Anesthetic and perioperative outcome of teenagers and adults with congenital heart disease.

OBJECTIVE: To compare the perioperative outcome of patients >or=13 years old undergoing surgery for congenital heart disease in a children's hospital by a dedicated congenital heart surgery and anesthesia team with procedure-matched younger control patients. DESIGN: Retrospective medical record review study. From October 1997 to July 2000, medical records of all patients >12 years old requiring cardiopulmonary bypass were reviewed. A control group of patients

The optimal length of insertion of central venous catheters for pediatric patients.

UNLABELLED: Incorrect positioning of central venous catheters (CVC) in infants and children may lead to serious complications such as perforation of the heart or great vessels. CVC position is not usually assessed until the first postoperative chest radiograph, potentially leaving malposition undetected for several hours. We studied a series of 452 right internal jugular and subclavian catheter placements in infants and children undergoing surgery for congenital heart disease, and measured the distance from the skin insertion site to the radiographic junction of the superior vena cava and right atrium (RA). Based on these data, the following formulae predict that a CVC will be positioned above the RA 97% of the time: correct length of insertion (cm) = (height in cm/10) - 1 for patients < or =100 cm in height, and (height in cm/10) - 2 for patients >100 cm in height. Weight-based recommendations were also developed which predict placement of CVC above the RA 98% of the time. IMPLICATIONS: This study assessed central venous catheter placement in 452 infants and children undergoing cardiac surgery. Simple, clinically useful guidelines based on height and weight were developed to prevent malposition of these catheters, which may cause serious complications such as perforation of the heart or great vessels.

Cardiovascular effects of sevoflurane, isoflurane, halothane, and fentanyl-midazolam in children with congenital heart disease: an echocardiographic study of myocardial contractility and hemodynamics.

BACKGROUND: The cardiovascular effects of halogenated anesthetic agents in children with normal hearts have been studied, but data in children with cardiac disease are limited. This study compared the effects of halothane, isoflurane, sevoflurane, and fentanyl-midazolam on systemic and pulmonary hemodynamics and myocardial contractility in patients with congenital heart disease. METHODS: Fifty-four patients younger than age 14 scheduled to undergo congenital heart surgery were randomized to receive halothane, sevoflurane, isoflurane, or fentanyl-midazolam. Cardiovascular and echocardiographic data were recorded at baseline and at randomly ordered 1 and 1.5 minimum alveolar concentrations, or predicted equivalent fentanyl-midazolam plasma concentrations. The shortening fraction and ejection fraction (using the modified Simpson rule) were calculated. Cardiac index was assessed by the velocity-time integral method. RESULTS: Halothane caused a significant decrease in mean arterial pressure, ejection fraction, and cardiac index, preserving only heart rate at baseline levels. Fentanyl-midazolam in combination caused a significant decrease in cardiac index secondary to a decrease in heart rate; contractility was maintained. Sevoflurane maintained cardiac index and heart rate and had less profound hypotensive and negative inotropic effects than halothane. Isoflurane preserved both cardiac index and ejection fraction, had less suppression of mean arterial pressure than halothane, and increased heart rate. CONCLUSIONS: Isoflurane and sevoflurane preserved cardiac index, and isoflurane and fentanyl-midazolam preserved myocardial contractility at baseline levels in this group of patients with congenital heart disease. Halothane depressed cardiac index and myocardial contractility.

Volume ventilation of infants with congenital heart disease: a comparison of Dräger, NAD 6000 and Siemens, Servo 900C ventilators.

UNLABELLED: We compared the ventilation and pulmonary mechanics produced by a new anesthesia ventilator (NAD 6000) using a circle system with that produced by a critical care ventilator (Servo 900C) using a nonrebreathing circuit in infants with congenital heart disease. Twenty patients, aged 1 day to 7 mo, weighing 2.1 to 4.6 kg, were studied. The NAD 6000 had improved alveolar ventilation: PaCO(2) 43 +/- 8 vs 47 +/- 5 mm Hg (P = 0.005), end-tidal CO(2) 34 +/- 7 vs 37 +/- 5 mm Hg (P = 0.042); larger inspired tidal volumes 12.9 +/- 2.8 vs 11.3 +/- 2.2 mL/kg (P < 0.001), but with higher mean airway pressures 9.7 +/- 1.6 vs 8.6 +/- 1.3 cm H(2)O (P < 0.001). These differences in ventilation and airway pressures were not clinically significant. Although there were differences in observed ventilatory variables, both machines provided adequate ventilation when set in the volume control mode. IMPLICATIONS: We compared two ventilators for use in infants. Twenty infants undergoing surgery for congenital heart defects were randomized to receive ventilation first with one ventilator, then with the other. Although there were differences in observed ventilatory variables, both machines provided adequate ventilation when set in the volume control mode.

Pressure control ventilation: three anesthesia ventilators compared using an infant lung model.

UNLABELLED: We compared three ventilators-Servo 900C (Siemens Medical Systems, Danvers, MA), Aestiva 3000 (Datex-Ohmeda, Madison, WI), and NAD 6000 (North American Dräger, Telford, PA)-set to deliver pressure control ventilation using an infant test lung model. Ventilator settings were selected to test "near-maximum" settings that would be used for a neonatal patient (peak inspiratory pressure [PIP] 30 cm H(2)O) or older child (PIP 60 cm H(2)O). When adjusted for set inspiratory pressure and compliance, the average tidal volume (V(t)) produced by the NAD 6000 was 5.8 mL less than the Servo 900C (P: = 0. 103), and the average V(t) produced by the Aestiva 3000 was 18.9 mL less than the Servo 900C (P: < 0.001). The Servo 900C generated increased peak pressures, tending to overshoot the set maximum inflating pressures, especially during rapid respiratory rates with decreased inspiratory times. The Aestiva 3000 did not achieve the set PIP during testing conditions of decreased inspiratory times, and the NAD 6000 was not greatly affected by changes in inspiratory time. All three ventilators measured expiratory V(t) to be larger than the actual V(t) delivered to the lung; however, the NAD 6000 was more accurate. IMPLICATIONS: There are differences in performance of ventilators when set to deliver pressure control ventilation to an infant test lung model.

The effects of transesophageal echocardiography on hemodynamic variables in small infants undergoing cardiac surgery.

OBJECTIVE: To assess the effects of transesophageal echocardiography (TEE) on hemodynamic variables during cardiac surgery in small infants. DESIGN: A prospective clinical study. SETTING: A medical college-affiliated tertiary care children's hospital. PARTICIPANTS: Twenty-three infants weighing 2 to 5 kg undergoing cardiac surgery. INTERVENTIONS: Baseline heart rate, arterial pressure, and central venous pressure were recorded. A pediatric TEE probe was inserted, and the hemodynamic variables were again recorded. Postoperatively the hemodynamic measurements were measured again before and after probe removal, with the addition of left atrial pressure and pulmonary artery pressure when available. Hemodynamic parameters were carefully observed during all phases of the TEE examinations for any changes attributable to probe manipulation. MEASUREMENTS AND MAIN RESULTS: No statistically significant changes occurred in this group of patients during TEE. No clinically significant changes in any individual patient occurred during the measurement or during manipulation of the TEE probe for the complete examination. CONCLUSION: Although hemodynamic compromise can occur in small infants, this study suggests that it is infrequent. Fear of hemodynamic compromise should not prevent use of intraoperative TEE in small infants when otherwise indicated.

The effect of transesophageal echocardiography on ventilation in small infants undergoing cardiac surgery.

UNLABELLED: Transesophageal echocardiography (TEE) is frequently used during congenital cardiac surgery. Complications are infrequent, but interference with ventilation has been reported, especially in small infants. Ventilation variables were measured prospectively in 22 infants, 2-5 kg, undergoing heart surgery with TEE. Measurements were made preoperatively before and after TEE probe insertion and postoperatively before and after TEE probe removal. The variables measured included arterial blood gases, expired tidal volume, peak inspiratory pressure, positive end-expiratory pressure, minute ventilation, airway resistance, dynamic compliance, and peak inspiratory and expiratory flow rates. No significant change in any ventilatory variable at either time period was noted in the infants. IMPLICATIONS: Ventilatory compromise is infrequent in small infants undergoing transesophageal echocardiography (TEE) examination. Careful ventilatory monitoring rapidly detects changes in ventilation during TEE examination. Small infants who benefit from TEE during heart surgery should not be excluded from receiving a TEE examination because of concern of ventilatory compromise.

Comparison of NAD 6000 and servo 900C ventilators in an infant lung model.

UNLABELLED: We compared the ability of the NAD 6000 (North American Dräger, Telford, PA) and the Servo 900C (Siemens-Elema AB, Solna, Sweden) anesthesia ventilators to maintain precise delivery of small tidal volumes (V(t)) and positive end-expiratory pressure using an infant test lung model. A variety of ventilator and lung model settings were selected to test clinical conditions simulating normal and extremely compromised lung function. Differences in ventilator output were analyzed by using an independent t-test with P <0.05 considered significant. With the ventilators set to deliver a V(t) of 30 mL, the actual delivered V(t) was significantly better for the NAD 6000 (25 +/- 2 mL) compared with the Servo 900C (18 +/- 3 mL), P <0.001. When the ventilators were set to deliver 100 mL V(t), their delivered V(t) were not significantly different, NAD 6000 (66 +/- 19 mL) and Servo 900C (60 +/- 12 mL), P = 0.09. The exhaled V(t) read by the anesthesia machines was significantly closer to the delivered V(t) for the NAD 6000 (11 +/- 9 mL) compared with the Servo 900C (37 +/- 11 mL), P < 0.001. Both ventilators maintained the end expiratory pressure delivered to the test lung within 2 cm H(2)O of the set positive end-expiratory pressure on average. As the conditions changed requiring the ventilator to develop a higher peak inflating pressure, both ventilators showed a decrease in V(t) delivered, which was proportionate to the tubing compression volume loss. IMPLICATIONS: The NAD 6000 (North American Dräger, Telford, PA) and Servo 900C (Siemens-Elema AB, Solna, Sweden) are able to precisely deliver small Tidal Volumes. They both decreased in performance when tested under extreme conditions. Earlier studies of traditional anesthesia ventilators suggest that the NAD 6000 and Servo 900C are superior pediatric ventilators.

Anesthetic management of living liver donors.

PURPOSE: Living organ donation is being performed with increasing frequency to overcome the shortage of organs for transplantation. Our experience in the anesthetic management of donors with relevant issues is discussed and complications encountered are recorded. METHODS: Data were collected retrospectively and analyzed on all 22 left lateral hepatectomies performed at our institution between 1993 to 1997 for transplantation. RESULTS: Major ethical concern was the risk to the donors and anesthetic issues were those of a major abdominal procedure. All except four donors were parents (mother/father). Average blood loss was 805 +/- 479 ml and only two donors required blood transfusion. Mean operative time was 8.2 +/- 1.5 hr. Thoracic epidural analgesia was the most commonly adopted mode of pain relief. Average time to return of bowel sound postoperatively was 3.1 +/- 1.0 days and was not influenced by the postoperative analgesic technique used. Total duration of hospital stay was 8.4 +/- 1.1 days. Three donors developed minor postoperative complications atrial fibrillation and retained JP drain; left lower lobe pneumonia; and incisional hernia. All patients recovered uneventfully. CONCLUSION: Living organ donors contribute towards decreasing the shortage of organs for transplantation. Minimizing the discomfort associated with the surgical intervention and providing a complication-free perioperative course will positively influence the continued availability of such donations. On review of the first 22 left lateral hapatectomies performed, we observed only minor complications. Postoperative pain was a serious problem and thoracic epidural provided satisfactory analgesia.

A controlled study of transesophageal echocardiography to guide central venous catheter placement in congenital heart surgery patients.

UNLABELLED: Transesophageal echocardiography (TEE) and central venous catheter (CVC) placement are often used during congenital cardiac surgery. Complications of CVC placement include cardiac perforation, inadvertent arterial placement, and erroneous hemodynamic data from unrecognized malposition. In this study, we used a prospective, randomized, controlled design to evaluate the use of TEE to guide depth of insertion and confirm superior vena cava cannulation, and to improve the percentage of correctly placed CVCs and reduce complications of CVC placement. One hundred forty-five patients were studied. Eighty patients were randomized to have subclavian vein insertion, 64 to have internal jugular insertion, and 1 to have external jugular insertion of CVC. TEE-guided CVC placement resulted in 100% correct placement when assessed by preoperative TEE, versus 86% in the control group (72 of 72 vs. 63 of 73; P = 0.01). There was no difference in correct placement between the two groups when assessed by postoperative chest radiograph (81.9% TEE versus 75.3% control; P = not significant). One significant complication, a superior vena cava perforation, occurred in the control group. Time to placement was 9.6 min in the TEE group versus 8.0 min in the control group (P = 0.015). IMPLICATIONS: Transesophageal echocardiography can be used to guide central venous catheter placement in congenital heart surgery. Central venous catheters that seem to be located high in the right atrium by chest radiograph in these patients are often actually in the superior vena cava and pose little risk of cardiac perforation.

The use of lidocaine for preventing the withdrawal associated with the injection of rocuronium in children and adolescents.

UNLABELLED: We designed this study to examine the incidence and degree of movement after the administration of rocuronium in children and adolescents and to measure the treatment effect of lidocaine for its prevention. One hundred patients (aged 5-18 yr) were randomly assigned to two groups. After general anesthesia was induced with 5 mg/kg thiopental sodium and manual occlusion of venous outflow was performed, one group of patients received 0.1 mL/kg 1% lidocaine i.v.. A second group received 0.1 mL/kg of isotonic sodium chloride solution as a placebo control. Venous outflow occlusion was held for 15 s, released, and immediately followed by the administration of rocuronium 1 mg/kg i.v.. The patient's response to rocuronium injection was graded using a 4-point scale. We observed that the incidence of withdrawal was 84% in the placebo group and was significantly decreased to 46% in patients pretreated with lidocaine (P < 0.001). This study demonstrates that the i.v. injection of rocuronium is commonly associated with a withdrawal reaction in anesthetized pediatric patients and that this reaction can be attenuated or eliminated by pretreatment with i.v. lidocaine. IMPLICATIONS: Pain on injection of rocuronium in pediatric patients can be alleviated by pretreatment with i.v. lidocaine.

Electrocardiographic artefact with SSEP monitoring unit during scoliosis surgery.

A case of somatosensory evoked potential (SSEP) induced electrocardiographic artefact simulating supraventricular tachycardia (SVT) is described in a three year old girl with Goldenhar syndrome, during anterior thoracoscopic discectomy with posterior spinal fusion for scoliosis. Adenosine was administered for this misinterpreted EKG with coincidental cessation of SVT like trace.

Early intravenous cannulation in children during inhalational induction of anaesthesia.

Intravenous cannulation is obtained in almost all patients scheduled for operative intervention under anaesthesia. In our practice, inhalational induction precedes cannulation in children in order to avoid pain and discomfort, and cannulation is delayed until the child is adequately anaesthetized in fear of precipitating laryngospasm due to painful stimulus of venepuncture in the light stage of anaesthesia. This study was performed on 150 patients between two to eight years of age to determine if there is a difference in the incidence of untoward incidents, if cannulation is performed when children are lightly anaesthetized (Early, Group E), as compared to when they are deeply anaesthetized (Late, Group L). In patients randomized to early cannulation, the results showed that there was a significantly shorter time from induction to venous cannulation, the halothane concentration was lower at the time of cannulation, there was a greater incidence of movement on cannulation and a greater incidence of changes in heart rate, blood pressure, and respiratory rate. There was no significant differences in the incidence of laryngospasm or in the success rate of intravenous cannulation between the two groups. We conclude that venous cannulation can be safely performed during the light stages of anaesthesia.

Analgesia for venepuncture in a paediatric surgery centre.

OBJECTIVE: To establish an effective and efficient method of painless venepuncture in children 8 years and older in an ambulatory paediatric surgery centre. METHODOLOGY: Sixty patients aged 8-21 years were randomized to one of three groups: (i) nitrous oxide with EMLA cream; (ii) nitrous oxide with intradermal lidocaine; and (iii) nitrous oxide alone (n = 20 in each group). Patients in all three groups received oral midazolam for pre-operative anxiolysis. The degree of patient sedation and anxiolysis was noted by two observers before and 2 min after the administration of 50% nitrous oxide. The patient's response to venepuncture or intradermal lidocaine was rated by the two observers using an Observer Response Score. After successful venepuncture, the nitrous oxide was discontinued and the patient was asked to rate the pain of venepuncture using a Patient Response Score. RESULTS: There were no differences in the degree of sedation and anxiolysis between the three groups before or after the administration of nitrous oxide. Patients in the control group (nitrous oxide alone) had a higher incidence of withdrawal or vocalization with venepuncture. When the patients rated the pain of venepuncture, there were no differences between the three groups. CONCLUSIONS: Oral midazolam in combination with 50% nitrous oxide provides adequate analgesia and anxiolysis for venepuncture in patients 8 years and older. The addition of EMLA cream or intradermal lidocaine will decrease the likelihood of patient movement.

Anaesthetic considerations for the patient with cri du chat syndrome.

Cri du chat syndrome is an inherited disease affecting multiple organ systems. Most characteristic is the anatomical abnormality of the larynx resulting in a cat-like cry. Issues important in developing an anaesthetic plan include: anatomical abnormalities of the airway, congenital heart disease, hypotonia, mental retardation, and temperature maintenance. We report the case of a 33-month-old patient with cri du chat syndrome undergoing patent ductus arteriosus (PDA) ligation and discuss the anaesthetic issues.

The safety of continuous pleural lignocaine after thoracotomy in children and adolescents.

Several studies have proven pleural bupivacaine effectively provides postthoracotomy analgesia for both children and adults. When 0.25% bupivacaine is administered as a continuous infusion or repeated bolus, serum bupivacaine levels frequently approach the toxic range. The hazards of bupivacaine toxicity are more difficult to monitor, especially in children who may not report symptoms of local anaesthetic toxicity. Because of this concern, we initiated the use of pleural lignocaine to provide postthoracotomy analgesia for paediatric patients. The records of all patients receiving pleural lignocaine from January 1991 to December 1992 were reviewed. A total of 98 pleural catheters were inserted in 96 patients ranging in age from five months to 20 years. Seven patients had lignocaine levels that exceeded 5 micrograms.ml-1 and no patient manifested symptoms of systemic toxicity. This study shows that the administration of pleural lignocaine is a safe method of providing postthoracotomy analgesia. Lignocaine infusions in the dosage range of 20 to 40 micrograms.kg-1.min-1 rarely produce toxic levels, and monitoring of lignocaine levels every 12 h is an effective method of screening for toxicity.

The metabolic effects of surface cooling neonates prior to cardiac surgery.

Neonates undergoing cardiac surgery at The Children's Hospital of Philadelphia frequently developed metabolic acidemia as they passively cooled prior to the start of cardiopulmonary bypass. This study was performed in an attempt to identify the mechanism for this acidemia. After receiving an initial dose of fentanyl (10 micrograms/kg) and pancuronium, 22 neonates were randomly assigned to maintain normothermia by active warming (Group I), or to permit passive cooling (Group II) before surgery. Arterial blood samples were obtained prior to, and at 10 and 45 min after entering the operating room for the analysis of pH, gas tensions, lactate, pyruvate, plasma free fatty acids, acetoacetate, beta-hydroxybutyrate, total CO2, and glucose concentrations. In the last 11 patients studied, the observation period was extended to 75 min at which time another arterial blood sample was obtained. There was a steady decrease in heart rate as the Group II patients cooled; however, arterial blood pressure did not change in either group. There were no changes in blood values measured in Group I neonates. In the Group II patients, there was a progressive decline in calculated base excess, total CO2, and an increase in serum lactate as the patients cooled. The metabolic acidemia that develops in neonates represents lactate accumulation as a consequence of surface cooling prior to surgery and the institution of cardiopulmonary bypass. Whether lactate accumulates as a result of anaerobic metabolism in underperfused tissue beds or reduced hepatic clearance could not be distinguished in this study. Since neither clinically significant hemodynamic changes nor differences in outcome were found between the two groups, the authors believe this mild lactic acidemia is inconsequential and does not require therapy.

Anaesthesia for the patient with neonatal adrenoleukodystrophy.

The authors present and discuss the care of a nine-month-old with neonatal adrenoleukodystrophy who required general anaesthesia for gastrointestinal endoscopy. Neonatal adrenoleukodystrophy is an inherited disorder of peroxisomal enzymes. Anaesthetic care may be affected by the presence of hypotonia, liver function abnormalities, gastroesophageal reflux, and impaired adrenocortical function. Preoperative sedation is contraindicated because of the risk of precipitating airway obstruction due to pre-existing hypotonia. Anaesthetic induction and tracheal intubation should be performed to minimize the risk for aspiration of gastric contents. The choice of muscle relaxant should take into account the pre-existing hypotonia as well as the possibility of hyperkalaemia in response to succinylcholine. Anaesthetic agents known to decrease the seizure threshold should be avoided in patients with a seizure disorder. In addition, anaesthetic agents that rely on the liver for metabolism should be used with caution in patients with cirrhosis. When time permits, these patients should be screened for adrenocortical insufficiency before surgery, and perioperative steroid coverage is advisable when preoperative testing of adrenocortical function is not feasible. While these patients eventually die after progressive deterioration, full recovery from the effects of anaesthesia and surgery can be achieved with attention to neurological, metabolic, and physical problems.