Peripheral measurements of venous oxygen saturation and lactate as a less invasive alternative for hemodynamic monitoring.

BACKGROUND: Peripheral measurement of venous oxygen saturation and lactate is a less invasive alternative to monitor tissue oxygenation as compared to measurements from a central venous catheter. However, there is a lack of evidence to support the use of peripheral measurements. In this study, we investigated the agreement between central and peripheral venous oxygen saturation and lactate. METHODS: We conducted a prospective observational study including 115 patients who underwent elective cardiac surgery between April and May 2015 at Rigshospitalet, Copenhagen, Denmark. Measurements were obtained simultaneously at induction of anaesthesia, upon arrival in the ICU and 3-4 h postoperatively. Bias and trending ability was identified using Bland-Altman analysis and a four-quadrant plot. RESULTS: Bias was 13.37% for venous oxygen saturation preoperatively (95% CI: 11.52-15.22, LoA: ±19.10, PE: 22.08%), 11.29% at arrival to the ICU (95% CI: 8.81-13.77, LoA: ±25.10, PE: 32.39%) and 16.49% at 3-4 h postoperatively (95% CI: 14.16-18.82, LoA: ±21.20, PE: 26.82%). A four-quadrant plot demonstrated an 89% concordance. Central and peripheral lactate showed a bias of 0.14 mmol/L preoperatively (95% CI: 0.11-0.17, LoA: ±0.30, PE: 32.08%), 0.16 mmol/L at arrival to ICU (95% CI: 0.09-0.23, LoA: ±0.70, PE: 38.88%) and 0.23 mmol/L at 3-4 h postoperatively (95% CI: 0.11-0.35, LoA: ±0.50, 25.18%). DISCUSSION: Measurements of peripheral oxygen saturation and lactate may be valuable in an emergency setting, avoiding unnecessary and time consuming application of a CVC. CONCLUSION: We found a high bias but an acceptable trending ability between central and peripheral venous oxygenation. Central and peripheral lactate had excellent agreement. Further studies are necessary to validate the use of peripheral venous samples to identify patients at risk of impaired tissue oxygenation.

Outcome After Surgery for Acute Aortic Dissection: Influence of Preoperative Antiplatelet Therapy on Prognosis.

OBJECTIVES: Outcome in patients with acute coronary syndrome (ACS) is improved with dual antiplatelet therapy (DAPT). Patients with acute aortic dissection type A (AAD) often present with similar symptoms and may therefore be prescribed DAPT before diagnosis. The aim of this study was to evaluate the use of antiplatelet therapy (APT) prior to AAD surgery and patient outcome, including indications according to the European Society of Cardiology's (ESC) recent guidelines. DESIGN: A retrospective, observational study. SETTING: A tertiary University Hospital, Rigshospitalet, Heart Centre, Copenhagen, Denmark. PARTICIPANTS: The study included 171 patients operated for AAD during 2010 to 2014. INTERVENTIONS: The independent relationship of preoperative APT was explored on 30-day mortality, intraoperative bleeding and perioperative transfusion requirements. Furthermore, the indications for APT were obtained. MEASUREMENTS AND MAIN RESULTS: Patients receiving APT (n = 73) did not have an increased 30-day mortality (29% v 20%, p = 0.18). However, APT increased intraoperative bleeding by 45% (p<0.001) and increased perioperative transfusion of red blood cells by 71%, fresh frozen plasma by 52%, and platelets by 56% (p = 0.002). Among patients receiving APT preoperatively, 26 patients received acetylsalicylic acid (ASA) alone and 46 patients received DAPT. Bleeding was significantly more pronounced in patients receiving DAPT (5.6±4.1 L), compared to ASA alone (3.6±3.1 L) and no APT (3.3±4.8 L) (p<0.001). However, there was no significant difference in mortality between groups. DAPT, including ticagrelor, increased intraoperative bleeding by 62% compared to DAPT with clopidogrel (p = 0.004). Among patients receiving DAPT, only 30% of the patients fulfilled ESC criteria for ACS treatment. CONCLUSIONS: The use of APT was associated with increased intraoperative bleeding and transfusion requirement; however, it was not associated with a statistically significant increased mortality. Only a minority of patients fulfilled ESC criteria for ACS treatment with DAPT.