Usefulness of Ultrasound for Diagnostic Pneumothorax after Central Venous Catheter Insertion

Mai Kishi, M.D., Akihiro Suzuki, M.D., Ph.D., Atsushi Kurosawa, M.D., Hirotsugu Kanda, M.D., Takayuki Kunisawa, M.D., Ph.D., and Hiroshi Iwasaki, M.D., Ph.D.

Department of Anesthesiology & Critical Care Medicine, Asahikawa Medical College

Introduction : Use of the ultrasound (US) is now became a strong tool to achieve safer central

venous catheter (CVC) insertion. Although pneumothorax is a rare complication related to CVC

placement, it cannot be avoided even with the US guided technique, particularly when the

vascular access was chosen via the subclavian vein. Recently, many techniques using US to

detect occult pneumothorax have been proposed in the field of critical care medicine. Not only

performing US before and during CVC insertion, but after the procedure to rule out

p n e u m o t h o r a x i s a l s o

important. We evaluated the normal lung signs after routine CVC insertion.

Methods : After institutional approval and written informed consent, thirty eight patient

requiring CVC insertion for cardiovascular and thoracic anesthesia were enrolled. Before CVC

insertion, anatomical structure of the vessels where CVC will be attempted were scanned. In

addition, anterior chest wall where accessible was quickly scanned with portable echograph

( M i c r o M a x , S o n o s i t e , B o t h e l l , W A , w i t h a

linear 5–10 MHz probe).

Normal lung is diagnosed with one or more of the following four signs: “lung sliding” is a to-and-

fro motion of the pleural line synchronized with respiration, “comet tail” is a roughly vertical

artifact arising from pleural line, “lung pulse” is a perception of heart activity at the pleural line,

and “power sliding” is the lung sliding enhanced with the power color doppler. When the sign

above was not recognized, or when the reverberation artifact was seen, it was diagnosed as

pneumothorax. Incidences of normal and abnormal signs were recorded. In all cases, chest XP

w a s t a k e n

postoperatively to confirm catheter position and to detect pneumothorax.

Results : Inserted sites were: 32 patients via right internal jugular vein, 1 patient via left, and 5

patients via the right subclavian vein. None was diagnosed as pneumothorax by chest

radiograph after CVC insertion. There was one case of pneumothorax, diagnosed

p r e o p e r a t i v e l y , w h o r e q u i r e t h o r a c o s c o p i c i n t e r v e n t i o n .

Disappearance of “lung sliding” was observed in 3 patients (5%), “comet tail” in 8 patients

(21%), “lung pulse” in 3 patients (9%), and “power sliding” in 14 patients (37%). In the

pneumothorax case, all these normal signs were disappeared and the reverberation artifact

w a s r e c o g n i z e d . T h e s e s i g n s w e r e n o t c h a n g e d b e f o r e a n d a f t e r

CVC insertion, and there was no case of iatrogenic pneumothorax after CVC insertion.

Conclusion : Our result indicates that each normal lung signs were not always recognized

with the US. Therefore, depending on sole normal sign may lead misdiagnosis there fore they

should be used in combination. With this technique, it is possible to exclude at least anterior

p n e u m o t h o r a x w h e n t h e m u l t i p l e s i g n s w e r e

used.

Abstract Results

Conclusion

Our result indicates that each normal lung signs w e r e not always recognized with the US.

Therefore, depending on sole normal sign may lead misdiagnosis there fore they should be used in combination.

With this technique, it is possible to exclude at least anterior pneumothorax when the multiple s i g n s w e r e

Fig.4 The upper arrow was the real pleura. Two other arrows

were the reverberation artifacts of a real pleura.

In pneumothorax case, several horizontal reverberations can

be seen in the background.

Fig.1 The utilization of US before vein puncture revealed a

movable thrombi in the right internal jugular vein. This case

had been inserted CVC for one week.

Background

Use of the ultrasound (US) is now became a strong tool to achieve

safer central venous catheter (CVC) insertion.

The utilization of US before vein puncture can provide important

anatomical information on the vessels and detect abnormalities such as

vein obstruction caused by thrombi (Fig.1).

Although pneumothorax is a rare complication related to CVC

placement, it cannot be avoided even with the US guided technique.

Not only performing US before and during CVC insertion, but also after

the procedure to rule out pneumothorax is also important.

thrombi

Objectives

To evaluate the normal lung signs after routine CVC insertion.

lung slidinga to-and-fro motion of the pleural line synchronized with respiration (Fig.3)

comet tai a roughly vertical artifact arising from pleural line (Fig.3)

lung pulse a perception of heart activity at the pleural line (Fig.2)

power sliding the lung sliding enhanced with the power color doppler (Fig.3)

Methods

Before CVC insertion, anatomical structure of the vessels where CVC

will be attempted were scanned.

In addition, anterior chest wall where accessible was quickly scanned

with portable echograph (MicroMax, Sonosite, Bothell, WA, with a

linear 5-10 MHz probe).

Normal lung is diagnosed with one or more of the following four signs,

When the sign above was not recognized, or when the

reverberation artifact was seen, it was diagnosed as

pneumothorax (Fig.4).

Incidences of normal and abnormal signs were recorded.

In all cases, chest XP was taken postoperatively to confirm

catheter position and to detect pneumothorax.

Fig.2 Time-motion mode at the pleural line. Regular bips

(arrows) whose frequency coincides with the heart beats can

be demonstrated.

Fig.3 White box which indicate an area of interest with the

color power doppler area demonstrated power sliding. Arrow

was lung pulse. (motion of the lung/wall interface is only visible

in real time.) A parenthesis demonstrated comet tail artifact

arising from the pleural line and heading deeper.

Fig5. The four sign detection rate in normal lung was

demonstrated. Appearance of “lung sliding” was observed in

70 patients (92%), “comet tail” in 60 patients (79%), “lung

pulse” in 70 patients (92%), and “power sliding” in 48 patients

(63%).

These signs were not changed before and after CVC insertion,

and there was no case of iatrogenic pneumothorax after CVC

insertion.

Lung sliding Comet tail Lung pulse

Power sliding

(%)

Table 1. Inserted sites were: 64 patients via right internal

jugular vein, 2 patient via left, and 10 patients via the right

subclavian vein.

None was diagnosed as pneumothorax by chest radiograph

after CVC insertion. There was one case of pneumothorax,

diagnosed preoperatively, who require thoracoscopic

intervention.

Age 69.9

Sex (M/F) 49/27

Height (cm) 159

Weight (kg) 58

Inserted site

right internal jugular vein 64

left internal jugular vein 2

right subclavian vein 10

left subclavian vein 0