A STUDY OF MALPOSITION OF CENTRAL VENOUS CATHETER – A COMPARATIVE STUDY BETWEEN ULTRASOUND GUIDED AND ANATOMICAL LANDMARK TECHNIQUE

Introduc on Central venous catheteriza on is a rou ne procedure for long-term infusion therapy and central venous pressure measurement. Some mes, the catheter p may be uninten onally placed at the posi on other than the junc on of superior vena cava and right atrium. This is called malposi on and can lead to erroneous pressure measurement, increase risk of thrombosis, venous obstruc on or other life threatening complica ons like pneumothorax, cardiac temponade. Objec ves This study aimed to observe the incidence of the malposi on and compare the same between ultrasound guided catheteriza on and blind anatomical landmark technique. Methodology This study was a prospec ve compara ve study conducted at the intensive care unit of Birat Medical College and Teaching Hospital for two-year dura on. All the catheteriza ons were done either with the use of real me ultrasound or blind anatomical landmark technique. The total numbers of central venous catheteriza on, the total incidences of malposi on were observed. Finally the incidences were compared between real me ultrasound guided technique and blind anatomical landmark technique. Results In two-year dura on of the study, a total of 422 central venous cannula ons were successfully done. The real me ultrasound was used for 280 cannula ons while blind anatomical landmark technique was used for 162 pa ents. The study observed various malposi on in 36 cases (8.5%). The most common malposi on was observed for subclavian vein to ipsilateral internal jugular vein (33.3%) followed by subclavian to subclavian vein (27.8%) and internal jugular to ipsilateral subclavian vein (16.7%). In four pa ents the catheter had a reverse course in the internal jugular vein while the p was placed in pleural cavity in three cannula ons. There was coiling of the catheter inside le subclavian vein in one pa ent. The malposi on was significantly reduced with the use of the real me ultrasound (P< 0.001). However there is no significant difference in the incidence of the various malposi on between ultrasound guidance technique and blind anatomical landmark technique when compared individually. Conclusion The malposi on of the central venous catheter p was common complica on with the overall incidence of 8.5%. The most common malposi on was subclavian vein to internal jugular vein. The use of real me ultrasound during the catheteriza on procedure can significantly reduced the risk of malposi on.


Results
In two-year dura on of the study, a total of 422 central venous cannula ons were successfully done.The real me ultrasound was used for 280 cannula ons while blind anatomical landmark technique was used for 162 pa ents.The study observed various malposi on in 36 cases (8.5%).The most common malposi on was observed for subclavian vein to ipsilateral internal jugular vein (33.3%) followed by subclavian to subclavian vein (27.8%) and internal jugular to ipsilateral subclavian vein (16.7%).In four pa ents the catheter had a reverse course in the internal jugular vein while the p was placed in pleural cavity in three cannula ons.There was coiling of the catheter inside le subclavian vein in one pa ent.The malposi on was significantly reduced with the use of the real me ultrasound (P< 0.001).However there is no significant difference in the incidence of the various malposi on between ultrasound guidance technique and blind anatomical landmark technique when compared individually.

Conclusion
The malposi on of the central venous catheter p was common complica on with the overall incidence of 8.5%.The most common malposi on was subclavian vein to internal jugular vein.The use of real me ultrasound during the catheteriza on procedure can significantly reduced the risk of malposi on.

INTRODUCTION
Central venous catheter inser on is a common invasive procedure indicated for fluid resuscita on, inotrope infusion, blood transfusion, chemotherapy and administra on 1 of various drugs.The most commonly used centrally placed veins for the cannula on are subclavian, internal jugular and femoral veins.The catheter is inserted by threading the catheter over the guide wire, a technique called seldinger technique.The catheter is placed at the right atrium with the p placed at the junc on of superior vena cava and right atrium.On chest radiograph, the p of the catheter should lie at 2 cm proximal to the pericardial 2 line.Op mal placement of central venous catheters (CVC) is essen al for accurate monitoring of central venous pressure (CVP) in major surgeries and ensuring long-term use of the catheter for managing the cri cally ill pa ent.
Inser on of the catheter in to the right atrium can be accomplished either by blind anatomical landmark technique or by the ultrasound guided real me cannula on technique.Technical exper se along with awareness of the poten al complica ons and a sound knowledge of the anatomy of the veins are essen al for the successful central venous 3 cannula ons.However, complica ons like pneumothorax, haematoma, thrombosis, nerve injury, arterial puncture, and malposi on are unavoidable in some cases even with the skillful hand and appropriate anatomical landmark 4 technique.Catheter p malposi on is one of such complica ons which can lead to the erroneous measurement of the central venous pressure and can predispose to the risk of venous obstruc on, thrombosis ,clo ng or even 5 erosion of the venous wall.The malposi on of catheter p can be suspected when there is erroneous CVP value or subop mal waveform pa ern which can be confirmed by 6 the chest radiography and real me ultrasound.The misplacement of the catheter p can occur at the me of inser on with the guide wire going into the wrong direc on or later on due to the migra on of the catheter p due to the inappropriate movement or intra thoracic pressure changes induced by coughing, sneezing or straining.The various factors like posi on of the head, force applied for threading the guide wire and catheter, the caliber of the vein can be 5 responsible for the inappropriate posi on of the p.
Incidence of malposi on of central venous catheteriza on 7 (CVC) ranges from 1-60%.The catheter p can be directed to the ipsilateral internal jugular vein from subclavian vein and vice versa or towards the contralateral subclavian vein.Rarely, the catheter can take a U turn with the reversal of the direc on.There are many literatures mainly case reports on the various malposi on of the catheter but however none of the literatures has actually measured the burden of the malposi on during central venous cannula on.
Thus, this study has put an effort to evaluate the incidence of the possible malposi on of the central venous catheter and comparing the incidence between ultrasound guided and anatomical landmark technique.

METHODOLOGY
This study was prospec ve observa onal and compara ve study conducted at department of intensive care medicine of Birat Medical College and Teaching Hospital.Ethical approval was taken from the ins tu onal review commi ee and wri en consent was taken from the close pa ent rela ves.The study dura on was two years star ng from January 2015 to January 2017.
The consultant anesthesiologist did all the central venous cannula ons.The choice of whether to use real-me ultrasound or anatomical land mark technique was le to the decision of the operator and subjected to the availability of the ultrasound at that par cular me in ICU.
The study used portable ultrasound (My Sono U6, Samsung Medison) with linear probe having frequency 5-12 HZ.Inser on was performed asep cally covering the probe with sterile probe cover.Similarly the universal precau on for sterility was strictly followed for landmark technique.
A chest radiograph was done immediately a er the comple on of the procedure in order to confirm the correct posi on of the catheter or other associated complica ons.
The total number of the central venous catheter inserted in two-year dura ons was included in the study.Central venous catheter inser on requiring more than two a empts, inser on done by the junior duty doctors was excluded from the study.The use of real me ultrasound and blind anatomical landmark were also noted for the co m p a r i s o n .T h e st u d y a n a l yze d o n e o f m a j o r complica ons of the central venous cannula on i.e. malposi on of the central venous catheter which was confirmed by the chest radiograph along with the absence of the free flow of the blood from any of the lumen.The following were the expected malposi ons in the study The study observed the overall incidence of the malposi on out of total central venous catheteriza on, the type of most common malposi on and finally compared the incidence of the different type of malposi on between real me ultrasound and anatomical landmark technique.
The collected data were compiled in windows excel and results were analyzed by means of SPSS 17, a so ware designed for quan ta ve data analysis.
Parametric con nuous data were expressed as mean with standard devia on while categorical data were expressed as percentage (%).Independent sample t test was used for con nuous parametric data for the comparison of mean and Chi-square test was used to compare incidences of the malposi on between the real me ultrasound and blind anatomical landmark technique.A P-value less than 0.05 was taken as significant.

RESULTS
A total of 422 successful central venous cannula ons were done in the study dura on.Real me ultrasound was used for 280 (66.4%) cannula ons while blind anatomical landmark technique was used for 142 (33.6%) cannula ons.Malposi on of the catheter was observed only in 36 cases that accounts to the incidence of 8.5% in total.
The demographic profile of the pa ents having malposi on was non significant as shown in table 1.

35.85±11.70
Malposi on of the catheter was observed in 13 (4.6%)cannula ons with the real me ultrasound guided technique while blind anatomical landmark technique had 23 (16.2%) cases with malposi on of the catheter (Table 2).
There was a strong associa on of the incidences of malposi on between USG and blind procedure (P<0.001).
The incidence of malposi on among blind procedure was found to be almost 4 mes more among USG procedure (16.2% Vs. 4.6%).
As shown in table no 3, the most common type of malposi on observed in the study was found during subclavian vein cannula on with the catheter p lying at ipsilateral internal jugular vein (subclavian to internal jugular, 33.3%).This was followed by right subclavian vein to le subclavian vein and vice versa (10 cases, 27.8%).The incidence of the malposi on from internal jugular vein to the ipsilateral subclavian vein was 16.7 %.Similarly, there was reversal of the direc on of the catheter in the internal jugular vein in 4 cases (11.1%).In three cases (8.3%), the catheter was inadvertently placed in the pleural space.All these three malposi on occurred with the blind anatomical landmark technique during internal jugular vein cannula on.As the infusion was not started and the malposi on was immediately detected by the absence of blood withdraw and immediate chest x ray, the unwanted complica ons like pneumothorax, pleural effusion were avoided in these cases.In one case there was coiling of the catheter inside the le subclavien vein but the p was correctly placed at the right atrium.
However, the differences of propor ons based on different types of malposi on in between two groups were non significant (P>0.05)(Table 3).

DISCUSSION
Central venous catheter (CVC) malposi on is one of the major complica ons of the procedure.The malposi on can lead to serious life threatening complica ons like bleeding, pneumothorax and pleural effusion if not detected and managed immediately.Moreover, malposi on of a CVC can lead to inaccurate measurement of the central venous pressure with abnormal waveform and can be unsuitable for the infusion of various vasoac ve drugs and other 8 situa ons requiring long-term infusions.
The present study was conducted to evaluate the incidence of the central venous catheter malposi on, the most common type of malposi on and comparison of the catheter malposi on between ultrasound guided technique and blind anatomical landmark technique.As observed in the study 36 (8.5%) out of 422 total cannula ons in two years dura on were found to have catheter p malposi on.This incidence was with in the range of the incidences of 7 malposi on reported in various literatures report.
The internal jugular vein and the subclavian vein on either side unite to form right and le brachiocephalic vein which in turn drains in to the superior venacana.The hemiazygous vein and the thoracic duct drains into the le brachiocephalic vein while azygous vein drains in to the superior venacava.The internal mammary vein, which travels along the border, also drains into the brachiocephalic vein.Because of these free communica on and close proximity of the various small veins draining in to the central vein, there is high possibility of the catheter passing into any of the inadvertent posi on.
It is more convenient to cannulate the right internal jugular vein as this provides a direct and straight pathway to the right atrium that decreases the possibility of malposi on.Similarly, the superior venacava is in close vicinity of the medias num making it more prone for perfora on with the guide wire, dilator or catheter and leading to the 9,10 malposi on and other life threatening complica ons.
Rajbanshi LK et al The study observed that the most common catheter malposi on was during subclavian vein cannula on with the catheter passing into the ipsilateral internal jugular vein (33.3%).This was followed by catheter passing from one subclavian vein to the contralateral subclavian vein and vice versa (27.8%).The possible reason for these malposi ons could be the change in the direc on of the J p of the guide 11 wire during the procedure.The malposi on can be minimized by constantly keeping the J p of the guide wire in a caudal direc on.Besides this, excessive force applied during threading of the guide wire or catheter and excessive length of the guide wire inser on can be the possible reason for misplacement of the catheter p.The op mal length of the guide wire that can be inserted with the least possibility 12,13 of malposi on was suggested to be 18 to 20 cm.
Posi on of the head and shoulder can some mes determine the direc on of the guide wire and the catheter subsequently.The angle between subclavian vein and ipsilateral internal jugular vein is usually acute in neutral head posi on.The angle is increased making the two veins more in line when the head is turned away from the needle puncture.This increases the risk of catheter passing in to 14,15 the internal jugular vein and vice versa. in the same way the angle between the subclavien vein and innominate vein is reduced by lowering the shoulder posi on and this 16 increases the risk of malposi on.Another effec ve method for minimizing the malposi on from subclavian to internal jugular vein is to apply external pressure on IJV during the threading of the guide wire.
In 16.7 % of the total catheter malposi on, the catheter p was located into the ipsilateral subclavien vein from the internal jugular vein.Again the possible reason for this malposi on could be the inappropriate direc on of the J p of guide wire, excessive length of the guide wire or inappropriate posi on of the head n shoulder.
The catheter took a reverse course in 11% (4 cases) during internal jugular vein cannula on.In one pa ent the catheter was found in the ipsilateral external jugular vein, which was confirmed by chest x-ray and ultrasound.Any obstruc on due to thrombosis, stenosis distal to the opening of internal jugular vein in the brachiocephalic vein or the wrongly directed p of guide wire can be the possible reasons for this malposi on.
The catheter p lying in the pleural space can be a rare but life threatening complica ons that was observed in 8.3% of total malposi on.
The right border of SVC, azygos, hemiazygos, and internal thoracic veins are immediately adjacent to the pleura.We assumed the excessive force during guide wire or catheter advancement and par al or complete obstruc on of the superior venacava can lead to erosion of the venous wall and guide wire or catheter can be wrongly inserted into the pleural cavity.The catheter malposi ons were immediately diagnosed with the chest x ray in all the three cases and subsequently removed.Fortunately none of the cases developed any complica on associated with the pleural puncture.
In one case, the catheter had coiling inside the le subclavian vein but the p was at the superior venacava.The valve present in the le subclavian vein might have obstructed the guide wire and made it coiled and later on the catheter following the same course.The catheter was le in situ without any manipula on as the blood flow was good and catheter p was placed in SVC.
The study compared the incidences of malposi on between the real-me ultrasound guided technique and blind anatomical approach.There was sta s cally significant reduc on (4.6% vs. 16.2%,P value < 0.001) in the incidence of malposi on with the use of ultrasound.However the individual comparison of different malposi oins between the two groups didn't show much difference.
Real-me ultrasound is rou nely used for the cannula on of the central veins as it provides a real-me image of the veins, artery and other surrounding so ssues.Moreover, the passage of guide wire inside the vein can easily be detected thus decreasing the possibility of malposi on.The real me ultrasound is helpful especially in older pa ent or in pa ent with shock where the veins are collapsed.The use of ultrasound has significantly decreased the incidences of 17 malposi on.
However, the other factors like head posi on, direc on of the p of the J point of guide wire, the force applied during threading of the guide wire and presence of any obstruc on play a vital role for the misplacement of the catheter p.

LIMITATION OF THE STUDY
The number of the cases for the comparison between the two groups could not be equalized because of the operator convenience and the technical difficulty in localizing the vein during cannula on.The comparable samples would have produced much more reliable result.The single centered study could not detect the other rare malposi ons like medias nal puncture, pericardial rupture, and intrathecal placement.

RECOMMENDATIONS
The study recommends the use of real me ultrasound for the cannula on procedure to minimize the complica ons.
The study strongly supports the fact that the real me sonology of needle, guide wire and catheter inser on and its ability to locate the catheter p can detect the malposi on at the earliest and prevent the unwanted complica ons.Similarly, technical exper se of the procedure, thorough knowledge of normal anatomy and anatomical varia ons of the veins are equally important to decrease the risk of malposi on

CONCLUSION
Central venous catheter malposi on is one of the major complica ons and can lead to life threatening condi ons if not detected and managed immediately.The study had observed a over all incidence of 8.3% malposi on.Catheter passing into internal jugular vein from subclavian vein was the most common malposi on.The use of real-me ultrasound has significantly decreased the incidence of the malposi on.The direc on of the J p of guide wire, length of the guide wire, posi on of the head and shoulder as well as caliber of the vein can be responsible for the malposi on of the catheter p.

u
Internal jugular vein to ipsilateral subclavien vein and vice versa u One subclavien vein to the contralateral subclavian vein and vice versa u Reversal of the direc on u Pleural puncture