Paweł Andruszkiewicz

Bedside Ultrasonographic Measurement of the Inferior Vena Cava Fails to Predict Fluid Responsiveness in the First 6 Hours After Cardiac Surgery: A Prospective Case Series Observational Study

OBJECTIVE To assess validity of respiratory variation of inferior vena cava (IVC) diameter to predict fluid responsiveness and guide fluid therapy in mechanically ventilated patients during the first 6 hours after elective cardiac surgery. DESIGN Prospective observational case series study. SETTING Single-center hospital. PATIENTS 50 consecutive patients undergoing elective cardiac surgery. INTERVENTIONS Transthoracic bedside echocardiography. MEASUREMENTS AND MAIN RESULTS Parameters derived from ultrasonographic assessment of the IVC diameter (collapsibility index [CI], distensibility index [DI], and IVC/aorta index). In the whole study group, change in fluid balance correlated with change in IVC maximum diameter (p = 0.034, r = 0.176). IVC-CI and IVC-DI correlated with IVC/aorta index. A weak correlation between central venous pressure (CVP) and IVC-derived parameters (IVC-CI and IVC-DI) was noticed. Despite statistical significance (p<0.05), all observed correlations expressed low statistical power (r<0.21). There were no statistically significant differences between fluid responders and nonresponders in relation to clinical parameters, CVP, ultrasound IVC measurement, and IVC-derived indices. CONCLUSION Dynamic IVC-derived parameters (IVC-CI, IVC-DI, and IVC/aorta index) and CVP are not reliable predictors of fluid responsiveness in the first 6 hours after cardiac surgery. Complexity of physiologic factors modulating cardiac performance in this group may be responsible for the difficulty in finding a plausible monitoring tool for fluid guidance. Bedside ultrasonographic measurement of IVC is unable to predict fluid responsiveness in the first 6 hours after cardiac surgery.

Ultrasound in critical care

Ultrasound has been revolutionising our specialty. The introduction of new, portable machines and goal-directed protocols has led many anaesthetists to use this diagnostic tool in their daily practice. Immediate, bedside ultrasound diagnosis of many life-threatening emergencies (pneumothorax, cardiac tamponade, or internal haemorrhage) enables not only the institution of proper treatment, but also the monitoring of its effectiveness. Ultrasound guided invasive procedures (such as vascular cannulations, toraco- and pericardiocentesis) have superseded the old anatomical landmarks-based techniques due to a greater safety margin. In order to perform a credible ultrasound examination, a proper level of competence is required. In this review article, the authors present various critical ultrasound applications.

Ultrasonographic caval indices do not significantly contribute to predicting fluid responsiveness immediately after coronary artery bypass grafting when compared to passive leg raising

BackgroundAppropriate fluid management is one of the most important elements of early goal-directed therapy after cardiothoracic surgery. Reliable determination of fluid responsivenss remains the fundamental issue in volume therapy.The purpose of the study was to assess the usefulness of dynamic IVC-derived parameters (collapsibility index, distensibility index) in comparison to passive leg raising, in postoperative fluid management in mechanically ventilated patients with left ventricular ejection fraction ≥ 30 %, immediately after elective coronary artery bypass grafting.MethodsProspective observational case series study including 35 patients with LVEF ≥ 30 %, undergoingelective coronary artery bypass grafting was conducted. Transthoracic echocardiography, passive leg raising and intravenous administration of saline were performed in all study subjects. Dynamic parameters derived from ultrasonographic assessment of the IVC diameter (collapsibility index–CI and distensibility index–DI), cardiac outputResultsThere were 24 (68.57 %) responders in the study population. There were no statistical differences between the groups in relation to: clinical parameters, pre- and postoperative LVEF, fluid balance and CVP. Change in cardiac output after passive leg raising correlated significantly with that after the volume expansion (p=0.000, r=0.822). Dynamic IVC derivatives were slightly higher in fluid responders, however this trend did not reach statistical significance. None of the caval indices correlated with fluid responsiveness.ConclusionDynamic IVC-derived parameters do not predict fluid responsiveness in mechanically ventilated patients with preserved ejection fraction immediately after elective coronary artery bypass grafting. Passive leg raising is not inferior to volume expansion in differentiating between fluid responders and nonresponders. Immediate fluid challenge after CABG is safe and well tolerated.

Simple mnemonic for focused cardiac ultrasound examination in an emergency.

Transthoracic echocardiography is an excellent bedside diagnostic tool enabling immediate diagnosis of life-threatening emergencies and monitoring of the effectiveness of the instituted treatment. Advances in technology and the introduction of portable machines with simple, user-friendly software have resulted in the growing popularity of this technology among intensivists and emergency physicians. One of the most important challenges for the examining physician is competent interpretation of the images. Due to the complexity of cardiac anatomy and function, cardiac ultrasound performed by noncardiologists carries a significant risk of missing relevant diseases. We present a simple, easy-to-remember mnemonic tool that provides a structure for cardiac ultrasound examination and has the potential to reduce the overlooking of common diseases.

Effectiveness and Validity of Sonographic Upper Airway Evaluation to Predict Difficult Laryngoscopy

Our objective was to evaluate the effectiveness of 9 airway sonographic parameters imaged from the submandibular view as predictors of difficult laryngoscopy. Additionally, we aimed to evaluate the validity of the models of combined sonographic and clinical tests in predicting difficult laryngoscopy.

A comparison of the ultrasound measurement of the inferior vena cava obtained with cardiac and convex transducers

Background Ultrasound measurement of the inferior vena cava diameter and its respiratory variability are amongst the predictors of fluid volume status. The primary purpose of the present study was to compare the consistency of inferior vena cava diameter measurements and the collapsibility index, obtained with convex and cardiac transducers. A secondary aim was to assess the agreement of the patient’s allocation to one of the two groups: “fluid responder” or “fluid non-responder”, based on inferior vena cava collapsibility index calculation made with two different probes. Methods 20 experienced clinicians blinded to the purpose of the study analysed forty anonymized digital clips of images obtained during ultrasound examination of 20 patients. For each patient, one digital loop was recorded with a cardiac and the second with a convex probe. The participants were asked to determine the maximal and minimal diameters of the inferior vena cava in all presented films. An independent researcher performed a comparative analysis of the measurements conducted with both probes by all participants. The calculation of the collapsibility index and allocation to “fluid responder” or “fluid non-responder” group was performed at this stage of the study. Results The comparison of measurements obtained with cardiac and convex probes showed no statistically significant differences in the measurements of the maximal and minimal dimensions and in the collapsibility index. We also noticed that the decision of allocation to the “fluid responder” or “non-responder” group was not probe-dependent. Conclusion Both transducers can be used interchangeably for the estimation of the studied dimensions.

Standards of the Polish Ultrasound Society. Ultrasound examination in anesthesiology and intensive care

This article has been prepared on the basis of the Ultrasonography Standards of the Polish Ultrasound Society (2011) and updated based on the latest findings and reports. Various applications of ultrasonography are used in anesthesiology and intensive therapy both for diagnosis and as a supportive tool during invasive procedures (such as vascular cannulation or regional anesthesia). Ultrasound examinations performed by anesthesiologists in intensive care units are not detailed scans, but they are focused on immediate identification of pathologies that lead to life-threatening conditions. Performing repeated US exams in time intervals enables a physician to monitor the effectiveness of the instituted treatment. Many simplified protocols are used in clinical practice which help to systemize the examination. Focused US examination should be verified by a physician competent in this imaging method as soon as possible. Due to the specificity of anesthesiologists’ practice and spatial limitations of operating rooms and intensive care units, portable robust ultrasound equipment with short power-on to scanning time is preferable. A growing number of indications show that ultrasound machine should be equipped with three basic transducers (linear, convex and sector), and in higher-reference centers with a transesophageal probe. The specificity of certain procedures guided by ultrasonography requires adherence to safety measures, e.g. full sterility condition during vein cannulation.

Measurement of cricoid pressure force during simulated Sellick’s manoeuvre

BACKGROUND Cricoid pressure is a standard anaesthetic procedure used to reduce the risk of aspiration of gastric contents during the induction of general anaesthesia. However, for several years its validity has been questioned. There still remains the question of whether we perform it correctly. The aim of the study was an evaluation of the theoretical knowledge of Sellicks manoeuvre, as well an assessment of practical skill related with it when simulated on a model of the upper airway. METHODS The study was performed on a cohort of anaesthetists and anaesthetic nurses working in various hospitals in the Warsaw area. Measurements were taken on an upper airway model placed on an electronic kitchen scale. Participants were asked to perform Sellicks manoeuvre in the way they do it in their clinical practice. The test was done twice. Both the position and pressures applied on the model were documented. Knowledge concerning current recommendations of cricoid force was noted. RESULTS 206 subjects participated in the study. Only 49% (n = 101) properly identified cricoid cartilage during their application of Sellicks manoeuvre. Application of the correct pressure on the model of the airway was noted in 16.5% (n = 34) during the first attempt and in 20.4% (n = 42) during the second attempt. The median force applied during simulated Sellicks manoeuvrewas 36 N (IQR: 26-55) in the first attempt, and 38 (IQR 25-55) in the second attempt. CONCLUSIONS Sellicks manoeuvre was performed incorrectly in many cases. Half of the participants of our study applied the pressure in the wrong place while the majority of them used an inappropriate amount of force. Thus, the application of cricoid pressure in patients should be preceded with simulation training.