Christian Seefelder

Thoracic epidural catheters placed by the caudal route in infants: the importance of radiographic confirmation.

Background: Cephalad advancement of epidural catheters to the thoracic region via the caudal route has been shown to be feasible in neonates and small infants. This has allowed many young infants to receive thoracic level epidural analgesia with dilute local anaesthetic solutions using the simpler caudal approach. Since radiographic confirmation of the catheter tip is routine at this institution, we wished to determine how often radiographic studies led to adjustment or replacement of the epidural catheter.

Effect of phenylephrine bolus administration on global left ventricular function in patients with coronary artery disease and patients with valvular aortic stenosis.

Background:Although phenylephrine bolus administration is frequently used to increase coronary perfusion pressure in patients with coronary artery disease or valvular aortic stenosis, there are no data describing its effect on left ventricular function (LVF) Methods:Twenty patients scheduled for elective coronary artery bypass grafting (group 1) and 18 patients scheduled for elective aortic valve replacement (group 2) entered the study. The effect of phenylephrine was compared with that of norepinephrine in those patients who developed a defined degree of arterial hypotension under general anesthesia. These patients were randomized to receive an initial bolus of either phenylephrine (1 μg/kg) or norepinephrine (0.05 μg/kg) followed by a bolus of the other drug after arterial pressure and heart rate (HR) had returned to baseline. Transesophageal echocardiography was used to evaluate LVF. Arterial pressure, HR, ejection time, and LV diameter, area, and wall thickness were recorded immediately before and for 3 min after bolus administration. Fractional diameter shortening, fractional area change, mean heart rate corrected velocity of circumferential fiber shortening (mVcfc), and LV meridional endsystolic wall stress (ESWS) were calculated. Results:Both substances effectively restored arterial pressure in both groups. However, in group 1, phenylephrine administration resulted in a reduction of fractional area change from 0.51 (median) to 0.39 (P=0.0007) and a reduction of mVcfcfrom 1.16 to 0.61 circ/s (P=0.0001). End-systolic wall stress increased from 98 to 186 103 dyne · cm-2 (P=0.0001). Administration of norepinephrine to group 1 and administration of either substance to the group 2 patients did not cause any significant changes of LVF Conclusions:The results indicate that phenylephrine given as an intravenous bolus to patients with CAD anesthetized with fentanyl causes a transient impairment of LV global function and that phenylephrine bolus administration is well tolerated in patients with valvular aortic stenosis

Perioperative management of a child with severe hypertension from a catecholamine secreting neuroblastoma

Increased catecholamine secretion from neuroblastomas can occasionally be demonstrated, but severe hypertension is uncommon. We report the perioperative management of a 5 year old child with stage III adrenal neuroblastoma who presented with malignant hypertension and high norepinephrine and dopamine levels. Hypertensive crises occurred during anesthesia for surgical biopsy and during chemotherapy. After blood pressure control using phenoxybenzamine and enalapril, doxazosin was used successfully as the preoperative α‐adrenergic receptor antagonist for surgical tumor resection.

Oesophageal perforation presenting as oesophageal atresia in a premature neonate following difficult intubation

Iatrogenic oesophageal perforation in neonates is well recognized in the medical and surgical literature with intubation injury listed as a possible contributing mechanism besides nasogastric tube placement and suctioning. Diagnosis can be difficult and sometimes confused with other entities. With early diagnosis, nonsurgical management often leads to complete resolution in neonates. We report the case of a 1‐day‐old premature neonate who was brought to the operating room with the preliminary diagnosis of proximal oesophageal atresia with stump perforation and distal tracheo‐esophageal fistula. His intubation for respiratory distress at birth had been difficult due to Pierre–Robin sequence with micrognathia. Oesophagoscopy in the operating room revealed a patent oesophagus but perforations in the pharynx and in the proximal oesophagus with the nasogastric tube entering the pharyngeal perforation. Oesophageal perforation and the limitations of the difficult airway algorithm in small neonates are discussed.

The effect of ephedrine bolus administration on left ventricular loading and systolic performance during high thoracic epidural anesthesia combined with general anesthesia.

We investigated the effect of ephedrine on left ventricular function in patients without cardiovascular disease under high thoracic epidural anesthesia combined with general anesthesia. Because the epidural block was extended to all cardiac segments, ephedrine was assumed to be deprived of its centrally mediated actions. Left ventricular (LV) function was assessed using transesophageal echocardiography. We measured arterial pressure (AP), heart rate (HR), LV end-systolic and end-diastolic diameter and area (ESA, EDA), wall thickness, and LV ejection time before and after intravenous ephedrine bolus administration. We calculated area ejection fraction (EFA), end-systolic wall stress (ESWS), and mean velocity of circumferential fiber shortening (mVcfc). Ephedrine had a biphasic effect on left ventricular function. It transiently decreased EDA from 18.9 to 16.5 cm2 (mean), whereas EFA and mVcfc were increased from 33% to 49%, and from 1.88 to 2.67 circumferences/s, respectively. During the second phase, ephedrine increased mean arterial pressure (MAP) from a baseline value of 62 to 87 mm Hg, EDA was restored to 19.3 cm2, and EFA and mVcfc remained above baseline (52% and 2.64 circumferences/s, respectively). ESWS was not significantly increased from baseline. We conclude that ephedrine improves left ventricular contractility, even in the presence of high thoracic epidural anesthesia, without causing relevant changes of left ventricular afterload.

Routine Extraluminal Use of the 5F Arndt Endobronchial Blocker for One-Lung Ventilation in Children up to 24 Months of Age

THORACIC SURGERY in neonates, infants, and small children increasingly is performed with minimally invasive techniques including thoracoscopy.1 One-lung ventilation (OLV) optimizes exposure during thoracoscopic surgery.1 The ediatric size 5F Arndt Endobronchial Blocker (AEB) (Cook edical Inc, Bloomington, IN) has been used successfully for ung isolation in children. A removable loop protruding through ts central lumen is used to guide it with a fiberoptic bronchocope (FOB) into the mainstem bronchus. Because a 4.5-mm nner-diameter (ID) endotracheal tube (ETT) or larger is reuired to accommodate the blocker concomitant with a peditric FOB for blocker placement, its endoluminal use is limited o children 2 years and older.2 The authors performed a retrospective review of their practice of placing the blocker outside the ETT (extraluminal) and to position the blocker with guidance by a bronchoscope inserted through the ETT (endoluminal) in children up to 24 months of age.

The perioperative management of a patient with complex single ventricle physiology and pheochromocytoma

Pheochromocytoma is associated with intense physiologic effects of alpha- and beta-adrenergic stimulation from catecholamine secretion. Perioperative management for these patients includes alpha-adrenergic receptor blockade, intravascular volume replacement, and, if necessary, beta-adrenergic receptor blockade. Significant perioperative changes in preload and afterload, fluid status, heart rate and rhythm, and inotropy can occur and may be contrary to anesthetic management goals for patients with certain conditions of congenital heart disease. We report the perioperative management with doxazosin of a patient with single ventricle physiology and cavo-pulmonary and aorto-pulmonary lung perfusion who presented for resection of a pheochromocytoma.

Life threatening tension pneumoperitoneum from intestinal perforation during air reduction of intussusception

Summary We present a case report of a child with intussusception who underwent air reduction which was complicated by bowel perforation. Life threatening tension pneumoperitoneum developed rapidly and immediate needle decompression was life saving in this case. The pathophysiology of hyperacute abdominal compartment syndrome is discussed.

The caudal catheter in neonates: where are the restrictions?

Purpose of review In neonates, epidural catheters inserted at the sacral hiatus can easily be advanced to a lumbar or thoracic level. These ‘caudal catheters’ are popular because they allow the neonate to benefit from epidural analgesia without the concerns of spinal cord injury potentially associated with primary thoracic placement in an asleep neonate. This review looks at use and benefits, and risks and complications of caudal epidural catheters in neonates. Recent findings Restrictions of neonatal caudal catheters are related to risks associated with placement and advancement of the catheters, infectious risks of caudal catheters, and toxicity risks related to the higher free fraction and lower clearance of bupivacaine in neonates. Caudal catheters in neonates are popular, but evidence that they improve outcome is lacking. Summary Epidural anesthesia and analgesia for neonates should be performed and managed by pediatric anesthesiologists. Potential risks and complications must be appreciated and all steps to maximize safety of the technique must be taken. In particular, close postoperative observation and pain service management are indispensable. Future research should investigate the risks of caudal and segmentally placed catheters in neonates, study the role of epidural analgesia in outcome improvement for neonates, and guide us to safer use of local anesthetics suitable for neonates with their pharmacologic immaturity.

The effect of phenylephrine bolus administration on left ventricular function during isoflurane-induced hypotension

By using transesophageal echocardiography, we examined the effect of phenylephrine (PHE) bolus administration on left ventricular function in 16 patients with no known cardiovascular disease during isoflurane-induced hypotension. PHE was compared with norepinephrine (NE). The patients received an intravenous bolus of PHE (2 micrograms/kg) or NE (0.1 microgram/kg) in random order. The second substance was administered after levels of arterial blood pressure and heart rate returned to baseline levels. We determined fractional area change, end-systolic wall stress, and rate-corrected mean velocity of circumferential fiber shortening. Both substances effectively restored arterial blood pressure. However, after PHE, fractional area change decreased from 0.45 to 0.31 (mean) and rate corrected mean velocity of circumferential fiber shortening from 0.88 to 0.57 circumference/s, whereas both variables remained unchanged in response to NE. End-systolic wall stress increased after PHE and NE from 47.4 to 91.2 and from 54.0 to 65.2 10(3) dyne/cm2, respectively. We conclude that phenylephrine, given as intravenous bolus to patients under isoflurane hypotension, causes a transient impairment of left ventricular systolic performance.