Evaluation of temperature-dependent fluctuations in skin microcirculation flow using a light-emitting diode based photoacoustic imaging device.

PURPOSE: Skin microvessels maintain temperature homeostasis by contracting and dilating upon exposure to changes in temperature. Under general anesthesia, surgical invasiveness, including incisions and coagulation, and the effects of anesthetics may cause variations in the threshold temperature, leading to the constriction and dilation of cutaneous blood vessels. Therefore, studies on skin microvascular circulation are necessary to develop appropriate interventions for complications during surgery. METHODS: We visualized and quantified skin microcirculatory fluctuations associated with temperature variations using a light-emitting diode photoacoustic imaging (LED-PAI) device. The hands of ten healthy volunteers were stressed with four different water temperatures [25℃ (Control), 15℃ (Cold1), 40℃ (Warm), and 15℃ (Cold2)]. The photoacoustic images of the fingers were taken under each condition, and the microvascular flow owing to temperature stress was quantified as the area of photoacoustic signal (S) in each image. The S values were compared with the variations in blood flow (Q) measured by laser Doppler flowmetry (LDF). RESULTS: The correlation between Q and S according to the 40 measurements was r = 0.45 (p＜0.01). In addition, the values of S under each stress condition were as follows: Scontrol = 10,826 ± 3364 pixels, Scold1 = 8825 ± 2484 pixels, Swarm = 13,369 ± 3001 pixels, and Scold2 = 8838 ± 1892 pixels; the differences were significant. The LDF blood flow (Q) showed similar changes among conditions. CONCLUSION: These findings suggest that the LED-PAI device could be an option for evaluating microcirculation in association with changes in temperature.

The effects of hydroxyethyl starch 130/0.4 on perioperative renal function in patients undergoing cardiac surgery: A randomised controlled trial.

Background: Acute kidney injury (AKI) after cardiac surgery increases the risk of morbidity and mortality. Hydroxyethyl starch (HES) is often used during surgery due to its plasma-volume expanding effect, but the impact of HES 130/0.4 on renal function in patients undergoing cardiac surgery remains unclear. The aim of our study is to investigate the impact of HES 130/0.4 on postoperative renal function in patients undergoing cardiac surgery using cardiopulmonary bypass. Methods: Our study was a randomised, single-center, single-blind study conducted on 60 adult patients who underwent cardiac surgery using cardiopulmonary bypass: 30 patients were intraoperatively administered with HES 130/0.4; the other 30 with Ringer's bicarbonate. The primary endpoints were occurrence of AKI within 30 days of surgery and the disease stages. Results: The mean dose of 6% HES 130/0.4 was 28 ml/kg. AKI occurred within 30 days of the operation in 8 cases (28.6%) in the HES group and 6 cases (21.4%) in the crystalloid group (no significance: p = 0.5371). Disease stages were as follows: "no AKI", "stage 1", "stage 2″ and "stage 3″, accounting for 20 cases (71.5%), 6 cases (21,4%), 2 cases (7.1%), and 0 cases, respectively, in the HES group, and 22 cases (78.6%), 6 cases (21.4%), 0 cases, and 0 cases, respectively, in the crystalloid group (no significance: p = 0.3508). Conclusion: There was no significant difference in the occurrences or stages of AKI during the 30 days following cardiac surgery with cardiopulmonary bypass between patients administered with HES 130/0.4 or Ringer's bicarbonate.

[A Case of a Stuck Bioprosthetic Mitral Valve Leaflet Diagnosed by Intraoperative Transesophageal Echocardiography: Suture Loop Jamming].

We present a case of a very rare complication of valvular surgery-suture loop jamming. A 77-year-old woman was admitted for surgical treatment of moderate aortic regurgitation, severe mitral regurgitation (MR) and severe tricuspid regur- gitation. She underwent mitral valve replacement (MVR) with porcine bioprosthetic valve and tricuspid annuloplasty by DeVega procedure. Before termination of cardiopulmonary bypass, transesophageal echocardiography (TEE) showed se- vere MR at the center of the bioprosthetic valve along the posterior left atrial wall In addition, echogenic fili- form structure which disturbed the movement of the leaflets was detected. The patient was placed on car- dioplegic arrest again and the heart was reopened, suture loop jamming around the stents of the biopros- thetic valve resulting in significant mitral regurgitation was diagnosed. The implanted bioprosthetic valve was removed and a new bioprosthetic valve was subse- quently re-implanted. Intraoperative TEE provided a visible assessment of mitral prosthetic valve dysfunction and we were immediately able to reach diagnosis of this rare and serious complication-suture loop jamming. Our case makes us recognize suture loop jamming as one of the complications of MVR.

[Anesthetic Management of a 69-year-old Patient with Eisenmenger Syndrome for Abdominoperineal Resection].

Although life expectancy of the patients with Eisenmenger syndrome (ES) is currently reported to be lower than 40 years, life span of the patients with ES may be extended because of development of medical care. According to recently reported middle-aged patients with ES undergoing non-cardiac surgeries, per-operative mortality and morbidity of the patients with ES undergoing non-cardiac surgeries may be lower than previously thought, and even elderly patients may be able to undergo major surgeries such as laparotomies for cancers. We described the anesthetic management of a 69-year-old patient with ES who had undergone abdominoperineal resection. In the anesthetic management it is important to maintain adequate blood volumne and systemic vascular resistance and this avoids increases of right-to-left shunt. Perioperative monitoring of pulmonary arterial pressure was useful for hemodynamic management. Good pain control and management of body temperature were also needed for a perioperative course with no adverse events. The appropriate anesthetic management of the 69-year-old patient with ES for abdominoperineal resection resulted in the successful perioperative course.

[Anesthetic management for a patient with chronic expanding hematoma of the thorax associated with respiratory failure].

Chronic expanding hematoma (CEH) of the thorax is an intractable disease which induces long-standing growing hematoma after tuberculosis or thoracic surgery. It causes respiratory failure and heart failure by compressing the mediastinum. A 68-year-old man with a history of tuberculosis during childhood had suffered from progressive exertional dyspnea for 20 years. Because a huge hematoma occupying whole right thoracic cavity compressed the heart and the trachea to the left, he was scheduled for extrapleural pneumonectomy. Bronchial arterial embolization was performed preoperatively to prevent hemoptysis and reduce intraoperative blood loss. There was no problem in the airway management using a double lumen endotracheal tube. However, severe hypotension and a decrease in cardiac index were observed due to excessive bleeding, leading to total blood loss of 11,000 g. In addition, surgical manipulation caused abrupt severe hypotension. Monitoring of arterial pressure-based cardiac output and deep body temperature was useful for the hemodynamic management during the operation. The successful postoperative course resulted in remarkable improvement of Huge-Jones dyspnea criteria from IV to II. In the anesthetic management of CEH precautions should be taken against the excessive intraoperative bleeding and abrupt hemodynamic changes.

[Anesthesia for pneumothorax surgery in a patient with type II chronic respiratory failure associated with inclusion body myositis].

A 40-year-old man was scheduled for video assisted thoracoscopic surgery due to pneumothorax. He had been diagnosed with inclusion body myositis and received nocturnal non-invasive positive pressure ventilation. Anesthesia was induced with propofol, remifentanil, and rocuronium, and maintained with propofol, remifentanil and fentanyl. The dosage of rocuronium was 10 mg. Although we administered neostigmine at the end of the operation and TOF ratio was over 90%, he was transported to the ICU with tracheal intubation because of poor spontaneous respiration. On POD 1, the tracheal tube was extubated and NPPV was administered again. Minitrach was inserted on POD 2, and he left the ICU on POD 4. Generally, in patients with myopathy the dose of muscle relaxant should be decreased in proportion to their muscle atrophy. Rocuronium 10 mg was administered in this case and we thought it could be antagonized by neostigmine, but extubation on the day of operation was impossible. We think this is not because of the residual effect of muscle relaxant, but because of decreases in pulmonary function. In this case, we expected long-term mechanical ventilation might be necessary, but he showed a good postoperative course owing to minimally invasive surgery, NPPV, and suctioning of sputum via Minitrach.

[A case of subglottic stenosis with bridging granuloma after intubation with double-lumen endotracheal tube].

We present a case of subglottic stenosis with rare bridging granuloma after intubation with double-lumen endotracheal tube. An 81-year-old woman was diagnosed with the lung tumor and scheduled for the thoracoscopic surgery. We induced anesthesia with propofol, remifentanil and rocuronium. A 35 Fr double-lumen intratracheal tube was inserted to the trachea with some resistance, when the tube passed through the glottis. A few days later, she suffered from respiratory discomfort. An otolaryngologist examined her larynx and subglottis. Laryngoscopic examination revealed bridging granuloma leading to tracheal stenosis. Tracheostomy and resection of granuloma were performed, and her symptom improved. If we feel resistance in intubating a double-lumen endotracheal tube in a patient with a history of intubation with a tracheal tube, we should operate gently adjusting the size of the tracheal tube.

Impact of changes of positive end-expiratory pressure on functional residual capacity at low tidal volume ventilation during general anesthesia.

PURPOSE: Several reports in the literature have described the effects of positive end-expiratory pressure (PEEP) level upon functional residual capacity (FRC) in ventilated patients during general anesthesia. This study compares FRC in mechanically low tidal volume ventilation with different PEEP levels during upper abdominal surgery. METHODS: Before induction of anesthesia (awake) for nine patients with upper abdominal surgery, a tight-seal facemask was applied with 2 cmH(2)O pressure support ventilation and 100 % O(2) during FRC measurements conducted on patients in a supine position. After tracheal intubation, lungs were ventilated with bilevel airway pressure with a volume guarantee (7 ml/kg predicted body weight) and with an inspired oxygen fraction (FIO(2)) of 0.4. PEEP levels of 0, 5, and 10 cmH(2)O were used. Each level of 5 and 10 cmH(2)O PEEP was maintained for 2 h. FRC was measured at each PEEP level. RESULTS: FRC awake was significantly higher than that at PEEP 0 cmH(2)O (P < 0.01). FRC at PEEP 0 cmH(2)O was significantly lower than that at 10 cmH(2)O (P < 0.01). PaO(2)/FIO(2) awake was significantly higher than that for PEEP 0 cmH(2)O (P < 0.01). PaO(2)/FIO(2) at PEEP 0 cmH(2)O was significantly lower than that for PEEP 5 cmH(2)O or PEEP 10 cmH(2)O (P < 0.01). Furthermore, PEEP 0 cmH(2)O, PEEP 5 cmH(2)O after 2 h, and PEEP 10 cmH(2)O after 2 h were correlated with FRC (R = 0.671, P < 0.01) and PaO(2)/FIO(2) (R = 0.642, P < 0.01). CONCLUSIONS: Results suggest that PEEP at 10 cmH(2)O is necessary to maintain lung function if low tidal volume ventilation is used during upper abdominal surgery.

[Anesthetic management of Y-shaped tracheobronchial stent insertion via tracheostomy site].

We report two cases of Y-shaped tracheobronchial stent insertion via tracheostomy site. A 62-year-old woman diagnosed with tracheo-gastric roll fistula after subtotal esophagectomy and a 47-year-old woman diagnosed tracheobronchial stenosis due to lung cancer underwent Y-shaped tracheobronchial stent insertion. In both cases, anesthesia was induced and maintained by propofol, remifentanil, and rocuronium. After general anesthesia was induced, oral tracheal tube was inserted and Y-shaped tracheobronchial stent was inserted via tracheostomy site. Patients were apneic during surgical procedure and ventilated via oral tracheal tube in case of Sp(O2) decrease. During ventilation, the operator closed tracheostomy by hand. We used oral tracheal tube with short cuff which enabled surgical procedure without extubation. Compared with metal stent, silicone Y-shaped tracheobronchial stent needs much more time for insertion. Therefore, oral insertion needs frequent intubation and extubation which causes airway mucosal edema or damage. Our method, stent insertion via tracheostomy site and ventilation via oral tracheal tube, was compatible with safer airway management and surgical procedure.

[Anesthetic management using epidural anesthesia and dexmedetomidine for thoracoscopic lung resection in a patient with compromised lung functions].

A 59-year-old man with poor pulmonary functions was scheduled for thoracoscopic lung resection because of right pneumothorax. In order to preserve spontaneous breathing and prevent left pneumothorax, we selected epidural anesthesia and intravenous dexmedetomidine. We could provide appropriate sedative and antianxiety effect without respiratory depression and hemodynamic change. With its unique features, dexmedetomidine is useful for thoracoscopic surgery in a patient with poor lung functions.

Prolonged relaxant effects of vecuronium in patients with deliberate hypermagnesemia: time for caution in cesarean section.

We present two cases showing significantly prolonged action of vecuronium from magnesium treatment after general anesthesia for urgent cesarean section. The serum magnesium levels were maintained at a therapeutic range for severe eclampsia in one patient (5.6 mg.dl(-1)) and for tocolysis in another with placenta previa totalis (6.9 mg.dl(-1)). The obstetrics-specific emergency in each patient led us to proceed with general anesthesia but using reduced-dose vecuronium, which failed to prevent prolongation of the neuromuscular block. As a result, the patients received prolonged mechanical ventilation. Our cases underscore the need for anesthesiologists as well as obstetricians to be aware of the prolongation of the action of nondepolarizing muscle relaxants as a result of magnesium treatment.