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When propofol is infused rapidly for induction of anesthesia in healthy adults younger than 65 years, the duration of preoperative fluid abstinence does not appear to affect MAP or propofol dose requirements.

Background: A novel, wireless, ultrasound biosensor that adheres to the neck and measures real-time Doppler of the carotid artery may be a useful functional hemodynamic monitor. A unique experimental set-up during elective coronary artery bypass surgery is described as a means to compare the wearable Doppler to trans-esophageal echocardiography (TEE). Methods: A total of two representative patients were studied at baseline and during Trendelenburg position. Carotid Doppler spectra from the wearable ultrasound and TEE were synchronously captured. Areas under the receiver operator curve (AUROC) were performed to assess the accuracy of changing common carotid artery velocity time integral (ccVTI∆) at detecting a clinically significant change in stroke volume (SV∆). Results: Synchronously measuring and comparing Doppler spectra from the wearable ultrasound and TEE is feasible during Trendelenburg positioning. In two representative cardiac surgical patients, the ccVTI∆ accurately detected a clinically significant SV∆ with AUROCs of 0.89, 0.91, and 0.95 when single-beat, 3-consecutive beat and 10-consecutive beat averages were assessed, respectively. Conclusion: In this proof-of-principle research communication, a wearable Doppler ultrasound system is successfully compared to TEE. Preliminary data suggests that the diagnostic accuracy of carotid Doppler ultrasonography at detecting clinically significant SV∆ is enhanced by averaging more cardiac cycles.

Providing intravenous (IV) fluids to a patient with signs or symptoms of hypoperfusion is common. However, evaluating the IV fluid ‘dose–response’ curve of the heart is elusive. Two patients were studied in the emergency department with a wireless, wearable Doppler ultrasound system. Change in the common carotid arterial and internal jugular Doppler spectrograms were simultaneously obtained as surrogates of left ventricular stroke volume (SV) and central venous pressure (CVP), respectively. Both patients initially had low CVP jugular venous Doppler spectrograms. With preload augmentation, only one patient had arterial Doppler measures indicative of significant SV augmentation (i.e., ‘fluid responsive’). The other patient manifested diminishing arterial response, suggesting depressed SV (i.e., ‘fluid unresponsive’) with evidence of ventricular asynchrony. In this short communication, we describe how a wireless, wearable Doppler ultrasound simultaneously tracks surrogates of cardiac preload and output within a ‘Doppler Starling curve’ framework; implications for IV fluid dosing are discussed.

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Orthodeoxia is a rare clinical syndrome characterized by deoxygenation in the upright position and relieved by recumbency. Our rounds illustrate how cardiovascular imaging and echocardiography can be used to diagnose the etiology of this syndrome with respect to its association with patent foramen ovale (PFO) and ascending aortic aneurysms. The rounds also demonstrate the use of peri-operative transesophageal echocardiography (TEE) in understanding the mechanisms contributing to the condition and aid in appropriately planning medical and surgical management.The purpose of this Perioperative Cardiovascular Rounds article is to illustrate how cardiovascular imaging and echocardiography can be used to diagnose the etiology of the rare clinical syndrome, orthodeoxia, which is characterized by deoxygenation following sitting or standing from a recumbent position. In this case, the rounds also demonstrate the use of perioperative transesophageal echocardiography (TEE) to help understand the mechanisms contributing to the condition and plan appropriate medical and surgical management. Written consent for publication of this article was obtained from the patient's son who has power of attorney.A 76-year-old male presented to a community hospital with sudden onset chest pain, dyspnea, and diaphoresis. His medical history was remarkable for hypertension and hyperlipidemia. He was an ex-smoker of 40 years and he denied excessive alcohol intake. The patient was diagnosed in the emergency room with a non-ST segment elevation myocardial infarction and he was treated medically. Coronary angiography revealed severe three-vessel disease, and a transthoracic echocardiogram demonstrated normal left and right ventricular function with inferior wall hypokinesis. He was referred to our institution for consideration of coronary artery bypass grafting.While awaiting surgery, the patient continued to experience intermittent chest pain, which was relieved by nitroglycerine spray. His blood pressure, pulse, and respiratory rate were within normal limits. Physical examination revealed normal heart sounds with no audible murmur or jugulovenous distension. However, pulse oximetry revealed an oxygen saturation (SpO 2 ) level of 87% with a fractional inspired oxygen concentration (F I O 2 ) of 0.21. There was no improvement noted after applying oxygen via a facemask at F I O 2 of 0.5. Electrocardiography was unremarkable, with the exception of lateral T-wave flattening. Chest radiography noted cardiomegaly in the left ventricular configuration with minor left-sided basal atelectasis. Arterial blood gas analysis following commencement of non-invasive ventilation at F I O 2 of 1.0 revealed an arterial oxygen saturation level of 91% (PaO 2 61 mmHg). Computed tomography (CT) imaging of the patient's thorax with radiocontrast failed to show any evidence of pulmonary embolism. Incidental findings were very mild peripheral interstitial Electronic supplementary material The online version of this article

A preload challenge (PC) is a clinical maneuver that, first, increases the cardiac filling (i.e., preload) and, second, calculates the change in cardiac output. Fundamentally, a PC is a bedside approach for testing the Frank-Starling-Sarnoff (i.e., "cardiac function") curve. Normally, this curve has a steep slope such that a small change in the cardiac preload generates a large change in the stroke volume (SV) or cardiac output. However, in various disease states, the slope of this relationship flattens such that increasing the volume into the heart leads to little rise in the SV. In this pathological scenario, additional cardiac preload (e.g., intravenous fluid) is unlikely to be physiologically effective and could lead to harm if organ congestion evolves. Therefore, inferring both the cardiac preload and output is clinically useful as it may guide intravenous (IV) fluid resuscitation. Accordingly, the goal of this protocol is to describe a method for contemporaneously tracking the surrogates of cardiac preload and output using a novel, wireless, wearable ultrasound during a well-validated preload challenge.