Ono Naomi, Nakahira Junko, Matsunami Sayuri, Sawai Toshiyuki, Minami Toshiaki
Department of Anesthesiology, Osaka Medical College, Takatsuki, Japan.
Anesth Pain Med. 2016 Oct 23;6(6):e42621. doi: 10.5812/aapm.42621. eCollection 2016 Dec.
Pressure and waveform at the catheter tip are continuously monitored during catheterization of pulmonary artery to ensure accurate catheter placement. We present a case in which pulmonary venous blood was unexpectedly collected from the pulmonary artery catheter despite pulmonary artery pressure and waveform detection at the catheter tip, and describe the measures taken to correct the catheter placement.
A 74-year-old male underwent mitral valve plasty for cardiac failure caused by mitral valve regurgitation. Preoperative transthoracic echocardiography showed no septal shunt. The pulmonary artery was catheterized through a sheath introducer in the right jugular vein, and the balloon was inflated after insertion of a 15-cm catheter. The catheter was advanced until a pulmonary artery waveform was detected and the pulmonary artery wedge pressure was 21 mmHg at end-expiration. The balloon was deflated and the catheter tip was pulled back 3 cm. Pulmonary artery waveforms and appropriate a and v waves were detected, and transesophageal echocardiography confirmed the location of the catheter tip in the right pulmonary artery. The first collected blood sample had an oxygen partial pressure of 358.8 mmHg, carbon dioxide partial pressure of 20.1 mmHg, and oxygen saturation of 99%, indicating pulmonary venous blood. The pulmonary artery catheter was pulled back 5 cm, but a second blood sample showed the same results. The catheter was pulled back a further 6 cm while the location of the catheter tip was monitored on X-ray fluoroscopy. Blood gas testing through the catheter tip showed oxygen saturation of 84.4 % and oxygen partial pressure of 41.6 mmHg. Surgery was performed uneventfully. Postoperative chest radiographs showed proper placement of the pulmonary artery catheter, but radiographs on postoperative day 1 showed over-insertion, although the insertion length was unchanged. The catheter was removed. The patient was discharged 2 months postoperatively.
Our case highlights the fact that the tip of the pulmonary artery catheter can easily advance into a peripheral branch of the pulmonary artery and cause pulmonary venous blood to be sampled instead of pulmonary arterial blood. A variety of monitoring techniques are needed to confirm accurate catheter placement.
在肺动脉插管过程中持续监测导管尖端的压力和波形，以确保导管准确放置。我们报告一例尽管在导管尖端检测到肺动脉压力和波形，但仍意外地从肺动脉导管采集到肺静脉血的病例，并描述纠正导管放置所采取的措施。
一名74岁男性因二尖瓣反流导致心力衰竭接受二尖瓣成形术。术前经胸超声心动图显示无室间隔分流。通过右颈静脉的鞘管插入器进行肺动脉插管，插入一根15厘米的导管后充盈球囊。导管向前推进，直至检测到肺动脉波形且呼气末肺动脉楔压为21 mmHg。球囊放气，导管尖端回撤3厘米。检测到肺动脉波形以及适当的a波和v波，经食管超声心动图确认导管尖端位于右肺动脉。首次采集的血样氧分压为358.8 mmHg、二氧化碳分压为20.1 mmHg、氧饱和度为99%，表明为肺静脉血。肺动脉导管回撤5厘米，但第二次血样结果相同。在X线透视监测导管尖端位置的同时，导管又进一步回撤6厘米。通过导管尖端进行血气检测显示氧饱和度为84.4%、氧分压为41.6 mmHg。手术顺利进行。术后胸部X线片显示肺动脉导管放置正确，但术后第1天的X线片显示导管插入过深，尽管插入长度未变。导管被拔除。患者术后2个月出院。
我们的病例突出了一个事实，即肺动脉导管尖端可轻易进入肺动脉的外周分支，导致采集到肺静脉血而非肺动脉血。需要多种监测技术来确认导管放置准确。
