Preoperative echocardiography as a predictor of spinal anesthesia-induced hypotension in older patients with mild left ventricular diastolic dysfunction: a retrospective observational study.

BACKGROUND: Spinal anesthesia-induced hypotension (SAH) frequently occurs in older patients, many of whom have mild left ventricular (LV) diastolic dysfunction, often asymptomatic at rest. This study investigated the association between preoperative echocardiographic measurements and SAH in older patients with mild LV diastolic dysfunction. METHODS: We conducted a retrospective observational study using data from electronic medical records. The patients ≥ 65 years old who underwent spinal anesthesia for urologic surgery between January 2016 and December 2017 and whose preoperative echocardiography within 6 months before surgery revealed grade I LV diastolic dysfunction were recruited. SAH was investigated using the anesthesia records. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed. RESULTS: A total of 163 patients were analyzed. SAH and significant SAH developed in 55 (33.7%) patients. The mitral inflow E velocity was an independent risk factor for SAH (odds ratio [OR], 0.886; 95% confidence interval [CI], 0.845-0.929; P < 0.001). The area under the ROC curve for mitral inflow E velocity to predict SAH was 0.819 (95% CI, 0.752-0.875; P < 0.001). If mitral inflow E velocity was ≤ 60 cm/s, SAH was predicted with a sensitivity of 83.6% and specificity of 70.4%. CONCLUSIONS: The preoperative mitral inflow E velocity demonstrated the greatest predictability of SAH in older patients with mild LV diastolic dysfunction. This may assist in identifying patients at high risk of SAH and guiding preventive strategies in the future.

Reducing the carbon footprint of operating rooms through education on the effects of inhalation anesthetics on global warming: A retrospective study.

Environmental concerns, especially global warming, have prompted efforts to reduce greenhouse gas emissions. Healthcare systems, including anesthesia practices, contribute to these emissions. Inhalation anesthetics have a significant environmental impact, with desflurane being the most concerning because of its high global warming potential. This study aimed to educate anesthesiologists on the environmental impact of inhalation anesthetics and assess changes in awareness and practice patterns, specifically reducing desflurane use. This study included data from patients who underwent surgery under general anesthesia 1 month before and after education on the effects of inhalation anesthetics on global warming. The primary endpoint was a change in inhalational anesthetic use. Secondary endpoints included changes in carbon dioxide equivalent (CO2e) emissions, driving equivalent, and medical costs. After the education, desflurane use decreased by 50%, whereas sevoflurane use increased by 50%. This shift resulted in a reduction in the overall amount of inhalational anesthetics used. The total CO2e and driving-equivalent values decreased significantly. The cost per anesthesia case decreased, albeit to a lesser extent than expected. Education on the environmental impact of inhalation anesthetics has successfully altered anesthesiologists' practice patterns, leading to reduced desflurane usage. This change has resulted in decreased CO2e emissions and has had a positive effect on mitigating global warming. However, further research is required to assess the long-term impact of such education and the variability in practice patterns across different institutions.

Effects of Intrathecal Ketamine on Cerebrospinal Fluid Levels of Brain-Derived Neurotrophic Factor and Mechanical Allodynia in a Rat Model of Mild Traumatic Brain Injury.

BACKGROUND Ketamine, a compelling candidate for neuropathic pain management, has attracted interest for its potential to elevate brain-derived neurotrophic factor (BDNF) levels. We aimed to assess the effects of intrathecally administered ketamine on the cerebrospinal fluid (CSF) levels of BDNF(c-BDNF) and allodynia in a rat model of traumatic brain injury (TBI). MATERIAL AND METHODS Forty-five rats were divided into 3 groups: sham operation (Group S), untreated TBI (Group T), and ketamine-treated TBI (Group K), with 15 rats in each group. Rats were anesthetized, and their skulls were secured in a stereotactic frame before undergoing craniotomy. A controlled cortical impact (CCI) was induced, followed by injection of ketamine (3.41 µg/g) into the CSF in Group K. In Group T, no drug was injected after CCI delivery. On postoperative days (POD) 1, 7, and 14, the 50% mechanical withdrawal threshold (50% MWT) and c-BDNF levels were assessed. RESULTS Groups T and K exhibited a significantly lower 50% MWT than Group S on POD 1(6.6 [5.7, 8.7] g, 10.0 [6.8, 11.6] g, and 18.7 [11.6, 18.7] g, respectively; P<0.001). The c-BDNF levels in Group K were significantly higher than those in Groups S and T on POD 1 (18.9 [16.1, 23.0] pg/ml, 7.3 [6.0, 8.8] pg/ml, and 11.0 [10.6, 12.3] pg/ml, respectively; P=0.006). CONCLUSIONS Intrathecal ketamine administration did not exhibit anti-allodynic effects following mild TBI. c-BDNF level is a promising potential indicator for predicting the expression of allodynia after mild TBI.

The effect of perineural injection therapy on neuropathic pain: a retrospective study.

Background: Among the various pain-related diseases that can be encountered at the clinic, there is a neuropathic pain that is difficult to treat. Numerous methods have been proposed to treat neuropathic pain, such as taking medication, nerve block with lidocaine, or neurolysis with alcohol or phenol. Recently, a method of perineural injection using dextrose instead of lidocaine was proposed. This study was designed to compare the effects of perineural injection therapy (PIT) with buffered 5% dextrose or 0.5% lidocaine on neuropathic pain. Methods: The data were collected from the database of pain clinic from August 1st, 2019 to December 31st, 2022 without any personal information. The inclusion criteria were patients diagnosed with postherpetic neuralgia (PHN), trigeminal neuralgia (TN), complex regional pain syndrome (CRPS), or peripheral neuropathy (PN), and patients who had undergone PIT with buffered 5% dextrose (Dextrose group) or 0.5% lidocaine (Lidocaine group) for pain control. The data of patients, namely sex, age, and pain score (numerical rating scale, NRS) were collected before PIT. The data of NRS, side effects, and satisfaction grade (excellent, good, fair, or poor) were collected one week after each of the four PIT, and two weeks after the last PIT. Results: Overall, 112 subjects were enrolled. The Dextrose group included 89 and Lidocaine group included 23 patients. Because the number of patients in the Lidocaine group was too small to allow statistical analysis, the trend in Lidocaine group was just observed in each disease. There were no significant side effects except for a few bruise cases on the site of injection in all groups. The NRS in most Dextrose groups except CRPS were reduced significantly; however, the Lidocaine group showed a trend of pain reduction only in PHN. The Dextrose group except CRPS showed increased satisfaction two weeks after the final PIT. Conclusion: From the results, it is suggested that PIT with buffered 5% dextrose may have a good effect for neuropathic pain without any side effect except for patients with CRPS. This may offer a window into a new tool that practitioners can employ in their quest to help patients with neuropathic pain.

Perioperative considerations of pyruvate dehydrogenase complex deficiency: a case report of two consecutive anesthesia.

BACKGROUND: Pyruvate dehydrogenase complex (PDHC) deficiency is a rare mitochondrial disorder caused by a genetic mutation affecting the activity of the PDHC enzyme, which plays a major role in the tricarboxylic cycle. Few cases of surgery or anesthesia have been reported. Moreover, there is no recommended anesthetic method. CASE: A 24-month-old child with a PDHC deficiency presented to the emergency room with respiratory failure, mental decline, systemic cyanosis, and lactic acidosis. During hospitalization period, the patient presented with pneumothorax, pneumoperitoneum, and multiple air pockets in the heart. Two surgeries were performed under general anesthesia using an inhalational anesthetic agent. The patient was discharged with home ventilation. CONCLUSIONS: Anesthesiologists should be wary of multiple factors when administering anesthesia to patients with PDHC deficiency, including airway abnormalities, acid-base imbalance, intraoperative fluid management, selection of appropriate anesthetics, and monitoring of lactic acid levels.

What we need to know and do on sugammadex usage in pregnant and lactating women and those on hormonal contraceptives.

Sugammadex is a chemically modified γ-cyclodextrin that is used as a selective reversal agent for steroidal neuromuscular blockade. The use of sugammadex has greatly increased globally; however, little is known about its potential adverse effects in pregnant and lactating women or those using hormonal contraceptives. There are three important theoretical assumptions. Firstly, pregnancy-related physiological changes involve most organs and affect the pharmacokinetic profiles of medications. Considering the physiological changes in pregnant women and the pharmacokinetic properties of sugammadex, alterations in the dosage and safety profiles of sugammadex may occur during pregnancy. Secondly, very large and polarized sugammadex molecules are expected to have limited placental transfer to the fetus and excretion into breast milk. Finally, sugammadex can bind to steroidal neuromuscular blocking agents as well as other substances with similar structures, such as progesterone. As a result of using sugammadex, progesterone levels can be reduced, causing adverse effects such as early pregnancy cessation and failure of hormonal contraceptives. This narrative review aims to demonstrate the correlations between sugammadex and pregnancy, lactation, and reproductive potential based on previously published preclinical and clinical studies. This will bridge the gap between theoretical assumptions and currently unknown clinical facts. Moreover, this review highlights what anesthesia providers should be aware of and what actions to take while administering sugammadex to such patients.

Intrathecal dexmedetomidine attenuates mechanical allodynia through the downregulation of brain-derived neurotrophic factor in a mild traumatic brain injury rat model.

BACKGROUND: This study evaluated the effects of dexmedetomidine and propofol on brain-derived neurotrophic factor level in the cerebrospinal fluid (c-BDNF) and mechanical allodynia in a mild traumatic brain injury (TBI) rat model. METHODS: After fixing the rat's skull on a stereotactic frame under general anesthesia, craniotomy was performed. After impact, 10 µl of drug was injected into the cisterna magna (group S: sham, group D: dexmedetomidine 5 µg/kg, group P: propofol 500 µg/kg, and group T: untreated TBI). The 50% mechanical withdrawal threshold (50% MWT) and c-BDNF level were measured on postoperative days (PODs) 1, 7, and 14. RESULTS: The 50% MWT measured on PODs 1, 7, and 14 was lower and the c-BDNF level on POD 1 was higher in group T than in group S. In group D, the c-BDNF level on POD 1 was lower than that in group T and was comparable with that in group S during the whole study period. The 50% MWT of group D was higher than that of group T throughout the postoperative period. In group P, there were no significant differences in the 50% MWT during the entire postoperative period compared with group T; the c-BDNF level was higher than that in group T on POD 1. CONCLUSIONS: Intrathecal administration of dexmedetomidine may attenuate TBI-induced mechanical allodynia for up to two weeks post-injury through immediate suppression of c-BDNF in mild TBI rats. The inhibition of c-BDNF expression in the acute phase reduced the occurrence of TBI-induced chronic neuropathic pain.

Increased Brain-Derived Neurotrophic Factor Levels in Cerebrospinal Fluid During the Acute Phase in TBI-Induced Mechanical Allodynia in the Rat Model.

BACKGROUND: The present study aimed to develop a rat model for mechanical allodynia after traumatic brain injury (TBI) and to investigate the expression of brain-derived neurotrophic factor (BDNF) in the cerebrospinal fluid (CSF) using this model. METHODS: A total of 180 rats were randomly allocated into three groups: a control group (group C), a sham-operated group (group S), and a controlled cortical impact induced TBI group (group T), 60 in each group. Von Frey test was performed to evaluate mechanical withdrawal thresholds. An enzyme-linked immunosorbent assay was performed to quantify BDNF level in CSF. RESULTS: The 50% withdrawal thresholds of group T were lower than those of group C and group S at all measuring points except for the preoperative period (P = 0.026, <0.001, and <0.001 for POD1, POD7, and POD14, respectively). The BDNF level of group T was higher than those of group C and group S at POD1 (P = 0.005). CONCLUSION: Upregulation of the BDNF expression in CSF was observed in rats who developed mechanical allodynia on the day after TBI. Based on our findings, to elucidate the relationship between TBI-induced neuropathic pain and BDNF expression in CSF, further research should be carried out through a multifaceted approach to a broad spectrum of pain behavior models.

Incidental operating room fire from a breathing circuit warmer system: a case report.

BACKGROUND: An airway-associated fire in an operating room can have devastating consequences for patients. Breathing circuit warmers (BCWs) are widely used to provide heated and humidified anesthetic gases and eventually prevent hypothermia during general anesthesia. Herein, we describe a case of a BCW-related airway fire. CASE PRESENTATION: In this case, an electrical short within a BCW wire caused a fire inside the circuit. Simultaneously, the fire was extinguished, ventilation was stopped, and the endotracheal tube was disconnected from the BCW. The patient was exposed to the fire for less than 10 s, resulting in burns to the trachea and bronchi. Immediately after airway burn, bronchoscopy showed no edema or narrowing except for soot in the trachea and both main bronchus. After the inhalation burn event, prophylactic antibiotics, bronchodilator, mucolytics nebulizer, and corticosteroid nebulizer were started. On bronchoscopy 3 days after the inhalation burn, mucosal erythematous edema was observed and the inflammatory reaction worsened. The inflammatory reaction showed aggravation for up to 2 weeks, and then gradually recovered, and the epithelium and mucous membrane of the upper respiratory tract returned to normal after 4 weeks. Eventually, the patient recovered without long-term complications and was successfully discharged. CONCLUSIONS: This is the first report of a fire caused by BCW. We wanted to share our experience of how we responded to an airway-related fire in an OR and treated the patient. It cannot be overemphasized that the electrical medical appliance associated with the airways are fatal to the patient in the event of a fire, so caution should always be exercised.

Sleep quality and emergence delirium in children undergoing strabismus surgery: a comparison between preschool- and school-age patients.

BACKGROUND: Emergence delirium (ED) is common in pediatric patients undergoing general anesthesia with sevoflurane. Preoperative sleep quality is associated with the risk factors for ED. However, research on the relationship between sleep quality and ED is limited. We aimed to investigate the relationship between ED and preoperative sleep quality in pediatric patients undergoing strabismus surgery. METHODS: This clinical trial included pediatric patients aged 4-12 years who underwent elective strabismus surgery. The patients and their parents were questioned about the patients' preoperative sleep quality using the Pittsburgh Sleep Quality Index (PSQI) questionnaire. For anesthesia induction, thiopental (5 mg/kg) and rocuronium (0.6 mg/kg) were used, and anesthesia was maintained with sevoflurane (minimum alveolar concentration, 1-1.5). After administration of a reversal drug, extubation was performed, and the patients were transferred to a post-anesthesia recovery unit. At 10 min after extubation, the degree of ED was measured using the pediatric anesthesia emergence delirium (PAED) and Watcha scale scores. RESULTS: Of the 62 enrolled patients, three pediatric patients were excluded. The overall incidence of ED was 22%. A total of 59 patients were divided into the two groups. The ED group and the non-ED group comprised 13 and 46 patients. Age, height and weight were significantly lower in the ED group than in the non-ED group. Preoperative PSQI and Watcha scale score were significantly higher in the ED group than in the non-ED group. Multivariate analysis showed that age (adjusted OR [95% CI]: 0.490 [0.290-0.828], p = 0.008) and preoperative PSQI score (adjusted OR [95% CI]: 2.149[1.224-3.771], p = 0.008) was associated with ED. In sub-group analysis, PAED scale and Watcha scale scores showed a moderate correlation with preoperative sleep quality in preschool-age patients. CONCLUSION: In conclusion, the incidence of ED tended to be higher in younger age and poorer preoperative sleep quality in pediatric patients. In particular, the poorer sleep quality score was associated with higher incidence of ED in the preschool-age. Large-scale clinical studies and long-term follow-up studies on ED and sleep quality are required. TRIAL REGISTRATION: This study was registered with Clinicaltrials.gov ( NCT03332407 ) at November 5th 2017.

Transient involuntary movement disorder after spinal anesthesia: A case report.

BACKGROUND: Spinal anesthesia is commonly used for various surgeries. While many complications occur after induction of spinal anesthesia, involuntary movement is an extremely rare complication. CASE SUMMARY: Herein, we report the case of a 54-year-old healthy male patient who experienced involuntary movements after intrathecal injection of local anesthetics. This patient had undergone metal implant removal surgery in both the lower extremities; 7 h after intrathecal hyperbaric bupivacaine administration, involuntary raising of the left leg began to occur every 2 min. When the movement disorder appeared, the patient was conscious and cooperative. No other specific symptoms were noted in the physical examination conducted immediately after the involuntary leg raising started; moreover, the patient's motor and sensory assessments were normal. The symptom gradually subsided. Twelve hours after the symptom first occurred, its frequency decreased to approximately once every three hours. Two days postoperatively, the symptoms had completely disappeared without intervention. CONCLUSION: Anesthesiologists should be aware that movement disorders can occur after spinal anesthesia and be able to identify the cause, such as electrolyte imbalance or epilepsy, since immediate action may be required for treatment. Furthermore, it is crucial to know that involuntary movement that develop following spinal anesthesia is mostly self-limiting and may not require additional costly examinations.

Diagnosis and management of ophthalmic zoster sine herpete accompanied by cervical spine disc protrusion: A case report.

BACKGROUND: Zoster sine herpete (ZSH) can be misdiagnosed because there are no typical vesicular eruptions characterized by a dermatomal distribution. However, incorrect treatment due to a misdiagnosis can lead to severe pain and fatal complications. CASE SUMMARY: A 75-year-old woman complained of sudden onset right shoulder pain and atypical headache. After 18 d, sudden hearing loss occurred in the left ear. In serology tests conducted after the onset of hearing loss, varicella-zoster virus IgM was positive. She had no history of a rash or trauma. Under the suspicion of ZSH, antiviral treatment and stellate ganglion block were administered four times, and the pain was effectively controlled. CONCLUSION: Early diagnosis and treatment of ZSH can help not only by reducing pain but also by preventing fatal complications.

Changes in the microvascular reactivity during spinal anesthesia.

PURPOSE: Anesthesia alters microcirculation and tissue oxygen saturation (StO2). We sought to examine changes in StO2 using near-infrared spectroscopy and a vascular occlusion test (VOT) during spinal anesthesia. METHODS: This prospective observational study was included 51 patients without comorbidities who underwent elective surgery under spinal anesthesia. We measured the StO2 in the lower extremity during VOT before and after intrathecal injection. RESULTS: The baseline, minimum, and maximum StO2 values during VOT significantly increased after intrathecal injection (baseline StO2 from 68.6 ± 7.3% to 77.1 ± 10.1%, minimum StO2 from 39.7 ± 14.9% to 48.8 ± 17.6%, and maximum StO2 from 74.2 ± 7.5% to 80.2 ± 10.0%, all P < 0.0001). The occlusion slope and ischemic stimulus did not significantly change after intrathecal injection. The reperfusion slope was 1.38 ± 0.69%/sec before intrathecal injection and significantly decreased to 1.15 ± 0.61%/sec after intrathecal injection (P = 0.0001). CONCLUSIONS: Our results showed that despite an increased perfusion, reperfusion rate was significantly decreased by spinal anesthesia. Further studies are required to confirm how these contradictory results (improving oxygenation while reducing microvascular reactivity) actually affect the clinical impact of spinal anesthesia on microvascular function.

Microvascular Reactivity Measured by Dynamic Near-infrared Spectroscopy Following Induction of General Anesthesia in Healthy Patients: Observation of Age-related Change.

Background: The purpose of this study was to investigate the effect of general anesthesia on microvascular reactivity and tissue oxygen saturation (StO2) using near-infrared spectroscopy in conjunction with vascular occlusion tests (VOT). Age-related changes of microvascular reactivity, that is, the capacity of capillary recruitment, were examined. Methods: This prospective observational study was performed on 60 patients without comorbidities who underwent elective surgery under general anesthesia. Baseline StO2 on thenar eminence, hemodynamics, and laboratory profile were monitored before (T0) and 30 min after general anesthesia (T1). During VOT, occlusion slope representing oxygen consumption of muscle and recovery slope representing microvascular reactivity were also collected at T0 and T1. Results: Baseline StO2 and minimum / maximum StO2 during VOT increased under general anesthesia. Occlusion slope decreased while the recovery slope increased under general anesthesia. To observe aging effect, Receiver operating characteristic analysis was performed and age less than 65 years old showed a fair performance in predicting the increase of microvascular reactivity after the induction of anesthesia (AUC 0.733, 95% CI 0.594-0.845, P= 0.003). For age-related analyses, 27 patients of younger group (< 65 years) and 26 patients of older group (≥ 65 years) were divided. Recovery slope significantly increased under general anesthesia in younger group (2.44 [1.91-2.81] % ∙ sec-1 at T0 and 3.59 [2.58-3.51] % ∙ sec-1 at T1, P <0.001), but not in older group (2.61 [2.21-3.20] % ∙ sec-1 at T0, 2.63 [1.90-3.60] % ∙ sec-1 at T1, P = 0.949). Conclusions: General anesthesia could improve StO2 through increase of microvascular reactivity and decrease of tissue metabolism. However, microvascular reactivity to capillary recruitment under general anesthesia significantly improves in younger patients, not in older patients.

Concealed congenital long QT syndrome during velopharyngeal dysfunction correction: a case report.

The congenital long QT syndrome (LQTS) is an inherited cardiac disorder characterized by increased QT intervals and a tendency to experience ventricular tachycardia, which can cause fainting, heart failure, or sudden death. A 4-year-old female patient undergoing velopharyngeal correction surgery under general anesthesia suddenly developed Torsades de pointes. Although the patient spontaneously resolved to sinus rhythm without treatment, subsequent QT prolongation persisted. Here, we report a case of concealed LQTS with a literature review.

Gradual aggravation of idiopathic glossopharyngeal neuralgia due to chronic tonsillitis: A case report.

RATIONALE: Glossopharyngeal neuralgia (GPN) is a rare type of neuralgia. Depending on the cause, it is classified as idiopathic GPN and secondary GPN. Secondary GPN can also be caused by a mass effect or inflammation of the tonsils, the innervation area of glossopharyngeal nerve. PATIENT CONCERNS: The patient was diagnosed idiopathic GPN 8 years ago. The patient had intermittent pain, but the pain was well controlled. From 5 months ago, the pain gradually worsened, the patient complained severe pain which impaired chewing and swallowing function. DIAGNOSES: Idiopathic GPN, secondary GPN, chronic tonsillitis INTERVENTIONS:: Percutaneous glossopharyngeal nerve block, glossopharyngeal neurolysis, and pulsed radiofrequency neuromodulation of glossopharyngeal nerve were performed. After the diagnosis of tonsillitis, antibiotic therapy was performed OUTCOMES:: Two weeks after the antibiotic treatment, the pain decreased simultaneously with the patient's tonsillitis recovery. LESSONS: In a Patient who had already been diagnosed with idiopathic GPN, both pain control and its cause should be considered when the pain is aggravated.

Randomized controlled trial assessing the effectiveness of midazolam premedication as an anxiolytic, analgesic, sedative, and hemodynamic stabilizer.

BACKGROUND: Midazolam premedication is widely used before general anesthesia, but lacks clinical evidence of effectiveness. The present study aimed to evaluate the effectiveness of midazolam premedication following 4 aspects: anxiety reduction, sedation, hemodynamic stabilization, and analgesia. METHODS: In a randomized, single-blind, prospective study, a total of 128 women were allocated to the midazolam premedication group (Group P, n = 64) or the control group (Group N, n = 64). The patients were asked to complete the Beck anxiety inventory (BAI) 2 times: on the day before surgery (BS) and 30 minutes after midazolam premedication (T0). Depth of anesthesia using state entropy (SE), conventional hemodynamic data using heart rate (HR) and mean blood pressure (MBP), and analgesic profiles using surgical pleth index (SPI) were acquired at the following 4 points: T1-pre-induction, T2-prior to intubation, T3-intubation, and T4-20 minutes after intubation. RESULTS: No change in BAI score was observed between BS and T0 in both groups P and N (median and interquartile range [IQR], Group P: BS-4.5 [2.0-7.0], T0-4.0 [1.0-9.0], P = .603; Group N: BS-4.0 [1.0-8.5], T0-3.5 [1.0-6.0], P = .066). Midazolam premedication reduced SE at T2-4 (mean difference with 95% confidence interval [95% CI], T2-7.1 [1.6-12.6], P = .012; T3-10.4 [6.5-14.4], P < .001; T4-9.2 [5.0-13.4], P < .001). Midazolam premedication also reduced HR (mean differences [95% CI], T1-7.3 [2.5-12.1], P = .003; T3-6.6 [1.1-12.2], P = .020) and MBP at T1 and T3 (mean differences [95% CI], T1-7.3 [2.5-12.1], P = .003; T3-8.6 [1.3-15.9], P = .021), and lowered SPI at T1-3 (mean differences [95% CI]: T1-12.7 [6.1-19.4], P < .001; T2-6.0 [0.5-11.5], P = .033; T3-7.9 [1.7-14.1], P = .012). CONCLUSION: Midazolam premedication did not reduce the level of anxiety. However, midazolam premedication reduced the entropy values, stabilized hemodynamics, and provided analgesia during the induction of anesthesia. The purpose of midazolam premedication needs to be reconsidered.

Ultrasound-guided superficial cervical plexus block under dexmedetomidine sedation versus general anesthesia for carotid endarterectomy: a retrospective pilot study.

Background: Carotid endarterectomy (CEA) has been performed under regional and general anesthesia (GA). The general anesthesia versus local anesthesia for carotid surgery study compared the two techniques and concluded that there was no difference in perioperative outcomes. However, since this trial, new sedative agents have been introduced and devices that improve the delivery of regional anesthesia (RA) have been developed. The primary purpose of this pilot study was to compare intraoperative hemodynamic stability and postoperative outcomes between GA and ultrasound-guided superficial cervical plexus block (UGSCPB) under dexmedetomidine sedation for CEA. Methods: Medical records from 43 adult patients who underwent CEA were retrospectively reviewed, including 16 in the GA group and 27 in the RA group. GA was induced with propofol and maintained with sevoflurane. The UGSCPB was performed with ropivacaine under dexmedetomidine sedation. We compared the intraoperative requirement for vasoactive drugs, postoperative complications, pain scores using the numerical rating scale, and the duration of hospital stay. Results: There was no difference between groups in the use of intraoperative antihypertensive drugs. However, intraoperative inotropic and vasopressor agents were more frequently required in the GA group (p<0.0001). In the GA group, pain scores were significantly higher during the first 24 h after surgery (p<0.0001 between 0-6 h, p<0.004 between 6-12 h, and p<0.001 between 12-24 h). The duration of hospital stay was significantly more in the GA group (13.3±4.6 days in the GA group vs. 8.5±2.4 days in the RA group, p<0.001). Conclusion: In this pilot study, intraoperative hemodynamic stability and postoperative outcomes were better in the RA compared to the GA group.

Observations on significant hemodynamic changes caused by a high concentration of epidurally administered ropivacaine: correlation and prediction study of stroke volume variation and central venous pressure in thoracic epidural anesthesia.

BACKGROUND: Thoracic epidural anesthesia (TEA) exacerbates hypotension due to peripheral vasodilator effects following the use of general anesthetics. This study aimed to compare the hemodynamic changes caused by three different concentrations of epidural ropivacaine and to evaluate the performance of the stroke-volume variation (SVV) and central venous pressure (CVP) during TEA with general anesthesia. METHODS: A total of 120 patients were administered 8 mL of ropivacaine solution via epidural injection, following randomization into one of three groups based on the concentration of ropivacaine in the study solution: 0.75%, 0.375%, or 0.2%. Hemodynamics were monitored for 30 min after loading. We analyzed the hemodynamic changes in the subgroups according to an age cutoff of 60 years. Receiver operating characteristic (ROC) analysis was performed to characterize the relationship of the SVV, CVP, and a 20% decrease in the mean arterial pressure (MAP) following TEA. RESULTS: Data from 109 patients were analyzed. MAP and systemic vascular resistance index were significantly decreased, and SVV was significantly increased after epidural loading only in the 0.75% ropivacaine group. There was a significant difference in hemodynamics between young and elderly subgroups in the 0.75% ropivacaine group. SVV showed a negative correlation with MAP, whereas CVP showed no correlation. The ROC analysis of SVV demonstrated a weak predictive ability of a 20% decrease in MAP at 10 min after the loading dose, with an area-under-the-curve of 0.687 and a 9.5% optimal cutoff value (sensitivity, 60.6%; specificity, 68.9%). CONCLUSIONS: A high concentration of ropivacaine through TEA caused a significant decrease in the systemic vascular resistance and blood pressure. More significant decreases were shown in the elderly patients. Though the change of SVV showed a negative correlation with hypotension and indicated functional hypovolemia after TEA, the predictability was limited. CLINICAL TRIALS REGISTRATION: Number: NCT01559285 , date: January 24, 2013.