Implementing point-of-care ultrasonography of the heart and lungs in an anesthesia department.

BACKGROUND: Implementation of point-of-care ultrasonography (POCUS) of the heart and lungs requires image acquisition skills among providers. We aimed to determine the effect of POCUS implementation using a systematic education program on image acquisition skills and subsequent use and barriers in a department of anesthesiology. METHODS: Twenty-five anesthesiologists underwent a systematic education program in POCUS during the fall of 2012. A POCUS expert evaluated images from baseline and evaluation examinations performed on two healthy individuals as useful or not useful for clinical interpretation. In August 2016, anesthesiologists employed at the department answered a questionnaire regarding the use of POCUS and perceived barriers to its use. RESULTS: The systematic education program increased the proportion of images useful for clinical interpretation from 0.70 (95% CI 0.65-0.75) to 0.98 (95% CI 0.95-0.99). This difference was significant when adjusted for prior cardiac ultrasonography courses, prior clinical cardiac ultrasonography experience, ultrasonography view, and ultrasound model (P < 0.001). After 3.5 years, 15/25 (60%) of perioperative medicine providers, 22/24 (92%) of intensive care providers, and 21/21 (100%) of pre-hospital care providers used POCUS either routinely, in selected patient groups, or sporadically. CONCLUSION: Implementation of POCUS by a systematic education program increased image acquisition skills across anesthesiologists employed at the department. POCUS was used in the intensive care setting, the pre-hospital setting, and to a lesser extent in the perioperative setting. Educational strategies for obtaining images under difficult conditions, practical equipment and evidence for effect on patient outcomes are required for full implementation of POCUS.

Effects of levosimendan in patients with left ventricular hypertrophy undergoing aortic valve replacement.

BACKGROUND: Left ventricular hypertrophy is associated with adverse outcomes, including death, during cardiac surgery. This may be facilitated by an increased oxygen demand and diastolic dysfunction. Levosimendan augments haemodynamics without further oxygen consumption and improves echocardiographic indices of diastolic dysfunction. This study aimed to describe the haemodynamic effects of short-term pre- and intra-operative levosimendan infusion including advanced echocardiographic measures of diastolic and systolic heart function. METHODS: The study was randomised, double-blinded and placebo-controlled performed at a single-centre university hospital. Patients with left ventricular hypertrophy and ejection fraction > 45% scheduled for single procedure aortic valve replacement were included and randomised to infusion of either levosimendan 0.1 µg/kg/min or placebo from 4 h before anaesthesia to the end of surgery. Outcome measures were echocardiographic indices of left ventricular diastolic function: E/e' (primary endpoint), e', e'/a' and indices of systolic function: longitudinal strain, ejection fraction and s'. Patients were followed until 6 months after surgery. In addition, invasive haemodynamic measures were obtained perioperatively. RESULTS: The trial was prematurely terminated due to an overall high incidence of post-operative atrial fibrillation (15/20, P = 0.002) after inclusion of 20 patients. The relative decrease in perioperative cardiac index was lower (P = 0.016) in the levosimendan group. There was no difference in E/e', and similar results were found for all measures of systolic function. CONCLUSION: Short-term levosimendan caused a transient relative increase in cardiac index, but no effect was seen on the first post-operative day and up to 6 months post-operatively with indices of systolic and diastolic heart function.

Routine pre-operative focused ultrasonography by anesthesiologists in patients undergoing urgent surgical procedures.

BACKGROUND: Unexpected cardiopulmonary complications are well described during surgery and anesthesia. Pre-operative evaluation by focused cardiopulmonary ultrasonography may prevent such mishaps. The aim of this study was to determine the frequency of unexpected cardiopulmonary pathology with focused ultrasonography in patients undergoing urgent surgical procedures. METHODS: We performed pre-operative focused cardiopulmonary ultrasonography in patients aged 18 years or above undergoing urgent surgical procedures at pre-defined study days. Known and unexpected cardiopulmonary pathology was recorded, and subsequent changes in the anesthesia technique or supportive actions were registered. RESULTS: A total of 112 patients scheduled for urgent surgical procedures were included. Their mean age (standard deviation) was 62 (21) years. Of these patients, 24% were American Society of Anesthesiologists (ASA) class 1, 39% were ASA class 2, 32% were ASA class 3, and 4% were ASA class 4. Unexpected cardiopulmonary pathology was disclosed in 27% [95% confidence interval (CI) 19-36] of the patients and led to a change in anesthesia technique or supportive actions in 43% (95% CI 25-63) of these. Unexpected pathology leading to changes in anesthesia technique or supportive actions was only disclosed in a group of patients above the age of 60 years and/or in ASA class ≥ 3. CONCLUSION: Focused cardiopulmonary ultrasonography disclosed unexpected pathology in patients undergoing urgent surgical procedures and induced changes in the anesthesia technique or supportive actions. Pre-operative focused ultrasonography seems feasible in patients above 60 year and/or with physical limitations but not in young, healthy individuals.

Ultrasonography-guided radial artery catheterization is superior compared with the traditional palpation technique: a prospective, randomized, blinded, crossover study.

BACKGROUND: Radial artery catheterization is gaining popularity for diagnostic and interventional procedures. Palpation technique is widely used for the procedure, but ultrasonography has been shown to increase catheterization success. A recently described ultrasonography technique is termed 'dynamic needle tip positioning'. We aimed to compare the traditional palpation technique and dynamic needle tip positioning technique in regard to clinically relevant end points. METHODS: The study was conducted as a randomized, patient-blinded, crossover study. Patients underwent bilateral radial artery catheterization using both techniques. The primary end point of the study was needle manipulation time. Additional end points were (1) the number of skin perforations, (2) the number of attempts targeting the vessel, (3) the number of catheters placed in first attempt and (4) the number of catheters used. RESULTS: Forty patients were analyzed. There was no significant difference in median needle manipulation time [32 s (range 11-96 s) vs. 39 s (range 9-575 s), P = 0.525], although the variance was lower in the dynamic needle tip positioning group (P < 0.001). In the traditional palpation technique group, a higher number of skin perforations (57 vs. 40, P = 0.003), catheters (46 vs. 40, P = 0.025) and attempts targeting the vessel (104 vs. 43, P < 0.001) were necessary compared with the ultrasonography dynamic needle tip positioning group. First attempt success rate was significantly higher in the ultrasonography dynamic needle tip positioning group (23/40 vs. 38/40, P < 0.001). CONCLUSION: Ultrasonography guidance using the dynamic needle tip positioning technique for radial artery catheterization significantly improves clinically relevant aspects of the procedure.

Pleural effusion decreases left ventricular pre-load and causes haemodynamic compromise: an experimental porcine study.

BACKGROUND: Although pleural effusion is a common complication in critically ill patients, detailed knowledge is missing about the haemodynamic impact and the underlining mechanisms. The aim of this study was to evaluate the haemodynamic effect of incremental pleural effusion by means of invasive haemodynamic parameters and transthoracic echocardiography. METHODS: This experimental interventional study was conducted using 22 female piglets (17.5-21.5 kg) randomized for right-side (n = 9) and left-side (n = 9) pleural effusion, or sham operation (n = 4). Pleural effusion was induced by infusing incremental volumes of saline into the pleural cavity. Invasive haemodynamic measurements and echocardiographical images were obtained at baseline, a volume of 45 ml/kg, a volume of 75 ml/kg and 45 min after drainage. RESULTS: No difference (all P > 0.147) was found between right- and left-side pleural effusion, and the groups were thus pooled. At 45 ml/kg cardiac output, mean arterial pressure, stroke volume and mixed venous saturation decreased (all P < 0.003); central venous pressure and pulmonary arterial pressure increased (both P > 0.003) at this point. The changes accelerated at 75 ml/kg. At 45 ml/kg left ventricular pre-load in terms of end-diastolic area decreased significantly (P < 0.001). The effect on haemodynamics and cardiac dimensions changed dramatically at 75 ml/kg. Cardiac output, mean arterial pressure, central venous pressure and left ventricular end-diastolic area returned to normal during a recovery period of 45 min (all P > 0.061). CONCLUSION: Incremental volumes of unilateral pleural effusion induced a significant haemodynamic impact fully reversible after drainage. Pleural effusion causes a significant decrease of left ventricular pre-load in a diverse picture of haemodynamic compromise.

Ultrasound assessment of inferior vena cava collapsibility is not a valid measure of preload changes during triggered positive pressure ventilation: a controlled cross-over study.

PURPOSE: Respiratory changes in the diameter of the inferior vena cava (IVC) have been validated as a measure of volume status and preload responsiveness during spontaneous breathing and mechanical ventilation. However, many intensive care patients are ventilated with triggered positive pressure ventilation (PPV). In this setting, there is no evidence regarding IVC collapsibility (IVCc) as a surrogate for preload. We aimed to elucidate the effects of increasing levels of triggered PPV and of varying preload conditions on the IVCc. MATERIALS AND METHODS: 10 healthy volunteers were connected to a ventilator through a tight-fitting mask and exposed to 6 different levels of positive end-expiratory pressure (PEEP) and pressure support (PS) after a baseline reading. All ventilator settings were performed at neutral preload (horizontal position), low preload (reverse-Trendelenburg) and high preload (Trendelenburg position with an intravenous fluid bolus). At each ventilator setting, the IVC was imaged throughout at least 1 respiratory cycle using 3 commonly used ultrasound techniques including sagittal M-mode and 2-dimensional echocardiography in both sagittal and transverse views. RESULTS: Increasing PS diminished IVCc (p = 0.01) in the reverse-Trendelenburg position, and increasing PEEP caused a higher IVCc in the Trendelenburg position (p = 0.02). In the horizontal position, no significant effects of increasing PS, PEEP or a combination of the two were seen. Overall ANOVA analysis showed that IVCc was not independent of preload. During PPV, IVCc was highest at neutral preload at most ventilator settings, IVCc was lowest at low preload, while high preload generally facilitated an IVCc between neutral and high preload. In addition, sagittal M-mode and transverse 2-dimensional echocardiography overestimated IVCc as compared to sagittal 2-dimensional echocardiography. CONCLUSION: The compiled results of this study show that IVCc cannot be held as a valid measure of preload status during PPV. This may be explained by systematic alterations in other determinants for IVCc. Comparison of methods encourages the use of sagittal 2-dimensional echocardiography for dynamic imaging of the IVC. Sagittal M-mode and transverse 2-dimensional echocardiography overestimate IVCc as compared to sagittal 2-dimensional echocardiography.

Focus-assessed transthoracic echocardiography in the sitting position: two life-saving cases.

Focus-Assessed Transthoracic Echocardiography (FATE) is a point-of-care ultrasound protocol allowing the fast evaluation of the cardio-pulmonary status. It has been well established that patients with an exacerbation of chronic obstructive lung disease and lung oedema benefit from the sitting position. These and other medical emergency situations may prevent patients from attaining the supine position, thus precluding standard echocardiography. Portable ultrasound machines with a wide range of different probes are now available at limited costs. This allows the physician to bring point-of-care ultrasound to the patient in almost any location. We present two cases of severely ill patients where FATE was performed in the sitting position with decisive impact on subsequent therapy.

New pocket echocardiography device is interchangeable with high-end portable system when performed by experienced examiners.

BACKGROUND: Cardiovascular status is a crucial determinant in the pre-operative assessment of patients for surgery as well as for the handling of patients with acute illness. We hypothesized that focus-assessed transthoracic echocardiography (FATE) could be performed with the subject in the semi-recumbent position. The aim was also to test whether the image quality of Vscan is interchangeable with a conventional high-quality portable echocardiography system. Furthermore, we evaluated the time needed to achieve an interpretable four-chamber view and to complete a full FATE examination. METHODS: Sixty-one subjects were included. All subjects were examined in accordance with the FATE protocol in the semi-recumbent position on two different systems: the novel Vscan pocket device and the high-quality portable Vivid i system. Two evaluations were performed. In group A (n=30), the focus was on image quality. In group B (n=31), the focus was on the time consumed. RESULTS: Group A: All patients (100%) had at least one image suitable for interpretation and no significant difference in image quality (P=0.32) was found between the two different systems. Group B: The mean value for the total time consumed for a full FATE was 69.3 s (59.8-78.8) on the Vscan and 63.7s (56.7-70.8) on the Vivid i, with no significant difference among the scanners (P=0.08). CONCLUSION: The Vscan displays image quality interchangeable with larger and more expensive systems. The apparatus is well suited for performing a FATE examination in a 1-day surgery setting and could very well also be applicable in almost any situation involving patients with acute illness.

A clinical case of tuberculosis with transient constrictive pericarditis and perimyocarditis.

Tuberculous pericarditis is a rare diagnosis seen among as few as 1% of tuberculosis (TB) patients in developed countries. We present a case of a 60-year-old male suffering from a transient constrictive pericarditis and subclinical involvement of the myocardium in a clinical case of tuberculous pericarditis with corresponding improvement after the initiation of anti-tuberculous treatment. We suggest monitoring of myocardial function using global longitudinal strain by myocardial speckle tracking strain analysis as supplement to routine left ventricular ejection fraction to assess clinical improvement in patients at risk of developing constrictive pericarditis. LEARNING POINTS: Tuberculous pericarditis is rare and a diagnostic challenge in low-incidence countries.Patients with tuberculosis and involvement of the heart are at high risk of developing constrictive pericarditis.Novel imaging techniques, such as estimation of global longitudinal strain using myocardial speckle tracking analysis, may be useful in assessing cardiac involvement in tuberculosis patients.

Endothelial dysfunction, ambulatory pulse pressure and albuminuria are associated in Type 2 diabetic subjects.

AIM: Elevated pulse pressure (PP) is associated with microvascular complications in Type 2 diabetic patients. In non-diabetic subjects, elevated PP has been associated with endothelial dysfunction. The relation between endothelial dysfunction and PP in diabetic subjects has not previously been examined. We examined the relation between PP, markers of endothelial activation and albuminuria in Type 2 diabetic patients. METHODS: In 46 Type 2 diabetic patients and 19 non-diabetic subjects, we performed 24-h ambulatory blood pressure (AMBP) monitoring. Urinary albumin excretion rate was measured as three urinary albumin/creatinine ratios. Von Willebrand factor (vWF), fibrinogen, E-selectin and soluble intercellular adhesion molecule 1 (ICAM-1) were measured in plasma. RESULTS: Thirty-four patients had normoalbuminuria (group N) and 12 had micro- or macroalbuminuria (group A). PP levels increased in a stepwise manner from the control group (group C) to group N and group A; night PP 43 +/- 5, 48 +/- 10 and 59 +/- 12 mmHg (groups C, N and A, respectively, P < 0.001). Likewise, plasma levels of vWF, fibrinogen, E-selectin and ICAM-1 increased from group C to group A; e.g. ICAM-1 [median (interquartile range)] 191 (160-217), 213 (189-262) and 316 (260-417) ng/ml, groups C, N and A, respectively, P < 0.001). In diabetic patients, night PP and plasma levels of E-selectin and ICAM-1 correlated (r = 0.38, P < 0.01 and r = 0.37, P = 0.01, night PP with E-selectin and ICAM-1, respectively). CONCLUSION: Increased PP is associated with endothelial activation and albuminuria in Type 2 diabetic patients. Thus, endothelial dysfunction may represent a pathophysiological link between an elevated PP and microvascular complications in these subjects. Prospective studies are needed to further elucidate these associations.