Masatoshi Fukumoto

Distorted perception of smell by volatile agents facilitated inhalational induction of anesthesia

Background:  Unpleasant smell of halogenated volatile agents is one of the frustrating factors for inhalational induction. We developed a new modification that might enable children to enjoy the smell itself while incrementally elevating sevoflurane concentration. Troposmia is usually a pathological quality change of smell perception and an olfactory stimulus is distortedly perceived in this state, which we applied to inhalational induction.

Flexible, tapered-tip tube facilitates conventional orotracheal intubation by novice intubators

Orotracheal intubation is the standard technique for airway management, but several untoward airway complications are possible with this method. To avoid airway trauma caused by the tube tip during intubation, the Parker Flex-Tip tube (PFT), which has a flexible, tapered tip, was developed. It has been reported that the PFT facilitates fiberoptic orotracheal intubation and introducer-guided tracheal intubation. In this study, we compared the PFT to a standard endotracheal tube (SET), regarding the time of intubation during conventional orotracheal intubation and the incidence of postoperative sore throat and hoarseness. One hundred and thirty-four patients scheduled for elective anesthesia using orotracheal intubation were randomized to either the PFT or SET and 132 completed the study. The intubators were classified into three groups: staff anesthesiologists, inexperienced anesthesiologists, and anesthesia trainees. The tube was selected by another anesthesiologist and the time required for intubation was measured. PFT did not shorten the time required for intubation and did not reduce the incidence of sore throat and hoarseness. However, a detailed analysis revealed that the PFT decreased the time required for intubation in the anesthesia trainee group. The PFT may help novice intubators to conduct a smooth intubation.

A case of paradoxical embolization and subsequent Takotsubo cardiomyopathy during general anesthesia

To the Editor: Paradoxical embolization is rare, but its significance during anesthesia has been emphasized in a number of reports. We have recently experienced a case of paradoxical embolization accompanied by Takotsubo cardiomyopathy. A 79-year-old female patient was admitted to our hospital for lumbar spine surgery. She could walk in her home and to nearby locations but used a wheelchair when going to more distant locations because of leg weakness. She had no medical history other than atrial fibrillation. Preoperative transthoracic echocardiography demonstrated no thrombus in the heart. The attending cardiologist recommended warfarin use after surgery. The surgery was performed under general anesthesia, with the patient carefully kept in a prone position to avoid unfavorable positions. During the 6-h-long surgical procedure, there was no fluctuation in the vital signs. Total bleeding was about 460 g, and fluid infusion was 3200 ml. When she was repositioned to a supine position, the electrocardiogram registered ventricular fibrillation. She was successfully resuscitated after 6 min of cardiac compression, the intravenous administration of epinephrine, and lidocaine injection. Direct cardioversion was avoided for fear of a possible unnoticed left atrial thrombus. Transesophageal echocardiography in the operating room demonstrated a floating high echoic mass in the left atrium (Fig. 1; upper). Right ventricular enlargement was not apparent. Emergent coronary angiography was performed to exclude myocardial infarction, and there was no obstructed coronary artery. A left ventriculography demonstrated ‘‘apical ballooning’’, which is a characteristic pattern of Takotsubo cardiomyopathy (TCM). Magnetic resonance imaging on the same day revealed multiple brain embolization. At that time we concluded that a previously unnoticed left atrial thrombus had caused cerebral thromboembolization upon patient repositioning, which in turn induced the TCM, although the cause of the ventricular fibrillation remained unclear. The circulatory state of the patient was comparatively stable in the intensive care unit. Echocardiographic studies demonstrated a considerable recovery of cardiac wall motion, and her trachea was extubated on the second postoperative day. She is currently following rehabilitation for right hemiplegia and aphasia. On postoperative day 11, a pulmonary arterial thrombus was incidentally observed on a computed tomography scan. Upon re-examination of the video of the transesophageal echocardiography in the operating room, the left atrial thrombus seemed to be projecting from the interatrial septum, and the thrombus could be distinguished in the right atrium (Fig. 1, lower). Based on these observations, we concluded that it was reasonable to speculate that the occurrence of a massive pulmonary embolization caused ventricular fibrillation and that the elevated right atrial pressure opened the foramen ovale, resulting in paradoxical embolization. There have been a number of reports on paradoxical embolization [1–3], but this is the first case report of M. Tomita (&) M. Fukumoto T. Kato A. Kondo A. Asai H. Nakano Department of Anesthesia, Okazaki City Hospital, 3-1 Goshoai, Koryuji-cho, Okazaki 444-8553, Japan e-mail: okazakimasui@gmail.com

Aspiration pneumonia associated with a giant epiglottic cyst after cardiac surgery

To the Editor: Epiglottic cysts are found incidentally during induction of general anesthesia and can hamper tracheal intubation.1 Several methods have been reported to overcome these situations, however, to our knowledge, there has been no report of postoperative respiratory complications in patients with epiglottic cysts. We describe a patient with a giant asymptomatic epiglottic cyst who developed aspiration pneumonia after cardiac surgery. A 71-yr-old man (height 154 cm, weight 42 kg) was scheduled to undergo coronary artery bypass grafting. During induction of general anesthesia, a giant epiglottic cyst was found (Figure). Though manual ventilation was easy, the cyst had almost obstructed the larynx and tracheal intubation was difficult. The surgery was carried out uneventfully and he was admitted to the intensive care unit for postoperative management. On postoperative day one (POD1), he was extubated and his respiratory state was stable. On POD2, he was able to drink water and the cough reflex was present. Immediately following the reintroduction of solid food, he developed aspiration pneumonia of the right lower lobe. Mechanical ventilation and administration of antibiotics proved effective and the cyst was removed surgically on POD5 under general anesthesia. The postoperative course after cystectomy was uneventful and oral intake was normal. There are several factors that increase the risk for aspiration pneumonia after surgery; namely, loss of protective airway reflexes, vomiting, pregnancy, obesity, diminished level of consciousness, anatomic distortion of the airway and a history of cerebrovascular disease.2,3 Especially after cardiac surgery, age and duration of intubation are independent predictors of swallowing dysfunction.4 In our patient, age, the residual effects of anesthetics, the use of transesophageal echocardiography, duration of intubation and anatomic distortion due to the giant epiglottic cyst are all possible factors explaining aspiration. We cannot tell which factor was predominant. However, the presence of this large epiglottic cyst may have resulted in postoperative epiglottic dysfunction and aspiration of solid food.

Difference in manual pressure pumping efficiency between two types of infusion line setting

第39回日本集中治療医学会学術集会のワーク ショップ「日本集中治療医学会専門医制度に期待する もの」において,本学会の専門医制度に関する今後の 展望を拝聴させていただいた。この議論の中で,集中 治療専門医の具体的な到達目標が明示される方向性で あることを特に歓迎し,尽力されておられる関係者の 方々に敬意を表したい。 日本集中治療医学会は1974年に日本集中治療研究 会として設立され,1989年より専門医制度を有してい る。しかしこれまでに,我が国の集中治療医が何をど こまで担う専門医かを示す具体的なガイドラインは存 在せず,専門医取得を目指す医師に何を教えていけば いいのか,ひいては専門医研修施設においていかなる 専門医取得プログラムを提供すべきかを明確にするこ くいからである。 藤川らの報告1)では,牛血の流量比較で有意差を認 めず,ポンピングチャンバーの利点は,三方活栓操作 のないことと,回路内圧の変化による血球損傷の低減 としている。特別な装備の必要のない90度法は,用手 ポンピングチャンバー付き急速輸血セット以上の流量 を確保できるため,急速輸血が必要な場面に遭遇する 機会の多い医師にとっては,是非知っておくべき臨床 のコツであるとわれわれは考える。 本稿の全ての著者には規定されたCOIはない。

Unexpected vomiting during anesthesia induction in a patient with undiagnosed congenital esophageal stenosis

was taken for blood gas analysis. This confirmed intraarterial placement. The cannula was left in situ and clearly marked as ‘arterial’. A 22G cannula was then placed in the left external jugular vein. The remainder of the case proceeded uneventfully. The color and perfusion of the left hand was monitored and appeared normal throughout the procedure. The cannula was removed postoperatively in the recovery room. The patient’s hand was observed and there were no sequelae from the incident. Intra-arterial injection in the dorsum of the hand in children has been described in this journal (1) In our patient, the vessel that was probably cannulated was a branch of the SRA. As the radial artery winds laterally around the wrist, it courses through the anatomical snuff box, deep to the tendons defining it. The SRA is an anatomical variation in which the radial artery courses over the tendons defining the snuff box and may end as a single branch passing through the first intermetacarpal space. It is a rare finding, with an incidence of <0.2% of upper limbs (4). The superficial ulnar artery is a more common anomaly than the SRA, observed in 3.75% of specimens in a large cadeveric survey (4). Cannulation of this vessel, in the antero-medial aspect of the forearm, has also been described (2). A recent review discussed the possible complications and management strategies of intra-arterial injection of several anesthetic drugs (5). Fentanyl and atropine have been administered intra-arterially without adverse effect. Intra-arterial atracurium can cause ischemia. Drugs which are not dissolved in water, e.g. propofol, etomidate, diazepam or with an alkaline pH, e.g. thiopentone should be avoided. Features suggestive of intra-arterial cannulation include pulsatile back flow of blood into the i.v. tubing, intense and immediate pain on injection and blanching around the site of the cannula. Unfortunately, many of these signs were not useful in this situation. The patient received an inhalational induction prior to cannulation and the cannula was attached to extension tubing with a locked threeway tap that prevented back flow. Predisposing factors towards intra-arterial cannulation include difficult venous access because of obesity, expected anatomical location of an artery and partial arterial flow occlusion by the use of a tight venous tourniquet. In summary, this case highlights the need to be aware that intra-arterial cannulation can occur when performed in the dorsum of the hand in children and to have an understanding of peripheral upper limb arterial supply and possible variation. It emphasizes the need to be aware of the features suggestive of intra-arterial cannulation and of the side effects of common anesthetic drugs when injected intra-arterially. John Friis Michael Browning Department of Anaesthetics, Maidstone Hospital, Hermitage Lane, Maidstone, Kent ME16 9QQ, UK (email: mikebrowning@nhs.net)