Paravertebral block catheter breakage by electrocautery during thoracic surgery.

Advantages of thoracic paravertebral analgesia (TPA) include placement of the catheter closer to the surgical field; however, the catheter can become damaged during the operation. We experienced a case of intraoperative TPA catheter breakage that prompted us to perform an experiment to investigate possible causes. A 50-year-old male underwent a thoracoscopic lower lobectomy under general anesthesia with TPA via an intercostal approach. Following surgery, it was discovered that the catheter had become occluded, as well as cut and fused, so we reopened the incision and removed the residual catheter. From that experience, we performed an experiment to examine electrocautery-induced damage in normal (Portex™, Smith's Medical), radiopaque (Perifix SoftTip™, BBraun), and reinforced (Perifix FX™, BBraun) epidural catheters (n = 8 each). Chicken meat was penetrated by each catheter and then cut by electrocautery. In the normal group, breakage occurred in 8 and occlusion in 6 of the catheters, and in the radiopaque group breakage occurred in 8 and occlusion in 7. In contrast, breakage occurred in only 3 and occlusion in none in the reinforced group, with the 5 without breakage remaining connected only by the spring coil. Furthermore, in 7 of the reinforced catheters, electric arc-induced thermal damage was observed at the tip of the catheter. A TPA catheter for thoracic surgery should be inserted via the median approach, or it should be inserted after surgery to avoid catheter damage during surgery.

[Adherence to and Issues on our Institutional Guidelines on Heparin Administration after Withdrawal of Warfarin before Elective Surgery].

BACKGROUND: We established local guidelines of heparin bridging therapy. However, it is unknown how adherence to our guidelines was achieved and whether our guidelines improved adherence compared with other universal guidelines. METHODS: A retrospective chart review was con- ducted on compliance with 3 recommendations in the guidelines; these are initial unfractioned heparin dose, timing of unfractioned heparin administration, and two times measurements of activated partial thromboplas- tin time (APTT). We compared 3 recommendations in the guidelines with platelet monitoring which is not described in the guidelines. We also investigated bleed- ing and thromboembolic events during heparin bridg- ing therapy according to the guidelines. RESULTS: Initial unfractioned heparin dose, timing of unfractioned heparin administration, measurements of APTT, and platelet monitoring were concordant with the guidelines in 78.9%, 19.7%, 67.6%, and 46.5%, respectively. Bleeding events occurred in 3 cases, but no thromboembolic events occurred. Adherence to rec- ommendations for timing of unfractioned heparin administration was the lowest and significantly lower than platelet monitoring. CONCLUSIONS: Our local guidelines were partially effective to improve adherence We have to alert phy- sicians to care bleeding complications during heparin bridging therapy in our hospital.

[Study of background factors of cerebral hyperperfusion syndrome in the anesthetic management of carotid endarterectomy].

BACKGROUND: We conducted a retrospective study to evaluate background factors of cerebral hyperperfusion syndrome (CHS) in the anesthetic management of carotid endarterectomy (CEA) for carotid artery stenosis. METHODS: A total of 118 ASA 1-2 adult patients were allocated to one of two groups: Group A of 13 patients who developed CHS after CEA, and Group B of the remaining 105 patients. We weighed control percent ratio of somatosensory evoked potential (%SEP). The rate of carotid artery stenosis, stump pressure of internal carotid artery, %SEP internal carotid artery blood flow (ICF), and preoperative anesthetic problems were compared between the two groups. RESULTS: The rate of carotid artery stenosis in Group A was 85%, significantly higher than 74% of Group B. Stump pressure in Group A was 28 mmHg, significantly lower than 37 mmHg of Group B. %SEP was 67% of Group A, and 87% of Group B, respectively ICF in Group A was 7+ +/- 33 ml min(-1), which decreaced significantly compared with 78 +/- 34 ml min(-1) of Group B. CONCLUSIONS: We conclude that the patients with high rate of carotid artery stenosis, low stump pressure and low ICF have a high risk of developing CHS after CEA and careful attention should be required in the anesthetic management of CEA.

["Right hand" mitral valve model: a simple and free model available at anywhere].

We have devised a simple and cost-free mitral valve model using "right hand", which is placed on the median portion of anterior chest and supinated by 30 degrees. The palm is used to resemble the mitral valve:the thenar eminence, its margin wrinkle, and adjacent palm as the anterior leaflet, coaptation line, and the posterior leaflet, respectively. As the thumb and its origin is assumed as the ascending aorta and aortic valve, this model represents the mitral and aortic valves as viewed from the left atrium. This model is anatomically accurate and facilitates comprehending image orientation in transesophageal echocardiographic probe manipulations.

Gender difference in mask ventilation training of anesthesia residents.

STUDY OBJECTIVE: To investigate whether gender difference has an effect on an anesthesia resident's ability to perform successful mask ventilation. DESIGN: Cohort study. SETTING: Surgical operation theater of a university-affiliated hospital. PATIENTS: 839 ASA physical status I, II, and III patients undergoing general anesthesia performed by residents. INTERVENTION: Mask ventilation was performed by 21 different anesthesia residents. MEASUREMENTS: Difficult mask ventilation was defined as the inability of an unassisted resident to maintain oxygen saturation, significant gas flow leakage beneath the face mask, need to increase gas flow, no perceptible chest movement, assistance required using a two-handed mask ventilation technique, or use of the oxygen flush valve more than twice. MAIN RESULTS: Instances of difficult mask ventilation were observed in 210 patients (25.0%), though all were adequately ventilated with a face mask. Difficult mask ventilation was observed significantly more often with female (29.8%) than male (20.0%) residents. Residents' gender was shown to be an independent risk factor for difficult mask ventilation. CONCLUSIONS: Gender difference has an effect on the mask ventilation learning process, as it was more difficult for female residents to provide a tight air seal in the early stage of training.

[In vitro response time of continuous cardiac output measurement in STAT mode of Vigilance after controlled flow change].

BACKGROUND: Continuous cardiac output measurement in STAT mode (STAT CCO) equipped with Vigilance displays cardiac output every 30 to 60 seconds. The aim of this study is to verify the hypothesis that each value with this system is computed only from the data collected in one update period. METHODS: The circuit was filled with normal saline and flowed by a roller pump in in vitro setting. The flow rate was set at either 2.5 l x min(-1) or 5.0 l x min(-1) and changed quickly to another state after each state had been maintained for 25 minutes. The change operation was repeated 10 times. The maximum difference was defined as the difference between the value at the start and the maximum change value. The response time was defined as the time from the start to the time to reach 80% of the maximum difference. In each operation, the response time of STAT CCO was calculated. RESULTS: The response time of STAT CCO was 9.7 +/- 1.3 min (mean +/- SD). CONCLUSIONS: The response time of STAT CCO was about 10 times longer than one update period. This result suggests that STAT CCO values are not computed only from the data collected in one update period.