The increases in potassium concentrations are greater with succinylcholine than with rocuronium-sugammadex in outpatient surgery: a randomized, multicentre trial.

BACKGROUND: Succinylcholine provides rapid onset of neuromuscular blockade and short duration of action, but its administration may be associated with hyperkalemia. Rocuronium is not known to increase potassium concentration, has fast onset of activity, and can be rapidly reversed by sugammadex. This study evaluated changes in plasma potassium concentrations in patients randomized either to rocuronium followed by sugammadex reversal or to succinylcholine in ambulatory surgery. METHODS: In this multicentre randomized active-controlled study, adult patients undergoing short surgical procedures in an outpatient setting received either rocuronium 0.6 mg·kg(-1) for intubation with sugammadex 4.0 mg·kg(-1) for reversal (n = 70) or succinylcholine 1.0 mg·kg(-1) with spontaneous recovery (n = 80). Blood potassium concentrations were assessed at baseline (before study drug administration) and at intervals up to 15 min after rocuronium, sugammadex, and succinylcholine. RESULTS: At the primary endpoint, five minutes post-administration, the changes in potassium concentrations from baseline were significantly smaller in patients treated with rocuronium than in those given succinylcholine [mean (SD): -0.06 (0.32) vs 0.30 (0.34) mmol·L(-1), respectively; P < 0.0001]. At baseline, potassium concentrations were similar in both groups, but they were greater at two, five, ten, and 15 min after succinylcholine than after rocuronium (P < 0.0001) for all time points. After sugammadex administration, there were no significant changes in mean potassium concentration from the pre-rocuronium baseline. No adverse effects related to hyperkalemia were observed. CONCLUSION: Succinylcholine was associated with a modest increase in potassium concentration; these changes were not seen after rocuronium or sugammadex ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00751179).

Effect of decreased fetal perfusion on placental clearance of volatile anesthetics in a dual perfused human placental cotyledon model.

Placental transfer of volatile anesthetics is a critical issue in managing fetal distress during cesarean section under general anesthesia. Using dual perfused human placental cotyledons obtained from parturients undergoing elective cesarean section (n = 5), we investigated the effect of decreased fetal perfusion on placental clearance of sevoflurane and isoflurane. Keeping the maternal flow rate fixed, fetal flow rate was consecutively decreased from 3 ml/min (control perfusion) to 2 ml/min (intermediate perfusion) and to 1 ml/min (hypoperfusion). Placental transfer was assessed by the clearance of anesthetics by the placenta, defined by the ratio of anesthetic concentration in fetal vein and maternal artery, multiplied by fetal flow rate. Placental clearance was compared between different fetal perfusion states and anesthetics. Hypoperfusion resulted in a lower clearance of sevoflurane and isoflurane compared with control (P = 0.002, P < 0.001) and intermediate (P = 0.04, P = 0.018) perfusion. Clearances of sevoflurane and isoflurane were comparable during control perfusion (P = 0.93), intermediate perfusion (P = 1.00), and hypoperfusion (P = 0.88). Thus, maintenance of volatile anesthetics at a marginally low concentration may not be necessary when fetal distress is observed during emergency cesarean delivery because placental transfer of volatile anesthetics decreases with decreasing fetal perfusion.

Intraoperative Assessment of Surgical Stress Response Using Nociception Monitor under General Anesthesia and Postoperative Complications: A Narrative Review.

We present a narrative review focusing on the new role of nociception monitor in intraoperative anesthetic management. Higher invasiveness of surgery elicits a higher degree of surgical stress responses including neuroendocrine-metabolic and inflammatory-immune responses, which are associated with the occurrence of major postoperative complications. Conversely, anesthetic management mitigates these responses. Furthermore, improper attenuation of nociceptive input and related autonomic effects may induce increased stress response that may adversely influence outcome even in minimally invasive surgeries. The original role of nociception monitor, which is to assess a balance between nociception caused by surgical trauma and anti-nociception due to anesthesia, may allow an assessment of surgical stress response. The goal of this review is to inform healthcare professionals providing anesthetic management that nociception monitors may provide intraoperative data associated with surgical stress responses, and to inspire new research into the effects of nociception monitor-guided anesthesia on postoperative complications.

Propofol in a modified cyclodextrin formulation: first human study of dose-response with emphasis on injection pain.

BACKGROUND: A new lipid-free preparation of propofol has been developed containing the drug, sulfobutylether ß-cyclodextrin and water. The primary objective of this study was to compare the effects of propofol in the lipid formulation with those of the new cyclodextrin formulation, particularly with regard to pain on injection. We hypothesized that the propofol in cyclodextrin would be associated with less pain on injection than propofol in lipid. METHODS: The study was a single-center, double-blind, 2-period, randomized, dose-escalating study using a completely balanced cross-over design in healthy volunteers. Pain on injection was compared between propofol in cyclodextrin and propofol in lipid using subject and observer assessments of pain rated at several different time points. Five response variables to pain were analyzed. RESULTS: Propofol in cyclodextrin had significantly higher pain scores for all 5 variables. Other endpoints, including sedation, showed no difference. CONCLUSION: The propofol in cyclodextrin formulation failed to reduce the pain on injection associated with propofol.

[Efficacy of cryoprecipitate transfusion for coagulopathy after cardiopulmonary bypass in thoracic aortic surgery].

BACKGROUND: Excessive bleeding after cardiopulmonary bypass remains a major complication for cardiac surgery. The principal causes of hemostatic bleeding are related to inadequate surgical hemostasis or diluted coagulopathy. We investigated the efficacy of cryoprecipitate (Cryo) transfusion in thoracic aortic surgery with cardiopulmonary bypass. METHODS: We divided 30 patients undergoing thoracic aortic surgery into two groups retrospectively. Fifteen patients transfused with cryoprecipitate and fresh frozen plasma (FFP) were defined as Group Cryo, and the other 15 patients transfused with FFP only were defined as Group FFP We compared the amount of blood products administered and the blood loss during the perioperative period between the two groups with P <0.05 to be significant. RESULTS: There were no significant differences in the clinical background between the two groups. There were significant differences in the volume of blood loss (Group Cryo 544 +/- 233 ml, Group FFP 888 +/- 339 ml), requirements of FFP (Group Cryo 0.6 +/- 1.7 unit, Group FFP 4.3 +/- 6.0 unit) in ICU. CONCLUSIONS: Cryoprecipitate transfusion is an effective treatment for coagulopathy caused by dilution of coagulation factors after cardiopulmonary bypass.

Three-day tracheal intubation manikin training for novice doctors using Macintosh laryngoscope, McGRATH MAC videolaryngoscope and Pentax AirwayScope.

BACKGROUND: We compared the intubation skills obtained by novice doctors following training using 3 instruments, the conventional Macintosh laryngoscope (Mac) and 2 types of indirect video-laryngoscopes (McGrathTM-MAC: McGrath (McG) and AirwayScope (AWS)), to determine the most appropriate instrument for novice doctors to acquire intubation skills, especially focusing on visual confirmation of vocal cords, during a 3-day intensive manikin training program. METHODS: Fifteen novice doctors who did not have sufficient experience in endotracheal intubation (ETI) and consented to participate in this study were included. We used AirSim and AMT (Airway management Trainer) manikins. First, an experienced anesthesiologist instructed the trainees on using the 3 instruments for a few minutes. Then, after familiarizing themselves with each device for 10 minutes, the participants attempted ETI on the 2 manikins with the 3 devices used in random order. Intubations with each device were practiced and performed for 3 successive days. We assessed the percentage of glottic opening (POGO) score, successful intubation rate and tracheal intubation time for each participant, with each device, and on each day. RESULTS: In the first manikin, AirSim, POGO scores in the McG and AWS groups were significantly higher than those in the Mac group on all 3 days (P < .0001). The number of intubation failures in the Mac group decreased from 2 cases on day 1, to 1 case on day 2 and zero cases on day 3. There were no failures in the McG and AWS groups on any of the days. With the second manikin, AMT, POGO scores in the Mac group were significantly lower than those in the McG and AWS groups on all 3 days. There were no intubation failures in the AWS group on all 3 days. In the Mac group, the number of intubation failures decreased from 3 on day 1, to 2 on day 2 and zero failures on day 3. In the McG group, there were only 3 failures on day 1. CONCLUSION: The 2 types of indirect video-laryngoscopes (McGRATH and AirwayScope) were demonstrated to be suitable instruments for novice doctors to achieve higher POGO scores in a 3-day intensive ETI training.

Imaging evaluation of continuous extrapleural intercostal nerve block for minimally invasive cardiac surgery: a case report.

BACKGROUND: Spinal nerve block is difficult with minimally invasive cardiac surgery (MICS), because of the risk of serious bleeding complications due to full heparinization. Continuous extrapleural intercostal nerve block (CEINB) is a postoperative pain treatment for intercostal thoracotomy, with fewer complications. Here, we report a case in which imaging evaluation of CEINB with contrast medium was conducted to anatomically confirm the spread of local anesthetics after MICS. CASE PRESENTATION: A 65-year-old woman with severe mitral regurgitation underwent mitral valve plasty under general anesthesia via right-sided mini-thoracotomy. A CEINB catheter was placed before the incision was closed, without creating a conventional extrapleural pocket. We conducted an imaging evaluation with a contrast medium via the inserted catheter and confirmed sufficient spread around the intercostal nerve area. In addition, postoperative pain was well controlled by the nerve block. CONCLUSIONS: Imaging evaluation of CEINB with contrast medium could increase analgesic quality and decrease complications post-MICS.

[Anesthetic management for pneumonectomy in a patient with cardiac amyloidosis].

Cardiac amyloidosis may cause restrictive cardiomyopathy associated with heart failure, conduction disorder and ischemic heart disease. Therefore, patients with amyloidosis require careful hemodynamic monitoring in perioperative period. A 63-year-old man with cardiac amyloidosis was scheduled for pneumonectomy. His transthoracic echocardiography assessment showed a hypertrophic interventricular septum and slight decreased ejection fraction of 55%, but left ventricular (LV) diastolic function was decreased. Pulse Doppler for mitral valve inflow showed that the early peak velocity/atrial peak velocity (E/A) ratio was 0.9, the deceleration time (DT) was 163 msec and the early diastolic mitral annular tissue velocity (E') was 4 cm x sec(-1). These data suggested a pseudonormalization state. We performed careful monitoring using arterial pressure-based cardiac output (APCO), central venous oxygen saturation (ScvO2) and transesophageal echocardiography. There were no severe complications such as circulatory collapse and arrhythmia in the perioperative period.

Comparison of placental transfer of local anesthetics in perfusates with different pH values in a human cotyledon model.

PURPOSE: We aimed to investigate the placental transfer of local anesthetics in perfusates with different pH values, using a dual-perfused human cotyledon model. METHODS: The dual-perfused human cotyledon model was prepared from placentas obtained following cesarean delivery (n = 5). Protein-free solution was perfused through both maternal and fetal arteries. Four amide-type local anesthetics (mepivacaine [Mep]; lidocaine [Lid]; bupivacaine [Bup]; and ropivacaine [Rop]) were added to the maternal perfusate at 1 microg ml(-1). Three conditions were tested (stage 1, maternal pH 7.4, fetal pH 7.4; stage 2, maternal pH 7.4, fetal pH 6.9; and stage 3, maternal pH 6.9, fetal pH 6.9). Venous blood samples were collected from the fetal circuit after stabilization. The fetal vein/maternal artery concentration ratio (F/M ratio) of the local anesthetics was used as an index of placental transfer. The concentration of human chorionic gonadotropin (hCG) in the maternal vein was measured at the end of each stage. RESULTS: The F/M ratios in all stages were in the order of: Mep > Lid > Bup [symbol: see text] Rop. The F/M ratios of Mep were significantly higher than those of the other local anesthetics in all stages. The F/M ratios of Lid were higher than those of Rop in stages 2 and 3. The F/M ratios of Lid and Rop were higher in stage 2 than in stage 3. However, the differences between the F/M ratios in the three stages were not as large as expected from the basic uncharged ([B]) condition and pH gap. The concentration of hCG showed a time-dependent decrease with increasing stage (stage 1, 81.0 +/- 58.9 mIU ml(-1); stage 2, 57.4 +/- 31.8 mIU ml(-1); stage 3, 32.1 +/- 19.7 mIU ml(-1)). CONCLUSION: Our data clearly show that it is the basic uncharged concentration that mainly determines the placental transfer of amide-type local anesthetics with protein-free perfusate. This finding suggests that Rop and Bup can be used more safely than Mep in terms of placental transfer.

[Unexpected tracheobronchomalacia during cardiac operation in a patient with Marfan's syndrome].

A 56-year-old man with Marfan's syndrome was scheduled for a valve-sparing aortic root replacement operation because of annuloaortic ectasia and aortic regurgitation. He had severe dyspnea. When the operation started, SpO2 decreased at the time of the median sternotomy, and increased by manual inflation. After sternal closure, PIP increased from 20 cmH2O to 28 cmH2O, SpO2 decreased from 98% to 66%, and the expiratory pattern indicated airway obstruction. Because hypoxemia persisted, we reopened the sternum, resulting in increased SpO2 and decreased PIP, but hypercapnea remained. Fiberoptic bronchoscopy revealed a narrowing of the tracheal and bronchial lumen. We suspected tracheobronchomalacia, and the tracheal tube was advanced to just above the carina. We succeeded in extubating 7 days after the operation. Since he had severe persisting dyspnea, we suggested reopening the partial sternum to decompress the intrathoracic pressure, and closing the skin. The sternum was reopened, and he had no dyspnea after the second operation. The mechanism of tracheobronchomalacia is considered to be related to the connective tissue defect of Marfan's syndrome. Suddenly SpO2 is decreased and PIP and Et(CO2) are increased after closure of the sternum. Bronchoscopy was useful in making the diagnosis.

The effects of dexmedetomidine and halothane on Fos expression in the spinal dorsal horn using a rat postoperative pain model.

We investigated the effect of an intrathecal injection of a selective alpha2 adrenergic receptor agonist, dexmedetomidine (Dex), and halothane anesthesia on Fos expression in the lumbar spinal dorsal horn after skin incision of the plantar surface of the hind paw, a postoperative pain model using rats. Fos immunoreactivity was induced particularly in the superficial layers of the spinal cord 2 h after surgery. Halothane anesthesia (0.5-1.5%) partially reversed Fos induction, but not in a dose-dependent manner. Preoperative spinal Dex (0.1-10 microg) dose-dependently reduced Fos immunoreactivity, while a relatively high dose of Dex (10 microg) was necessary to produce a profound effect. When used with halothane anesthesia, relatively low doses of Dex (1-3 microg) completely suppressed Fos induction in the superficial spinal layers. These findings indicate that preoperative Dex treatment may provide anesthesia that does not induce stress on spinal neurons.

Blood transfusion-induced anaphylaxis and coronary artery spasm during general anesthesia.

Anaphylactic reactions to blood transfusion can lead to life-threatening cardiovascular disruptions. We describe a case in which anaphylaxis due to blood transfusion during general anesthesia was the probable cause of coronary artery spasm. Thirty minutes after the transfusion of concentrated red blood cells, the patient's blood pressure had dropped to 70/40 mmHg and peak airway pressure had increased to 35 cmH2O. The ST segment of the ECG was simultaneously elevated, and the left upper arm became extensively flushed. The tryptase concentration in the patient's plasma collected 3 h postoperatively was 13.9 microg x l(-1) (normal range, 2.1-9.0 microg x l(-1)). This case report emphasizes that anaphylactic reactions to blood transfusion can potentially lead to coronary artery spasm.