Timing For Single View Bedside Cardiac Ultrasound

This is a multi-center, prospective, observational trial involving sites across the United States and Canada. Residents will be enrolled when performing ultrasound imaging on non-critically ill patients in the emergency department. Residents obtaining cardiac ultrasound images on patients in the emergency department during pre-planned educational sessions will be enrolled in a prospective manner.

Physicians participating in this study will undergo a short educational session on both techniques of cardiac ultrasound as well as rationale for performing cardiac ultrasound rapidly during cardiac arrest. This educational intervention will provide the cognitive framework for the physicians to participate in the study. Physicians will be told to obtain the images as fast as possible and to get good quality images but they will be able to stop imaging if they are unable to obtain the images rapidly.

Individual physicians will be randomized to obtain a single parasternal or sub-xyphoid view of the hear first, followed by the other view. TTE will be performed on conscious and awake patients in the emergency department. Imaging will be performed in front of research staff. Primary outcome is time from transducer-skin contact to completion of the digital recording of a visible heart beating. Secondary outcome is the quality of the ultrasound image using a 5-point image quality scale.

Patients who will be imaged in this study will be those patients that would have been imaged during the existing educational session (scan shift). The patient will not need consent but can be told about the study if needed. No patient will be imaged if they have the possibility of having a clinical deterioration during the ultrasound imaging. Each set of images (PSL and SX) will be from a unique patient.

Subject data, with Protected Health Information (PHI) removed, will be recorded on data sheets prior to uploading into a centralized electronic database as soon as possible. Data will be obtained during the educational encounter including: Resident ID, post graduate year (PGY) level, Number of Cardiac Ultrasounds performed prior to starting study, US view attempted first, Imaging duration (seconds), Patient height, weight gender and age.

The imaging protocol will be standardized for consistency of timing. Prior to the ultrasound imaging the patient and ultrasound machine will be positioned with the patient laying flat on their back with the ultrasound machine immediately next to the patient's stretcher. A numbered study identification number (ID) will be entered into the US machine instead of any actual patient identifiers. The patient will have the area of their chest and abdomen exposed where imaging will occur. No instructions will be given to the patient about the imaging other that to lay still and lay flat. The patient will not be told to take a deep breath or to hold their breath or to position themselves in any way. The study subject (i.e. physician) will stand to the left or right of the patient with the transducer in hand.

Imaging will commence when directed by research staff. The study subject (i.e. physician) is instructed to obtain a specific view of the heart as rapidly as possible, with an end goal of obtaining a clear view of the heart as it contracts. The study subject is instructed to balance speed and imaging quality, but the predominant instruction is to get it a view of the heart beating as quickly as possible. The study subject will record a 4 second digital clip of the heart and remove the transducer from the patient's skin when they are done. Upon completing the imaging of the first view the images will be scored and the subject will prepare to be timed on the second view.

The study subject (i.e. the physician) will be randomized to initially one of two views, PSL or SX. Ultrasound images will consist of a single recorded view, either subxyphoid or parasternal. The randomization will occur immediately prior to obtaining the images. Randomization will occur using binary randomization app on smart phone and this will be recorded on study sheet. The second view (whichever view was not done the first time) will be recorded immediately after the completion and recording of data from the first view.

TIMING OF CARDIAC IMAGES Timing will occur using a standardized protocol. The subject will be told to start their imaging at the direction of research staff. The timing will start when the ultrasound transducer touches the patients skin.The timing will end when the transducer is removed from the patients skin for the last time.

INTERPRETATION OF CARDIAC IMAGES Images will be rated for quality by both the subject and research staff immediately after image review. This will occur blinded to each other's rating. All ultrasound images will be recorded for later review. Ultrasound images will be rated using a 5 point imaging scale. Images will be blindly reviewed by research staff at UMASS later using the same 5 point imaging scale and categorization. Images will also be reviewed later for identification of specific cardiac landmarks including Mitral Valve, Aortic Valve, Left Ventricle and Right Ventricle.