[Case of delayed extubation in a woman with low pulmonary function].

A 78-year-old woman with low pulmonary function (forced expiratory volume in 1 second of 450 ml) underwent an open incisional pulmonary tissue biopsy for suspected diffuse panbronchiolitis and anti-neutrophil cytoplasmic antibody-associated vasculitis. She was intubated with a double-lumen tracheal tube after receiving 0.57 mg x kg(-1) of rocuronium and 0.9 mg kg(-1) of propofol. Under one-lung ventilation, the PaCO2 was 54-74 mmHg and PaO2 was 121-127 mmHg until 50 min after lung recruitment, after which the PaCO2 decreased to 62-66 mmHg and PaO2 increased to 283-382 mmHg. The operation ended uneventfully. Although the rocuronium-induced neuromuscular blockade was reversed by 2.0 mg x kg(-1) of sugammadex (train-of-four ratio, nearly 100%), it seemed a little difficult to extubate the patient just after the operation because blood gas analysis showed a pH 7.39, PaCO2 of 66 mmHg and PaO2 382 mmHg with FIO2 1.0. The blood gas analysis revealed pH 7.52, PaCO2 44.5 mmH and PaO2 144 mmHg with FIO2 of 0.4. The patient was successfully extubated with no respiratory complication 10 h after the end of the operation on the first postoperative day.

[Pediatric use of cuffed tracheal tubes under general anesthesia].

BACKGROUND: Although the use of cuffed tracheal tubes (CTT) in children less than 8 years of age has increased, the criteria for selecting CTTs of appropriate sizes have not been determined. METHODS: To study the criteria for choosing tubes of appropriate sizes (internal diameter: 4.0, 4.5, 5.0, or 5.5mm), we intubated 51 children aged 2-8 years under general anesthesia using an original protocol. We excluded 2 patients who received 4.0-mm tubes; thus, the outcomes in 48 patients were analyzed statistically. RESULTS: A larger CTT was replaced with a smaller one in 1 patient, and a CTT was replaced with an uncuffed tracheal tube (UTT) in another patient (excluded from analysis). No tube changes were required in 49 patients. Post-extubation stridor was observed in 3 patients. The 4.5-mm tubes seemed appropriate in 12 cases because average airway leakage in these cases was > 10%; 5.0- and 5.5-mm tubes did not seem appropriate in 17 and 19 cases, respectively, because the leakage was < 10% of the tidal volume. CONCLUSIONS: We recommend the pediatric use of CTTs because of the very low tube-exchange ratio and the acceptable incidence of stridor. However, the protocol may require modification.

[Four cases of cardiac arrest during spinal anesthesia].

Incident rates of cardiac arrest are reported as being from 0.54 to 17.5 per 10,000 (0.54-17.5/10,000) spinal anesthesia patients. In our hospital, four cases of cardiac arrest occurred in 903 spinal and combined spinal and epidural anesthesia patients over 15 months (44.3/ 10,000). Common denominators were ages below 60 years, ASA-PS 1, rapid onset of T10 blockade within 2 minutes and leg raising from 3 to 6 minutes after administration of hyperbaric bupivacaine and T4 blockade. All patients recovered without any side effects. The conditions suspected of causing strong bradycardia leading to cardiac arrest are thought to be maintained parasympathetic activity, lack of blood volume before anesthesia, rapid progress of spinal blockade, decreased blood return to the heart by high spinal blockade (T4) and protective cardiac parasympathetic reflex (Bezold-Jarisch reflex).

[Pediatric central venous catheterization through the axillary veins using ultrasound guidance].

BACKGROUND: Axillary veins (AXVs) are selected for the central venous catheterization (CVC) in adults using ultrasound echo but quite rarely in children. We evaluated the relationships between the widths and the depths of the pediatric AXVs. METHODS: The widths and the depths of the AXVs were measured using an ultrasound echo apparatus in fifty patients. RESULTS: The widths and depths of the AXVs were about 3.8 and 10.0 mm in patients of about 75.7 cm in height. In 35 children less than 80 cm in height, AXVs depth to width ratios (D/W) averaged 3.6, and the CVC through the AXVs seemed difficult, whereas in 7 children of more than 100 cm in height, D/W averaged 1.7, and it seemed easy. CONCLUSIONS: We should know the AXV characteristics to secure the pediatric CVC through the AXV.

[On the characteristics of axillary veins and internal jugular veins in pediatric patients].

BACKGROUND: Axillary veins (AxV) are increasingly selected instead of the subclavian veins (SCV) for safe and successful catheterization in adults using ultrasound echo although quite rarely in children. The diameters and depths of the pediatric internal jugular veins (IJV) are well known but those of pediatric AxV are unfamiliar even to anesthesiologists. We evaluated the diameters and the depths of the AxV and IJV in children undergoing cardiac surgery. METHODS: The diameters and the depths of the AxV and IJV were measured using an ultrasound echo apparatus (TiTAN, SonoSite) in fifty pediatric patients. RESULTS: The patients' ages, heights, and weights averaged about 27.5 months, 77.3cm, and 9.8kg, respectively. The maximal widths, lengths and depths of the AxV and IJV were about 4.2, 3.3 and 10 mm and 7.5, 4.9 and 6.6 mm, respectively. The widths of the AxV and IJV correlated well with the patients' heights (r=0.831 and 0.700, respectively). CONCLUSIONS: The diameters of the AxV are about 0.6 times and the depths are about 1.5 times those of the IJV and it seems difficult to use AxV for pediatric CVC from the standpoint of venous diameters and depths.

[A case report of a ventricular septal defect with congenital portosystemic venous shunt].

A three-month-old baby boy was scheduled for a ventricular septal defect (VSD) repair. The patient was complicated with pulmonary hypertension (PH) and congenital portosystemic venous shunt (CPSVS). Because it was unclear whether the CPSVS was the main cause of the PH or not, the PH was treated with ordinary methods for the management of anesthesia for VSD patients with PH. He underwent the repair of the VSD, and his postoperative course was uneventful. The mechanism of PH in patients with CPSVS is different from that in those with VSD. We speculated that his pulmonary arteries were not affected with the CPSVS, because no PH was observed after the repair of VSD. Fresh frozen plasma was effective for hemostasis during weaning from cardiopulmonary bypass, because he could not produce enough coagulation factors.

[First clinical impressions of ProSeal laryngeal mask].

ProSeal laryngeal mask airway (PLMA, LMA-ProSeal) is a newly developed laryngeal mask airway intended to overcome two major disadvantages of the conventional laryngeal mask airway, i.e., poor protection of the airway from gastric regurgitation and low sealing effect around the laryngeal inlet. The new PLMA can provide air-tight sealing by a second cuff positioned at the back of the mask and a bypass channel for the alimentary tract by a second tube (drain tube) opening at the tip of the mask. However, clinical feature of this new device has been assessed by few authors. Forty adult patients (19 males and 21 females) under general anesthesia immobilized with vecuronium were included in this study. A PLMA size 4 was inserted with (n = 10) or without (n = 30) an introducer at first (n = 37), second (n = 2) or third (n = 1) attempt and clear airway was obtained in all patients. After placing the PLMA in 10 patients (5 males and 5 females) sealing pressure was measured at cuff pressure of 0, 20, 40 and 60 cmH2O and at completely deflated cuff state. Averaged seal pressure at the 60 cm H2O cuff pressure was 22.7 +/- 8.0 cmH2O in the all 40 patients. Averaged seal pressure was higher in female than in male at all cuff pressure. The average seal pressure was 15.1 cmH2O even when the cuff was deflated completely. A lubricated 16-French gastric tube was inserted easily through the drain tube in all patients except one in which the mask was found to be deflected backward. There were no significant complications related to the PLMA. We concluded that the PLMA can provide high sealing pressure and isolate the airway from the alimentary tract. Further study including adverse effect of the high sealing effect should be required.