The specific objectives focus on using a train-the-trainer model to educate CHWs in Pakistan on performing and interpreting pediatric lung POCUS. In the first phase, the POCUS experts from Toronto will rigorously train the first generation of local lung POCUS users who are Pakistani health care providers to become local lung POCUS trainers. These first generation trainers will subsequently collaborate with the POCUS experts from Toronto to develop a two-day training program for lung POCUS image interpretation and acquisition that is tailored to novice users (CHWs) in low-resource settings. In the second phase, the first generation local lung POCUS trainers will deliver and evaluate the new training program to the second generation of users - a group of CHWs in Karachi. In the third phase, we will establish the reliability of CHWs to perform lung POCUS on pediatric patients with respiratory symptoms, upon completion of the training program developed by local trainers.

POCUS is an example of technologies that are moving out of hospitals and to the point-of-care. The true potential of these novel diagnostics to improve global pediatric pneumonia outcomes will only be realized if they can be employed by CHWs in community settings in LMICs. No work has yet focused on the performance of POCUS by non-medically-trained CHWs in LMICs. Demonstrating that accurate POCUS performance and interpretation can be achieved by non-medically-trained CHWs after focused and succinct training is the first step towards developing a novel pediatric pneumonia diagnosis and management algorithm for LMICs. Feedback from these ultrasound-naïve users about their lung POCUS learning experience is also needed to clarify which POCUS findings would be best suited to this algorithm.

The research team in AKUH will recruit and consent interested CHWs from AKU field sites in Karachi. The target is to recruit a convenience sample of 3 CHWs, who will be as representative as possible of the experience and skill sets as the average CHW in a government program. Study participants will be identified and approached by clinical team members in the AKUH emergency department, outpatient clinic and pediatric ward.

Triaging children with ARI into accurate treatment categories will lead to increased paediatric pneumonia survival, improved antibiotic stewardship, and more appropriate resource use, all of which are clinically and programmatically significant in highest disease burden settings. This project also lays the foundation for future projects that harness the trans-formative potential of POCUS for global child health.

Children between the ages of 2 to 59 months who is presenting with at least one of the following in the last 72 hours:

• patient reported symptoms (cough, coryza, reported fast breathing) AND
• WHO CRITERIA (FAST BREATHING (≥50 /min age if 2-12months, ≥40/min if age 1-5years) AND/OR CHEST INDRAWING and DANGER SIGNS (unable to drink, persistent vomiting, convulsions, lethargic or unconscious, stridor in a calm child, severe malnutrition) AND/ OR STRIDOR
• AND/OR Oxygen saturation < 96% OR CXR/CT pneumonia OR MD diagnosed pneumonia ● Patients admitted for non-respiratory symptoms may be included in the absence of exclusion criteria (this group will only be considered for the study if interim analysis reveals low recruitment of patients with a normal lung POCUS appearance)

Exclusion criteria:

• patients that previously underwent lung POCUS by the same lung POCUS operator during the same visit to AKUH
• chest tube insertion or video-assisted thoracoscopic surgery (VATS) during the current visit to AKUH (since the equipment in situ and/or dressing might bias POCUS interpretation)
• inability to understand informed consent

Children between age of 2 months to 5 years and presenting with signs and symptoms of pneumonia, will be identified and approached by clinical team members in the AKUH emergency department, outpatient clinic and pediatric ward. The research member will review the study with the family and obtain informed consent from parents.