Simplified equation for determining proper depth of peripherally inserted central catheter in relation to anatomical landmarks

Development and validation of an updated PICC length prediction formula based on anteroposterior chest radiographs for the ultrasound-guided bedside placement

Bedside peripherally inserted central catheter (PICC) placement is sometimes required when the patient's intrahospital transport is restricted, and the ideal catheter length prediction is needed. This study aimed to develop an updated formula that predicts the optimal length of a PICC based on anteroposterior chest radiographs (AP-CXRs). This retrospective study collected PICC procedure data as the training and validation sets in three hospitals, including cubital crease-puncture point distance (CP), the actual PICC length (aCL), and the approach side. Horizontal and vertical measurement variables were set on the AP-CXRs. Two dependent variables were ipsilateral upper arm length (AL) and ideal truncal catheter length (iTCL). Simple and multiple regression analyses were used for formula development, and it was applied to the test set to evaluate the length prediction performance. The study included 309 patients in the training and validation sets and 91 intensive care patients in the test set. The final derived formula was: (AL + iTCL = CP + estimated PICC length, cm) = 19.831 - 0.062 × (contralateral clavicle length, cm) + 0.255 × (2nd ribs horizontal distance, cm) + 0.720 × (humero-vertebral distance, cm) + 0.761 × (thoraco-carinal distance, cm) + 1.024 × (the vertical distance of two vertebral body units, cm). (If approaching from the left, add 2.843cm, and if female, subtract 0.821cm.) In the test set, there was no case of length prediction failure. Moreover, the catheter tip position was evaluated as optimal in 82 cases (90.1%). This study's results suggest an updated formula to predict the ideal PICC length using only AP-CXRs for bedside placement.

Anatomical Structures to Be Concerned With During Peripherally Inserted Central Catheter Procedures

BACKGROUND

The central line has been frequently used for drug and nutrition supply and regular blood sampling of patients with chronic diseases. However, this procedure is performed in a highly sensitive area and has several potential complications. Therefore, peripherally inserted central catheters (PICC), which have various advantages, are being extensively used. Although the number of PICC procedures is increasing, the anatomy for safe procedures has not yet been properly established. Therefore, we studied basic anatomical information for safe procedures.

METHODS

We used 20 fixed cadavers (40 arms) donated to the Korea University College of Medicine. The mean age was 76.75 years (range, 48-94 years). After dissection of each arm, the distribution pattern of the basilic vein and close structures was recorded, and some important parameters based on bony landmarks were measured. In addition, the number of vein branches (axillary region) and basilic vein diameter were also checked.

RESULTS

The mean length from the insertion site to the right atrium was 38.39 ± 2.63 cm (left) and 34.66 ± 3.60 cm (right), and the basilic vein diameter was 4.93 ± 1.18 mm (left) and 4.08 ± 1.49 mm (right). The data showed significant differences between the left and right arms (P < 0.05). The mean distance from the basilic vein to brachial artery was 8.29 ± 2.78 mm in men and 7.81 ± 2.78 mm in women, while the distance to the ulnar nerve was 5.41 ± 1.67 mm in men and 5.52 ± 2.06 mm in women.

CONCLUSION

According to these results, the right arm has a shorter distance from the insertion site to the right atrium, and the left arm has a wider vein diameter, which is advantageous for the procedure. In addition, the ulnar nerve and brachial artery were located close to or behind the insertion site. Therefore, special attention is required during the procedure to avoid damaging these important structures.

Validation of the PICC length prediction formula based on anteroposterior chest radiographs for bedside ultrasound-guided placement

This study aimed to validate the accuracy of the peripherally inserted central catheter (PICC) length prediction formula using only anteroposterior chest radiographs (AP-CXR) and the technical feasibility of bedside ultrasound-guided PICC placement. This study included 156 Asian adult patients who underwent bedside PICC placement at three hospitals from September 2021 to March 2022. The shortest straight-line distance from the cubital crease to the puncture point (CP) was measured first. Using the formula of a previous study, the CP + estimated PICC length (eCL) was calculated with the parameters measured on AP-CXR. The formula was as follows: 19.409 + 0.424 × (MHTD, maximal horizontal thoracic diameter) + 0.287 × (CL, clavicle length) + 0.203 × (DTV, distance of thoracic vertebrae) + (2VBUs, two vertebral body units below the carina inferior border) (if from the left, 3.063cm was added; if female, 0.997cm was subtracted). Catheters were pretrimmed according to calculated eCL prior to the procedure. Technical success was evaluated, and the validation success of catheter length prediction was classified according to the catheter tip position as follows: optimal position or suboptimal position. Technical success was achieved in 153 cases (98.1%). Evaluation of validation success revealed that the position was “optimal” in 108 cases (70.6%) and “suboptimal” in 45 cases (29.4%). There was no validation failure. There was no case where the catheter was inserted too deep as to wedge into the right atrial wall. In conclusion, the PICC could be positioned accurately using the formula based on only AP-CXR. Furthermore, this bedside procedure was technically feasible.

Estimating the insertion length of pediatric peripherally inserted central catheters

BACKGROUND

It is difficult to determine the insertion length of peripherally inserted central catheters (PICCs) without fluoroscopy. The objectives of this study were to examine the relationship between the length from the anterior axillary point to the level of the carina (L_carina ) and patient's height, and to obtain possible estimation formulas that can be considered for validation in future studies.

METHODS

We retrospectively analyzed PICCs from the upper arm in the pediatric intensive care unit (PICU) between May 2017 and September 2018. We evaluated the relationship between L_carina and the patient's height using linear regression. We also conducted simulated performance assessment of simplified formulas based on the observed relationships.

RESULTS

Fifty-four PICCs from the right arm and 49 from the left for patients at the median age of 1 year were analyzed. The following linear correlations between L_carina and the patient's height were observed: 0.105 × height (cm) + 1.53 (cm) (P < 0.001, R² = 0.71) from the right arm, and 0.125 × height (cm) + 1.21 (cm) (P < 0.001, R² = 0.65) from the left arm. In the simulated performance assessment, with a simplified formula, [0.1 × height (cm) + 1 (cm)], 93% (50/54) of the PICCs from the right arm and 96% (47/49) from the left arm were expected to be inserted in the subclavian vein, innominate vein, or superior vena cava.

CONCLUSIONS

The level of the carina was correlated with the patient's height. A simplified formula, 0.1 × height (cm) + 1, seemed to perform acceptably and appeared to be worth validating in future studies.

A retrospective comparison for prediction of optimal length of right subclavian vein catheterization in infants: landmark-based estimation vs. linear regression model

Background

The optimal insertion length for right subclavian vein catheterization in infants has not been determined. This study retrospectively compared landmark-based and linear regression model-based estimation of optimal insertion length for right subclavian vein catheterization in pediatric patients of corrected age < 1 year.

Methods

Fifty catheterizations of the right subclavian vein were analyzed. The landmark related distances were: from the needle insertion point (I) to the tip of the sternal head of the right clavicle (A) and from A to the midpoint (B) of the perpendicular line drawn from the sternal head of the right clavicle to the line connecting the nipples. The optimal length of insertion was retrospectively determined by reviewing post-procedural chest radiographs. Estimates using a landmark-based equation (IA + AB – intercept) and a linear regression model were compared with the optimal length of insertion.

Results

A landmark-based equation was determined as IA + AB – 5. The mean difference between the landmark-based estimate and the optimal insertion length was 1.0 mm (95% limits of agreement –18.2 to 20.3 mm). The mean difference between the linear regression model (26.681 – 4.014 × weight + 0.576 × IA + 0.537 × AB – 0.482 × postmenstrual age) and the optimal insertion length was 0 mm (95% limits of agreement –16.7 to 16.7 mm). The difference between the estimates using these two methods was not significant.

Conclusions

A simple landmark-based equation may be useful for estimating optimal insertion length in pediatric patients of corrected age < 1 year undergoing right subclavian vein catheterization.

Comparison of formula-based PICC catheterisation versus common method for the treatment of newborns

AIMS

Whether PICC in newborns can improve its success rate and reduce the complications by using the formula method to calculate the depth of catheterisation.

METHODS

A total of 130 newborns were prospectively studied from December 2018 to December 2019. All newborns were randomly divided into two groups that use formula method and common method respectively. The PICC catheter length of the two groups was observed. The unplanned extubation rate, one-time puncture success rate, catheter indwelling time, complications, duration of hospital stays and pain scores were recorded during the whole research process and compared between these two groups.

RESULTS

The formula method significantly improved the puncture success rate and reduced the secondary adjustment rate. The length of the catheter adjustment was significantly lower than the control group. The retention time also increased significantly. The incidence of PICC-related complications, including phlebitis, thrombosis, catheter-related infection and catheter displacement, was significantly reduced by using the formula method.

CONCLUSIONS

The formula method in neonatal PICC catheter had great outcomes in terms of improving the success rate of one-time puncture and prolonging the indwelling time of catheter.

New formulas to predict the length of a peripherally inserted central catheter based on anteroposterior chest radiographs

PURPOSE

To develop formulas that predict the optimal length of a peripherally inserted central catheter (PICC) from variables measured on anteroposterior (AP) chest radiography (CXR).

MATERIALS AND METHODS

A total of 134 patients who underwent PICC insertion at the angiography suites were included. Clinical information such as patient height, weight, sex, age, cubital crease to inferior carina border length (CCL), and approach side were recorded. The following variables via measurement on AP-CXR were also collected: (1) distance from the T1 to T12 vertebra (DTV), (2) maximal horizontal thoracic diameter (MHTD), and (3) clavicle length (CL).

RESULTS

Significant correlations between CCL and the following variables were identified in linear regression analyses: approach side, height, weight, sex, DTV, MHTD, and CL. Multiple regression results motivated the following two formulas: (1) with height data, estimated CCL (cm) = 12.429 + 0.113 × Height + 0.377 × MHTD (if left side, add 2.933 cm, if female, subtract 0.723 cm); (2) without height data, estimated CCL = 19.409 + 0.424 × MHTD + 0.287 × CL + 0.203 × DTV (if left side, add 3.063 cm, if female, subtract 0.997 cm). Estimated final PICC length can be calculated as (Estimated CCL, cm) + 4.0 (distance from inferior carina border to about 2.0 vertebra body unit, cm) - (distance from set cubital crease to designated puncture point, cm).

CONCLUSION

This study suggests new formulas to predict the appropriate PICC length for bedside insertion using previous AP-CXRs. With this formula, ideal positioning of the catheter's tip can be achieved in the clinical practice, avoiding or minimalizing the exposed catheter out of skin. These formulas may be helpful for patients who cannot undergo intra-hospital transport due to hemodynamic instability or who are concerned about isolation precautions due to any infectious-related contamination.

Value of Anterior Band of the Inferior Glenohumeral Ligament Area as a Morphological Parameter of Adhesive Capsulitis

Objective

Thickened inferior glenohumeral ligament (IGHL) is considered as one of the major morphological parameters of adhesive capsulitis (AC). Previous studies reported that the anterior band of inferior glenohumeral ligament thickness (aIGHLT) is correlated with shoulder capsular contracture, luxatio erecta humeri, and AC. However, the thickness varies from the measured angle. To reduce this measurement error, we devised a new morphological parameter, called the anterior band of inferior glenohumeral ligament area (aIGHLA).

Methods

The aIGHL samples were collected from 54 patients with AC and from 50 control subjects who underwent shoulder magnetic resonance imaging (MRI) without any evidence of AC. Coronal T2-weighted MRI images were obtained at the shoulder level from each patient. We measured the aIGHLA and aIGHLT at the maximal view of the IGHL in the coronal plane using our picture archiving and communication system. The aIGHLA was measured at the whole cross-sectional area of the IGHL in the most hypertrophied segment of the coronal MR images. The aIGHLT was measured at the thickest point of the IGHL.

Results

The average aIGHLA was 55.58 ± 14.16 mm² in the control group and 83.71 ± 28.45 mm² in the AC group. The average aIGHLT was 3.47 ± 0.99 mm in the control group and 4.52 ± 1.02 mm in the AC group. AC patients showed significantly greater aIGHLA (p < 0.001) and aIGHLT (p < 0.001) than control subjects. Receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off score of the aIGHLA was 63.37 mm², with 79.6% sensitivity, 80.0% specificity, and AUC of 0.84 (95% CI, 0.76–0.92). The optimal cut-off point of the IGHLT was 3.81 mm, with 74.1% sensitivity, 74.0% specificity, and AUC of 0.77 (95% CI, 0.68–0.86).

Conclusions

Although the aIGHLA and aIGHLT were both significantly associated with AC, the aIGHLA was a more sensitive diagnostic parameter.