A medical ventilation monitoring system for use in ventilation of a patient at the scene of an emergency, comprising: a patient ventilation unit providing an airflow path and arranged so that when the unit is applied to the patient, the airflow path is in fluid communication with the patient's airway; an airflow sensor (106; 206) positioned in the airflow path to sense the presence of ventilation airflow to or from the patient; and an external unit, separate from the patient ventilation unit, and comprising a portable medical device or portable computing device and arranged to receive from the airflow sensor a signal that indicates the occurrence of ventilation events, wherein the external unit is configured to determine a ventilation rate and/or a ventilation volume and to provide feedback that communicates to a rescuer and guides the rescuer regarding appropriate ventilation rate and/or ventilation volume for proper administration of ventilation that is manually performed by the rescuer; wherein the external unit is configured to: provide an initial treatment protocol for providing care to the patient comprising applying ventilation at an initial ventilation rate and at an initial ventilation volume and wherein said feedback that communicates to the rescuer and guides the rescuer is provided based on a comparison of said determined ventilation rate and/or said determined ventilation volume to the initial treatment protocol; receive data regarding one or more patient parameters; and provide a revised treatment protocol for providing care to the patient comprising applying ventilation at an updated ventilation volume different from the initial ventilation volume, or at an updated ventilation rate different from the initial ventilation rate, the revised treatment protocol being based at least in part on information from the airflow sensor and the received one or more patient parameters and wherein said feedback that communicates to the rescuer and guides the rescuer is provided based on a comparison of said determined ventilation rate and/or said determined ventilation volume to the revised treatment protocol so that the rescuer adapts their manually performed ventilations to the revised treatment protocol. a patient ventilation unit providing an airflow path and arranged so that when the unit is applied to the patient, the airflow path is in fluid communication with the patient's airway; an airflow sensor (106; 206) positioned in the airflow path to sense the presence of ventilation airflow to or from the patient; and an external unit, separate from the patient ventilation unit, and comprising a portable medical device or portable computing device and arranged to receive from the airflow sensor a signal that indicates the occurrence of ventilation events, wherein the external unit is configured to determine a ventilation rate and/or a ventilation volume and to provide feedback that communicates to a rescuer and guides the rescuer regarding appropriate ventilation rate and/or ventilation volume for proper administration of ventilation that is manually performed by the rescuer; provide an initial treatment protocol for providing care to the patient comprising applying ventilation at an initial ventilation rate and at an initial ventilation volume and wherein said feedback that communicates to the rescuer and guides the rescuer is provided based on a comparison of said determined ventilation rate and/or said determined ventilation volume to the initial treatment protocol; receive data regarding one or more patient parameters; and provide a revised treatment protocol for providing care to the patient comprising applying ventilation at an updated ventilation volume different from the initial ventilation volume, or at an updated ventilation rate different from the initial ventilation rate, the revised treatment protocol being based at least in part on information from the airflow sensor and the received one or more patient parameters and wherein said feedback that communicates to the rescuer and guides the rescuer is provided based on a comparison of said determined ventilation rate and/or said determined ventilation volume to the revised treatment protocol so that the rescuer adapts their manually performed ventilations to the revised treatment protocol.