New Noninvasive Method for the Assessment of Central Venous Oxygen Saturations in Critically Ill Patients

OBJECTIVES

To compare noninvasive external jugular vein oxygen saturations (SjvO2) and central venous oxygen saturation (ScvO2) from a blood sample in patients admitted to the intensive care unit.

DESIGN

A prospective, comparative, monocentric clinical trial design was used.

SETTING

The study was performed in the Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva (Switzerland).

PARTICIPANTS

A total of 79 patients were enrolled; patients with confirmed COVID-19 infection requiring invasive mechanical ventilation (patients with COVID-19, n = 36) and patients after liver transplantation (posttransplant patients, n = 43).

INTERVENTIONS

Simultaneous measurement of SjvO2 by near-infrared spectroscopy and ScvO2 from central venous blood samples using a blood gas analyzer in stable hemodynamic conditions.

MEASUREMENTS AND MAIN RESULTS

A strong linear correlation was evidenced in both the COVID-19 and posttransplant patient groups between the 2 modalities. The Bland-Altman analysis showed low bias in accordance with low percentage error in both groups (0.57% and 8.09% for patients with COVID-19; 0.00% and 13.72% for posttransplant patients).

CONCLUSIONS

Central venous oxygen saturation can be estimated reasonably by the continuous noninvasive measurement of SjvO2 using near-infrared spectroscopy.

Informing Family About Patient Trajectory During Surgery: Design and Preliminary Evaluation

The patient empowerment movement has highlighted the importance of providing information to the patients to improve care outcome. However, relatives of patients are not yet taken into consideration. This is especially problematic during surgeries since families are often left without real-time information about the trajectory of the patient, inducing worries. Based on this observation we have developed the SMS-Chir solution that connects our surgery service management system with the automatic sending of SMS at key moments in order to inform families about the progression of the surgery. The system has been conceived thanks to the results of a focus group involving four experts. The evaluation was done by monitoring the use of the system over time and by sending questionnaires after intervention. Results analysis shows a limited use of the system but a high satisfaction of the beneficiaries. This study highlights the importance of managerial factors (resistance to change) in order to onboard the necessary stakeholders in the process.

Myocardial injury after major noncardiac surgery: A secondary analysis of a randomized controlled trial

BACKGROUND

Myocardial injury after noncardiac surgery frequently occurs and may influence survival. The aims of this study were to examine the association between myocardial injury after noncardiac surgery and patient and procedural factors as well as its impact on postoperative clinical outcome.

METHODS

A retrospective analysis was conducted from data collected in adults enrolled in a randomized trial in elective major open abdominal surgery. Preoperative patient characteristics, intraoperative hemodynamic changes, and postoperative adverse events were analyzed, and Kaplan-Meier curves were built for postoperative survival probability. After adjustment for baseline patient and procedural characteristics, the effect of myocardial injury after noncardiac surgery on postoperative outcomes was analyzed in a propensity score matched cohort.

RESULTS

Among 394 patients, myocardial injury after noncardiac surgery was reported in 109 (27.7%) and was associated with a higher cardiovascular risk profile, prolonged surgery (333 ± 111 min vs 295 ± 134 min, P = .010), greater need for transfusions (41.3% vs 19.3%, P < .001), higher incidence of major adverse cardiac events (22.9% vs 6.7%, P < .001), pulmonary complications (31.2% vs 17.9%, P = .004) , acute kidney injury (30.3% vs 18.2%, P = .009), and systemic inflammatory syndrome (28.4% vs 13.0%, P < .001). After propensity score matching, the operative time and the need for blood transfusion remained higher among myocardial injury after noncardiac surgery patients who experienced more frequent major adverse cardiac events and acute kidney injury. In both the entire and matched cohorts, survival up to 30 months after surgery was determined mainly by the presence of cancer.

CONCLUSION

The burden of cardiovascular disease and operative stress surgery is predictive of myocardial injury after noncardiac surgery and, in turn, with a higher incidence of cardiac adverse events, whereas the presence of cancer is associated with poor survival in patients undergoing major open abdominal surgery. Further studies are needed to determine whether myocardial injury after noncardiac surgery can be prevented by better control of the patient's cardiovascular condition and implementation of less invasive of surgical procedures.

The hypoxic pulmonary vasoconstriction: From physiology to clinical application in thoracic surgery

More than 70 years after its original report, the hypoxic pulmonary vasoconstriction (HPV) response continues to spark scientific interest on its mechanisms and clinical implications, particularly for anesthesiologists involved in thoracic surgery. Selective airway intubation and one-lung ventilation (OLV) facilitates the surgical intervention on a collapsed lung while the HPV redirects blood flow from the "upper" non-ventilated hypoxic lung to the "dependent" ventilated lung. Therefore, by limiting intrapulmonary shunting and optimizing ventilation-to-perfusion (V/Q) ratio, the fall in arterial oxygen pressure (PaO₂) is attenuated during OLV. The HPV involves a biphasic response mobilizing calcium within pulmonary vascular smooth muscles, which is activated within seconds after exposure to low alveolar oxygen pressure and that gradually disappears upon re-oxygenation. Many factors including acid-base balance, the degree of lung expansion, circulatory volemia as well as lung diseases and patient age affect HPV. Anesthetic agents, analgesics and cardiovascular medications may also interfer with HPV during the perioperative period. Since HPV represents the homeostatic mechanism for regional ventilation-to-perfusion matching and in turn, for optimal pulmonary oxygen uptake, a clear understanding of HPV is clinically relevant for all anesthesiologists.