Portable echocardiography

[Prehospital ultrasound and cardiological emergencies]

Technological advances over the past two decades have paved the way for the prehospital use of ultrasound. This practice was first developed in traumatology and then in a multitude of other indications, including cardiology. The development of pulmonary ultrasound is certainly the most visible illustration of this. Firstly, because it is an extra-cardiac examination that provides the answer to a cardiac question. Secondly because from a theoretical point of view this ultrasound indication was a bad indication for the use of ultrasound due to the air contained in the thorax. Thirdly, because this indication has become a 'standard of care' when caring for a patient with dyspnea - a practice that has become widespread during the COVID epidemic. In patients with heart failure, ultrasound has a high diagnostic power (including for alternative diagnoses) which is all the more precise since the technique is non-invasive, the response is obtained quickly, the examination can be repeated at desire to follow the evolution of the patient. The main other indications for prehospital ultrasound are cardiac arrest to search for a curable cause, identification of residual mechanical cardiac activity, monitoring of cerebral perfusion; chest pain, for both positive and negative diagnoses; shock for the search for an etiology and therapeutic follow-up or even pulmonary embolism or ultrasound for the search for dilation of the right ventricle which is now at the forefront of the recommendation algorithm.

Echocardiography practice, training and accreditation in the intensive care: document for the World Interactive Network Focused on Critical Ultrasound (WINFOCUS)

Echocardiography is increasingly used in the management of the critically ill patient as a non-invasive diagnostic and monitoring tool. Whilst in few countries specialized national training schemes for intensive care unit (ICU) echocardiography have been developed, specific guidelines for ICU physicians wishing to incorporate echocardiography into their clinical practice are lacking. Further, existing echocardiography accreditation does not reflect the requirements of the ICU practitioner. The WINFOCUS (World Interactive Network Focused On Critical UltraSound) ECHO-ICU Group drew up a document aimed at providing guidance to individual physicians, trainers and the relevant societies of the requirements for the development of skills in echocardiography in the ICU setting. The document is based on recommendations published by the Royal College of Radiologists, British Society of Echocardiography, European Association of Echocardiography and American Society of Echocardiography, together with international input from established practitioners of ICU echocardiography. The recommendations contained in this document are concerned with theoretical basis of ultrasonography, the practical aspects of building an ICU-based echocardiography service as well as the key components of standard adult TTE and TEE studies to be performed on the ICU. Specific issues regarding echocardiography in different ICU clinical scenarios are then described. Obtaining competence in ICU echocardiography may be achieved in different ways - either through completion of an appropriate fellowship/training scheme, or, where not available, via a staged approach designed to train the practitioner to a level at which they can achieve accreditation. Here, peri-resuscitation focused echocardiography represents the entry level--obtainable through established courses followed by mentored practice. Next, a competence-based modular training programme is proposed: theoretical elements delivered through blended-learning and practical elements acquired in parallel through proctored practice. These all linked with existing national/international echocardiography courses. When completed, it is anticipated that the practitioner will have performed the prerequisite number of studies, and achieved the competency to undertake accreditation (leading to Level 2 competence) via a recognized National or European examination and provide the appropriate required evidence of competency (logbook). Thus, even where appropriate fellowships are not available, with support from the relevant echocardiography bodies, training and subsequently accreditation in ICU echocardiography becomes achievable within the existing framework of current critical care and cardiological practice, and is adaptable to each countrie's needs.

Physiological changes of pregnancy and monitoring

Advances in medical care have led to increasing numbers of complex, high-risk obstetric patients. Specialist training and a sound knowledge of normal maternal physiology are essential to optimize outcomes. One of the earliest observed changes is peripheral vasodilatation; this causes a fall in systemic vascular resistance and triggers physiological changes in the cardiovascular and renal systems, with 40-50% increases in cardiac output and glomerular filtration rates. Safety concerns over Swan Ganz catheters have driven the increasing interest in alternative techniques, such as echocardiography, thoracic bioimpedance and pulse contour analysis, although their exact roles in future obstetric high-dependency care have yet to be established. Analysis of arterial blood gases is fundamental to the management of sick patients, and correct interpretation can be aided by a systematic approach. Observation charts are almost ubiquitous in all aspects of medicine, but little evidence exists to support their use in the high-dependency setting.

Cardiovascular symptoms and signs in evaluating cardiac murmurs in children

BACKGROUND

The aim of the present study was to determine the usefulness of cardiovascular symptoms and signs in the recognition of significant congenital heart lesions that required surgical or catheter interventions in different pediatric age groups.

METHODS

A retrospective chart review was carried out of 110 patients with significant heart anomalies that required surgical or catheter interventions (group I) and 113 children, presenting with cardiac murmurs, with congenital heart conditions not requiring any interventions. (group II).

RESULTS

Clinical symptoms or signs were significantly more common in group I than in group II subjects (85% vs 32%, P < 0.0001). The odds of having significant lesions requiring interventions in the presence of either cardiovascular symptoms or signs were 37.5 (95% confidence interval [CI]: 6.5-218.1) for neonates, 14.5 (95%CI: 4.7-51.7) for infants, and 8.0 (95%CI: 3.3-19.2) for children and adolescents. In neonates, the negative predictive values of the absence of symptoms or signs in isolation were relatively low at 64% and 65%, respectively. In children beyond infancy, the positive predictive values of the presence of symptoms or signs in isolation were also low at 62% and 68%, respectively.

CONCLUSIONS

Clinical assessment of cardiovascular symptoms and signs remains useful in the evaluation of the significance of pathological cardiac murmurs in children in the present era of technology. Nonetheless, the predictive values vary with different pediatric age groups.

Fatal cardiac tamponade as a result of a peripherally inserted central venous catheter: a case report and review of the literature

We present a case of fatal cardiac tamponade that occurred in association with a peripherally inserted central catheter (PICC) inserted from the right antecubital fossa. Migration of the catheter from the right atrium within 24 h of insertion lead to the administration of a potassium-enriched sodium chloride solution into the pericardial space with the development of ST-segment elevation and progression to pulseless electrical activity and, subsequently, ventricular fibrillation. Although signs of tamponade were seen on echocardiography, we propose that myocardial hyperkalaemia from the diffusion of potassium through the epicardium accounted for some of the clinical picture. PICC lines carry a greater risk of migration because of the tip movement associated with arm abduction and, therefore, care must be taken to ensure that the catheter tip is correctly positioned to reduce this risk. When such catheters are used for intra-operative central venous access, we believe chest radiography is mandatory before fluid administration through the catheter, but that this is unnecessary when the catheter is being used solely for central venous pressure monitoring. The use of softer catheters may reduce the risk of vessel perforation. Once tamponade is suspected, all drugs and infusions administered via the catheter should be reviewed, the catheter aspirated and echocardiography performed urgently. This may be facilitated by the greater availability of limited bedside echocardiography within critical care units and theatre complexes.

Management of sepsis during the early "golden hours"

Severe sepsis and septic shock are common causes of morbidity and mortality. Interventions directed at specific endpoints, when initiated early in the "golden hours" of patient arrival at the hospital, seem to be promising. Early hemodynamic optimization, administration of appropriate antimicrobial therapy, and effective source control of infection are the cornerstones of successful management. In patients with vasopressor-dependent septic shock, provision of physiologic doses of replacement steroids may result in improved survival. Administration of drotrecogin alfa (activated), (activated protein C) has been shown to improve survival in patients with severe sepsis and septic shock who have a high risk of mortality. In this article we review the multi-modality approach to early diagnosis and intervention in the therapy of patients with severe sepsis and septic shock.

Cardiorespiratory symptoms during pregnancy – not always pulmonary embolism

We describe a case of sudden onset severe cardiorespiratory compromise in a parturient at 36 weeks' gestation. She received treatment for infection, pulmonary oedema and pulmonary embolism before a diagnosis of aortic dissection was made. Successful repair was undertaken following caesarean section. We discuss the difficulties of diagnosis of cardiorespiratory symptoms and the potential hazards of instituting therapy before a definitive diagnosis is reached. The value of a multidisciplinary team approach and the use of portable echocardiography in the investigation of both pulmonary embolism and cardiac disease are emphasised.

Screening for ventricular remodeling

Current guidelines emphasize the importance of preventing heart failure (HF) by targeting people with preclinical forms of the disease. Accordingly, there is considerable interest in identifying left ventricular (LV) remodeling, the fundamental substrate for HF, in asymptomatic individuals in the community. Increased LV mass and asymptomatic LV systolic and LV diastolic dysfunction are the remodeling phenotypes that could be potentially considered for population-wide screening. Plasma levels of natriuretic peptides (NP) have been extensively investigated for such screening purposes. However, a majority of investigations suggest that their performance characteristics are suboptimal for identifying LV remodeling phenotypes unless high-risk individuals (eg, older men with hypertension) are targeted. In general, the prevalence of LV systolic dysfunction in women is too low to justify screening. In recent reports, sequential screening strategies combining urine and plasma NP or plasma NP and hand-held portable echocardiography have been advocated as potential approaches to identify asymptomatic LV systolic dysfunction in a cost-effective manner. Additional studies are warranted to confirm these findings.

Usefulness of hand-held ultrasound devices in out-of-hospital diagnosis performed by emergency physicians

OBJECTIVE

To evaluate the usefulness of ultrasonographic examinations as a diagnostic tool for emergency physicians in out-of-hospital settings.

METHODS

Prospective study performed in a French teaching hospital. Eight emergency physicians given ultrasound training for out-of-hospital diagnosis of pleural, peritoneal, or pericardial effusion; deep venous thrombosis; and arterial flow interruption. After clinical examination, a probability of diagnosis ("clinical score") was assigned on visual analog scale from 0 (absent lesion) to 10 (present lesion). Clinical score between 3 and 7 was considered as clinically doubtful. After ultrasound examination, a second probability ("ultrasound score") was similarly determined. Potential usefulness of ultrasound examination was evaluated by calculating the absolute difference between clinical and ultrasound scores. Patients were followed up to determine final diagnosis: present or absent lesion. "Ultrasound usefulness score" (USS) was determined attributing a positive (when ultrasonography increased diagnostic accuracy) or a negative (when ultrasonography decreased diagnostic accuracy) value to the absolute difference between clinical and ultrasound scores.

RESULTS

One hundred sixty-nine patients were included and 302 ultrasound examinations performed. Median duration of examination was 6 minutes (5-10 minutes). The suspected lesion was found in 45 cases (17%). Mean USS was +2 (0-4). Ultrasonographic examination improved diagnostic accuracy (ie, positive USS) in 181 (67%) cases, decreased it (ie, negative USS) in 22 (8%) cases, and was not contributive (ie, USS was 0) in 67 (25%) cases. When initial diagnosis was uncertain (n = 115), diagnostic performance reached +4 (3-5) and ultrasonographic examination improved diagnostic accuracy in 103 (90%) cases.

CONCLUSION

Out-of-hospital ultrasonography increased diagnostic accuracy in out-of-hospital settings.

The Use of Hand-carried Ultrasound in the Hospital Setting-A Cost-effective Analysis

OBJECTIVES

We sought to assess the accuracy of hand-carried ultrasound (HCU) in the prediction of a normal study, and its cost-effectiveness in reducing the number of standard departmental echocardiograms (SDE) performed on hospital inpatients.

METHODS

The setting was a district general hospital. Participants were 157 consecutive inpatients, mean age 68 (range: 18-97) years, 95 men (61%), referred for SDE. HCU was performed at the bedside as part of the clinical assessment. SDE was performed routinely. Main outcome measures were: (1) assessment of the accuracy of HCU in detection of a normal or abnormal study as determined by SDE; and (2) a cost-effectiveness analysis.

RESULTS

Indications for echocardiography were: left ventricular (LV) function assessment, n = 101 (64.3%); valvular abnormalities, n = 11 (7%); arrhythmia, n = 4 (2.6%); miscellaneous, n = 10 (6.4%); and no reason stated, 31 (19.7%). The sensitivity, specificity, and positive and negative predictive values of HCU predicting a completely normal scan were 74%, 96%, 94%, and 81%, respectively, and of predicting normal LV function in requests specific for LV function assessment were 81%, 100%, 100%, and 77%, respectively. If either all inpatients or those with requests for LV function assessment underwent HCU initially, and only those with abnormal scans underwent further SDE, there would be a 29% and 22% reduction in departmental workload and a cost saving of pound sterling 23,000 and pound sterling 30,000, respectively.

CONCLUSION

HCU is an accurate method of identifying patients with normal hearts as determined by SDE. Its routine use is cost-effective and can significantly reduce the number of SDE that need be performed.