Incidence, Risk Factors, and Outcomes of Severe Hypoxemia After Cardiac Surgery

Immediate effects of upper limb exercises with and without deep breathing on lung function after cardiac surgery - a randomized crossover trial

BACKGROUND

Open heart surgery, involving median sternotomy, may cause diminished chest wall motion and restrictive pulmonary function in the early postoperative period. Thoracic and upper extremity range of motion (ROM) exercises are often recommended after surgery but have not been evaluated regarding effect on lung volumes and oxygenation. The objective of this study was to evaluate the immediate effect of upper limb elevations, with or without simultaneous deep breathing, on lung function after cardiac surgery.

METHODS

In a randomized 2 × 2 crossover trial, 22 adult patients (> 18 years old) were assessed during one of the first days after surgery in the spring of 2022 at Örebro University Hospital, Sweden. Exercises involving five bilateral upper limb elevations, performed either with simultaneous deep breathing (ROM-DB) or without (ROM), while sitting in an upright position at the edge of the bed, were evaluated. Peripheral oxygen saturation (Rad-5v; Masimo, Irvine, USA) was the primary outcome. Tidal volume and respiratory rate were recorded continuously during the exercises (Spiropalm; Cosmed, Rome, Italy). Heart rate, pain, exertion and dyspnoea were evaluated before and after the exercises.

RESULTS

Both ROM-DB and ROM momentarily increased peripheral oxygen saturation (+ 1% ± 1, p = 0.004 and + 1% ± 1, p < 0.001, respectively), with no significant differences between these exercises (p = 0.525). ROM-DB significantly increased the VT compared with ROM (798 ± 316 vs. 602 mL ± 176, p = 0.004). However, ROM-DB induced more pronounced pain (p = 0.012), exertion (p = 0.035) and dyspnoea (p = 0.013) than ROM.

CONCLUSIONS

Upper limb elevations improved oxygenation momentarily, both performed with and without simultaneous deep breathing, with no significant differences between these exercises. The additive deep breathing improved tidal volume compared with upper limb elevations alone, but induced more pain, exertion and dyspnoea during the performance of exercise.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05278819).

sTREM2 in the prognostic evaluation of acute lung injury after cardiac surgery in infants

BACKGROUND

Previous studies have shown that TREM2 plays a protective role in acute lung injury (ALI). This prospective study aimed to investigate the role of sTREM2 as a forecasting factor for ALI in infants after pediatric cardiac surgery undergoing cardiopulmonary bypass (CPB).

METHODS

Seventy-five consecutive patients younger than 1 year who underwent cardiac surgery were enrolled in this study. Sixty-one fulfilled the inclusion criteria and had been divided into ALI and non-ALI groups. Children's demographic characteristics and clinical data were collected. Perioperative sTREM2 levels were analyzed at five timepoints.

RESULTS

In this study, children in the ALI group were younger, lighter, with higher RACHS-1 scores and underwent significantly longer CPB time. Post-CPB ALI had an impact on clinical outcomes, which contributed to a longer duration of mechanical ventilation, ICU and hospital stay than non-ALI group. Significant differences were manifested off-CPB, 1 h/6 h after CPB, and day 1 after surgery between the two groups. Binary logistic models revealed that off-CPB sTREM2 was significantly associated with the incidence of post-CPB ALI after adjustment. ROC analysis showed that the AUC of off-CPB sTREM2 level was 0.791, and the optimal cutoff value was 788.6 pg/ml.

CONCLUSIONS

The off-CPB sTREM2 level was an independent prognostic factor for post-CPB ALI in infants.

IMPACT

Plasma sTREM2 works together with downstream TREM2 to regulate inflammation response by binding the receptor to other cells. Previous studies have shown that TREM2 plays a protective role in ischemia-reperfusion and has anti-inflammatory effects on acute lung injury (ALI). This study analyzed the risk factors of post-cardiopulmonary bypass (CPB) ALI. We found that weight and off-CPB sTREM2 level were independent prognostic factors for post-CPB ALI. Plasma sTREM2 may serve as an early biomarker in the prognostic evaluation of acute lung injury after cardiac surgery in infants.

Obesity and acute type A aortic dissection: unraveling surgical outcomes through the lens of the upper hemisternotomy approach

Background

Acute type A aortic dissection (ATAAD) is a pressing cardiovascular emergency necessitating prompt surgical intervention. Obesity, a pervasive health concern, has been identified as a significant risk factor for ATAAD, introducing unique surgical challenges that can influence postoperative outcomes. This study aimed to investigate the outcomes of ATAAD surgery across various body mass index (BMI) categories, focusing on the implications of the upper hemisternotomy (UHS) approach.

Methods

Between April 2017 and October 2023, 229 patients diagnosed with ATAAD underwent aortic arch intervention via UHS at the General Hospital of Northern Theater Command. Based on BMI (WS/T 428-2013), patients were categorized into normal weight, overweight, and obese. The primary outcomes included perioperative parameters, intraoperative details, and postoperative complications, with specific emphasis on hypoxemia, defined by the Berlin criteria as a PaO2/FiO2 ratio of ≤300 mmHg.

Results

The average age of the cohort was 50.1 ± 11.2 years with a male predominance (174 males). Preoperatively, 49.0% presented with hypoxemia, with the Obese group exhibiting a significantly elevated rate (77.9%, P < 0.001). Postoperatively, while the Normal group demonstrated a lower thoracic drainage volume 24 h post-surgery [180.0 (140.0) ml; P < 0.001], the Obese group indicated prolonged durations for mechanical ventilation and ICU stay, without statistical significance. Unlike the Normal and Overweight groups, the Obese group showed no notable changes in pre- and postoperative PaO2/FiO2 ratio. No significant difference was observed in severe postoperative complications among the groups. Further ROC curve analysis identifies a BMI cutoff of 25.5 for predicting postoperative hypoxemia, with 76.3% sensitivity and 84.4% specificity. And multivariate analysis reveals BMI and preoperative hypoxemia as independent predictors of postoperative hypoxemia.

Conclusion

Obesity, although presenting unique challenges in ATAAD interventions, does not necessarily portend adverse outcomes when managed with meticulous surgical planning and postoperative care. The study emphasizes the significance of individualized patient assessment and tailoring surgical strategies, suggesting the potential of UHS in addressing the surgical intricacies posed by obesity in ATAAD patients. Further research is warranted to consolidate these findings.

Risk factors for intraprocedural hypoxemia in patients with acute cerebral ischemia treated with vascular intervention and its impact on prognosis: A retrospective cohort study

BACKGROUND

Acute cerebral infarction (ACI) is one of the most common ischemic cerebrovascular diseases in neurology, with high morbidity, mortality, and disability. Early thrombolytic treatment of ACI has significant efficacy, but intraprocedural complications of hypoxemia can significantly reduce the efficacy. This study aims to analyze the risk factors for intraprocedural hypoxemia in patients with ACI, so as to take effective measures in advance to reduce the likelihood of adverse patient outcomes.

METHODS

We retrospectively analyzed a total of 238 patients with ACI treated with vascular interventions from May 2017 to May 2022. To assess and collate the patients' characteristics, factors associated with the development of intraprocedural hypoxemia. The independent risk factors for the development of intraprocedural hypoxemia were analyzed by binary logistic regression.

RESULTS

A total of 238 patients were included in this study. Of these, intraprocedural hypoxemia occurred in 89 (37.4%). The results showed that old age (odds ratio [OR] = 2.666, P = 0.009), obesity (OR = 3.029, P = 0.003), smoking history (OR = 2.655, P = 0.010), preoperative oxygen saturation (SpO2) (OR = 0.001, P = 0.042), preoperative C-reactive protein (OR = 1.216, P = 0.002), and time from puncture to vascular recanalization (OR = 1.135, P = 0.000) were independent risk factors for intraprocedural hypoxemia in patients. The prognosis of the patients was assessed according to the modified Rankin scale, and the prognosis of the nonhypoxemia group was significantly better than that of the hypoxemia group. Regression analysis showed that intraprocedural hypoxemia (OR = 0.360, P = 0.001), postoperative lower extremity vein thrombosis (OR = 0.187, P = 0.018), hydrocephalus (OR = 0.069, P = 0.015), intracranial hemorrhage (OR = 0.116, P = 0.002), and reocclusion (OR = 0.217, P = 0.036) were independent risk factors for poor prognosis.

CONCLUSIONS

Currently, intravascular hypoxemia in patients with ACI has a serious impact on prognosis. Clinical work should attach great importance to the clinical characteristics of patients, identify relevant risk factors, and aggressively take personalized therapeutic actions to improve patients' prognosis.

Balanced Nonopioid General Anesthesia With Lidocaine Is Associated With Lower Postoperative Complications Compared With Balanced Opioid General Anesthesia With Sufentanil for Cardiac Surgery With Cardiopulmonary Bypass: A Propensity Matched Cohort Study

BACKGROUND

There are no data on the effect of balanced nonopioid general anesthesia with lidocaine in cardiac surgery with cardiopulmonary bypass. The main study objective was to evaluate the association between nonopioid general balanced anesthesia and the postoperative complications in relation to opioid side effects.

METHODS

Patients undergoing cardiac surgery with cardiopulmonary bypass between 2019 and 2021 were identified. After exclusion of patients for heart transplantation, left ventricular assistance device, and off-pump surgery, we classified patients according to an opioid general balanced anesthesia or a nonopioid balanced anesthesia with lidocaine. The primary outcome was a collapsed composite of postoperative complications that comprise respiratory failure and confusion, whereas secondary outcomes were acute renal injury, pneumoniae, death, intensive care unit (ICU), and hospital length of stay.

RESULTS

We identified 859 patients exposed to opioid-balanced general anesthesia with lidocaine and 913 patients exposed to nonopioid-balanced general anesthesia. Propensity score matching yielded 772 individuals in each group with balanced baseline covariates. Two hundred thirty-six patients (30.5%) of the nonopioid-balanced general anesthesia versus 186 patients (24.1%) presented postoperative composite complications. The balanced lidocaine nonopioid general anesthesia group was associated with a lower proportion with the postoperative complication composite outcome OR, 0.72 (95% CI, 0.58-0.92; P = .027). The number of patients with acute renal injury, death, and hospital length of stay did not differ between the 2 groups.

CONCLUSIONS

A balanced nonopioid general anesthesia protocol with lidocaine was associated with lower odds of postoperative complication composite outcome based on respiratory failure and confusion.

Nomogram and Risk Calculator for Postoperative Tracheostomy after Heart Valve Surgery

Postoperative tracheostomy (POT) is an important indicator of critical illness, associated with poorer prognoses and increased medical burdens. However, studies on POTs after heart valve surgery (HVS) have not been reported. The objectives of this study were first to identify the risk factors and develop a risk prediction model for POTs after HVS, and second to clarify the relationship between POTs and clinical outcomes. Consecutive adults undergoing HVS from January 2016 to December 2019 in a single cardiovascular center were enrolled, and a POT was performed in 1.8% of the included patients (68/3853). Compared to patients without POTs, the patients with POTs had higher rates of readmission to the ICU and in-hospital mortality, as well as longer ICU and hospital stays. Five factors were identified to be significantly associated with POTs after HVS by our multivariate analysis, including age, diabetes mellitus, pulmonary edema, intraoperative transfusion of red blood cells, and surgical types. A nomogram and a risk calculator were constructed based on the five factors, showing excellent discrimination, calibration, and clinical utility. Three risk intervals were defined as low-, medium-, and high-risk groups according to the nomogram and clinical practice. The findings of this study may be helpful for early risk assessment and perioperative management.

High-Sensitivity Cardiac Troponin T in Prediction and Diagnosis of Early Postoperative Hypoxemia after Off-Pump Coronary Artery Bypass Grafting

To investigate the relationship of preoperative high-sensitivity cardiac troponin T (hs-cTnT) with early postoperative hypoxemia (EPH) following off-pump coronary artery bypass grafting (OPCAB). Records of patients undergoing OPCAB between 2018 and 2022 were reviewed. Baseline characteristics and postoperative arterial blood gas analysis were derived from the cardiovascular surgery electronic medical records. Preoperative hs-cTnT levels were measured routinely in all patients. Logistic regression analyses were performed to test the association of preoperative hs-cTnT with EPH. A total of 318 OPCAB patients were included, who had a preoperative hs-cTnT test available for review. Before surgery, 198 patients (62%) had a rise in hs-cTnT level (≥14 ng/L) and 127 patients (40%) had a more severe hs-cTnT level (≥25 ng/L). The preoperative hs-cTnT level was associated with EPH (odds ratio per ng/L, 1.86; 95% confidence interval 1.30−2.68; p < 0.001), prolonged intensive care unit stay (odds ratio, 1.58; 95% confidence interval 1.08−2.32; p = 0.019), and delayed extubating time (odds ratio, 1.63; 95% confidence interval 1.15−2.34; p = 0.007). On multivariable analysis, adjusted for BMI, hypertension, smoking status, serum creatinine, and cardiac function, preoperative hs-cTnT remained an independent factor associated with EPH. Elevation of hs-cTnT concentrations are significantly associated with EPH after OPCAB. Review of presurgical hs-cTnT concentration may help identify patients who would benefit from OPCAB to improve surgical risk assessment.

Clinical presentation and in-hospital outcomes of intraoperative red blood cell transfusion in non-anemic patients undergoing elective valve replacement

Background

Intraoperative transfusion is associated with adverse clinical outcomes in cardiac surgery. However, few studies have shown the impact of intraoperative red blood cell (RBC) transfusion on non-anemic patients undergoing cardiac surgery. We assessed the in-hospital clinical outcomes of non-anemic patients undergoing isolated valve replacements and investigated the predictors associated with intraoperative RBC transfusion.

Methods

We enrolled 345 non-anemic patients undergoing isolated valve replacements in our department from January 2015 to December 2019. The patients were stratified by the receipt of intraoperative RBC transfusion. Baseline characteristics were compared between groups and multiple logistic regression was used to identify the predictors for intraoperative RBC transfusion. The association between intraoperative RBC transfusion and in-hospital outcomes was also evaluated.

Results

Intraoperative RBC transfusion developed in 84 of the 345 enrolled patients (24.3%). Three independent predictors for intraoperative RBC transfusion of non-anemic patients undergoing isolated valve replacements were identified by multivariate logistic analysis, including female, iron deficiency and hemoglobin level. When the two groups were compared, a significant tendency of higher in-hospital mortality (6.0% vs. 1.1%, P = 0.033) and higher incidence of postoperative hypoxemia (9.5% vs. 2.7%, P = 0.007) were observed in the intraoperative RBC transfusion group. After adjustment, the presence of intraoperative RBC transfusion was associated with an increase in postoperative hypoxemia (OR = 3.36, 95% CI: 1.16–9.71, P = 0.026).

Conclusion

Intraoperative RBC transfusion was associated with poorer clinical outcomes in non-anemic adults undergoing isolated valve replacements, which significantly increased the risk of postoperative hypoxemia. The independent predictors of intraoperative RBC transfusion, such as iron deficiency and female, were identified, which may be helpful for risk assessment and perioperative management.