Muneaki Shimada

Pulmonary edema after long-term beta-adrenergic therapy and cesarean section.

P -Adrenergic agonists, such as ritodrine and terbutaline, have been widely used for the inhibition of premature uterine contraction in preterm patients (1,2). However, these drugs can cause pulmonary edema during the initial phase of tocolytic therapy, probably secondary to excessive intravascular fluid administration, cardiac failure (l-4), and/or pulmonary capillary endothelial damage (5,6). We describe a patient who received 11 wk of ritodrine administration prior to cesarean section and developed pulmonary edema, unlikely related to excessive intravascular fluid volume, after the surgery.

A case of atrioventricular block (Wenckebach type) induced by sugammadex

To the Editor: Summadex is a muscle relaxant antagonist that reverses muscle relaxation by binding to muscle relaxants. There is almost no known noteworthy adverse reaction to this drug, although there have been some reports of QT prolongation on electrocardiogram (ECG) induced by summadex [1–3]. We recently encountered a case who developed seconddegree atrioventricular block (Wenckebach type) after having received sugammadex. A 21-year-old female patient (height 165 cm, body weight 47 kg) had no noteworthy previous disease history, and preoperative tests revealed no abnormalities of the ECG, serum electrolytes, or other factors. Surgery for resection of nevus pigmentosus of the brachium and face was scheduled. Anesthesia was induced with propofol (100 mg) and rocuronium (40 mg) and maintained with oxygen (40 %), sevoflurane (1.5 %), and remifentanil (0.02 lg/kg/min). The surgeon gave locally 6 ml 1 % lidocaine mixed with 1:200,000 epinephrine to maintain a bloodless surgical field with local anesthesia. Circulation dynamics remained stable intraoperatively. The operation lasted for 60 min. At the completion of the operation, when consciousness was restored, sugammadex (200 mg) was administered. Before tracheal extubation, the patient showed ECG changes consistent with second-degree atrioventricular block (Wenckebach type) (Fig. 1). There were no changes of the heart rate, blood pressure, or SpO2 after the administration of sugammadex as compared with preadministration values. When the course of atrioventricular block was followed, the block converted to firstdegree atrioventricular block within 3 min and to normal sinus rhythm within a few more minutes. In this young patient for whom no particular problem was detected in preoperative tests, second-degree atrioventricular block (Wenckebach type) developed after a dose of sugammadex. Sugammadex binds to muscle relaxants, forming an inactive complex (inclusion compound), thereby effectively removing the muscle relaxant from the neuromuscular junction. Features of sugammadex that are advantageous over the conventional anticholinesterase agents include the lack of a ceiling effect, capability of the drug to reverse even deep muscle relaxation, the slight effects of acid–base balance, body temperature, or anesthetic agents on the drug’s actions, rapid manifestation of action, lack of muscarinic receptor stimulation, and lack of paradoxical reduction of the muscle strength [1–4]. Known adverse reactions to sugammadex include nausea/vomiting, cough, and hypotension. Anaphylaxis and QT prolongation have been reported as serious adverse reactions to this drug [1– 3]. QT prolongation is considered to show no association with the dose level of sugammadex [5]. Tachycardia and bradycardia, for example, often appear when the patient emerges from anesthesia following treatment with anticholinesterase agents or sugammadex [1–4]. However, it is rare for atrioventricular block to develop in a patient with no organic heart disease emerging from anesthesia. Y. Osaka (&) N. Shimada M. Satou T. Masuda T. Ando Y. Kozono M. Shimada Department of Anesthesiology, Tokyo Metropolitan Ohtsuka Hospital, 2-8-1 Minami-ohtsuka, Toshima-ku, Tokyo 170-8476, Japan e-mail: bluesapphire1226@gmail.com

Transient third-degree AV block following sugammadex.

To the Editor: A 64-year-old female undergoing abdominal surgery developed transient third-degree atrio-ventricular block (IIIAVB) after a dose of sugammadex. She had no noteworthy abnormalities on the ECG (ESM Fig. 1A) or of the serum electrolytes and no history of allergy or sugammadex usage. After the epidural catheter was inserted, general anesthesia was induced with propofol, fentanyl, and rocuronium, and maintained with desflurane, remifentanil, and rocuronium. Her hemodynamics remained stable (the operation time 559 min, bleeding 709 ml). When she regained consciousness, sugammadex was administered. Then IIIAVB was developed 4 min after 200 mg sugammadex administration (ESM Fig. 1B). The ECG converted to a wide QRS pattern after 0.5 mg of atropine, and 0.1 mg of epinephrine administration, to sinus rhythm within few minutes (ESM Fig. 1C, D). The examination about her ECG was uneventful after surgery. Anaphylaxis has been reported as an adverse reaction to sugammadex [1]. Animal study and several clinical reports suggest that allergic reactions are the possible cause of AVB [2, 3]. Considering the allergic reaction to sugammadex, we should have checked plasma level of histamine and tryptase.

Contribution of rib cage and abdominal movement to ventilation for successful weaning from mechanical ventilation

In order to test the hypothesis whether the breathing pattern is helpful in predicting weaning outcome in patients being weaned from mechanical ventilation, 38 patients who underwent operation for esophageal cancer were evaluated at weaning from mechanical ventilation (19 unsuccessful weanings, group U, and 19 successful weanings in age‐matched patients, group S). Since all patients initially fullfilled our weaning criteria, ventilatory parameters such as tidal volume, respiratory frequency, minute ventilation, and arterial blood gas analysis showed no significant differences between the groups. The breathing pattern was registered quantitatively by means of respiratory inductive plethysmography at 3 cmH2O (0.3 kPa) of CPAP prior to weaning. The contribution of rib cage movement to tidal volume (%RC) was significantly greater in group U than in group S (P<0.05). Indeed, 84% of the patients in group S showed %RC less than 50%, compared to only 16% of the patients in group U ((P<0.05). The results suggest that the breathing pattern is one important factor in predicting the outcome of weaning in patients after thoraco‐abdominal surgery. Diaphragmatic fatigue is suspected to be the mechanism for the increase in the RC component in patients with unsuccessful weaning outcome.

Ectasis and pallor of peripheral airways during mechanical ventilation

STUDY OBJECTIVE To evaluate morphologic changes in peripheral airways associated with positive-pressure ventilation (PPV). DESIGN Single-blind study. SETTING Intensive care unit of a university hospital. PATIENTS Ten patients who required mechanical ventilation due to acute respiratory failure but had no history of prior pulmonary disease. INTERVENTIONS Seventeen fiberoptic bronchoscopy procedures were performed using a fine fiberoptic bronchoscope of 1.8 mm outside diameter. MEASUREMENTS AND MAIN RESULTS The main morphologic findings were pallor and ectasis. Increased secretions, pigmentation, and stenosis or collapse in peripheral airways also were observed. Patients with ectasis were more likely to have had prolonged mechanical ventilation (17 +/- 9 days) as compared with those patients without ectasis (9 +/- 5 days). CONCLUSION The structural alterations in peripheral airways noted in patients on prolonged PPV suggest that barotrauma may be more widespread than previously recognized.

Fiberoptic Evaluation of Peripheral Airways of Two Patients with Acute Respiratory Failure during Mechanical Ventilation

Fiberoptic bronchoscopy is an useful examinations to evaluate the patients airway in intensive care unit because this technique is relatively non-invasive and can be repeated. A conventional fiberoptic bronchoscope, however, is too large in diameter to observe the peripheral airways. Recent technological development in fiberoptic bronchoscope has enabled us to observe more peripheral airways. To evaluate the changes and the courses of the peripheral airways of acute respiratory failure during mechanical ventilation, we observed the peripheral airways by using a fiberscope of 1.8 mm outer diameter (BF-1.8T; Olympus) in two patients who needed artificial ventilation due to acute respiratory failure. Patients were informed of the study before the examination.

Comparison between Ultrasonographic Visibility during Sciatic Nerve Block by Medial Approach and Popliteal Approach

Yoshimune Osaka1,2*, Naho Okuda2, Ikue Saito2, Rie Saito2 and Muneaki Shimada2 1Department of Anesthesiology, Kawasaki Municipal Hospital, Japan 2Department of Anesthesiology, Ostuka Metropolitan Hospital, Japan *Corresponding author: Yoshimune Osaka, Department of Anesthesiology, Kawasaki Municipal Hospital, 12-1 Shinkawa Street, Kawasaki-ku, Kawasaki City, Kanagawa 210-0013, Japan, Tel: +81-44-233-5211/+90-2469-3931; E-mail: bluesapphire1226@gmail.com

A case of a patient who experienced diaphragmatic hernia after repair of inguinal hernia

To the Editor: Diaphragmatic hernia commonly occurs at birth, and the reported incidence is 1 per 2,000 live births [1]. We encountered a patient who experienced diaphragmatic hernia that was not detected at birth but after repair of an inguinal hernia. The patient was a 4-month-old female infant measuring 43.9 cm and weighing 2.4 kg who had been delivered by cesarean section at 23 weeks and 6 days, with a birth weight of 642 g. Respiratory care was provided from immediately after birth. No congenital abnormalities were observed, except for an inguinal hernia containing the prolapsed left ovary. The tracheal tube was removed at 56 days of life, and oxygen supplementation was continued thereafter until 120 days of life. At 130 days after birth (corrected age, 42 weeks and 3 days), definitive left inguinal herniorrhaphy was planned. An ilioinguinal nerveiliohypogastric nerve block was given in addition to general anesthesia for the surgery. The surgery time was 30 min and the anesthesia time 87 min. No specific problems were detected in the postoperative X-ray after the surgery (Fig. 1a). On postoperative day 4, the infant suddenly experienced cyanosis and rapid respiration with a decrease of the oxygen saturation. Chest X-ray showed a left diaphragmatic hernia, seemingly a prolapsed colon (Fig. 1b). Tracheal intubation was performed followed by mechanical ventilation, and repair of the diaphragmatic hernia was performed. General anesthesia was induced and maintained with midazolam, fentanyl, vecuronium, and remifentanil. The surgery time was 93 min, and the anesthesia time 122 min. The postoperative course was uneventful, and the tracheal tube was removed on day 3 after the diaphragmatic hernia repair. Diaphragmatic hernia normally develops at birth from respiratory failure and abdominal retraction. As a consequence of elective treatment instituted during infancy itself, the mortality rate has decreased [1]. Fetal age at the time of development of the diaphragmatic hernia determines the degree of hypoplasia of the lung. Among cases of congenital diaphragmatic hernia (CDH), the reported incidence of diaphragmatic hernia appearing after birth is 3 %, and in 80 % of these cases, it appears as a complication of cardiac anomalies before 1 month of age [2]. CDH developing within 1 year of birth is more common on the right side and is often chronic in onset. The younger infants present with more respiratory symptoms than gastrointestinal symptoms, and the symptoms are often acute in onset [2–4]. CDH develops after thoracic surgery in some cases [5]. There is a possibility of defects in the diaphragm appearing spontaneously [2]. As the present case was an extremely low-birth-weight infant with a corrected age of 42 weeks and 3 days; although she was 130 days old, there is a possibility that this could have predisposed to anatomical weakness or a preexisting hole in the diaphragm. It is thought that a lower corrected age at the time of surgery may be associated with a higher risk of occurrence of diaphragmatic Y. Osaka (&) N. Shimada M. Satou T. Masuda T. Ando Y. Kozono M. Shimada Department of Anesthesiology, Tokyo Metropolitan Ohtsuka Hospital, 2-8-1 Minami-Ohtsuka, Toshima-ku, Tokyo 170-8476, Japan e-mail: bluesapphire1226@gmail.com

Changes in free and total catecholamine concentrations in plasma in patients undergoing coronary artery bypass grafting under high-dose fentanyl anesthesia

We measured free and total catecholamine in ten patients undergoing coronary artery-bypass grafting under high-dose fentanyl (93.9±2.2 μg·kg−1, mean±SE) anesthesia. Arterial blood samples were obtained: 1) before induction of anesthesia (control), 2) 1 min after intubation, 3) 1 min after skin ininsion, 4) 1 min after median sternotomy and, 5) just before termination of cardiopulmonary bypass (CPB). The concentrations of free and total catecholamine were measured by HPLC using fully automated analyzer, 8030-TOHSO.Free and total catecholamine concentrations did not change significantly before CPB. At the termination of CPB, however, the levels in free dopamine, norepinephrine and epinephrine all increased several fold as compared with control. Similarly, total norepinephrine and epinephrine also increased at the end of PCB, while total dopamine did not change. Present results indicated that 1) the measurement of free CAs is more significant than the measurement of total CAs for the assessment of sympathoadrenal responses to surgical stimuli, and that 2) high-doses of fentanyl produce hemodynamic stability by suppressing sympathoadrenal responeses elicited by the usual surgical procedures. However, stress triggered by CPB could not be suppressed totally by fentanyl even with high dose.