Predictors for the development of preoperative oxygenation impairment in acute aortic dissection in hypertensive patients

Background Acute aortic dissection (AAD) is an acute life-threatening cardiovascular disease, which is frequently complicated with oxygenation impairment (OI). We aim to investigate predictors of the development of OI in the patients with AAD.Methods We retrospectively collected clinical data of AAD in hypertensive patients from July 2012 to March 2020. The patients included in this study were divided into OI (+) group (oxygenation index≤200) and OI (-) group (oxygenation index>200). Both groups were compared according to demographic and clinical characteristics, and laboratory findings. Characteristics of hypertension in the patients with AAD were described. Predictors for the development of OI were assessed. And cutoff values were determined by receiver operating characteristics (ROC) curve.Results A total of 208 patients were included in this study and the incidence of OI was 32.2%. In OI (+) group, patients had significantly higher peak body temperature (37.85±0.60 vs 37.64±0.44℃, P= .005), higher levels of CRP (42.70±28.27 vs 13.90±18.70mg/L, P= .000) and procalcitonin (1.07±3.92 vs 0.31±0.77ug/L, P= .027), and lower levels of albumin (34.21±5.65 vs 37.73±4.70g/L, P= .000). Spearman’s rank correlation test showed that the minimum oxygenation index was positively correlated with albumin, and was negatively correlated with the peak body temperature, serum CRP, procalcitonin, BNP and troponin. The stepwise multiple linear regression analysis showed that the peak body temperature, serum CRP and albumin were independently associated with development of OI. An optimal cutoff value for CRP for predicting OI was ≥9.20 mg/L, with a sensitivity of 91.0% and a specificity of 61.0%.Conclusions The peak body temperature, serum CRP and albumin were independent predictors of OI development in the patients with AAD. The serum CRP on admission≥9.20 mg/L might be a valuable and reliable indicator in predicting the development of OI.

Predictors for the development of preoperative oxygenation impairment in acute aortic dissection in hypertensive patients

Background Acute aortic dissection (AAD) is an acute life-threatening cardiovascular disease, which is frequently complicated with oxygenation impairment (OI). Objective We aim to investigate predictors of the development of OI in the patients with AAD. Methods We retrospectively collected clinical data of AAD in hypertensive patients from July 2012 to March 2020. The patients included in this study were divided into OI (+) group (oxygenation index ≤ 200) and OI (-) group (oxygenation index > 200). Both groups were compared according to demographic and clinical characteristics, and laboratory findings. Characteristics of hypertension in the patients with AAD were described. Predictors for the development of OI were assessed. And cutoff values were determined by receiver operating characteristics (ROC) curve. Results A total of 208 patients were included in this study and the incidence of OI was 32.2%. In OI (+) group, patients had significantly higher peak body temperature (37.85 ± 0.60 vs 37.64 ± 0.44℃, P = .005), higher levels of CRP (42.70 ± 28.27 vs 13.90 ± 18.70 mg/L, P = .000) and procalcitonin (1.07 ± 3.92 vs 0.31 ± 0.77ug/L, P = .027), and lower levels of albumin (34.21 ± 5.65 vs 37.73 ± 4.70 g/L, P = .000). Spearman’s rank correlation test showed that the minimum oxygenation index was positively correlated with albumin, and was negatively correlated with the peak body temperature, serum CRP, procalcitonin, BNP and troponin. The stepwise multiple linear regression analysis showed that the peak body temperature, serum CRP and albumin were independently associated with development of OI. An optimal cutoff value for CRP for predicting OI was ≥ 9.20 mg/L, with a sensitivity of 91.0% and a specificity of 61.0%. Conclusions The peak body temperature, serum CRP and albumin were independent predictors of OI development in the patients with AAD. The serum CRP on admission ≥ 9.20 mg/L might be a valuable and reliable indicator in predicting the development of OI.

Oxygenation Impairment during Anesthesia

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Anesthesia is increasingly common in elderly and overweight patients and prompted the current study to explore mechanisms of age- and weight-dependent worsening of arterial oxygen tension (Pao2). Methods This is a primary analysis of pooled data in patients with (1) American Society of Anesthesiologists (ASA) classification of 1; (2) normal forced vital capacity; (3) preoxygenation with an inspired oxygen fraction (Fio2) more than 0.8 and ventilated with Fio2 0.3 to 0.4; (4) measurements done during anesthesia before surgery. Eighty patients (21 women and 59 men, aged 19 to 69 yr, body mass index up to 30 kg/m2) were studied with multiple inert gas elimination technique to assess shunt and perfusion of poorly ventilated regions (low ventilation/perfusion ratio []) and computed tomography to assess atelectasis. Results Pao2/Fio2 was lower during anesthesia than awake (368; 291 to 470 [median; quartiles] vs. 441; 397 to 462 mm Hg; P = 0.003) and fell with increasing age and body mass index. Log shunt was best related to a quadratic function of age with largest shunt at 45 yr (r2 =0.17, P = 0.001). Log shunt was linearly related to body mass index (r2 = 0.15, P < 0.001). A multiple regression analysis including age, age2, and body mass index strengthened the association further (r2 = 0.27). Shunt was highly associated to atelectasis (r2 = 0.58, P < 0.001). Log low showed a linear relation to age (r2 = 0.14, P = 0.001). Conclusions Pao2/Fio2 ratio was impaired during anesthesia, and the impairment increased with age and body mass index. Shunt was related to atelectasis and was a more important cause of oxygenation impairment in middle-aged patients, whereas low, likely caused by airway closure, was more important in elderly patients. Shunt but not low increased with increasing body mass index. Thus, increasing age and body mass index impaired gas exchange by different mechanisms during anesthesia.