Anthony M. -H. Ho

Outpatient anesthesia clinics are well established in North America, Europe and Australia, but few economic evaluations have been published. The Perioperative Systems in Hong Kong are best described as a hybrid model of the new and old systems of surgical care. In this matched cohort study, we compared the costs and effects of an outpatient anesthesia clinic (OPAC) with the conventional system of admitting patients to the ward a day before surgery for their pre-anesthesia consultation. A second objective of the study was to determine the patient’s median Willingness To Pay (WTP) value for an OPAC. A total of 352 patients were matched (1:1) on their elective surgical procedure to either the clinic group or to the conventional group. The primary outcome was quality of recovery score and overall perioperative treatment cost (US$). To detect a difference in the joint cost-effect relationship between groups, a cost-effectiveness acceptability curve (CEAC) was drawn. A modified Poisson regression model was used to examine the factors associated with patients willing to pay more than the median WTP value for an OPAC. The quality of recovery scores on the first day after surgery between the clinic and conventional groups were similar (mean difference, -0.1; 95% confidence interval (CI), -0.6 to 0.3; P = 0.57). Although the preoperative costs were less in the clinic group (mean difference, -$463, 95% CI, -$648 to -$278 per patient; P <0.001), the total perioperative cost was similar between groups (mean difference, -$172; 95% CI, -$684 to $340 per patient; P = 0.51). The CEAC showed that we could not be 95% confident that the clinic was cost-effective. Compared to the conventional group, clinic patients were three times more likely to prefer OPAC care (relative risk (RR) 2.75, 95% CI, 2.13 to 3.55; P <0.001) and pay more than the median WTP (US$13) for a clinic consultation (RR 3.27, 95% CI, 2.32 to 4.64; P <0.001). There is uncertainty about the cost-effectiveness of an OPAC in the Hong Kong setting. Most clinic patients were willing to pay a small amount for an anesthesia clinic consultation.

To describe a novel airway management technique for thoracoscopic repair of a type C tracheoesophageal fistula (TEF) in a neonate. A full-term neonate with a type C TEF presented for thoracoscopic repair. The fistula was at the level of the carina, making its isolation from positive pressure ventilation using traditional techniques difficult. In addition, non-ventilation of the right lung was required. The use of two Fogarty type balloon-tipped embolectomy catheters placed alongside the endotracheal tube successfully achieved the goal of blocking ventilation of the fistula and the right lung. The use of fibreoptic bronchoscopy greatly facilitated placement of the blockers. The patient made an uneventful recovery. Placing two balloon-tipped blockers, one in the TEF and the other in the right mainstem bronchus, is a viable technique for thoracoscopic fistula repair when the fistula is at or very close to the level of the carina. Décrire une nouvelle technique de prise en charge des voies respiratoires pour la réparation d’une fistule trachéo-oesophagienne (FTO) de type C par thoracoscopie chez un nouveau-né. Un nouveau-né à terme avec une FTO de type C a été admis pour une réparation par thoracoscopie. La fistule était située au niveau de la carène, rendant difficile son isolation de la ventilation à pression positive avec des méthodes traditionnelles. De plus, la non-ventilation du poumon droit était nécessaire. Grâce à l’utilisation de deux cathéters d’embolectomie à ballonnet de type Fogarty, placés le long du tube endotrachéal, la ventilation de la fistule et du poumon droit a pu être bloquée. Le recours à une bronchoscopie par fibres optiques a grandement facilité le placement des bloqueurs. Le patient s’est rétabli sans complications. Lorsque la fistule est au niveau de la carène ou en est très proche, le placement de deux bloqueurs à ballonnet, l’un dans la FTO et l’autre dans la bronche souche droite, est une technique viable pour la réparation thoracoscopique d’une fistule.

Randomized controlled trials of how best to administer fresh frozen plasma (FFP) in the presence of ongoing severe traumatic hemorrhage are difficult to execute and have not been published. Meanwhile, coagulopathy remains a common occurrence during major trauma resuscitation and hemorrhage remains a major cause of traumatic deaths, suggesting that current coagulation factor replacement practices may be inadequate. We used a pharmacokinetic model to simulate the dilutional component of coagulopathy during hemorrhage and compared different FFP transfusion strategies for the prevention or correction, or both, of dilutional coagulopathy. Assuming the rates of volume replacement and loss are roughly equal, we derived the hematocrit and plasma coagulation factor concentration over time based on the rate of blood loss and replacement, the hematocrit and coagulation factor concentration of the transfusate, and the hematocrit and plasma factor concentration at the time when FFP transfusion begins. Once excessive deficiency of factors has developed and bleeding is unabated, 1-1.5 units of FFP must be given for every unit of packed red blood cells (PRBC) transfused. If FFP transfusion should start before plasma factor concentration drops below 50% of normal, an FFP:PRBC transfusion ratio of 1:1 would prevent further dilution. During resuscitation of a patient who has undergone major trauma, the equivalent of whole-blood transfusion is required to correct or prevent dilutional coagulopathy.

Summary: Continuous central pressure monitoring and simultaneous continuous infusion via the same central venous catheter are sometimes necessary. Based on theoretical calculations and experimental measurements, we have determined that pressure monitoring is essentially unaffected if the continuous infusion rate is 50 ml.h ⁻¹ or less for an adult and a paediatric central catheter. At rates > 200 ml.h ⁻¹ , the central venous pressure is exaggerated by up to 4 mmHg and 8 mmHg for the adult and paediatric catheters, respectively.

To report a case of complete upper airway obstruction after topicalization with lidocaine in a completely conscious patient with partial upper airway obstruction. A 69-yr-old man with a history of neck cancer and radiation presented for resection of recurrent neck tumour. No preoperative sedation was given. He had inspiratory and expiratory stridor but had no history of aspiration or swallowing problem. Phonation was distorted but effective. The surgeon was reluctant to perform an awake tracheostomy under local anesthesia. In preparation for a fibrescope-assisted orotracheal intubation, the non-sedated patient was given topical upper airway lidocaine during which he developed total airway obstruction and hypoxemia. He was immediately intubated with a fibrescope. His vocal cords were not edematous although the supraglottic structures appeared to be. The vocal cords were abducted and their movement was limited and not paradoxical. Tumour resection was uneventful upon successful tracheal intubation and general anesthesia. Tracheostomy at the end of the case was difficult, as expected. The patient tolerated the procedures and regained consciousness with no neurologic sequelae. Dynamic airflow limitation associated with local anesthesia of the upper airway may lead to complete upper airway obstruction in a compromised airway. The main cause may be the loss of upper airway muscle tone, exacerbated by deep inspiration during panic. Présenter un cas d’obstruction complète des voies aériennes supérieures après pulvérisation de lidocaïne chez un patient tout à fait conscient mais souffrant déjà d’obstruction respiratoire partielle. Un homme de 69 ans aux antécédents de cancer du cou et de radiothérapie s’est présenté pour la résection d’une tumeur récurrente au cou. Aucune sédation préopératoire n’a été administrée. Il présentait un stridor inspiratoire et expiratoire, mais n’avait pas d’antécédent de trouble d’aspiration ou de déglutition. La phonation était déformée mais efficace. Le chirurgien était réticent à réaliser une trachéotomie vigile sous anesthésie locale. Pendant la préparation de l’intubation orotrachéale fibroscopique, de la lidocaïne topique a été administrée dans les voies aériennes supérieures du patient éveillé chez qui s’est développée une obstruction totale des voies aériennes et de l’hypoxémie. Il a été immédiatement intubé avec un fibroscope. Ses cordes vocales n’étaient pas œdémateuses même si les structures supraglottiques semblaient l’être. Les cordes vocales étaient écartées et leur mouvement était limité mais non paradoxal. La résection tumorale s’est bien déroulée sous intubation trachéale réussie et anesthésie générale. Comme prévu, la trachéotomie a été difficile à réaliser à la fin de l’opération. Le patient a bien toléré les interventions et s’est réveillé sans séquelles neurologiques. Une limitation dynamique du débit d’air associé à l’anesthésie locale des voies aériennes supérieures peut conduire à une obstruction complète des voies respiratoires supérieures en cas d’ob-struction partielle préalable. La principale cause pourrait être la perte du tonus musculaire des voies respiratoires supérieures, exacerbée par l’inspiration profonde pendant les moments de panique.

During double-lumen tube (DLT) placement, the anesthesiologist must be mindful of the margin of safety. We determined how this margin is affected by the presence of a tracheal bronchus by elucidating the mathematical relationship between some relevant physical dimensions of the trachea, bronchi, and DLT. Our results suggest that a tracheal bronchus only rarely affects the intrinsic margin of safety of DLT placement. When the tracheal bronchus is located much higher than its most frequently seen location (within 2 cm from the carina), however, there is increased risk that it could be blocked by the tracheal cuff of a left-sided DLT.

Haemostatic deficiencies, common among cirrhotic patients, may deteriorate further after hepatectomy, increasing the bleeding risk associated with the use of thoracic epidural analgesia. We describe two patients who enjoyed immediate post-operative tracheal extubation and satisfactory analgesia using mainly right thoracic paravertebral analgesia after right lobe hepatectomy.