Optimal Insertion Length Research Articles

Prediction of internal jugular vein catheter length inserted through the posterior approach of the sternocleidomastoid muscle.

This study aimed to determine an equation to estimate the optimal insertion length for catheter placement via the posterior approach of the sternocleidomastoid muscle in cancer patients. This retrospective study included patients with cancer who underwent infusion port implantation surgery in the Oncology Department of the 900th Hospital of Joint Logistic Support Force of the Chinese People Liberation Army from April 2017 to September 2023. Patient height (H), weight (W), chest length (C), and length of the internal jugular vein catheter (L) were collected from medical records. The patients were randomized 7:3 to the training and validation sets. Linear regression analyses were used in the training set to determine formulas to predict catheter length. The formula predictive value was analyzed using the Bland-Altman method in the validation set. This study included 336 patients, with a mean age of 58.27 ± 11.70 years, randomized in the training (n = 235) and validation (n = 101) sets. Linear regression analysis revealed that the equations for catheter length relative to H, body mass index (BMI), and C are L = 0.144 × H - 8.258 (R² = 0.608, P < .001), L = -0.103 × B + 17.384 (R² = 0.055, P < .001), and L = 0.477 × C + 1.769 (R² = 0.342, P < .001), respectively. The multivariable linear regression analysis showed that the equation between the length of the catheter and H and C was L = 0.131 × H + 0.086 × C-8.515 (R² = 0.614, P < .001). The Bland-Altman analysis in the validation set showed that the predicted values of internal jugular vein catheter length and the actual values showed good agreement. The optimal L might be determined by simple formulas based on patients H and C.

External anatomical landmarks for urethral catheter positioning in male newborns: A prospective observational study

BackgroundImproper urethral catheterization may lead to complications such as urethral injury, catheter entanglement and urinary tract infection. Most of the related literature has focused on aseptic surgical technique, but there are no guidelines on the optimal insertion length for neonatal urinary catheterization. ObjectiveTo explore the external anatomical landmarks for urethral catheter positioning in male newborns. MethodsThis research is based on an observational study in Beijing Children's Hospital, China. Hospitalized male neonates who required Foley balloon catheters were prospectively enrolled in this study. The actual insertion length of the urethral catheter for male neonates and the anticipated insertion length based on anatomical landmarks were measured and compared. ResultsA total of 67 male neonates were enrolled. The mean body length was 50.66 ± 2.93 cm, and the mean body weight was 3.33 ± 0.70 kg. The mean actual insertion length of catheter was 8.77 ± 0.94 cm, while the anticipated length was 10.89 ± 0.95 cm. All the anticipated lengths exceeded the actual insertion length by 0.5–4.6 cm, which was deemed suitable for the procedure. ConclusionsEstimating the insertion length of urethral catheters based on external anatomical landmarks is clinically feasible. Selecting an anatomical landmark is a safe method for nurses or doctors to ensure the correct positioning of a urethral catheter. Tweetable abstractThe data of 67 male neonates shows that external anatomical landmarks for urethral catheter positioning in male newborns are possible.

Height best predicts the optimal insertion length of orotracheal tubes in children

IntroductionAccurate formulae to predict the optimal insertion length of endotracheal tubes (ETT) are necessary for safe care and have been based on height, weight, age, and ETT size. We believe height best reflects the somatic growth of the trachea. Our goal is to compare a formula generated using height for optimal initial insertion length of ETT to previously published formulae based on height, weight, age, and ETT size.MethodsWe retrospectively reviewed chest radiographs over a two-year period where the head was assured in midline and midposition. We excluded children with conditions altering tracheal dimensions or stature, and scoliosis. We chose 2 cm above the carina to be the optimal insertion length of the ETT which was then correlated to height. We created linear regression equations and Bland-Altman plots.ResultsTwo hundred three orotracheally intubated children were included. The optimal ETT insertion length using the formula Height (cm)/8 + 3.4 had a high association with linear regression and Bland-Altman plots had the narrowest 95% limits of agreement as compared to previously published formulae.ConclusionsWe found optimal insertion length = Height (cm)/8 + 3.4 is more accurate as compared to commonly used formulae that are based on weight, age, or ETT size. This formula places the ETT 2 cm above the carina which should be safe until a chest radiograph is obtained. We find that the use of formulae that divide the height by 10 overestimates the depth of insertion in younger, smaller children and underestimates the depth of insertion in older children.

Precise Terminology and Specified Catheter Insertion Length in Ultrasound-Guided Infraclavicular Central Vein Catheterization.

Background and Objectives: As the latest research encourages the ultrasound-guided infraclavicular central venous approach, due to the lateral puncture site displacement, in comparison to the anatomical landmark technique based on subclavian vein catheterization, the need to re-calculate the optimal catheter insertion length and possibly to rename the punctuated vessel emerges. Although naming a particular anatomical structure is a nomenclature issue, a suboptimal catheter position can be associated with multiple life-threatening complications and must be avoided. The main study objective is to determine the optimal catheter insertion length by the most proximal ultrasound-guided, in-plane infraclavicular central vein approach, to compare results with the anatomical landmark technique based on subclavian vein catheterization and to clarify the punctuated anatomical structure. Materials and Methods: 109 patients were enrolled in this study. All procedures were performed according to the same catheterization protocol. In order to determine optimal insertion length, chest X-ray scans with an existing catheter were performed. The definition of punctuated vessel was based on computer tomography and evaluated by radiologists. Independent predictors for optimal insertion length were identified, prediction equations were generated. Results: The optimal catheter insertion length is approximately 1.5 cm longer than estimated by Pere's formula and can be accurately calculated based on anthropometric data. Computed tomography revealed: five cases with subclavian vein puncture and three cases with axillary vein puncture. Conclusions: Even the most proximal ultrasound-guided infraclavicular central vein access does not guarantee subclavian vein catheterization. A more accurate term could be infraclavicular central venous access, with the implication that the entry point could be through either subclavian or axillary veins. The optimal insertion length is approximately 1.5 cm deeper than the length determined for the anatomical landmark technique based on subclavian vein catheterization.

A Bedside Equation to Estimate Endotracheal Tube Length for Infants

To develop a bedside equation that can be used to estimate the ideal oral and nasal endotracheal tube length for children under 1 year of age. Retrospective database analysis of 735 children under 1 year of age admitted to pediatric intensive care (PIC) at Evelina London Children's Hospital (ELCH) from June 1, 2019 through August 31, 2021. Endotracheal tube (ETT) positions were determined by tube tip superimposition over vertebral body on post-intubation chest radiograph by trained medical students and pediatric radiologists with bedside assessment of ETT length at nostril or lip as recorded electronically by nursing staff. The position of 1,176 ETTs were evaluated of which 784 (66%) were nasal and 392 (33%) were oral. After averaging length to account for multiple intubation events per patient, 281 (39%) nasal tubes and 105 (28%) oral tubes were found to be positioned optimally at T2. Using weight was superior to age or corrected age at estimating ETT length. Regression analysis revealed that optimal (T2) positioning of oral ETTs occurs at a length of (weight2+8)cm and in nasal ETTs at (weight2+9.5)cm with a mean absolute prediction error of 5%. The formulae did not require adjustments for those with comorbidities or prematurity. The optimal insertion length of ETTs placed both orally and nasally in children up to 1 year of age can be estimated with appropriate accuracy by a simple bedside formula using weight as the only variable.

Determination of the optimal length of insertion for central venous catheterization via axillary vein cannulation using preoperative chest X-ray- A prospective feasibility study.

Ensuring safe central venous catheter tip placement is important. Multiple techniques are available to estimate the length of catheter insertion for subclavian and internal jugular approaches. However, the methods to determine the length of insertion for the axillary route have not been validated. The purpose of this feasibility study was to evaluate a simple method for the calculation of catheter length to be inserted and assess whether it accurately predicts the correct tip placement. A total of 102 patients requiring preoperative central venous cannulation were evaluated, out of which 60 had successful axillary vein (AxV) cannulation. The length of insertion was calculated using the formula: (2/3* A + B) +Y (A: Clavicular length on chest radiograph [CXR], B: Vertical distance between the sternal head and carina on CXR, Y: Perpendicular distance from the skin to the AxV on ultrasound). A postoperative CXR was used to assess the accurate tip placement (2 cm above the carina to 0.5 cm below it). The primary outcome of the study was the rate of successful placement of the central venous catheter (CVC) in terms of the correct position of the tip of the catheter when the length of the catheter inserted was predicted by the formula described previously. Optimal placement was observed in 83.33% of the cases. A higher rate of accuracy was seen in the females (P value = 0.03) and shorter patients (P value = 0.01). A Bland-Altman plot depicted a high degree of agreement. Use of the formula using a CXR and ultrasound allowed P successful placement of the CVC tip at the desired location in 83.33% of the cases.

Proper Depth of Percutaneous Central Venous Catheter via the Great Saphenous Vein for Very Low Birth Weight Infants: A Single-Center, Prospective Cohort Study.

A proper depth of percutaneous central venous catheter (PCVC) is very important to reduce procedural time and prevent various complications in very low birth weight (VLBW) infants who require minimal handling or have a sensitive skin. The objective of this study was to suggest a formula for faster and proper insertion of PCVC in VLBWIs to prevent unintended consequences of patients' conditions. Prospective data of VLBW infants admitted from June 2015 to January 2018 who had PCVC inserted via the great saphenous vein within seven days after birth were analyzed. Correlations of length of inserted PCVC with body weight, body length, and postmenstrual age at the date of PCVC insertion were determined with a linear regression analysis. Using results of this analysis, a formula to determine the optimal insertion length of PCVC was derived. Coefficient of determination was used to assess how well outcomes were replicated by the formula. The formula to predict the proper insertion length of PCVC via the great saphenous vein at popliteal crease level was obtained as follows: Optimal Length (cm) = 3.8 × Body Weight (kg) + 11.1. With everyday movements such as flexion and extension of the lower extremities, the mean difference in catheter tip position was 7.0 ± 3.9 mm, which was not significant enough to escalate the risk of catheter tip displacement. The rate of catheter-related complications was as low as 4.9% in this study. The formula derived from this study to predict the optimal PCVC insertion length could benefit VLBW infants by reducing procedural time and lowering the risk of complications.

Optimal insertion length of endotracheal tube in neonates

Optimal insertion length of endotracheal tube in neonates

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

BackgroundThe 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.MethodsFifty 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.ResultsA 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.ConclusionsA 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.

'Lip-to-Tip' study: comparison of three methods to determine optimal insertion length of endotracheal tube in neonates.

The aim of this prospective observational study was to compare the incidence of endotracheal tube (ETT) malposition using weight-based (Tochen), gestation-based (Kempley), and nasotragal length (NTL) methods in deceased neonates and fresh stillbirths. We enrolled deceased neonates and fresh stillbirths within 2 ± 1 h of death or delivery, respectively; without hydrops, tracheostomy or major congenital anomalies affecting face, neck, or thorax. Each enrolled subject was intubated orotracheally, with lip-to-tip distance determined by three methods in random succession. Chest X-ray was acquired after each insertion. The primary outcome was proportion of malpositioned ETTs on chest X-ray (defined as ETT tip not lying between upper border of T1 and lower border of T2 vertebrae), assessed by two experts masked to the methods used. The proportion of malpositioned tubes was not significantly different with any of the three methods: (weight 27/50 (54%), gestation 35/50 (70%), and NTL 35/50 (70%), p value 0.055). The malpositioned tubes were too far in (87/150; 58%) than too far out (10/150; 6.7%).Conclusions: None of the currently recommended methods accurately predicts optimal ETT length in neonates. There is an urgent need for newer bedside modalities for estimating ETT position in neonates. What is known? • NRP guidelines recommend gestation-based and nasotragal length (NTL) methods to estimate initial ETT depth in neonates. Weight-based (Tochen) method is still widely used in neonatal units for ETT depth estimation. Evidence till date has not proven superiority of one method over the other. What is new? • All three methods for ETT depth estimation (Tochen, gestation-based, and NTL) resulted in high rates of ETT malposition in neonates. Formulae, devised from this study based on linear regression models, did not perform well for estimation of optimal ETT position.

The Optimal Length of Insertion for Central Venous Catheters Via the Right Internal Jugular Vein in Pediatric Cardiac Surgical Patients

The primary objective was to identify the best among 4 techniques that could predict the length of central venous catheter insertion through the right internal jugular vein, which, in turn, would ensure the ideal placement of the catheter tip in pediatric cardiac surgical patients. The techniques evaluated were those based on operator experience, topography/landmark methods, and one that relied on a patient's height-related formula. Based on the outcome of the study, the possibility of arriving at a formula was investigated that would predict with reasonable certainty the ideal length of catheter to be inserted for the correct catheter placement through the right internal jugular vein in pediatric cardiac surgical patients belonging to the authors' geographic area. A prospective observational study. Tertiary care cardiac center. Children younger than 5 years of age undergoing cardiac surgery. Right internal jugular vein cannulation by the Seldinger technique method. A total of 120 children aged younger than 5 years undergoing cardiac surgery were included in the study. The participants were randomized to 4 groups: group 1 (n = 30), the length of the central venous catheter was determined empirically by the operator based on clinical experience; group 2 (n = 30), the depth of insertion of the catheter was determined by the distance from the site of skin puncture to the second intercostal space; group 3 (n = 30), the depth of insertion of the catheter was determined by the distance from the skin puncture site to the third intercostal space; and group 4 (n = 30), the length of catheter was determined by a height-based formula that was followed routinely at the authors' institution. Central venous catheterization through the right internal jugular vein was performed according to out-of-plane ultrasound guidance in all patients. The ideal catheter tip location was assumed to be at the level of the carina or within 1.5 cm proximal to it. The number of patients who had ideal catheter tip placement were recorded from postoperative chest radiograph in all groups. Any relationship between acceptable catheter tip and demographic data (mean ranks of age, height, weight, and body surface area) of the patients were studied. The central vein catheter tip was at the level of the carina or within 1.5 cm in more patients in group 2 (39%, p = 0.02) compared with the other groups. This was followed by group 4 (40%), group 3 (30%), and group 1 (23%). There was a statistically significant difference in the mean distance between catheter tip and carina, with group 2 patients having the tip closest to the carina (p = 0.03). There was a significant correlation between acceptable catheter tip positioning and a patient's height (p = 0.04). A new formula was developed based on this correlation. A landmark-based topographic method in which the length of insertion of the catheter was determined by the distance from the skin puncture site to the second intercostal space for achieving correct placement of the catheter tip was found to be more reliable compared with other techniques. Height-based formula has the disadvantage of being affected by the skin puncture site. Assuming that a skin puncture at the midpoint between the right mastoid process and clavicular insertion of sternocleidomastoid muscle insertion is ensured, a new formula based on height has been proposed.

Estimation of nares-to-epiglottis distance for selecting an appropriate nasopharyngeal airway.

The nasopharyngeal airway is an important equipment in airway management, a correct placement is crucial for its effectiveness. We measured the nares-to-epiglottis distance (NED) and examined the correlations of the optimal insertion length (NED-1) with patient characteristics and various external facial measurements. We aimed to develop a simple method for estimating the optimal insertion length and to help select an appropriate nasopharyngeal airway.Two hundred patients of ASA grade I & II aged >20 years undergoing elective surgery under general anesthesia were enrolled. We measured nares-to-ear tragus distance (NTD), nares-to-mandibular angle distance (NMD), philtrum-to-ear tragus distance (PTD), and philtrum-to-mandibular angle distance (PMD). The NED was measured by fiber-optic bronchoscope. All measurements were obtained in centimeters. NED-1 (cm) was defined as the optimal insertion length. The patient's sex, age, body weight, body height, and body mass index were recorded.The NED-1 significantly correlated with body weight, body height, NTD, NMD, PTD, and PMD. Backward stepwise multiple linear regression analysis yielded the formula for predicting NED-1: 0.331 − 0.018 × BW + 0.061 × BH + 1.080 × NMD – 1.256 × PMD + 0.697 × PTD (r = 0.640, P < .001). The regression lines of the optimal insertion length versus PTD showed the best fit to the equality line. The measurements of PTD showed the minimal differences from NED-1 and with the most patients showing <1 cm differences from NED-1.The optimal insertion depth of nasopharyngeal airway can easily be predicted by the distance from philtrum-to-ear tragus, and a nasopharyngeal airway of an appropriate size can be selected accordingly.

Evaluation of Optimal Insertion Length of Tracheal Tube in Orotracheal Intubation in Indian Adults

Evaluation of Optimal Insertion Length of Tracheal Tube in Orotracheal Intubation in Indian Adults

The equations of the inserted length of percutaneous central venous catheters on neonates in NICU

In neonatal intensive care units, a percutaneous central venous catheter (PCVC) is inserted peripherally and threaded into a central venous location, when intravenous access is anticipated for an extended period of time. The tip location of PCVCs should be checked by an X-ray after the procedure. The present study aimed to determine an equation to estimate the optimal insertion length of PCVCs in neonates prior to the procedure. The data of all neonates who had PCVC insertion between May 1st 2015 and April 30th 2016 was reviewed. Their gender, body weight and body length at the insertion date, any complications and the tip culture of their PCVCs were recorded. The tip location of the PCVC, which was confirmed by X-ray, was either in the inferior vena cava near to the diaphragm or in the superior vena cava before the right atrial junction, depending on the insertion site. We analyzed the correlation among inserted length of PCVCs, body weight and body length by linear regression to determine an equation for estimating the optimal insertion length of PCVCs. The accuracy of the equations was evaluated prospectively by Pearson's correlation analysis, and the adjusting rate of PCVCs after the initial insertion was compared between the traditional method and using the equation. The equation of PCVCs inserted in the foot was "insertion length (cm)=16+4.27 × body weight (kg)", in the femoral vein was "inserted length (cm)=9.8+1.7 × body weight (kg)", in the popliteal vein was "inserted length (cm)=-0.3+0.45 × body length (cm)", in the hand was "inserted length (cm)=4.46+0.32 × body length (cm)", and in the axillary vein was inserted length (cm)=1+0.18 × body length (cm). The adjusting rate of PCVCs after initial insertion was decreased from 73.5% to 53% following use of the equation. Equations provided a convenient and accurate method to estimate the optimal insertion length of PCVCs before their placement.

Estimación de la longitud óptima de inserción del tubo orotraqueal en adultos

IntroductionAn accurate estimation of the optimal length of endotracheal tube insertion can prevent complications such as endobronchial intubation, airway trauma and accidental extubation, all of which have a negative impact on patient safety and are associated with an increase in both morbidity and mortality. ObjectiveTo determine the optimal insertion length of endotracheal tubes in female and male adults according to their height. Materials and methodsA cross-sectional analytical study conducted with 516 adult ASA I-II female and male patients who had different surgical procedures requiring endotracheal intubation. The mouth-carina distance was obtained using a flexible fiberoptic bronchoscope. The data analysis was performed using the SPSS 15.0 software. ResultsHeight and mouth-carina distance showed a direct and statistically significant correlation. Two equations for estimating optimal endotracheal insertion length were obtained, according to sex: men=11.413+(0.072 x height in cm) - 3; and women=13.555+(0.056 x height in cm) - 3. ConclusionThe traditional method of determining the insertion length of the endotracheal tube, 21cm for women and 23cm for men, shows a high incidence of endobronchial intubations in the analyzed population. The optimal insertion depth of the endotracheal tube can be reliably estimated through the use of prediction equations based on patient height, as proposed in this study.

Estimation of the optimum length of endotracheal tube insertion in adults

IntroductionAn accurate estimation of the optimal length of endotracheal tube insertion can prevent complications such as endobronchial intubation, airway trauma and accidental extubation, all of which have a negative impact on patient safety and are associated with an increase in both morbidity and mortality. ObjectiveTo determine the optimal insertion length of endotracheal tubes in female and male adults according to their height. Materials and MethodsA cross-sectional analytical study conducted with 516 adult ASA I-II female and male patients who had different surgical procedures requiring endotracheal intubation. The mouth-carina distance was obtained using a flexible fiberoptic bronchoscope. The data analysis was performed using the SPSS 15.0 software. ResultsHeight and mouth-carina distance showed a direct and statistically significant correlation. Two equations for estimating optimal endotracheal insertion length were obtained, according to sex: men=11.413+(0.072×height in cm)−3; and women=13.555+(0.056×height in cm)−3. ConclusionThe traditional method of determining the insertion length of the endotracheal tube, 21cm for women and 23cm for men, shows a high incidence of endobronchial intubations in the analyzed population. The optimal insertion depth of the endotracheal tube can be reliably estimated through the use of prediction equations based on patient height, as proposed in this study.

Optimal insertion lengths of right and left internal jugular central venous catheters in children

Knowledge of the optimal lengths for central venous catheterization prior to the procedure may lessen the need for repositioning and prevent vascular complications. To establish the optimal lengths for non-tunneled central venous catheter insertion through the right and left internal jugular veins. We included 92 children who received US-guided central venous catheterization via right or left internal jugular veins in intensive care units. The calculated distance between the skin and carina was considered the optimal length for right and left internal jugular venous catheterization. Univariate and multivariate linear regression analyses was used to identify predictors. Age, height and weight showed significant correlations with optimal insertion lengths for right and left internal jugular vein approaches on univariate analysis, while height was the only significant independent predictor of optimal insertion length. The optimal insertion lengths (cm) suggested by our data are, for the right internal jugular vein 0.034 × height (cm) + 3.173, and for the left 0.072 × height (cm) + 2.113.

Previsión a pie de cama de la extensión de inserción de catéter en vena subclavia derecha

Background and objectiveThe present study aimed to evaluate whether right subclavian vein (SCV) catheter insertion depth can be predicted reliably by the distances from the SCV insertion site to the ipsilateral clavicular notch directly (denoted as I-IC), via the top of the SCV arch, or via the clavicle (denoted as I-T-IC and I-C-IC, respectively). MethodIn total, 70 SCV catheterizations were studied. The I-IC, I-T-IC, and I-C-IC distances in each case were measured after ultrasound-guided SCV catheter insertion. The actual length of the catheter between the insertion site and the ipsilateral clavicular notch, denoted as L, was calculated by using chest X-ray. ResultsL differed from the I-T-IC, I-C-IC, and I-IC distances by 0.14±0.53, 2.19±1.17, and −0.45±0.68cm, respectively. The mean I-T-IC distance was the most similar to the mean L (intraclass correlation coefficient=0.89). The mean I-IC was significantly shorter than L, while the mean I-C-IC was significantly longer. Linear regression analysis provided the following formula: Predicted SCV catheter insertion length (cm)=−0.037+0.036×height (cm)+0.903×I-T-IC (cm) (adjusted r2=0.64). ConclusionThe I-T-IC distance may be a reliable bedside predictor of the optimal insertion length for a right SCV cannulation.

Previsão do comprimento de inserção de cateter em veia subclávia direita à beira do leito

Background and objectiveThe present study aimed to evaluate whether right subclavian vein (SCV) catheter insertion depth can be predicted reliably by the distances from the SCV insertion site to the ipsilateral clavicular notch directly (denoted as I‐IC), via the top of the SCV arch, or via the clavicle (denoted as I‐T‐IC and I‐C‐IC, respectively). MethodIn total, 70 SCV catheterizations were studied. The I‐IC, I‐T‐IC, and I‐C‐IC distances in each case were measured after ultrasound‐guided SCV catheter insertion. The actual length of the catheter between the insertion site and the ipsilateral clavicular notch, denoted as L, was calculated by using chest X‐ray. ResultsL differed from the I‐T‐IC, I‐C‐IC, and I‐IC distances by 0.14±0.53, 2.19±1.17, and −0.45±0.68cm, respectively. The mean I‐T‐IC distance was the most similar to the mean L (intraclass correlation coefficient=0.89). The mean I‐IC was significantly shorter than L, while the mean I‐C‐IC was significantly longer. Linear regression analysis provided the following formula: Predicted SCV catheter insertion length (cm)=−0.037+0.036×Height (cm)+0.903×I‐T‐IC (cm) (adjusted r2=0.64). ConclusionThe I‐T‐IC distance may be a reliable bedside predictor of the optimal insertion length for a right SCV cannulation.

Bedside prediction of right subclavian venous catheter insertion length

Background and objectiveThe present study aimed to evaluate whether right subclavian vein (SCV) catheter insertion depth can be predicted reliably by the distances from the SCV insertion site to the ipsilateral clavicular notch directly (denoted as I-IC), via the top of the SCV arch, or via the clavicle (denoted as I-T-IC and I-C-IC, respectively). MethodIn total, 70 SCV catheterizations were studied. The I-IC, I-T-IC, and I-C-IC distances in each case were measured after ultrasound-guided SCV catheter insertion. The actual length of the catheter between the insertion site and the ipsilateral clavicular notch, denoted as L, was calculated by using chest X-ray. ResultsL differed from the I-T-IC, I-C-IC, and I-IC distances by 0.14±0.53, 2.19±1.17, and −0.45±0.68cm, respectively. The mean I-T-IC distance was the most similar to the mean L (intraclass correlation coefficient=0.89). The mean I-IC was significantly shorter than L, while the mean I-C-IC was significantly longer. Linear regression analysis provided the following formula: Predicted SCV catheter insertion length (cm)=−0.037+0.036×Height (cm)+0.903×I-T-IC (cm) (adjusted r2=0.64). ConclusionThe I-T-IC distance may be a reliable bedside predictor of the optimal insertion length for a right SCV cannulation.