Background

As pulmonary diffusing capacity is related to mortality risk and prognosis in patients with heart failure (HF), it is measured frequently. As such, it would be essential to know the week-to-week variability (reproducibility) of pulmonary diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO). This variability would let clinicians understand what a clinically measurable change in DLCO and DLNO would be in these patients.

Methods

On three different days spanning over ten weeks, 40 H F patients underwent testing for DLCO and DLNO. DLCO was determined after a 4 s and 10 s breath-hold maneuver, while DLNO was determined after a 4 s breath-hold maneuver.

Results

Forty heart failure patients (66 ± 10 years; BMI = 28.4 ± 4.6 kg∙m⁻²; 28 males), that were referred to our clinic were able to complete the protocol. DLCO (4 s breath-hold) and DLNO (4 s breath-hold) were 79 ± 19 % and 59 ± 14 % predicted, respectively. Fifty percent of patients (n = 20) were below the lower limit of normal (LLN, below the 5th percentile) for predicted DLCO (4 s), while 78 % of patients (n = 31) were below the LLN for predicted DLNO. All 16 patients that were below the LLN for DLCO were also below the LLN for DLNO. Over a ten week period, the reproducibility of DLNO (4 s) DLCO (4 s) and DLCO (10 s) was 18.9, 8.2, and 5.9 mL min mmHg^-1, respectively.

Conclusions

The week-to-week fluctuation in DLNO (4 s), as a percentage, is less than DLCO (4 s) in patients with HF. The reproducibility of DLNO in patients with HF is like that of healthy subjects.

中文翻译：

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心力衰竭肺弥散能力的变异性。

背景

由于肺弥散能力与心力衰竭 (HF) 患者的死亡风险和预后相关，因此经常对其进行测量。因此，了解一氧化碳 (DLCO) 和一氧化氮 (DLNO) 的肺弥散能力的每周变化（再现性）至关重要。这种可变性将使临床医生了解这些患者的 DLCO 和 DLNO 的临床可测量变化。

方法

在跨越十周的三天内，40 名 H F 患者接受了 DLCO 和 DLNO 检测。DLCO 在 4 s 和 10 s 屏气操作后确定，而 DLNO 在 4 s 屏气操作后确定。

结果

被转诊到我们诊所的40 名心力衰竭患者（66 ± 10 岁；BMI = 28.4 ± 4.6 kg∙m ^-2；28 名男性）能够完成方案。DLCO（4 秒屏气）和 DLNO（4 秒屏气）的预测值分别为 79 ± 19 % 和 59 ± 14 %。50% 的患者 (n = 20) 低于预测 DLCO (4 s) 的正常下限 (LLN，低于第 5 个百分位数)，而 78% 的患者 (n = 31) 低于预测 DLNO 的 LLN。DLCO 低于 LLN 的所有 16 名患者也低于 DLNO 的 LLN。在十周内，DLNO (4 s) DLCO (4 s) 和 DLCO (10 s) 的重现性分别为 18.9、8.2 和 5.9 mL min mmHg ^-1。

结论

在 HF 患者中，DLNO (4 s) 的每周波动百分比小于 DLCO (4 s)。DLNO 在 HF 患者中的重现性与健康受试者相似。