Evidence-Based Considerations for the Design of an Open-Source Ventilator: A Systematic Review

OBJECTIVE: To inform the design of open-source ventilators, we performed a systematic review of clinical practice guidelines (CPGs) to consolidate the evidence on mechanical ventilation strategies that result in improved patient-important outcomes for acute hypoxic respiratory failure. DATA SOURCES: We developed a search strategy to identify relevant CPGs from Ovid Medline, Ovid Medline In-Process & Other Non-Indexed Citations, Embase, the Cochrane Library, Mendeley, and Google scholar from 2010 to February 17, 2022. STUDY SELECTION: Using a two-step screening process with two independent reviewers, we included CPGs that made recommendations on mechanical ventilation strategies of interest. Guidelines that reported at least one recommendation about mechanical ventilation in ICU patients with acute hypoxic respiratory failure were included. DATA EXTRACTION: From the 13 eligible guidelines, we collected data on country, aim, patient population, impact on morbidity and mortality (effect size and CIs), recommendations, strength of Recommendation (as per Grading of Recommendations, Assessment, Development and Evaluations), and details of supporting evidence base. DATA SYNTHESIS: We identified three ventilation strategies that confer a mortality and morbidity benefit for ventilated patients with acute hypoxic respiratory failure: low-tidal volume ventilation, plateau pressures of less than 30 cm H2O, and higher positive end-expiratory pressure (PEEP). These moderate-to-strong recommendations were based on moderate-to-high certainty in evidence. We identified several other recommendations with no or minimal certainty in evidence. CONCLUSIONS: Our systematic review of international CPGs identified no recommendations favoring specific mode of ventilation and three ventilation strategies that confer mortality and morbidity benefits, backed by moderate-to-strong evidence. Ventilator design teams must include the ability to consistently provide and measure low-tidal volume ventilation, plateau pressures of less than 30 cm H2O, and higher PEEP into their designs. Based on our findings, we provide the first public framework for open-source ventilator design

Examining the choice behind refusal of obstetric anaesthesia

Many women refuse an epidural during delivery, despite most women perceiving labour pain as the most excruciating event of their lifetime. This can be baffling to a physician involved in their care, but there are many historical and personal factors at play that must be taken into account. Use of obstetric anaesthesia began in 1847 and was met with controversy. In a time when childbirth physiology was poorly understood, physicians disagreed over the utility of labour pain and pain was even used as an indicator to guide delivery. Religious justification also perpetuated the reservations regarding obstetric anaesthesia. Despite initial overwhelming opposition to obstetric anaesthesia within the medical community, attitudes began to shift in favour of obstetric anaesthesia as a result of clinical observations and feminist advocacy. Obstetric anaesthesia has since been well-studied and routinely used, but historical misconceptions have endured and epidural refusal continues to linger in childbirth communities. Furthermore, there are some evidence-based concerns voiced by patients, including the risk of instrumental delivery and low risk for adverse events, which must be carefully addressed by physicians involved in patient care. In addition to concerns regarding safety of obstetric anaesthesia, pain is a subjective experience that may add meaning/fulfilment to childbirth for some patients. In conclusion, there are many historical and personal factors at play when it comes to refusal of obstetric anaesthesia, which must be understood by physicians to optimise patient care