inconsistently influenced smoking cessation. Pharmaceutical aids were viewed favorably among participants. Individualized behavioral counseling sessions were effective at promoting smoking cessation, as was input from local communities in the planning and implementation phases of study. Conclusion A successful smoking cessation intervention in Indigenous North Americans includes Tribal or community input in intervention design and implementation; should provide individualized counseling sessions for participants, and offer access to validated smoking cessation tools including pharmacotherapy. Implications This study identifies a paucity of smoking interventions utilizing standard of care interventions in Indigenous North Americans. Standard of care interventions including individualized cessation counseling and pharmacotherapy were effective at promoting cessation. The use of novel culturally tailored cessation interventions was not more effective than existing evidence-based care with the exception of including Tribal and local community input in intervention implementation. Future smoking cessation interventions in Indigenous North Americans should prioritize the use of standard of care cessation interventions.

BACKGROUND: Residual volume (RV) is a derived lung compartment that correlates with air trapping in the context of air flow obstruction on spirometry. The significance of an isolated elevation in RV in the absence of other pulmonary function test (PFT) abnormalities is not well defined. We sought to assess the clinical and radiologic findings associated with isolated elevation in RV. METHODS: We searched our out-patient PFT database at Mayo Clinic (Rochester, Minnesota) from 2016–2018 for adult patients with isolated elevation in RV. We defined isolated elevation in RV as RV ≥ upper limit of normal or ≥ 130% predicted with normal total lung capacity (TLC), spirometry, and diffusion capacity of the lung for carbon monoxide (D LCO ). We then matched this high-RV group by age and sex to an equal number of individuals with normal RV, TLC, spirometry, and D LCO (normal-RV group). RESULTS: We identified 169 subjects with isolated elevation in RV on PFTs, with a median age of 73 y; 55.6% were female, and median body mass index was 26.8 (vs 29.8 in the normal-RV group). The median RV was 3.08 L (134% predicted, interquartile range [IQR] 130–141) in the high-RV group and 2.26 L (99% predicted, IQR 90–109) in the normal-RV group (P < .001). Subjects with high RV were more likely to have smoked (54% vs 40%, P = .01) and almost twice as likely to have a maximum voluntary ventilation < 30 times the FEV 1 (21% vs 12%, P = .02). Clinically, asthma (21% vs 11%, P = .01) and non–tuberculous mycobacterial lung infections (12% vs 2%, P = .001) were more prevalent in the high-RV group. On chest computed tomography, bronchiectasis (31% vs 15%, P = .008), bronchial thickening or mucus plugging (46% vs 22%, P < .001), and emphysema (13% vs 5%, P = .046) were more common in the high-RV group. CONCLUSIONS: Isolated elevation in RV on PFTs is a clinically relevant abnormality associated with airway-centered diseases.