Anesthetic experience does not reduce accidental dural puncture in surgical patients: a retrospective case-controlled study.

BACKGROUND: Accidental dural puncture (ADP), which is a complication of epidural anesthesia, still exists and leads to worse outcomes in surgical patients. While residency training is important for epidural competency, it remains unknown whether anesthetic experience reduces ADP in surgical patients. Using an incident reporting system along with anesthetic records, this case-controlled study retrospectively investigated risk factors associated with ADP in surgical patients. METHODS: Patients who experienced ADP during epidural anesthesia who were registered in the incident reporting system of our institution between April 2012 and March 2019 were enrolled. Patients with ADP were control-matched with those who without ADP in a 1:3 ratio, to compare the potential risk factors and calculated odds ratios (ORs) for ADP. The primary hypothesis was that anesthesiologists' experience reduces the incidence of ADP. The secondary hypothesis was that there are risk factors for ADP. Between-group differences in anesthesiologists' experience were compared using the Mann-Whitney U test. Significance was set at P < 0.05. RESULTS: Thirty-five patients who experienced ADP were identified from the incident reporting system. These were matched with 69 patients who did not experience ADP. There was no difference in the years of experience of anesthesiologists between the groups that did and did not experience ADP (8 [3-20] vs. 9 [3-18] years, respectively; P = 0.65). CONCLUSIONS: Having an experienced anesthesiologist did not guarantee the prevention of ADP. Daily individual training and briefings would be needed to reduce the incidence of ADP.

Effects of hyperventilation on cerebral oxygen saturation estimated using near-infrared spectroscopy: A randomised comparison between propofol and sevoflurane anaesthesia.

BACKGROUND: Near-infrared spectroscopy estimates cerebral regional tissue oxygen saturation (rSO2), which may decrease under hyperventilation. Propofol and sevoflurane act differently on cerebral blood vessels. Consequently, cerebral blood flow during hyperventilation with propofol and sevoflurane anaesthesia may differ. OBJECTIVES: The first aim of this study was to compare the changes in rSO2 between propofol and sevoflurane anaesthesia during hyperventilation. The second aim was to assess changes in rSO2 with ventilation changes. DESIGN: A randomised, open-label study. SETTING: University of Yamanashi Hospital, Yamanashi, Japan from January 2014 to September 2014. PARTICIPANTS: Fifty American Society of Anesthesiologists physical status 1 or 2 adult patients who were scheduled for elective abdominal surgery were assigned randomly to receive either propofol or sevoflurane anaesthesia. Exclusion criterion was a known history of cerebral disease such as cerebral infarction, cerebral haemorrhage, transient ischaemic attack and subarachnoid haemorrhage. INTERVENTIONS: After induction of anaesthesia but before the start of surgery, rSO2, arterial carbon dioxide partial pressure (PaCO2) and arterial oxygen saturation were measured. Measurements were repeated at 5-min intervals during 15 min of hyperventilation with a PaCO2 around 30 mmHg (4 kPa), and again after ventilation was normalised. MAIN OUTCOME MEASURES: The primary outcome was the difference of changes in rSO2 between propofol anaesthesia and sevoflurane anaesthesia during and after hyperventilation. The second outcome was change in rSO2 after the initiation of hyperventilation and after the normalisation of ventilation. RESULTS: Changes of rSO2 during hyperventilation were -10 ±â€Š7% (left) and -11 ±â€Š8% (right) in the propofol group, and -10 ±â€Š8% (left) and -9 ±â€Š7% (right) in the sevoflurane group. After normalisation of PaCO2, rSO2 returned to baseline values. Arterial oxygen saturation remained stable throughout the measurement period. The rSO2 values were similar in the propofol and the sevoflurane groups at each time point. CONCLUSION: The effects of hyperventilation on estimated rSO2 were similar with propofol and sevoflurane anaesthesia. Changes in rSO2 correlated well with ventilation changes. TRIAL REGISTRATION: Japan Primary Registries Network (JPRN); UMIN-CTR ID; UMIN000010640.

The effects of topical and intravenous JM-1232(-) on cerebral pial microvessels of rabbits.

BACKGROUND: JM-1232(-) is a novel anesthetic agent which acts through gamma-aminobutyric acid receptors. Cerebral pial vascular effects of JM-1232(-) are unknown. We thus evaluated topical and intravenous effects of JM-1232(-) on cerebral pial microvessels in rabbits, and the extent to which carbon dioxide (CO2) reactivity is preserved. METHODS: Closed cranial windows were used to visualize cerebral pial circulation in 29 Japanese white rabbits. In the first experiment, the cranial window was superfused with increasing concentrations of JM-1232(-): 10(-11), 10(-9), 10(-7), 10(-5) mol/L, n = 8 per concentration. In the second experiment, we examined the effects of an intravenous bolus of 1 mg/kg bolus of JM-1232(-), followed by the continuous infusion at 0.3 mg/kg/minute on cerebral pial vascular alteration (n = 9). In the third, we examined CO2 reactivity of cerebral pial vessels under JM-1232(-) (n = 6) or sevoflurane anesthesia (n = 6). RESULTS: Topical application of JM-1232(-) did not change pial venular diameter, and constricted arterials only at the highest concentration. Intravenous administration of JM-1232(-) produced cerebral pial constriction which gradually diminished over time. Under intravenous administration of JM-1232(-) and inhaled sevoflurane, diameters of vessels increased in parallel with CO2 partial pressure. Slopes of linear regression and correlation coefficients in arterioles and venules were comparable for JM-1232(-) anesthesia and sevoflurane anesthesia. CONCLUSIONS: Topical application of JM-1232(-) had little effect on cerebral pial vessels. Intravenous administration produced vasoconstriction of cerebral pial arterioles and venules, however those changes were clinically unimportant. In addition, JM-1232(-) did not impair CO2 responsiveness. At least from the perspective of vascular reactivity, JM-1232(-) thus appears safe for neurosurgical patients.

[Femoral nerve block for total knee arthroplasty].

BACKGROUND: Femoral nerve block and sciatic nerve block are used to provide intraoperative and postoperative analgesia for total knee arthroplasty. Sciatic nerve block is contraindicated in our hospital, because orthopedists want to assess peroneal nerve function after the surgery. We retrospectively assessed postoperative analgesic effect and complications of the continuous femoral nerve block for total knee arthroplasty. METHODS: We included 19 cases in 17 patients scheduled to undergo total knee arthroplasty under femoral nerve block combined with general anesthesia. Ultrasound-guided femoral nerve block was performed before the surgery. The ultrasound linear probe was used to visualize the femoral nerve. A 22 gauge needle attached to a nerve stimulator, was inserted with in-plane method. Five percent glucose solution was injected through the needle to encircle the femoral nerve. Then, the 22 gauge needle was withdrawn and an 18 gauge needle was inserted with out-of-plane method. Five percent glucose solution was injected through the needle to confirm the needle tip and perineural catheter was inserted through the needle. To achieve femoral nerve block, 0.375% ropivacaine 20 ml was injected through the needle. Perineural infusion with 0.15% ropivacaine at 4 ml x hr(-1) was initiated at the end of the surgery. Intravenous patient-controlled analgesia (IV-PCA) was also conducted postoperatively. We assessed pain at rest with a verbal numeric pain rating score (0-10) including pain on moving, and nausea as well as vomiting. RESULTS: Patients with numeric pain scores at 3 or less were 14 out of 19. Two patients complained of severe pain. There were 4 cases suffering pain on moving. CONCLUSIONS: Femoral nerve separation with 5% glucose solution using in-palne method and catheter placement with out-of-plane method could be useful for perineural catheter placement. Perineural infusion of 0.15% ropivacaine at 4 ml x hr(-1) combined with IV-PCA provided a good postoperative analgesia in patients receiving total knee arthroplasty.

[Assessment of intraoperative hemodynamics, infusion volume, urinary output and dose of circulatory drugs in general anesthesia with transversus abdominis plane block for cholecystectomy].

We retrospectively reviewed intraoperative hemodynamics, infusion volume, urinary output and dose of circulatory drugs in patients undergoing cholecystectomy in 3 types of anesthesia group: General anesthesia (GA group), general anesthesia with epidural anesthesia (EPI group) and general anesthesia with transversus abdominis plane (TAP) block (TAPB group). TAP block was performed using ultrasound-guided subcostal method and 20-30 ml of ropivacaine (0.2-0.3%) was injected to TAP bilaterally. Though, the blood pressure in TAPB group was lower than that in GA group, the degree of low blood pressure was smaller than that in EPI group. Less changes in intraoperative blood pressure, infusion volume and dose of phenylephrine in TAPB group compared to those in EPI group can be the advantage of TAP block alternative to epidural anesthesia.

[Anesthetic management of an emergency open-heart surgery for entrapment of a circular mapping catheter by chordae tendineae with mitral valve damage undergoing atrial fibrillation ablation].

The entrapment of a circular mapping catheter by chordae tendineae during catheter ablation is a very rare but serious complication requiring, in some cases, surgical treatment. We report a case that required open heart surgery for catheter removal and mitral valve repair. A 79-year-old man underwent catheter ablation for paroxysmal atrial fibrillation in other hospital. During the operation, he moved accidentally, despite circular mapping catheter was in the left atrium. The circular mapping catheter was uncontrolable due to resistance interfering with catheter removal, and the patient was brought to our hospital for open heart surgery to remove catheter. General anesthesia was induced and maintained with midazolam, fentanyl. Transesophageal echocardiography was performed to monitor catheter position and mitral valve condition. Transesophageal echocardiography revealed that circular catheter tip was located adjacent to the posterior mitral leaflet and the presence of moderate mitral valve regurgitation. Circular catheter tip was entraped by chordae tendineae and caused posterior mitral leaflet damage. Intracardiac foreign body removal and posterior mitral leaflet repair were completed uneventfully under cardiopulmonary bypass. The postoperative course was uneventful. It is expected that catheter ablation for atrial fibrillation will increase in number. This rare complication of catheter ablation may become a threat to cardiologist, cardiac surgeon and anesthesiologist.

[Low doses of ketamine have no effect on bispectral index during stable propofol-remifentanil anesthesia].

BACKGROUND: Ketamine is associated with an increase in the bispectral index (BIS) values that can lead to an overdose of hypnotic agents. We investigated the effect of ketamine on BIS values during general anesthesia with a target-controlled infusion (TCI) of propofol and infusion of remifentanil. METHODS: Forty-five ASA I or II patients undergoing gynecological surgery were included in this study. After 5 min of steady-state anesthesia (BIS at 35-45) without surgical stimulation, patients received either a bolus administration of ketamine 0.2 mg x kg(-1) (LK group) or ketamine 0.5 mg x kg(-1) (HK group). Patients in the control group received no intervention. BIS values were recorded every minute until 15 min after ketamine administration. RESULTS: After ketamine administration, BIS value in HK group increased significantly compared with that at baseline. There were no significant changes for BIS values in LK group and control group over time. BIS values in HK group were significantly higher than those in the LK group and control group after ketamine injection. BIS values were not statistically different between LK group and control group. CONCLUSIONS: Under stable propofol and remifentanil anesthesia, a small dose of ketamine did not increase the BIS value over the next 15 min.

[Anesthetic hazards in an undiagnosed case of retroperitoneal paraganglioma].

We report a patient with undiagnosed retroperitoneal paraganglioma who developed an intraoperative hypertensive crisis. A 64-year-old female was scheduled for right partial mastectomy and removal of an abdominal mass, preoperatively diagnosed as a small intestine GIST. Surgery was performed under general anesthesia combined with epidural anesthesia with close monitoring. Immediately after the surgical manipulation of the abdominal mass, her systolic blood pressure rose to over 200 mmHg. This hypertensive crisis was managed with nicardipine and alprostadil combined with increased infusion rate of remifentanil and propofol. Thereafter, the patient was hemodynamically stable and the postoperative course was uneventful. Pathological examination identified the tumor as extraadrenal paraganglioma. The possibility of paraganglioma should be considered even in asymptomatic abdominal mass, and adequate precautions are required in such cases.

Delayed awakening with apnea as a sign of cerebellar hemorrhage after vestibular schwannoma surgery: A case report.

Cerebellar hemorrhage after surgery is a rare but critical complication requiring prompt diagnosis and intervention. However, anesthetics can mask most brain compression signs. Prolonged coma with apnea after tumor resection under general anesthesia may indicate the need for prompt imaging to detect or exclude cerebellar lesions.

Sudden onset pacemaker-induced diaphragmatic twitching during general anesthesia.

BACKGROUND: Involuntary muscle contraction caused by extracardiac stimulation is a rare complication induced by a pacemaker. We report a case who developed sudden onset diaphragmatic contractions during general anesthesia caused by a DDD mode pacemaker. CASE PRESENTATION: A 74-year-old woman with a permanent pacemaker was scheduled to undergo mastectomy. The pacing mode was switched from DDD to VOO intraoperatively to avoid electromagnetic interference. Immediately after returning the pacing mode to DDD after surgery, diaphragmatic contractions occurred, mimicking bucking type of movements. After switching the pacing to A-sense V-pace, the twitching ceased. Because no structural problems were noted, and the twitching disappeared after terminating atrial pacing, diaphragmatic contractions might be caused by stimulation of the right phrenic nerve located near the right appendage where the electrode was installed. CONCLUSION: The potential risk of muscle twitching should be carefully evaluated preoperatively especially in patients with atypical position of pacemaker leads.

Optimal doses of sevoflurane and propofol in rabbits.

BACKGROUND: Although sevoflurane and propofol are commonly used anesthetics in rabbits, optimal doses of remain unclear. We thus assessed the optimal hypnotic doses of sevoflurane and propofol, and evaluated the influence of dexmedetomidine on sevoflurane and propofol requirements. METHODS: Twenty-eight Japanese white rabbits were randomly assigned to one of four groups (n=7 each). Rabbits were given either sevoflurane, propofol, sevoflurane+dexmedetomidine, or propofol+dexmedetomidine (injected 30 µg∙kg(-1)∙hr(-1) for 10 min followed by an infusion of 3.5 µg∙kg(-1)∙hr(-1)). Hypnotic level was evaluated with Bispectral Index (BIS), a well-validated electroenchalographic measure, with values between 40 and 60 representing optimal hypnosis. BIS measurements were made 10 minutes after the adjustment of target end-tidal sevoflurane concentration in the sevoflurane group and sevoflurane+dexmedetomidine group, and at 10 min after the change of infusion rate in the propofol group and propofol+dexmedetomidine group. RESULTS: BIS values were linearly related to sevoflurane concentration and propofol infusion rate, with or without dexmedetomidine. Sevoflurane concentration at BIS=50 was 3.9±0.2% in the sevoflurane group and 2.6±0.3% in the sevoflurane+dexmedetomidine group. The propofol infusion rate to make BIS=50 was 102±5 mg∙kg(-1)∙hr(-1) in the propofol group, and 90±10 mg∙kg(-1)∙hr(-1) in the propofol+dexmedetomidine group. CONCLUSIONS: The optimal end-tidal concentration of sevoflurane alone was thus 3.9%, and optimal infusion rate for propofol alone was 102 mg∙kg(-1)∙hr(-1). Dexmedetomidine reduced sevoflurane requirement by 33% and propofol requirement by 11%.