Subramanyam Rajeev

Anatomic consideration of caudal epidural space: A cadaver study

The knowledge of sacral hiatus anatomy is imperative in clinical situations requiring caudal epidural block for various diagnostic and therapeutic procedures of the lumbosacral spine to avoid failure and dural injury. In this study, a detailed anatomic study of the sacral region was carried out on 49 male adult Indian cadavers. Dorsal surface of sacral region was dissected to study sacral cornua, sacral hiatus, and the dimensions of triangle formed by the right and left posterosuperior iliac spines with apex of the hiatus. Midsagittal sections were subjected for various anatomical measurements. The angle of needle insertion and the depth of caudal space were noted. Cornu was not palpable bilaterally in 7 (14.3%) and palpable unilaterally in 12 (24.5%) specimens. Mean (standard deviation) distance between apex of hiatus and coccyx tip was 57.5 (8.7) mm and length of sacrococcygeal ligament was 34.2 (7.4) mm. The dimensions of the triangle were found to be interchangeable in 25 cadavers. Once the needle is introduced into the canal after penetrating the sacrococcygeal ligament, it should not be advanced >5 mm to prevent dural puncture. The level of maximum curvature of sacrum was S3 in 34 (69.4%) of cases. The dural sac was found to terminate at S2 in 41 (83.6%). The mean (SD) angle of depression of the needle was 65.7 (5.5) (range 58–78). The measurements described for the identification of the sacral hiatus, optimal angle of depression, and depth of the needle may improve the safety and reliability of a caudal epidural block. Clin. Anat. 22:730–737, 2009.

Anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles in fetuses measured ex vivo.

Background:  The increasing opportunities to consider fetal intervention in selected cases of life‐threatening malformations have necessitated airway management of fetuses with low gestational age. This study is aimed to determine the anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles and their correlation to age and crown rump length (CRL) in fetuses.

Dose-response study of intrathecal fentanyl added to bupivacaine in infants undergoing lower abdominal and urologic surgery.

Background:  Intrathecal (IT) adjuncts often are used to enhance the duration of spinal bupivacaine. Fentanyl is a spinal analgesic that could be a useful adjunct, and enhances the duration and quality of sensory block in adult surgical and obstetric population. However, no data exist to assess the dose–response characteristics of IT fentanyl when added to bupivacaine in infants.

A dose-ranging study of intraarticular midazolam for pain relief after knee arthroscopy.

BACKGROUND: A variety of analgesic techniques have been used to manage postoperative pain after arthroscopic knee surgery. Intraarticular midazolam may have an analgesic effect similar to that seen when midazolam is used in a centroneuraxial fashion. METHODS: Sixty ASA status I or II patients undergoing knee arthroscopy with general anesthesia were randomized to receive intraarticular midazolam 50 &mgr;g/kg, 75 &mgr;g/kg, or isotonic saline. We assessed the efficacy of the analgesic technique with visual analog scale pain scores, time until first request for analgesics, and cumulative analgesic consumption. Patients were observed for 48 h. RESULTS: The addition of intraarticular midazolam significantly reduced visual analog pain scores in the early postoperative period compared with saline. Both doses similarly prolonged duration until first request for analgesic compared with saline (4.7 and 4.6 vs 0.7 h). There was no statistically significant difference between the two doses of midazolam or cumulative 48 h analgesic consumption. CONCLUSIONS: We conclude that when intraarticular midazolam was compared with placebo there was a reduction in pain after day-case arthroscopic knee surgery; however, this pain relief was of relatively short duration.

Tramadol Added to Bupivacaine Does Not Prolong Analgesia of Continuous Psoas Compartment Block

The primary aim of our study was to evaluate the quality and duration of analgesia when tramadol was added to 0.25% bupivacaine for continuous psoas compartment block (CPCB) using visual analog pain scores. Thirty patients were prospectively randomized into two equal groups (n = 15). Visual analog scale pain score was not significantly different between the groups during the 48‐hour follow‐up period. Rescue analgesic consumption, nausea and vomiting, and the satisfaction scores were comparable between the groups (P > 0.05). Success with catheter placement adjacent to the lumbar plexus was 100%, and none of the patients developed any catheter‐related complications. In conclusion, tramadol does not provide a clinically significant analgesic action as an adjunct to 0.25% bupivacaine for CPCB.

Management of pilot balloon assembly malfunction in an armored endotracheal tube in a child.

intubation. A Portex Blue Line cuffed oral/ nasal endotracheal tube size 5.5 (Smiths Medical International, UK, Colonial Way, Watford) was deemed an appropriate size. However, resistance was encountered during an attempt to insert it via the right nostril after induction. Repeat attempt in the left nostril was also unsuccessful. Instead of forcing the endotracheal tube through, a size 12F suction catheter was inserted through the endotracheal tube and further into the pharynx. (see Figure 1) The smaller and blunt tip of the suction catheter causes less damage. The endotracheal tube could then be advanced over the suction catheter into the pharynx with less resistance and hence, less trauma. The suction catheter was then removed before the endotracheal tube was further advanced into the trachea. Thong Sze Ying Hwand Nian Chin Singapore General Hospital – Anaesthesia, Singapore (email: thongszeying@gmail.com)

Airway rescue with laryngeal mask airway during sclerotherapy of a large arteriovenous malformation in the oral and maxillofacial region.

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Octreotide‐induced severe paradoxical hyperglycemia and bradycardia during subtotal pancreatectomy for congenital hyperinsulinism in an infant

relies on effective spread of local anesthetic to neural structures which are subject to considerable interindividual variation because of surgical intervention. Moreover, the lack of familiarity and experience of surgical and ⁄ or anesthesia colleagues in placing epidural catheters, in addition, to their postoperative management also may influence the comfort level of clinicians in accepting and utilizing such techniques. To a certain extent, these factors may partly explain, why epidural analgesia did not achieve a widespread use in pediatric anesthesia practice as a whole. Despite being a regional anesthesia fanatic, I believe, we must not disregard the pursuit of adjunctive pharmacologic means in achieving satisfactory postoperative comfort. Unfortunately, the conflicting data for using NSAIDs (as outlined by Dr Borgeat) does add a dimension of some concern in relation to their safety after major spinal surgery. In this context, we agree that the evidence is weak and we would like to clarify that the reported case simply described local practice and preference. In retrospect, we would preferably emphasize that: ‘Despite the paucity of strong evidence to support their position, our surgical colleagues recommend the avoidance of NSAID and epidural techniques.’ Finally, with respect to Dr Borgeats’ other important point related to the limited clinical impact of a single case report. We concur that it is impossible to verify if any observed benefit in a single case is because of a true pharmacologic effect or simply a placebo effect. Obviously, future comparative studies are essential to perform in addressing outcomes of safety, side effects and success rates of this intervention. This would be important to help determine the true benefit of ketamine use in clinical practice. This is why, we have clearly stated in our conclusion ‘further comparative studies are needed to determine the true merit of low-dose ketamine infusions as an adjuvant therapy after major spinal surgery.’ In fact, we did carry out such study and its result will be available in near future. Nevertheless, improvements in overall patient care with a focus on patient satisfaction with reliable and reproducible outcomes will ultimately determine the future role of both pharmacologic means and regional anesthesia for pain control after major spinal surgery. B A N C.H. T S U I M D M S c F R C P C Department of Anesthesiology and Pain Medicine, University of Alberta Hospitals, Edmonton, AB, Canada (email: btsui@ualberta.ca)

Anesthetic management of bilateral pheochromocytoma with paradoxical hypotension in a 11-year-old child.

SIR—Pheochromocytomas in children, in contrast with those in adults, are frequently familial (9–50%), bilateral (7–53%), extraadrenal (8–43%) and multifocal (1). The similarity that exists between pheochromocytoma in children and adults includes methods of diagnosis and treatment (2). The possibility of a familial syndrome must be considered and should always be thoroughly evaluated in children. Patients with pheochromocytoma may present to the anesthesiologist for definitive, curative surgery, during radiological investigation, or as a crisis during anesthesia for unrelated surgery (3). A 11-year-old boy, weighing 25 kg, was diagnosed with bilateral adrenal and extraadrenal pheochromocytoma. This child initially presented with a history of vomiting and headache of 1 month and altered conscious level of 1 day duration. Examination revealed sinus tachycardia (146 bÆmin), hypotension (60/ 36 mmHg), neck stiffness and positive Kernig’s sign. He was treated with dopamine, dobutamine and ceftriaxone for neurogenic shock. Inotropes were tapered as hypotension improved, but the blood pressure (BP) increased to >160/100 mmHg and required control with sodium nitroprusside (SNP) 0.5–3 lgÆkgÆmin. He was started on oral labetelol and SNP was gradually reduced. Computed tomography (CT) scan of the head revealed cerebral hemorrhage. With treatment, consciousness improved and the child became neurologically normal over 2 days. Contrast-enhanced CT of the chest and abdomen revealed a mass lesion of heterogeneous attenuation in bilateral paraaortic regions at the level of the left renal hilum (Figure 1). Urinary 24 h vanillylmandelic acid (VMA) and norepinephrine levels were 18.7 mg (reference range 1–8 mg) and 924 lg (1–66 lg), respectively. Fundoscopy revealed hypertensive changes. Preoperatively, his BP was stabilized with prazosin 1 mg q3 h, atenolol 25 mg q12 h, amlodipine 5 mg q12 h, and enalapril 5 mg q12 h. After appropriate counseling, the child was screened for familial syndromes and their association was ruled out. At the preoperative visit his BP over the past 2 weeks were between 140/90 and 110/70 mmHg with heart rate (HR) between 80 and 110 bÆmin. There was a fall in hemoglobin from 118 to 110 gÆdl. ECG revealed a rate of 84 bÆmin, sinus rhythm, left ventricular hypertrophy and left axis deviation. Echocardiography revealed an ejection fraction of 78%. Blood glucose level was 6.1 mmolÆl and serum calcium was 2.4 mmolÆl. The child was premedicated with 5 mg of diazepam the night before and on the morning of surgery. Enalapril was withheld on the day of surgery. On the morning of surgery, after attaching standard monitors, he was sedated with 20 lg of fentanyl and 0.5 mg midazolam to facilitate the placement of right internal jugular and radial artery cannulas. Baseline values were recorded (Figure 2). Anesthesia was induced with fentanyl 20 lg and propofol 60 mg, and the airway secured with a 6.5 mm cuffed tracheal tube after lignocaine 10% spray to the pharynx. An 18G epidural catheter was placed in the T11-12 interspinous space. After confirming the position of the catheter with a test dose, continuous infusion of 0.25% bupivacaine was started and titrated to hemodynamics. Anesthesia was maintained with O2, N2O, and isoflurane. The surgical procedure carried out was resection of the tumor with left total and right partial adrenalectomy. An increase in HR and BP occurred (Figure 2) following intubation, which was controlled with 12 mg of esmolol, and that following dissection, with SNP. An episode of hypotension occurred after tumor removal, managed with isotonic saline and 100 lg phenylephrine. One unit of fresh whole blood and 300 ml of fresh frozen plasma Figure 1 Contrast-enhanced CT scan at the level of the left renal hilum showing mass lesion of heterogeneous attenuation in bilateral paraaortic regions (tumor is shown with black arrows). Pediatric Anesthesia 2007 17: 295–304

Anesthesia management of a ganglioneuroma with seizures presenting as pheochromocytoma.

Ganglioneuromas (GN) are neural crest cell‐derived tumors which may coexist with pheochromocytomas, secrete various neuropeptides or the symptoms may mimic that of a pheochromocytoma, producing hypertension or a hypotensive crisis during anesthesia for these tumors. We report here the case of a 7‐year‐old female child with an adrenal tumor suspected to be a pheochromocytoma, later confirmed by histology as a GN. This child presented with episodic headache, anxiety, palpitations and 3D helical (spiral) computed tomography of the abdomen revealed an adrenal tumor. In addition, the child was diagnosed to have a seizure disorder. She was managed as a pheochromocytoma. Although the childs preoperative catecholamine levels were normal, tumor manipulation caused a hypertensive crisis. We discuss the clinical characteristics of this unusual case, anesthesia management, and the postoperative course.