Effect of lidocaine on intraoperative blood pressure variability in patients undergoing major vascular surgery.

BACKGROUND: Dynamic fluctuations of arterial blood pressure known as blood pressure variability (BPV) may have short and long-term undesirable consequences. During surgical procedures blood pressure is usually measured in equal intervals allowing to assess its intraoperative variability, which significance for peri and post-operative period is still under debate. Lidocaine has positive cardiovascular effects, which may go beyond its antiarrhythmic activity. The aim of the study was to verify whether the use of intravenous lidocaine may affect intraoperative BPV in patients undergoing major vascular procedures. METHODS: We performed a post-hoc analysis of the data collected during the previous randomized clinical trial by Gajniak et al. In the original study patients undergoing elective abdominal aorta and/or iliac arteries open surgery were randomized into two groups to receive intravenous infusion of 1% lidocaine or placebo at the same infusion rate based on ideal body weight, in concomitance with general anesthesia. We analyzed systolic (SBP), diastolic (DBP) and mean arterial blood (MAP) pressure recorded in 5-minute intervals (from the first measurement before induction of general anaesthesia until the last after emergence from anaesthesia). Blood pressure variability was then calculated for SBP and MAP, and expressed as: standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and coefficient of hemodynamic stability (C10%), and compared between both groups. RESULTS: All calculated indexes were comparable between groups. In the lidocaine and placebo groups systolic blood pressure SD, CV, AVR and C10% were 20.17 vs. 19.28, 16.40 vs. 15.64, 14.74 vs. 14.08 and 0.45 vs. 0.45 respectively. No differences were observed regarding type of surgery, operating and anaesthetic time, administration of vasoactive agents and intravenous fluids, including blood products. CONCLUSION: In high-risk vascular surgery performed under general anesthesia, lidocaine infusion had no effect on arterial blood pressure variability. TRIAL REGISTRATION: ClinicalTrials.gov; NCT04691726 post-hoc analysis; date of registration 31/12/2020.

Efficacy of Lidocaine Infusion in High-Risk Vascular Surgery-A Randomized, Double-Blind, Placebo-Controlled Single-Center Clinical Trial.

BACKGROUND: In perioperative pain control, adjuvants such as lidocaine can reduce opioid consumption in a specific type of surgery. The aim of this single-center prospective double-blinded randomized controlled trial was to determine opioid consumption in the perioperative period in patients receiving continuous lidocaine infusion. METHODS: Patients undergoing elective abdominal aorta and/or iliac arteries open surgery were randomized into two groups to receive 1% lidocaine or placebo at the same infusion rate based on ideal body weight (bolus of 0.15 mL/kg during the induction of anesthesia followed by continuous infusion of 0.2 mL/kg/h during surgery; postoperatively 0.1 mL/kg/h for 24 h) additionally to standard opioid analgesia. RESULTS: Total opioid consumption within 24 h after surgery was 89.2 mg (95%CI 80.9-97.4) in the lidocaine and 113.1 mg (95%CI 102.5-123.6) in the placebo group (p = 0.0007). Similar findings were observed in opioid consumption intraoperatively (26.7 mg (95%CI 22.2-31.3) vs. 35.1 mg (95%CI 29.1-41.2), respectively, p = 0.029) and six hours postoperatively (47.5 mg (IQR 37.5-59.5) vs. 60 mg (IQR 44-83), respectively, p = 0.01). CONCLUSIONS: In high-risk vascular surgery, lidocaine infusion as an adjunct to standard perioperative analgesia is effective. It may decrease opioid consumption by more than 20% during the first 24 h after surgery, with no serious adverse effects noted during the study period.

The efficiency of continuous renal replacement therapy for rewarming of patients in accidental hypothermia--An experimental study.

Severe accidental hypothermia carries high mortality and morbidity and is often treated with invasive extracorporeal methods. Continuous veno-venous hemodiafiltration (CVVHDF) is widely available in intensive care units. We sought to provide theoretical basis for CVVHDF use in rewarming of hypothermic patients. CVVHDF system was used in the laboratory setting. Heat balance and transferred heat units were evaluated for the system without using blood. We used 5L of crystalloid solution at the temperature of approximately 25°C, placed in a thermally insulated tank (representing the "central compartment" of a hypothermic patient). Time of warming the central compartment from 24.9 to 30.0°C was assessed with different flow combinations: "blood" (central compartment fluid) 50 or 100 or 150 mL/min, dialysate solution 100 or 1500 mL/h, and substitution fluid 0 or 500 mL/h. The total circulation time was 1535 minutes. There were no differences between heat gain values on the filter depending on blood flow (P = .53) or dialysate flow (P = .2). The mean heating time for "blood" flow rates 50, 100, and 150 mL/min was 113.7 minutes (95% CI, 104.9-122.6 minutes), 83.3 minutes (95% CI, 76.2-90.3 minutes), and 74.7 minutes (95% CI, 62.6-86.9 minutes), respectively (P < .01). The respective median rewarming rate for different "blood" flows was 3.6°C/h (IQR, 3.0-4.2°C/h), 4.8 (IQR, 4.2-5.4°C/h), and 5.4 (IQR, 4.8-6.0°C/h), respectively (P < .01). The dialysate flow did not affect the warming rate. Based on our experimental model, CVVHDF may be used for extracorporeal rewarming, with the rewarming rates increasing achieved with higher blood flow rates.

The Influence of Inflammation on Fibrinogen Turnover and Redistribution of the Hemostatic Balance to a Prothrombotic State in High On-Treatment Platelet Reactivity-Dual Poor Responder (HTPR-DPR) Patients.

Knowledge about the influence of inflammation on platelet function and relocation of hemostatic balance to hypercoagulable state is still unclear. We compared two groups of patients who suffer from acute vs. chronic inflammatory process and additionally present high on-treatment platelet reactivity-dual platelet resistance. We did not found any differences in platelet aggregation between both investigated groups, but patients who suffer from chronic inflammation presented stronger relocation of the hemostatic balance to the hypercoagulability. A high concentration of prothrombin fragment F1+2 together with higher activity of von Willebrand factor in critical limb ischemia shows more exaggerated fibrinogen turnover although the blood concentration of this factor was in normal range. We concluded that high on-treatment platelet reactivity-dual platelet resistance and intensified inflammation are linked with elevated platelet and fibrinogen turnover to counteract proper hemostatic balance in favor of a prothrombotic state.

Comparing transpulmonary thermodilution monitoring to lung ultrasound during pneumonia: an observational study.

INTRODUCTION: Monitoring lung function during pneumonia is essential for the evaluation of the effectiveness of therapy in ICU patients. Among various bedside techniques, two particularly interesting are the lung ultrasound and the transpulmonary thermodilution technique. In this observational single center study we want to assess the correlation between the lung ultrasound examination (LUS) and transpulmonary thermodilution volumetric parameters such as extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI). MATERIAL AND METHODS: We analyzed data obtained from medical history of twelve patients requiring mechanical ventilation and hemodynamics monitoring with PICCO catheter due to newly diagnosed pneumonia. We compared lung ultrasound examination performed on the first and third day of new antimicrobial therapy with results of transpulmonary thermodilution examination made on same day. We also calculate the difference between values obtained on first and third day to compare the trends. RESULTS: We did not find any association between tested variables, except a correlation between PVPI and EVLWI, both measured at the same day (Rho = 0.3; 95%CI -0.02-0.59; p = 0.03), and trends in the period of 3 days (Rho = 0.6; 95%CI 0.2-0.8; p = 0.005). CONCLUSIONS: The results of the study indicate that volumetric values achieved using the PiCCO method as well as lung ultrasound should be interpreted with care and related to the clinical state of a patient, keeping in mind that no correlation between the result achieved and the actual state of inflammatory changes in the lungs may be possible.

Inter-arm differences in blood pressure among subjects with disseminated atherosclerosis scheduled for vascular surgery.

BACKGROUND: The measurement of blood pressure (BP) is routinely performed in perioperative care. The reliability of results is essential for the implementation of treatment ensuring haemodynamic stability. The aim of the present study was to assess the prevalence and basic determinants of inter-arm BP differences among patients with advanced peripheral atherosclerosis undergoing vascular surgical procedures of the lower limbs. METHODS: The prospective study was carried out in patients scheduled for elective lower limb vascular surgery. One-time non-invasive BP measurements were performed sequentially on the brachial arteries of both upper extremities before the induction of anaesthesia, maintaining the shortest possible interval between measurements. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded. RESULTS: The results of 173 patients (including 123 men aged 67 ± 8 years) were analysed. In 16 (9.3%) patients, an inter-arm difference in BP was already observed during the preoperative examination. SBP and DBP was higher in the right limb in 86 (49.7%) an 80 (46.3%) patients, respectively. Moreover, the medians of inter-arm differences in SBP, DBP and MAP were 9 (IQR 4-17), 5 (IQR 3-10) and 7 mm Hg (IQR 3-12), respectively. An evaluation of the determinants of BP differences related to the presence of additional diseases demonstrated that patients with arterial hypertension were characterised by higher SBP and MAP disproportions (P = 0.04 and P = 0.01). CONCLUSIONS: In the population of patients with disseminated atherosclerosis, the inter-arm differences in BP substantially exceed the measurement error limits and are likely to be associated with arterial hypertension. If in doubt about BP disproportions, intraoperative monitoring of BP should be recommended using an invasive method on the limb presenting higher non-invasively measured values.