Osamu Takaki

Internal jugular vein catheterization in infants undergoing cardiovascular surgery : an analysis of the factors influencing successful catheterization

Central venous catheterization for pressure monitoring and drug administration is often important in the anesthetic management of infants undergoing cardiovascular surgery. We examined the effects of patient age, weight, and central venous pressure and the experience of the anesthesiologist on the rate of successful catheterization and catheterization time of the internal jugular vein (IJV) in a prospective study. We studied 106 infants undergoing IJV catheterization for cardiovascular surgery over a 7-mo period at our institution. We catheterized the IJV by the high approach. The direct venipuncture or the Seldinger method was used according to the patients weight. Overall successful catheterization rate was 97.2%, and the average catheterization time was 353 +/- 21 s (mean +/- SEM). Complications included arterial puncture in 12 cases (11.3%), hematoma formation in four cases (3.8%), and catheter malposition in two cases (1.9%), but pneumothorax was not observed. When a patient was younger than 3 mo or weighed less than 4.0 kg, successful catheterization rate decreased significantly to 81.3% and 78.6%, respectively. Catheterization time was inversely correlated with both age and weight, whereas central venous pressure did not affect either successful catheterization rate or catheterization time. We were unable to demonstrate that the experience of the anesthesiologist plays a significant role in the success or complication of the catheterization procedure. Our results indicate that IJV catheterization by the high approach is a reliable and useful technique in infants, and that the weight and age of the patient significantly influence the rate of successful catheterization.

Optimal placement of CVP catheter in paediatric cardiac patients.

For correct monitoring of central venous pressure (CVP) the tip of the CVP catheter should be placed in the superior vena cava (SVC). Since there is no useful guide for the optimal depth of insertion of CVP catheter in children undergoing cardio-vascular surgery, we examined the relationship between the depth of the CVP catheter and easily measured body-size variables, such as age, weight and height, and then created a guide for the optimal placement of the paediatric population. The CVP catheterization was performed through the right internal jugular vein by the high approach. The position of the catheter tip was determined by the wave form of the CVP tracing and the depth of insertion was assessed by the external marking on the catheter at the cannulation site. The position of the catheter tip, determined by postoperative AP chest x-ray, was identified by the level of thoracic vertebra (T) corresponding to the position of the catheter tip. We analyzed the relationship between the depth of the catheter and patient’s age, weight and height by linear regression analysis. The position of tip was normally distributed from T1 to T7 and the tips were centralized at levels of T3 T4 and T5 which anatomically correspond to SVC. The r values between the catheter depth and the three factors at each level were comparable, although the correlation between the depth of catheter and height was best. A simple guide for placement of the catheter tip at T3, T4 and T5 levels as a function of patient’s height was created. Since height is a primary information variable which is available even in emergency cases, we believe that the guide is acceptable and valuable to anaesthetists.RésuméPour monitorer la pression veineuse centrale (PVC) correctement, le bout du cathéter de PVC doit être situé dans la veine cave supérieure (VCS). Comme il n’existe pas de paramètre sûr pour déterminer la profondeur d’insertion optimale d’un cathéter de PVC chez l’enfant opéré pour une chirurgie cardiovasculaire, nous avons établi la relation entre la profondeur du cathéter de PVC et les variables facilement mesurables comme l’âge, le poids et la taille; nous avons construit un guide pour établir la position optimale du cathéter de PVC chez l’enfant. La jugulaire interne droite a été canulée haut dans le cou. La position de l’extrémité du cathéter a été déterminée grâce à la forme de l’onde sur le tracé de PVC et la profondeur de l’insertion évaluée au niveau du site de canulation par les repères externes du cathéter. La position de l’extrémité du cathéter, déterminée par une radiographie postopératoire, a été identifiée par la projection de l’extrémité du cathéter sur la vertèbre thoracique (T) correspondante. Nous avons analysé le rapport entre la profondeur du cathéter et l’âge, le poids et la taille par régression linéaire. Normalement, la position de l’extrémité du cathéter était répartie entre T1 et T7 et était en position centrale à T3, T4 et T5, ce qui correspond anatomiquement à la VCS. Les valeurs r pour la profondeur du cathéter et les trois facteurs étaient comparables à chacun des niveaux, bien que la corrélation ait été meilleure entre la profondeur du cathéter et la taille du sujet. Un guide simple conçu en fonction de la taille et permettant de situer le bout du cathéter aux niveaux T3, T4 et T5 a été fabriqué. Comme la taille constitue toujours un renseignement disponible, même en urgence, nous croyons que ce guide est acceptable et peut être utilisé par les anesthésistes.

Anaesthetic management of phaeochromo-cytoma associated with tricuspid atresia

The anaesthetic management of a patient with phaeochromo-cytoma, tricuspid atresia and pulmonary vascular stenosis is reported. The patient received no preoperative preparation with adrenergic blockers. Anaesthesia was induced and maintained with fentanyl, diazepam and sevoflurane. Intraoperative blood pressure was controlled with sodium nitroprusside, sevoflurane, phentolamine, and propranolol. For hypotension after resection of the tumour norepinephrine was required. This patient did not have a systemic to pulmonary shunt procedure performed, so the maintenance of pulmonary blood flow in the presence of haemodynamic instability during operation for phaeochromocytoma was a major concern. Monitoring of oxyhaemoglobin saturation (SpO2) with a pulse oximeter was considered to be useful because SpO2 may reflect pulmonary flow. During serious haemodynamic disturbances due to the manipulation of the tumour, the heart rate was inversely correlated with SpO2, but the relationship between mean arterial pressure and SpO2 was weak. Therefore, control of heart rate appeared to be more important than control of blood pressure in this case.RésuméLa conduite anesthésique d’un patient atleint de phaeochromo-cytome, atresie tricuspidienne et de sténose pulmonaire est reportée. Le patient n’a pas reçu de traitement pré-opératoire avec des bloqueurs adrénergiques. L’anesthésie fut induite et maintenue avec du fentanyl, diazepam et sevoflurane. La pression artérielle per-opératoire fut contrôlée avec du nitro-pussiate, servoflurane, phentolamine et propranolol. Pour l’hypotension après la résection de la tumeur la norepinephrine fut requise. Ce patient n’a pas eu de Shunt systémique pulmonaire et ainsi le maintien du flot sanguin pulmonaire en présence d’une instabilité hémodynamique durant l’operation représentait un souci majeur. La surveillance de la saturation de l’oxyhaemoglobine (SpO2) avec un saturomètre de pouls fut considérée utile car la SpO2. peut refléter le flot sanguin pulmonaire. Lors des altérations hémodynamiques sévères dues à la manipulation de la tumeur, la fréquence cardiaque fut inversement correlée à la SpO2 et la relation entre la pression artérielle moyenne et la SpO2 était faible. Ainsi, le contôle de la fréquence cardiaque nous a paru plus important que le contrôle de la pression artérielle dans ce cas.

Anesthetic management of patients undergoing bilateral unifocalization

We report on the anesthetic management of eight patients undergoing unifocalization for pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries. Unifocalization was performed separately on the right and left lungs in the lateral decubitus position. During unifocalization, pulmonary blood flow to the nondependent lung is interrupted and arterial oxygenation is dependent solely on the blood flow to the dependent lung. Thus, PaO2 and SaO2 decreased significantly and PaCO2 increased significantly during unifocalization, as compared with before and after unifocalization. When these values are compared between first and second stage of unifocalization, SaO2 during second stage was lower than during first stage. Although PaO2, PaCO2, and pH during second stage tended to be worse than during first stage, the differences did not reach statistical significance. During unifocalization, especially in second stage, to prevent deterioration of these arterial gas variables, pulmonary blood flow had to be increased by frequent administration of catecholamine. In addition, bicarbonate infusion was also used to prevent progressive metabolic acidosis due to hypoxia during unifocalization. Because anticoagulant therapy was required during unifocalization, airway bleeding was a common complication.