Recently, the Internet of Things has been leading the technological revolution in several fields and applications. This revolution affected healthcare services adding more value to the concept of e-health. To improve the quality of these services, remote monitoring allows healthcare professionals to observe and diagnose their patients without being physically present. Since the spreading factor affects the energy consumption, the data rate, the receiver sensitivity and the time on air. A monitoring healthcare system using LoRa technology is proposed on this work to adopt the data transmission in a reliable and energy-efficient way. We propose a method to select the most convenient spreading factor based on the patients medical state. This method takes in consideration the distance to gateway, the packet error rate and the energy consumption requirements.We first determine the criticality level of the patient using the Early Warning Score system. Second, a decision about the optimal spreading factor is taken based on this level. We use a method based on the technique for order preference by similarity to an ideal solution to select a spreading factor. We use real data to show that the results reflect an acceptable increase in energy consumption while applying our selection method. In contrast, the results show that the selection method reduces the error rate especially for patients with a high critical level.