Comparison of the effect of dexmedetomidine and midazolam under spinal anesthesia for cesarean delivery: a randomized controlled trial, single center study in South Korea

Background@#Cesarean section under spinal anesthesia may cause anxiety and hypotension. Administration of sedative drugs after delivery can diminish these side-effects, but may increase hemodynamic instability. We evaluated the effect of the administration of 0.7 μg/kg dexmedetomidine and compared it with that of 0.03 mg/kg midazolam for usefulness of sedation of the parturient after delivery during cesarean section. @*Methods@#After obtaining written consent and the ethics board approval, 60 parturients aged 20–43 years who underwent elective cesarean delivery under spinal anesthesia were recruited. A total of 0.5% hyperbaric bupivacaine (8–10 mg) and intrathecal fentanyl (10 μg) was given to induce anesthesia. Parturients were then randomly allocated to receive either midazolam (0.03 mg/kg; group M) or dexmedetomidine 0.7 (μg/kg; group D) after delivery. The primary outcome measure was patient satisfaction score. Secondary outcomes included vital signs; vasopressor dosage; incidence of shivering, nausea, and vomiting; incidence of bradycardia; time to sensory and motor recovery; postoperative nausea and vomiting score; and postoperative pain visual analog scale at 6, 24, and 48 h. @*Results@#Satisfaction scores for sedation were similar between the two groups. The systolic blood pressure, heart rate, oximetry saturation, and tympanic temperature were comparable between the two groups. The predicted mean systolic blood pressure of group D was 106.3 mmHg and that of group M was 107.5 mmHg. Both groups showed comparable adverse intraoperative and postoperative outcomes. @*Conclusions@#Dexmedetomidine and midazolam showed similar hemodynamic effects and patient satisfaction in parturients under spinal anesthesia.

Epidural hematoma after total knee arthroplasty in a patient receiving rivaroxaban: A case report

Rivaroxaban, a factor Xa inhibitor, is one of the newly developed direct oral anticoagulants (DOAC). In recent times, it has been increasingly used in the prevention of pulmonary embolism in patients undergoing orthopedic surgery. This report describes a case of epidural hematoma in an elderly patient who underwent combined spinal epidural anesthesia for total knee arthroplasty; the patient received rivaroxaban postoperatively for 7 days to prevent pulmonary embolism. Additionally, the epidural hematomas developed on the 5th postoperative day but the patient recovered well with conservative treatment. Although rivaroxaban has a low need for monitoring and is easily administered, the guidelines should be carefully checked for the postoperative administration schedule in patients undergoing regional anesthesia. In addition, rivaroxaban should be used with caution, especially in elderly patients.

Spinal anesthesia in a patient with postoperative iatrogenic pseudomeningocele: A case report

Although spinal anesthesia is one of the most reliable anesthetic techniques in clinical practice, failures may occur in daily practice at rare occasions. Their causes are diverse and they include anatomical structural variations. In particular, postoperative anatomical changes often occur in patients who have undergone spine surgery and may cause failures of spinal anesthesia. Postoperative pseudomeningocele constitutes extradural cerebrospinal fluid collected from a dural tear and it is considered a very rare complication of spine surgery. We describe the case where a patient with unexpected postoperative iatrogenic pseudomeningocele received lower extremity surgery under spinal anesthesia.

Current clinical application of dexmedetomidine for sedation and anesthesia

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.

Current clinical application of dexmedetomidine for sedation and anesthesia

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.

The relationship between postoperative cognitive dysfunction and the depth of sedation with propofol during spinal anesthesia in elderly patients

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common perioperative complication. The definitive causes of POCD have not been identified, but depth of anesthesia or sedation has been reported to influence POCD. The purpose of the present study was to assess the possible effect of the level of sedation on POCD at 1 week after surgery under spinal anesthesia in elderly patients. METHODS: We included 48 patients aged over 60 years, who were scheduled for elective knee and hip joint surgery under spinal anesthesia. Those patients were randomly allocated to one of the 2 groups: deep sedation group and light sedation group. The depth of sedation was monitored by entropy and observer's assessment of alertness/sedation (OAA/S) score. Cognitive function was assessed by 5 neurocognitive tests before and at 1 week after surgery. A postoperative deficit was defined as a postoperative decrement to preoperative score greater than 1 standard deviation on any test. A patient whose postoperative performance deteriorated by 1 or more standard deviations on 2 or more tests was classified as having experienced POCD. RESULTS: POCD occurred in 7 patients (28%) in the deep sedation group and in 4 patients (17.4%) in the light sedation group. The incidence of the POCD was not significantly different between the 2 groups. CONCLUSIONS: We were unable to detect a significant association between the depth of sedation and the presence of POCD at 1 week after surgery under spinal anesthesia.

Comparison of hemodynamic changes between old and very old patients undergoing cemented bipolar hemiarthroplasty under spinal anesthesia / 대한마취과학회지

BACKGROUND: The old age population, including the very old aged (> or = 85 years), is rapidly increasing, and femur neck fracture from accidents is commonly seen in the elderly. Use of bone cement during bipolar hemiarthroplasty can cause bone cement implantation syndrome. METHODS: This study was prospectively conducted on the elderly who were scheduled to undergo elective cemented bipolar hemiarthroplasty under spinal anesthesia. Patients were divided into 2 groups: the old age (65-84 years) and very old age groups (> or = 85 years). Hemodynamic parameters were recorded at the following time points: the start of the operation, femoral reaming, cement insertion, every 2 minutes after cement insertion for 10 minutes, femoral joint reduction, and the end of operation. When hypotension occurred, ephedrine was given. RESULTS: Sixty-five patients in the old age group and 32 patients in the very old age group were enrolled. Mean ages were 78.9 and 89.4 years, respectively, in the old age and very old age groups. The very old age group showed constantly decreased levels of cardiac index and stroke volume from cementing until the end of the operation compared to the old age group. To maintain hemodynamic stability after cement insertion, the requirement of ephedrine was higher in the very old age group than in the old age group (13.52 +/- 7.76 vs 8.65 +/- 6.38 mg, P = 0.001). CONCLUSIONS: Bone cement implantation during bipolar hemiarthroplasty may cause more prominent hemodynamic changes in very elderly patients. Careful hemodynamic monitoring and management are warranted in very elderly patients undergoing cemented bipolar hemiarthroplasty.

Optimal dose of remifentanil for the prevention of hemodynamic responses during induction of anesthesia with desflurane

BACKGROUND: This study was designed to determine the optimal dose of remifentanil single bolus for the prevention of cardiovascular disturbance due to both a rapid increase in desflurane concentration and stimulation by intubation. METHODS: One hundred three adult patients were enrolled in this prospective, double-blind, randomized study. Before anesthesia induction, all patients received normal saline (control) or one of the following 3 doses of remifentanil: 1.0 microg/kg of remifentanil (remifentanil 1.0), 1.5 microg/kg of remifentanil (remifentanil 1.5), and 2.0 microg/kg of remifentanil (remifentanil 2.0). After induction with propofol and rocuronium, 1.3 minimal alveolar concentration of desflurane with oxygen was administered via a face mask. Heart rate (HR) and mean blood pressure (MBP) were recorded before remifentanil administration, and 1, 2, and 3 min after inhalation of desflurane, as well as 0, 1, 2, and 3 min after intubation. The proportions of patients with hemodynamics that maintained within +/- 25% of preinduction values (MBP and HR proportion) were calculated. RESULTS: MBP and HR were lower in the 3 remifentanil groups than in the control group throughout the study period. The MBP proportion was higher in remifentanil 1.0 group than in control group. The HR proportion was higher in the 3 remifentanil groups than in control group. CONCLUSIONS: A single bolus injection of remifentanil (1.0-2.0 microg/kg) may be effective in alleviating adverse hemodynamic changes induced by both desflurane inhalation and tracheal intubation. Especially, administration of remifentanil 1.0 microg/kg maintained more stable blood pressure compared to the control group throughout the study period.

EC50 and EC95 of remifentanil to prevent rocuronium-induced withdrawal movements in children / 대한마취과학회지

BACKGROUND: Intravenous administration of rocuronium induces intense pain in most patients (60-100%). This could be harmful during anesthesia induction because of the unintended reflex movement of an unconscious patient in response to the pain. Previous studies have reported that remifentanil effectively reduces rocuronium-induced pain and withdrawal movements. This study was designed to evaluate the EC50 and EC95 of remifentanil to prevent withdrawal movements in children. METHODS: We enrolled a total of 171 pediatric patients scheduled for general anesthesia in this study. Remifentanil was administrated by target-controlled infusion. Effect-site target concentrations ranged from 0.5 to 3.0 ng/ml. At each concentration, experiments were repeated in 10-20 patients. Propofol 2 mg/kg and rocuronium 0.9 mg/kg were administrated after equilibration of plasma and effect-site target remifentanil concentration. The withdrawal movements were graded on a 4-point scale. The EC50 and EC95 of remifentanil to prevent rocuronium-induced withdrawal movements were determined by using a logistic regression model. RESULTS: The logistic regression model showed that the probability of preventing rocuronium-induced withdrawal movement was as follows: exp (-3.49 + 2.07 x remifentanil concentration) / (1 + exp [-3.49 + 2.07 x remifentanil concentration]). EC50 and EC95 were 1.69 ng/ml (95% confidence intervals [CIs], 1.42-1.87) and 3.11 ng/ml (95% CIs, 2.79-3.72), respectively. CONCLUSIONS: Administration of remifentanil at an effect-site target concentration of 3.1 ng/ml could effectively prevent rocuronium-induced withdrawal movements.

Antiemetic effect of propofol administered at the end of surgery in laparoscopic assisted vaginal hysterectomy / 대한마취과학회지

BACKGROUND: Postoperative nausea and vomiting (PONV) commonly occur after general anesthesia, especially in women. In this study, we evaluated the antiemetic efficacy of propofol administered at the end of surgery in highly susceptible patients undergoing a laparoscopy-assisted vaginal hysterectomy. METHODS: A total of 107 women undergoing a laparoscopy-assisted vaginal hysterectomy under general anesthesia were enrolled for this prospective, double-blind, randomized study. Fifteen minutes before the end of surgery, all patients received 50 microg fentanyl and 1 of following 3 doses; 0.5 mg/kg of propofol (propofol 0.5 group), 1 mg/kg of propofol (propofol 1.0 group), and normal saline (control group). All patients received intravenous patient-controlled analgesia (PCA). Emergence time, a visual analog scale for pain and nausea, duration of postanesthesia care unit (PACU) stay, and frequency of antiemetic use were recorded at 0-2, 2-24, and 24-48 hours postoperatively. RESULTS: The incidence of nausea significantly lower in the propofol 0.5 and propofol 1.0 groups than in the control group (12.1 vs 14.7 vs 40%). During the first postoperative 2 hours, antiemetics were less frequently administered in the propofol 0.5 and propofol 1.0 groups than in the control group (3.0 vs 5.9 vs 22.5%). Emergence time was slightly longer in the propofol 0.5 and propofol 1.0 groups than in the control group, but there was no significant difference in PACU stay time was observed between the 3 groups. CONCLUSIONS: The results of this study suggest that low-dose propofol administration at the end of surgery may effectively reduce the incidence of PONV within 2 hours postoperatively in highly susceptible women undergoing a laparoscopiy-assisted vaginal hysterectomy and receiving opioid-based PCA.

A case of postpartum cerebral angiopathy with intracranial hemorrhage in Cesarean delivery: A case report

The occurrence of stroke during pregnancy and the postpartum period is uncommon but is a leading cause of maternal death. Postpartum cerebral angiopathy is one of the causes of the occurrence of stroke during peripartum. A 39-year-old woman with a gestational age of 38 weeks and with uncomplicated pregnancy was admitted to these authors' hospital and was made to undergo emergency Cesarean section under spinal anesthesia due to fetal distress. After the Cesarean delivery, it was found that her state of mind had changed into drowsiness to stupor in the post-anesthetic care unit. The brain computed tomography showed intracranial and subarachnoid hemorrhage. On the cerebral angiography, no aneurysm or arteriovenous malformation was found, except for the focal stenosis of the callosomarginal artery. Emergency decompressive craniectomy was done. After the craniectomy, the patient showed an alert mental status, mild Rt hemiplegia, and slight dysarthria three months after the surgery.

Current therapeutic agents and anesthetic considerations for diabetes mellitus / 대한마취과학회지

As the incidence of diabetes mellitus (DM) continues to increase worldwide, more diabetic patients will be presented for surgery and anesthesia. This increase of DM is a consequence of the rise in new patients of type 2 DM, and is likely attributable to rapid economic development, improved living standards, aging population, obesity, and lack of exercise. The primary goal of management in DM is to delay, or prevent the macro- and microvascular complications by achieving good glycemic control. More understanding of the pathophysiology of DM has contributed to the advance of new pharmacological approaches. In addition to the conventional therapy for DM, glucagon-like peptide-1 (GLP-1) mimetics, dipeptidyl peptidase-4 (DPP-4) inhibitors, thiazolidinediones (TZDs), and insulin analogues are currently available effective hypoglycemic agents for the management of the patients with DM in the perioperative period and also consider the adverse effects of newly introduced agents that need more clinical observations.

Wrapping of the lower limbs for prevention of post spinal hypotension during cesarean section under spinal anesthesia

BACKGROUND: Hypotension is the most frequent complication associated with spinal anesthesia during cesarean section. Prehydration and/or vasopressor therapy is commonly used for prevention of hypotension in cesarean deliveries. Wrapping of the legs is simple to perform before surgery and was reported be effective for the prevention of post spinal hypotension in a few obstetric units. So we investigated whether wrapping of the legs prevents post spinal hypotension during cesarean section. METHODS: 45 patients were randomly allocated to one of 3 groups (15 in each group): prehydration with 10 ml/kg (group I), prehydration with 10 ml/kg and wrapping of the legs (group II), prehydration with 5 ml/kg and wrapping of the legs (group III). Hypotension was defined as a 20% decrease from initial systolic arterial pressure (SAP) or SAP lower than 90 mmHg and was treated with intravenous ephedrine (4 mg, repeated). Blood pressure was recorded before spinal anesthesia and every min for 10 min and then every 2 min for another 10 min after spinal anesthesia. RESULTS: Group I showed a significant decrease in SAP compared to group II and group III 1 min after spinal anesthesia, but after that, there was no significant difference between the three groups. Group II showed a significant difference in incidence of severe hypotension after spinal anesthesia compared with group I, but there was no difference of the incidence of hypotension between the three groups. CONCLUSIONS: Wrapping of the legs for prevention of post spinal hypotension during elective cesarean section reduces the severity of hypotension.

Comparison of ramosetron's and ondansetron's preventive anti-emetic effects in highly susceptible patients undergoing abdominal hysterectomy / 대한마취과학회지

BACKGROUND: This study compared the preventive effects of ramosetron and ondansetron on postoperative nausea and vomiting (PONV) in highly susceptible patients undergoing abdominal hysterectomy. METHODS: In a prospective, randomized, double-blinded study, a total of 120 highly susceptible women (nonsmokers, those receiving opioid-based IV patient-controlled analgesia [PCA]) undergoing abdominal hysterectomy were included in the study. Patients were divided into 2 groups and each group received either 0.3 mg of ramosetron or 4 mg of ondansetron, IV. All patients received fentanyl-based IV PCA during the 48 h postoperative periods. The incidences of PONV and side effects of 5-HT3 antagonists (headache and dizziness) were assessed at 3 intervals (<2 h, 2-24 h and 24-48 h) postoperatively. RESULTS: Patients in the ramosetron group showed a significantly higher ratio of complete response and lower incidence of nausea during the 24-48 h interval after surgery compared with those the ondansetron group. CONCLUSIONS: Ramosetron (0.3 mg) is more effective in preventing delayed PONV in highly susceptible women undergoing abdominal hysterectomy compared with ondansetron (4 mg).

Effects of preoxygenation with the three minutes tidal volume breathing technique in the elderly / 대한마취과학회지

BACKGROUND: Preoxygenation with tidal volume breathing for 3 min is commonly used technique. An end tidal expiratory oxygen concentration greater than 90% is considerd to be adequate for preoxygenation. The aim of this study was to check the effects of preoxygenation on elderly patients through the comparison with young patients during the 3 min tidal volume breathing technique. METHODS: Sixty patients from ASA class I or II who were scheduled for elective orthopedic general surgery were divided into an elderly (>65 yr) group and a control (25-65 yr) group. Patients were instructed in the technique of preoxygenation. Preoxygenation was accomplished with an appropriately sized face mask connected to an anesthesia machine with 100% oxygen during 3 min with patients in both groups. Expired O2, CO2 concentration and oxygen saturation were recorded simultaneously for 3 min. RESULTS: The elderly group showed significantly lower end tidal oxygen concentration than the control group from 50 sec to the end of study (180 sec) with the 3 min tidal volume breathing technique (P < 0.05). In 180 sec, the control group had over 90% (91.5%) end tidal oxygen concentration, but in the elderly group end tidal oxygen concentration could not reach 90% (86.2%). In oxygen saturation, the elderly group showed a significantly lower level until 40 sec from the start of study, and then two groups showed a similar levels of oxygen saturation until the end of study. CONCLUSIONS: End tidal oxygen concentration did not reach 90% in 180 sec in the elderly group during preoxygenation with the 3 min tidal volume breathing technique.

The changes of the sternomental distance under general anesthesia and with increasing age

BACKGROUND: Because the sternomental distance (SMD) is evaluated in conscience patients and in the sitting position, this could change under general anesthesia, which is a state that the patient is unconscious and fully relaxed in the supine position. Increasing age also affects the SMD. We investigated the change in the SMD with the patients under general anesthesia and we also investigated the effect of age on the SMD. METHODS: A total of 108 patients were allocated to Group Y (20-30 yr), Group M (31-50 yr) and Group O (51-70 yr). The SMD, as measured when the patients were awake and sitting, was defined as baseline. The SMD was measured in the supine position, the shoulder-suppressed supine position, at the time of loss of consciousness (LOC), 4 min after vecuronium administration and in the sniffing position. The percent change of the SMD (%) was defined as (the baseline SMD - the measured SMD)/the baseline SMD x 100. RESULTS: Compared with the baseline, the SMD decreased significantly in the supine position, the shoulder-suppressed supine position, at the time of LOC, during neuromuscular blockade and in the sniffing position in all the groups. Group O showed a shorter SMD than did Groups Y and M for all the measurements. There was no significant difference in the percent change of the SMD between the groups. CONCLUSIONS: This study demonstrated that the SMD was significantly reduced by the supine position, the sniffing position, at the time of loss of consciousness and during neuromuscular blockade with the patient under general anesthesia and also with the increasing age of the patient.