Verification of the performance of the Bispectral Index as a hypnotic depth indicator during dexmedetomidine sedation

Background@#Differences in the effects of propofol and dexmedetomidine sedation on electroencephalogram patterns have been reported previously. However, the reliability of the Bispectral Index (BIS) value for assessing the sedation caused by dexmedetomidine remains debatable. The purpose of this study is to evaluate the correlation between the BIS value and the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scale in patients sedated with dexmedetomidine. @*Methods@#Forty-two patients (age range, 20–80 years) who were scheduled for elective surgery under spinal anesthesia were enrolled in this study. Spinal anesthesia was performed using 0.5% bupivacaine, which was followed by dexmedetomidine infusion (loading dose, 0.5–1 μg/kg for 10 min; maintenance dose, 0.3–0.6 μg/kg/h). The MOAA/S score was used to evaluate the level of sedation, and the Vital Recorder program was used to collect data (vital signs and BIS values). @*Results@#A total of 215082 MOAA/S scores and BIS data pairs were analyzed. The baseline variability of the BIS value was 7.024%, and the decrease in the BIS value was associated with a decrease in the MOAA/S score. The correlation coefficient and prediction probability between the two measurements were 0.566 (P < 0.0001) and 0.636, respectively. The mean ± standard deviation values of the BIS were 87.22 ± 7.06, 75.85 ± 9.81, and 68.29 ± 12.65 when the MOAA/S scores were 5, 3, and 1, respectively. Furthermore, the cut-off BIS values in the receiver operating characteristic analysis at MOAA/S scores of 5, 3, and 1 were 82, 79, and 73, respectively. @*Conclusion@#The BIS values were significantly correlated with the MOAA/S scores. Thus, the BIS along with the clinical sedation scale might prove useful in assessing the hypnotic depth of a patient during sedation with dexmedetomidine.

The latest trend in neuromuscular monitoring: return of the electromyography

To reduce the risk of residual neuromuscular blockade, neuromuscular monitoring must be performed. Acceleromyography (AMG)-based neuromuscular monitoring was regarded as “clinical gold standard” and widely applied. However, issues related to patient’s posture and overestimation of train-of-four ratio associated with AMG-based neuromuscular monitoring have increased. Recently, electromyography (EMG)-based neuromuscular monitoring is receiving renewed attention, since it overcomes AMG’s weaknesses. However, both AMG-based and EMG-based systems are useful when certain considerations are followed. Ultimately, to assure the patient’s good outcomes, the choice of monitoring system is not as important as the monitoring itself, which should be always implemented in such patients.

The latest trend in neuromuscular monitoring: return of the electromyography

To reduce the risk of residual neuromuscular blockade, neuromuscular monitoring must be performed. Acceleromyography (AMG)-based neuromuscular monitoring was regarded as “clinical gold standard” and widely applied. However, issues related to patient’s posture and overestimation of train-of-four ratio associated with AMG-based neuromuscular monitoring have increased. Recently, electromyography (EMG)-based neuromuscular monitoring is receiving renewed attention, since it overcomes AMG’s weaknesses. However, both AMG-based and EMG-based systems are useful when certain considerations are followed. Ultimately, to assure the patient’s good outcomes, the choice of monitoring system is not as important as the monitoring itself, which should be always implemented in such patients.

Additional effect of magnesium sulfate and vitamin C in laparoscopic gynecologic surgery for postoperative pain management: a double-blind randomized controlled trial

Background@#This clinical trial was conducted to determine whether combined use of magnesium sulfate and vitamin C more significantly reduced postoperative fentanyl consumption and pain than magnesium sulfate or vitamin C alone. @*Methods@#The prospective, double-blinded, randomized controlled study enrolled 132 patients scheduled for laparoscopic gynecologic surgery. The patients were randomly allocated to one of the four groups (n = 33 for each group; Group M [magnesium sulfate 40 mg/kg], Group V [vitamin C 50 mg/kg], Group MV [magnesium sulfate 40 mg/kg and vitamin C 50 mg/kg] and Group C [isotonic saline 40 ml]). Cumulative postoperative fentanyl consumption (primary endpoint measure), postoperative pain score by numeric rating scale, and postoperative nausea and vomiting were recorded at 1, 6, 24, and 48 h after discharge from the postanesthesia care unit. @*Results@#Cumulative postoperative fentanyl consumption was significantly less in Groups M, V, and MV than in Group C at all time points. Group MV showed significantly less cumulative postoperative fentanyl consumption than Group M at postoperative 24 h (mean ± standard deviation, 156.6 ± 67.5 vs. 235.6 ± 94.6 μg, P = 0.001), as well as significantly less consumption than Groups M and V at postoperative 48 h (190.8 ± 74.6 vs. 301.0 ± 114.8 or 284.1 ± 128.6 μg, P < 0.001, P = 0.003, respectively). @*Conclusions@#Combined use of magnesium sulfate and vitamin C provides an additional benefit in postoperative pain management after laparoscopic gynecologic surgery in comparison to single administration of magnesium sulfate or vitamin C.

The potential risks of sugammadex

Sugammadex provides fast and safe recovery from neuromuscular blockade without causing major adverse effects, and its clinical use is increasing. However, there are some reports on the potential risks of sugammadex, such as severe bradycardia, interactions with steroids, coagulopathy, and neuronal damage. Although these potential risks are not clearly proven, they are considered to be dose-dependent and occur more frequently with the free-form of sugammadex. Until further pieces of evidence are accumulated, it is prudent to be aware of these potential risks and avoid an overdose of sugammadex.

The efficacy of vitamin C on postlaparoscopic shoulder pain: a double-blind randomized controlled trial

BACKGROUND: This study evaluated the effect of vitamin C on post-laparoscopic shoulder pain (PLSP) in patients undergoing benign gynecological surgery during the first 72 h. METHODS: Sixty patients (aged 20 to 60 years, with American Society of Anesthesiologists physical status classification I or II) scheduled for elective laparoscopic hysterectomy were enrolled in this study. The vitamin C group (Group C) received 500 mg of vitamin C in 50 ml of isotonic saline infusion intravenously twice a day from the day of surgery to the third day after surgery. Patients in the saline group (Group S) received the same volume of isotonic saline over the same period. Post-operative analgesic consumption, pain scores of the incision site and the shoulder, and the incidence of PLSP were all evaluated at 1, 6, 24, 48, and 72 h following surgery. RESULTS: Cumulative post-operative fentanyl consumption was significantly less in Group C at 24 and 48 h after surgery (P = 0.002, P = 0.012, respectively). The pain intensity of PLSP was also significantly lower in Group C 24 h after the operation (P = 0.002). Additionally, the incidence of PLSP was significantly lower in Group C 24 and 48 h after the operation (P = 0.002, P = 0.035, respectively). CONCLUSIONS: Perioperative intravenous administration of vitamin C (500 mg, twice a day) reduced post-operative analgesic consumption and significantly lowered the pain intensity and incidence of PLSP.

Fluid loading during spinal anesthesia can reduce bradycardia after intravenous dexmedetomidine infusion

BACKGROUND: Dexmedetomidine has been widely used during spinal anesthesia to provide sedation. However, dexmedetomidine frequently causes significant bradycardia. This study was designed to evaluate whether fluid loading could reduce the incidence of bradycardia after intravenous dexmedetomidine infusion in patients under spinal anesthesia. METHODS: A total of 99 patients, 18 to 65 years of age, with American Society of Anesthesiologists physical status 1 or 2, who were scheduled for elective total knee replacement or internal fixation of lower leg fracture under spinal anesthesia were enrolled. The patients were randomly assigned into one of the three groups, and fluid was loaded as follows: group LOW - 4 ml/kg, group MID - 8 ml/kg, and group HI - 12 ml/kg. After fluid loading and spinal anesthesia, dexmedetomidine was infused as follows: 1 μg/kg of loading dose for 10 minutes, thereafter continuous infusion at 0.4 μg/kg/h. RESULTS: The heart rate of group HI was significantly higher than that of group LOW (P = 0.049). The dosage of atropine administration was significantly lower in group HI than in group LOW (P = 0.003). The change in thoracic fluid contents was significantly higher in group HI than in group LOW (P = 0.018). CONCLUSIONS: Fluid loading during spinal anesthesia can reduce the incidence and extent of bradycardia after intravenous dexmedetomidine infusion.

Effects of topical dexamethasone in postoperative sore throat / 대한마취과학회지

BACKGROUND: Postoperative sore throat (POST) is a complication that undermines patient satisfaction and increases discomfort in the postoperative period. The present study examined the effects of dexamethasone gargle and endotracheal tube cuff soaking on the incidence and severity of POST. METHODS: Ninety patients undergoing laparoscopic cholecystectomy were randomly allocated into three groups: 0.9% normal saline gargling and tube soaking (group C), 0.05% dexamethasone solution gargling and 0.9% normal saline tube soaking (group G), 0.9% normal saline gargling and 0.05% dexamethasone tube soaking (group S). The incidence and severity of POST were then assessed and recorded at 24 hours after surgery. RESULTS: The total incidence of POST was significantly different among the groups (P < 0.05), and group S exhibited a significantly lower incidence of POST than group C (P < 0.0167). In addition, the POST intensity of group G and group S was less severe than those of group C (Both P < 0.0167). CONCLUSIONS: Among patients undergoing laparoscopic cholecystectomy, those who gargled with 0.05% dexamethasone solution exhibited lower severity of POST than the control group, and those whose endotracheal tube cuff was soaked in the dexamethasone solution before intubation exhibited significantly lower incidence and severity of POST than the control group.

Heating of infusion fluids through heated breathing circuits

BACKGROUND: Hypothermia is a common physiological condition that occurs during surgical operations. The goal of this experiment is to measure the temperature of the fluids flowing through heated breathing circuits with respect to changes in infusion speed. METHODS: The infusion pump was connected to the intravenous inlet of a heated breathing circuit with two 50 cm extension lines connected to the outlet. Fluids were injected through the heated breathing circuit at 100, 200, 300, 400, 500, 600, and 700 ml/h, with measurement of the fluid temperature immediately after transit (OP 20), 70 cm after transit (OP 70), and 120 cm after transit (OP 120). RESULTS: The mean fluid temperatures at OP 20, OP 70, and OP 120 were 40.7 ± 4.8℃, 35.1 ± 3.22℃, and 31.7 ± 2.5℃, respectively. CONCLUSIONS: The heated breathing circuit was effective to heat the fluid. After passing out the heated breathing circuit, the temperature of the fluid continuously reduced. A length of 70 cm can be used to efficiently supply heated fluid to the patient. From this experiment, it is expected that supplying heated fluid to a patient using the heated breathing circuit will help maintain the patient's body temperature.

Intractable postherpetic neuralgia after herpes zoster duplex bilateralis in an immunocompromised patient: A case report

Herpes zoster is caused by the reactivation of the varicella-zoster virus, and it typically presents as single dermatomal rash and vesicles. It can cause postherpetic neuralgia as a common complication. In immunocompromised patients, the lesions can be cutaneous, disseminated into two non-contiguous dermatomes, and this entity is referred to as herpes zoster duplex unilateralis or bilateralis. We present a case of postherpetic neuralgia after herpes zoster duplex bilateralis in a 60-year-old immunocompromised man. He had a past history of acute lymphocytic leukemia and was treated with allogeneic peripheral blood stem cell transplantation 1 year before herpes zoster reactivation. His postherpetic neuralgia pain was difficult to treat and it was refractory to conservative medication and neuraxial block.

Tension hydrothorax induced by malposition of central venous catheter: A case report

Central venous catheterization is a useful method for monitoring central venous pressure and maintaining volume status. However, it is associated with several complications, such as pneumothorax, hydrothorax, hemothorax, and air embolism. Here we describe a case of iatrogenic tension hydrothorax after rapid infusion of fluid into the pleural space, following the misplacement of an internal jugular vein catheter. Despite ultrasonographic guidance during insertion of the central venous catheter, we were not able to avoid malposition of the catheter. The patient went into hemodynamic compromise during surgery, necessitating chest tube drainage and a mechanical ventilator postoperatively. This case shows that central venous catheter insertion under ultrasonographic guidance does not guarantee proper positioning of the catheter.

Relating factors to wearing personal radiation protectors among healthcare professionals

BACKGROUND: With increasing use of medical radiologic procedures, wearing proper protector should be emphasized to reduce occupational radiation exposures. This research describes the rates of lead apron wearing for radiation protection and assessed occupational factors related to wearing rates for various types of healthcare professionals. METHODS: We conducted a self-administered questionnaire survey through a website, on-site visits, fax, and mail. Of the 13,489 participants, 8858 workers who could not completely separate themselves from radiological procedure areas. Their general characteristics (sex and age), work history (job title, duration of employment, and hospital type), and practices (frequency of radiation procedures, ability to completely separate from radiation, and frequency of wearing protective lead aprons) were examined. RESULTS: The mean rate of lead apron wearing during radiologic procedures was 48.0 %. The rate was different according to sex (male: 52.9 %, female: 39.6 %), hospital type (general hospital: 63.0 %, hospital: 51.3 %, clinic: 35.6 %, dental hospital/clinic: 13.3 %, public health center: 22.8 %), and job title (radiologic technologist: 50.3 %, doctor: 70.3 %, dentist/dental hygienist: 15.0 %, nurse/nursing assistant: 64.5 %) (p < 0.001). By logistic regression analysis stratified by job title, use of lead aprons by radiologic technologists and nurses/nursing assistants was associated with hospital type and exposure frequency score. For doctors, apron wearing was associated with employment duration. For dentists/dental hygienists, apron wearing was associated with the exposure frequency score. CONCLUSIONS: To improve working environments for healthcare professionals exposed to radiation, it is necessary to consider related factors, such as job title, duration of employment, and hospital type, when utilizing a planning and management system to prevent radiation-related health problems.

The oropharyngeal bleeding after esophageal stethoscope insertion: A case report

The daily insertion of endotracheal tubes, laryngeal mask airways, oral/nasal airways, gastric tubes, transesophageal echocardiogram probes, esophageal dilators and emergency airways all involve the risk of airway structure damage. In the closed claims analysis of the American Society of Anesthesiologists, 6% of all claims concerned airway injury. Among the airway injury claims, the most common cause was difficult intubation. Among many other causes, esophageal stethoscope is a relatively noninvasive monitor that provides extremely useful information. Relatively not many side effects that hardly is ratable. Some of that was from tracheal insertion, bronchial insertion resulting in hypoxia, hoarseness due to post cricoids inflammation, misguided surgical dissection of esophagus. Also oropharyngeal bleeding and subsequent anemia probably are possible and rarely pharyngeal/esophageal perforations are also possible because of this device. Careful and gentle procedure is necessary when inserting esophageal stethoscope and observations for injury and bleeding are needed after insertion.

Preoperative interscalene brachial plexus block aids in perioperative temperature management during arthroscopic shoulder surgery / 대한마취과학회지

BACKGROUND: Hypothermia is common during arthroscopic shoulder surgery under general anesthesia, and anesthetic-impaired thermoregulation is thought to be the major cause of hypothermia. This prospective, randomized, double-blind study was designed to compare perioperative temperature during arthroscopic shoulder surgery with interscalene brachial plexus block (IBPB) followed by general anesthesia vs. general anesthesia alone. METHODS: Patients scheduled for arthroscopic shoulder surgery were randomly allocated to receive IBPB followed by general anesthesia (group GB, n = 20) or general anesthesia alone (group GO, n = 20), and intraoperative and postoperative body temperatures were measured. RESULTS: The initial body temperatures were 36.5 ± 0.3℃ vs. 36.4 ± 0.4℃ in group GB vs. GO, respectively (P = 0.215). The body temperature at 120 minutes after induction of anesthesia was significantly higher in group GB than in group GO (35.8 ± 0.3℃ vs. 34.9 ± 0.3℃; P < 0.001). The body temperatures at 60 minutes after admission to the post-anesthesia care unit were 35.8 ± 0.3℃ vs. 35.2 ± 0.2℃ in group GB vs. GO, respectively (P < 0.001). The concentrations of desflurane at 0, 15, and 120 minutes after induction of anesthesia were 6.0 vs. 6.0% (P = 0.330), 5.0 ± 0.8% vs. 5.8 ± 0.4% (P = 0.001), and 3.4 ± 0.4% vs. 7.1 ± 0.9% (P < 0.001) in group GB vs. GO, respectively. CONCLUSIONS: The present study demonstrated that preoperative IBPB could reduce both the intraoperative concentration of desflurane and the reduction in body temperature during and after arthroscopic shoulder surgery.

The combination of sugammadex and neostigmine can reduce the dosage of sugammadex during recovery from the moderate neuromuscular blockade / 대한마취과학회지

BACKGROUND: Sugammadex is a novel neuromuscular reversal agent, but its associated hypersensitivity reaction and high cost have been obstacles to its widespread use. In the interest of reducing the necessary dosage of sugammadex, the reversal time of the combined use of sugammadex and neostigmine from moderate neuromuscular blockade were investigated. METHODS: The patients enrolled ranged in age from 18 to 65 years old with American Society of Anesthesiologists class 1 or 2. The subjects were randomly assigned into one of the four groups (Group S2, S1, SN, and N; n = 30 per group). The reversal agents of each groups were as follows: S2 - sugammadex 2 mg/kg, S1 - sugammadex 1 mg/kg, SN - sugammadex 1 mg/kg + neostigmine 50 microg/kg + glycopyrrolate 10 microg/kg, N - neostigmine 50 microg/kg + glycopyrrolate 10 microg/kg. The time to recovery of the train-of-four (TOF) ratio was checked in each group. RESULTS: The time to 90% recovery of TOF ratio was 182.6 +/- 88.9, 371.1 +/- 210.4, 204.3 +/- 103.2, 953.2 +/- 379.7 sec in group S2, S1, SN and N, respectively. Group SN showed a significantly shorter recovery time than did group S1 and N (P < 0.001). However, statistically significant differences between the S2 and SN groups were not be observed (P = 0.291). No hypersensitivity reactions occurred in all groups. CONCLUSIONS: For the reversal from rocuronium-induced moderate neuromuscular blockade, the combined use of sugammadex and neostigmine may be helpful to decrease the recovery time and can also reduce the required dosage of sugammadex. However, the increased incidence of systemic muscarinic side effects must be considered.

Airway dimensions and margin of safety with the left-sided double-lumen tube in patients of a short stature

BACKGROUND: The size and depth of the double-lumen tube (DLT) are important for one-lung ventilation (OLV). In patients of a short stature, it is difficult to perform OLV successfully. We designed this study to evaluate the dimensions and margin of safety of the left main bronchi in patients of a short stature for appropriate OLV. METHODS: Chest computed tomography (CT) scans of 241 patients (22 male, 219 female) of a short stature (height below 155 cm) were analyzed retrospectively. The diameters of the trachea (DT), the right and left main bronchi (DR and DL), and the lengths of the right and left main bronchi (LR and LL) were measured at the coronal section of the chest CT scans using a picture archiving communication system program. RESULTS: There were no significant correlations between the heights and lengths of the right and left main bronchi. In addition, the ages and weights of the patients showed no significant correlations with the airway dimensions. The lengths of the bronchial lumen of the left-sided Mallinckrodt DLT show variations of 3 to 5.5 mm with tubes of identical sizes. The margin of safety is 13.8 +/- 4.1 mm assuming that appropriately sized DLTs are inserted. CONCLUSIONS: For successful and safe OLV in patients of a short stature, anesthesiologists should consider the length of the main bronchus and the actual length of the bronchial lumen of the DLT.

Effect of perioperative infusion of lidocaine vs. dexmedetomidine on reduced consumption of postoperative analgesics after laparoscopic cholecystectomy

BACKGROUND: Postoperative pain is the most common complaint of patients following laparoscopic cholecystectomy (LC). Intravenous lidocaine has analgesic, anti-hyperalgesic, and anti-inflammatory effects, and dexmedetomidine has anti-nociceptive and analgesic sparing effects. We evaluated the effects of perioperative intravenous infusion of lidocaine and dexmedetomidine on postoperative pain control and analgesic consumption after LC. METHODS: Eighty-four patients, aged 20-60 years, who were undergoing elective LC were assigned randomly to three groups (n = 28 in each). The patients in group L received an intravenous lidocaine bolus of 1.5 mg/kg and then continuous infusion of 2 mg/kg/hr. The group D received an intravenous dexmedetomidine bolus of 1 microg/kg, followed by continuous infusion of 0.4 microg/kg/hr. The group N received saline as described for group L. Bolus doses were given during the 10 minutes before the induction of anesthesia, followed by continuous infusion until end of the surgery. Visual analogue scale (VAS) score and postoperative analgesics consumption were evaluated during 24 hours after the surgery. RESULTS: No significant difference was observed in VAS score among the groups during the first 24 hr after LC. The amount of fentanyl consumption in the post-anesthesia care unit was significantly less in groups L and D compared to group N. CONCLUSIONS: Both perioperative intravenous infusion of dexmedetomidine and lidocaine reduced postoperative requirements of fentanyl in the early post-operative period after LC. However, there was no significant difference between dexmedetomidine and lidocaine in the analgesic sparing effect.

Effect of pretreatment with palonosetron on withdrawal movement associated with rocuronium injection / 대한마취과학회지

BACKGROUND: The main disadvantage of rocuronium is the pain associated with vascular injection. We evaluated the efficacy of palonosetron for reducing pain after rocuronium injection. METHODS: Eighty patients scheduled for elective surgery were randomly divided into two groups: Group C (normal saline 1.5 ml, n = 40) and Group P (palonosetron 0.075 mg, n = 40). Anesthesia was induced with thiopental 5 mg/kg and the test drug was injected over 10 seconds. Thirty seconds after the injection of the test drug, rocuronium 0.6 mg/kg was injected over 30 seconds and the response was recorded. Injection pain was graded using a 4-point scale. The grade was 0 points for no movement, 1 point for wrist movement, 2 points for elbow or shoulder movement, and 3 points for whole body movement. Mean arterial pressure and heart rate were recorded on arrival in the operating room and before and 30 seconds after rocuronim injection. RESULTS: There was no significant difference in the grade 1 response between the two groups; however, the grade 2 and 3 responses in Group P were 5 (12.5%) and 4 (10%), respectively, which were significantly lower than in Group C, with 13 (32.5%) responses for each grade. There were no significant differences in hemodynamic changes within each group. However, the difference in mean arterial pressure before and after the injection of rocuronium was significantly larger in Group C compared to Group P. CONCLUSIONS: Pretreatment with palonosetron 0.075 mg reduced the incidence and severity of withdrawal movement after rocuronium administration.

Anesthetic management of thyrotoxicosis patient using total intravenous anesthesia: A case report

It is uncommon that anesthesiologists experience patients with thyroid storms. In our case, the patient had been medicated for 5 years, however, she developed agranulocytosis. Anti-thyroid drugs were stopped and hyperthyroidism progressed. Her symptoms and laboratory results revealed manifestation of thyroid storm: TSH of 7.77 ng/dl, T3 of 403.1 ng/dl, and T4 of 22.15 microg/dl. The euthyroid state had not been achieved before the surgery. From the judgment of difficulty controls of hyperthyroidism, the surgeon requested for an emergency operation. We report a case of total intravenous anesthesia with propofol and remifentanil which achieved hemodynamic stability.

The comparison of the effects of intravenous ketamine or dexmedetomidine infusion on spinal block with bupivacaine / 대한마취과학회지

BACKGROUND: Ketamine and dexmedetomidine are commonly used for sedation and analgesia in patients. We tried to compare the effects of intravenous ketamine and dexmedetomidine infusion on spinal block with bupivacaine. METHODS: Ninety American Society of Anesthesiologists physical status class I or II patients, who were scheduled to spinal anesthesia were randomly assigned to one of three groups (n = 30). Normal saline 10 ml, 5 ml/hr (loading dose for 10 minutes, infusion) (Group NS), dexmedetomidine 1 microg/kg, 0.5 microg/kg/hr (Group DEX), or ketamine 0.2 mg/kg, 0.5 mg/kg/hr (Group KET) was infused intravenously before spinal anesthesia. We recorded the time to highest sensory block level, sensory and motor regression, and hemodynamic changes. RESULTS: Patients in Groups KET had a significantly faster onset time of sensory block than patients in Group NS. The highest sensory block levels were not significantly different between groups. Average time of sensory regression and knee flexion, was significantly longer in the Group KET and Group DEX than the Group NS. CONCLUSIONS: Intravenous dexmedetomidine and ketamine were found to have a similar synergistic effect with intrathecal bupivacaine. Hemodynamic stability showed better results in Group KET.