The anatomic relationship between the internal jugular vein and the carotid artery in children after laryngeal mask insertion. An ultrasonographic study.

BACKGROUND: Central venous cannulation, although challenging in children and prone to complications, is frequently required for total parenteral nutrition and infusion of drugs. AIM: The aim of this study was to determine the anatomic relationship between the internal jugular vein (IJV) and carotid artery (CA) before, and after, insertion of laryngeal mask airway (LMA) in children using ultrasound. METHODS: Patients aged 2-16 were recruited to this prospective study and divided into three groups of 20 patients each: group 1: LMA size 2, group 2: LMA size 2½, and group 3: LMA size 3. Prior to, and following, LMA insertion, the position and depth of the vessels, and time to locate them were recorded. All measurements were taken at the level of the cricoid cartilage in a neutral head position in the spontaneously breathing patient during expiration. The IJV position in relation to the CA was noticed as anterior (A), anterolateral (AL), lateral (L), or medial (M). RESULTS: The position of the IJV was found to be in the anterolateral (AL) or anterior (A) position to the CA in the majority of cases. The anatomic relationship changed in 10/120 (8.3%) following insertion of the LMA. The mean depth was 0.80 (± 0.15) cm for the right IJV before LMA insertion and 0.84 (± 0.17) cm after insertion. Similar measurements were taken on the left side [0.81 (± 0.14) cm and 0.83 (± 0.18) cm]. The diameter as well as the depth of the IJV increased with the age and weight of the patient. CONCLUSIONS: This study demonstrates that the IJV is anterior or anterolateral to the artery in the majority of cases and that the anatomic relationship may change following the insertion of the LMA. It supports the need for using ultrasound-guided techniques for IJV cannulation following LMA insertion in spontaneously breathing children.

Airway exchange catheters use in the airway management of neonates and infants undergoing surgical treatment of laryngeal stenosis.

BACKGROUND: Congenital and acquired upper airway obstruction in infants commonly manifests as an acute, potentially life-threatening condition or a slow and gradual deterioration and can be a challenge to the pediatric anesthesiologist. This case series reports the nonconventional use of pediatric airway exchange catheters emergent and short-term airway management and lung ventilation in neonates and infants with severe laryngotracheal stenosis. CASE SERIES: After the approval of local Institutional Review Board, 11 consecutive patients presenting with severe laryngotracheal stenosis exceeding 70% were prospectively studied. Median (range) age and weight were 32 days (0-96) and 2.7 kg (2.1-3.4), respectively. Induction of anesthesia consisted of sevoflurane 5% in oxygen followed by sevoflurane 3% in an air/oxygen mixture (Fio2 = 0.5). Spontaneous ventilation was maintained in all patients. The trachea was intubated using an Airway Exchange Catheter with an inner diameter of 1.6 mm (Cook Airway Exchange Catheters, Cook Medical, Bloomington, IN). An Airway Exchange Catheter was inserted through the stenosis and manually assisted ventilation was confirmed using capnography. Median (range) ventilation duration was 28 minutes (12-61 mins). In one neonate, the Airway Exchange Catheter failed to ensure proper ventilation and an emergency tracheostomy was performed. Respiratory distress was likely due to a significant increase in airway resistance at the stenosis level or distal accumulation of secretions. CONCLUSION: Airway exchange catheters represent a useful additional tool for short-term advanced airway management for both oxygenation and ventilation in neonates and infants presenting with severe laryngotracheal stenosis.

Airway management in children: ultrasonography assessment of tracheal intubation in real time?

BACKGROUND: Pediatric tracheal intubation requires considerable expertise and can represent a challenge to many anesthesiologists. Confirmation of correct tracheal tube position relies on direct visualization or indirect measures, such as auscultation and capnography. These methods have varying sensitivity and specificity, especially in the infant and young child. Ultrasonography is noninvasive and is becoming more readily available to the anesthesiologist. In this study, we investigated the characteristic real-time ultrasonographic findings of the normal pediatric airway during tracheal intubation and its suitability for clinical use. METHODS: Thirty healthy children with normal airways requiring tracheal intubation were studied. Ultrasonographic measurements of the pediatric airway during tracheal intubation under deep inhaled anesthesia were performed using a Sonosite Titan (Sonosite, Bothell, WA) scanner while recording characteristic images during this process. Correct tracheal tube placement was further confirmed using auscultation and satisfactory end-tidal capnography. RESULTS: The mean (+/- sd) age of studied patients was 48 +/- 37 mo, weight was 19.7. +/- 8.6 kg and the sex ratio (m/f) was 1:2. Successful tracheal intubation was verified using the following criteria: 1) identification of the trachea and tracheal rings, 2) visualization of vocal cords, 3) widening of glottis as the tracheal tube passes through, and 4) tracheal tube position above carina and demonstration of movement of the chest wall visceroparietal pleural interface (i.e., sliding sign) after manual ventilation of the lungs. One esophageal intubation was readily recognized by visualization of the tube in the left paratracheal space. CONCLUSION: This study describes characteristic ultrasonographic findings of the pediatric airway during tracheal intubation. It suggests that ultrasonography may be useful for airway management in children.

THIS ARTICLE HAS BEEN RETRACTED Anatomic relationship between the internal jugular vein and the carotid artery in pre-school children--an ultrasonographic study.

BACKGROUND: Central venous cannulation (CVC) in young children is technically difficult and may lead to potentially serious complications especially when performed blindly or using anatomical landmarks only. The aim of this study was to determine the anatomical relationship of the internal jugular vein (IJV) and the common carotid artery (CA) in preschool children using ultrasound. METHODS: Forty-five children aged 60 months and under were included prospectively and divided into three groups: Group 1: <6 months, Group 2: 7-18 months and Group 3: 19-60 months. With the head in neutral position the location of the left and right IJV was noted as anterior, anterolateral (AL), lateral or medial in relation to the CA at the level of the cricoid cartilage. Depths of IJV and CA as well as time taken to locate the vessels were recorded. RESULTS: The IJV was more commonly found in the AL position in all groups. The mean depth was 0.96 cm in Group 1, 0.95 cm in Group 2 and 3. Mean duration for localization of the vessels was 4.2 s in Group 1, 4 s in Group 2 and 4.3 s in Group 3. The differences between the groups were not significant. CONCLUSION: This study demonstrates that the IJV cover the CA in the majority of young children. Depth of the IJV is rarely more than 1 cm deep to the skin. Ultrasound location of the IJV and CA is easy and does not necessarily delay the procedure. The findings of this study support the use of ultrasound guidance for CVC in children.

Anatomic relationship between the internal jugular vein and the carotid artery in preschool children--an ultrasonographic study.

BACKGROUND: Central venous cannulation in young children is technically difficult and may lead to potentially serious complications especially when performed blindly or using anatomical landmarks only. AIM: The aim of this study was to determine the anatomical relationship of the internal jugular vein (IJV) and the common carotid artery (CA) in preschool children using ultrasound. METHODS: Forty five children aged 60 months and under were included prospectively and divided into three groups: group 1: <6 months, group 2: 7-18 months and group 3: 19-60 months. With the head in neutral position the location of the left and right IJV was noted as anterior (A), anterolateral (AL), lateral (L) or medial (M) in relation to the CA at the level of the cricoid cartilage. Depths of IJV and CA as well as time taken to locate the vessels were recorded. RESULTS: The IJV was more commonly found in the AL position in all groups. The mean depth was 0.96 cm in group 1, 0.95 cm in group 2 and 3. Mean duration for localization of the vessels was 4.2 s in group 1, 4 s in group 2 and 4.3 s in group 3. The differences between the groups were not significant. CONCLUSION: This study demonstrates that the IJV cover the CA in the majority of young children. Depth of the IJV is rarely more than 1 cm deep to the skin. Ultrasound location of the IJV and CA is easy and does not necessarily delay the procedure. The findings of this study support the use of ultrasound guidance for CVC in children.

Prenatal and early postnatal morphogenesis and growth of human laryngotracheal structures.

Advances in neonatal medicine have resulted in increased care of fetal and neonatal airways. These advances have required an exhaustive knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of laryngotracheal structures during the fetal and immediate postnatal period and to correlate these observations with other fetal biometric parameters to estimate developmental particularities of the fetal airway. An anatomical prospective study was based on examination of larynx and trachea from 300 routine autopsies of fetuses and infants, free of malformation and never intubated. Anatomical measurements of cricoid cartilage, thyroid cartilage, glottis, arytenoid cartilage and trachea were performed using a precision calliper and precision divider. Statistical analysis was performed to represent the growth of anatomical structures and to evaluate the correlation with biometric data. Raw data and 10th and 90th percentile curves were fitted satisfactorily with a linear model for gestational age. A linear relationship between laryngotracheal measurement and body weight and height was observed except for glottis length, interarytenoid distance and anterior cricoid height. The diameter of the cricoid lumen was significantly less than that of the trachea and glottis lumen. A sexual dysmorphism was noted for thyroid cartilage measurements and interarytenoid distance, with measurements significantly smaller in females. This study reports the anatomical development of normal laryngotracheal structures during the fetal period. Despite the fact that this study was performed during postmortem examination, these observations can be useful to develop criteria, materials and surgical procedures adapted to fetal and neonatal airways as well as for the purposes of early diagnosis and management of laryngotracheal malformations.

Determination of endotracheal tube size in a perinatal population: an anatomical and experimental study.

BACKGROUND: This study aimed at correlating anatomical dimensions of the larynx and trachea to age and weight in a prenatal population. Endotracheal tube size determination was then proposed according to these considerations. METHODS: Anatomical measurements were obtained during 150 fetal and infant postmortem examinations. The optimal endotracheal tube size was determined by three methods: clinically, by a pressure method using calibrated inextensible balloons, and anatomically by comparing the laryngotracheal perimeter to the tube perimeters. Based on these results, recommended tube sizes were calculated. RESULTS: In premature babies before 37 weeks gestation, the optimal tube size according to pressure estimation was significantly greater than that determined by anatomical measurement alone. This difference was no longer valid after 40 weeks gestation. CONCLUSIONS: This study identified the elasticity of laryngeal structures in premature babies, allowing intubation with tube sizes greater than predicted by anatomical measurements with an increasing injury risk located in the posterior part of the glottic plane. This elasticity disappears near 40 weeks gestation, and the injury risk then predominates in the subglottic region. These results lead the authors to recommend that the size of the endotracheal tube used in the perinatal population should be based on anatomical and experimental data to limit the injury risks.