Department of Critical Care Medicine, West China Medical School, West China Hospital, Sichuan University, Chengdu, PR China.
Northern Clinical School Intensive Care Research Unit, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
BMC Pulm Med. 2023 Sep 13;23(1):343. doi: 10.1186/s12890-023-02633-y.
Diaphragmatic dysfunction is known to be associated with difficulties weaning from invasive mechanical ventilation and is related to worse patient outcomes yet our understanding of how to prevent diaphragmatic dysfunction remains incomplete. We examined potentially modifiable risk factors for diaphragmatic dysfunction and attempted to estimate benefits attributable to altering these modifiable risk factors.
This prospective multicenter observational study was undertaken in the general ICUs of two tertiary care teaching hospitals. Critically ill adults expected to receive invasive mechanical ventilation for at least 48 h were enrolled. Diaphragm function was assessed by ultrasound each study day, with dysfunction defined as thickening fraction less than 20%.
From January to December 2019, 856 patients were screened and 126 patients were enrolled. Overall, 40.5% (51/126) of patients experienced diaphragmatic dysfunction during invasive mechanical ventilation. Patients with diaphragmatic dysfunction were more likely to develop ventilator associated pneumonia (risk difference [RD] + 12.9%, 95% Confidence Interval [CI] 1.4 to 24.4%, P = 0.028), were more likely to experience extubation failure (RD + 8.5%, 95% CI 0.4 to 16.6%, P = 0.039) and required a longer duration of invasive mechanical ventilation (RD + 1.3 days, 95% CI 0.1 to 2.5 days, P = 0.035). They also required a longer hospital stay (RD + 1.2 days, 95% CI 0.04 to 2.4 days, P = 0.041) and were more likely to die before hospital discharge (RD + 18.1%, 95% CI 3.7 to 32.5%, P = 0.014). Multivariable analysis considered the impact of age, sex, pre-existing nutritional status, caloric intake, amino acid intake, acute disease severity, modes of mechanical ventilation, measures of respiratory status, sedation, pain control and baseline diaphragm thickness. Only SOFA score (P = 0.008) and early amino acid intake (P = 0.001) remained significant independent risk factors for the onset of diaphragmatic dysfunction. Causal path modeling suggested early amino acid intake may significantly reduce diaphragmatic dysfunction (RRR 29%, 95% CI 10% to 48%, P = 0.003) and may also reduce mortality (RRR 49%, 95% CI 25% to 73%, P < 0.0001).
Amino acid intake during the first 24 h of ICU stay may represent an important, modifiable risk factor for diaphragmatic dysfunction and may have a direct causal effect on mortality. We recommend additional research on this topic.
膈肌功能障碍与脱离有创机械通气的困难有关，与患者预后较差有关，但我们对如何预防膈肌功能障碍的理解仍不完整。我们研究了与膈肌功能障碍相关的潜在可改变的危险因素，并试图估计改变这些可改变的危险因素的获益。
这是一项在两家三级教学医院的普通 ICU 进行的前瞻性多中心观察性研究。预计需要接受至少 48 小时有创机械通气的重症成人患者被纳入研究。每天通过超声评估膈肌功能，将功能障碍定义为增厚分数小于 20%。
2019 年 1 月至 12 月，对 856 名患者进行了筛查，126 名患者入组。总体而言，40.5%（51/126）的患者在有创机械通气期间发生膈肌功能障碍。有膈肌功能障碍的患者更有可能发生呼吸机相关性肺炎（风险差异[RD] + 12.9%，95%置信区间[CI] 1.4 至 24.4%，P=0.028），更有可能发生拔管失败（RD + 8.5%，95% CI 0.4 至 16.6%，P=0.039），需要更长的有创机械通气时间（RD + 1.3 天，95% CI 0.1 至 2.5 天，P=0.035）。他们还需要更长的住院时间（RD + 1.2 天，95% CI 0.04 至 2.4 天，P=0.041），并且更有可能在出院前死亡（RD + 18.1%，95% CI 3.7 至 32.5%，P=0.014）。多变量分析考虑了年龄、性别、预先存在的营养状况、热量摄入、氨基酸摄入、急性疾病严重程度、机械通气模式、呼吸状态测量、镇静、疼痛控制和基线膈肌厚度的影响。只有 SOFA 评分（P=0.008）和早期氨基酸摄入（P=0.001）仍然是膈肌功能障碍发生的独立显著危险因素。因果路径建模表明，早期氨基酸摄入可能显著降低膈肌功能障碍（RRR 29%，95% CI 10%至 48%，P=0.003），并可能降低死亡率（RRR 49%，95% CI 25%至 73%，P<0.0001）。
入住 ICU 后 24 小时内的氨基酸摄入可能是膈肌功能障碍的一个重要的、可改变的危险因素，并且可能对死亡率有直接的因果关系。我们建议对此主题进行更多研究。
