Ziegler M U, Reinelt H
Klinik für Herz‑, Thorax‑, Gefäßchirurgie, Abteilung Kardioanästhesie, Universitätsklinik Ulm, Albert-Einstein-Allee 23, 89081, Ulm, Deutschland.
Anaesthesist. 2018 May;67(5):351-358. doi: 10.1007/s00101-018-0431-8. Epub 2018 Apr 5.
Patients undergoing cardiac surgery need extensive and invasive monitoring, which needs to be individually adapted for each patient and requires a diligent risk-benefit analysis. The use of a pulmonary artery catheter (PAC) seems to be justifiable in certain cases; therefore, the preoperative diagnosis of pulmonary hypertension represents an indication for perioperative monitoring with PAC in the S3 guidelines of the German Society for Anesthesiology and Intensive Care Medicine (DGAI). In many cases, however, this preoperative diagnosis cannot be confirmed intraoperatively.
We wanted to find out whether this is just an impression or whether there actually are significant differences between preoperative, intraoperative and postoperative pulmonary artery pressures.
After obtaining ethical approval, we retrospectively compared the pulmonary pressures of cardiac surgery patients with an elevated pulmonary pressure during preoperative right heart catheterization with those obtained intraoperatively and postoperatively by means of a PAC. All patients with a preoperatively documented pulmonary artery pressure of 40 mmHg or above and an intraoperative use of a PAC during a 4-year period were included. Exclusion criteria were intracardiac shunts, cardiogenic shock, emergency procedures, pulmonary hypertension of non-cardiac origin and a time span of more than 1 year between right heart catheterization and surgery. We included 90 patients.
In the whole group and in the subgroups (according to diagnosis, time elapsed between heart catheterization and operation and pulmonary pressure), there were significant differences between preoperative and intraoperative pulmonary and systemic pressures. Systemic and pulmonary artery pressures were significantly higher during preoperative catheterization than intraoperatively. The systemic systolic pressure/systolic pulmonary pressure ratio, however, remained constant. The intraoperative and postoperative systemic and pulmonary artery pressures showed no significant differences. As a normal ejection fraction does not exclude heart failure with preserved ejection fraction and as we did not have any information on this condition, we did not group the patients according to the ejection fraction.
An elevated pulmonary pressure obtained preoperatively during right heart catheterization is not indicative of an elevated pulmonary pressure either intraoperatively or postoperatively. There are various explanations for the differences (e.g., different physiological and pathophysiological settings, such as sedation with potential hypercapnia versus anesthesia with vasodilation when measured; newly prescribed medication coming into effect between the right heart catheterization and surgery; intraoperative positioning). Even though the inherent risks of a PAC seem to be low, we recommend refraining from using a PAC in patients with a once documented elevated pulmonary pressure by default. As an alternative we suggest estimating the pulmonary pressure by transesophageal echocardiography (TEE) as an aid to decide whether the patient will benefit from the use of a PAC. Especially if it is not possible to identify tricuspid valve regurgitation for determining the peak gradient, it is helpful to check for additional signs of pulmonary hypertension. But we also have to bear in mind that in the postoperative period only a PAC can provide continuous measurement of pulmonary pressure.
接受心脏手术的患者需要广泛且侵入性的监测，这种监测需要针对每个患者进行个体化调整，并且需要进行细致的风险效益分析。在某些情况下，使用肺动脉导管（PAC）似乎是合理的；因此，在德国麻醉与重症医学学会（DGAI）的S3指南中，术前诊断肺动脉高压是围手术期使用PAC进行监测的一个指征。然而，在许多情况下，这种术前诊断在术中无法得到证实。
我们想弄清楚这只是一种印象，还是术前、术中和术后肺动脉压力之间确实存在显著差异。
在获得伦理批准后，我们回顾性比较了术前右心导管检查时肺动脉压力升高的心脏手术患者的肺动脉压力与术中及术后通过PAC获得的压力。纳入了所有在4年期间术前记录的肺动脉压力为40mmHg或以上且术中使用PAC的患者。排除标准包括心内分流、心源性休克、急诊手术、非心脏源性肺动脉高压以及右心导管检查与手术之间间隔超过1年。我们纳入了90例患者。
在整个组以及各个亚组（根据诊断、心导管检查与手术之间的时间间隔以及肺动脉压力）中，术前与术中的肺循环和体循环压力存在显著差异。术前导管检查时的体循环和肺动脉压力显著高于术中。然而，体循环收缩压/收缩期肺动脉压力比值保持恒定。术中与术后的体循环和肺动脉压力没有显著差异。由于正常射血分数并不排除射血分数保留的心力衰竭，且我们没有关于这种情况的任何信息，所以我们没有根据射血分数对患者进行分组。
术前右心导管检查时测得的肺动脉压力升高并不意味着术中或术后肺动脉压力也升高。对于这些差异有多种解释（例如，不同的生理和病理生理状态，如测量时镇静可能导致高碳酸血症与麻醉伴血管扩张；右心导管检查与手术之间新开具的药物生效；术中体位）。尽管PAC的固有风险似乎较低，但我们建议对于曾记录到肺动脉压力升高的患者，默认情况下避免使用PAC。作为替代方案，我们建议通过经食管超声心动图（TEE）估计肺动脉压力，以辅助决定患者是否会从使用PAC中获益。特别是如果无法识别三尖瓣反流以确定峰值梯度时，检查肺动脉高压的其他征象会有所帮助。但我们也必须牢记，在术后阶段，只有PAC能够提供肺动脉压力的连续测量。
