Current clinical application of dantrolene sodium

Dantrolene sodium (DS) was first introduced as an oral antispasmodic drug. However, in 1975, DS was demonstrated to be effective for managing malignant hyperthermia (MH) and was adopted as the primary therapeutic drug after intravenous administration. However, it is difficult to administer DS intravenously to manage MH. MH is life-threatening, pharmacogenomically related, and induced by depolarizing neuromuscular blocking agents or inhalational anesthetics. All anesthesiologists should know the pharmacology of DS. DS suppresses Ca2+ release from ryanodine receptors (RyRs). RyRs are expressed in various tissues, although their distribution differs among subtypes. The anatomical and physiological functions of RyRs have also been demonstrated as effective therapeutic drugs for cardiac arrhythmias, Alzheimer’s disease, and other RyR-related diseases. Recently, a new formulation was introduced that enhanced the hydrophilicity of the lipophilic DS. The authors summarize the pharmacological properties of DS and comment on its indications, contraindications, adverse effects, and interactions with other drugs by reviewing reference articles.

Effects of chlorpheniramine on emergence agitation after general anesthesia for ureteroscopic stone surgery: a retrospective cohort study

The presence of a urinary catheter, postoperative pain, and postoperative nausea and vomiting are risk factors for emergence agitation (EA). Antimuscarinic agents are primary agents used in the prevention and treatment of urinary catheter-related bladder discomfort. Chlorpheniramine has antimuscarinic, antinociceptive, and antiemetic effects. This retrospective study investigated the role of chlorpheniramine in EA prevention following ureteroscopic stone surgery. Methods: Of 110 adult patients who underwent ureteroscopic stone surgery under general anesthesia between January and December 2019, the medical records of 93 patients were analyzed retrospectively. The patients were divided into control (n = 52) and chlorpheniramine (n = 41) groups according to the receipt of intravenous chlorpheniramine before the induction of anesthesia. The incidence and severity of EA were compared between the groups as primary and secondary endpoints, respectively. The effects of chlorpheniramine on the requirement for inhalation anesthetic (desflurane) during surgery, changes in mean blood pressure and heart rate during emergence, and adverse events were also compared. Results: The incidence (21.2% in the control group, 24.4% in the chlorpheniramine group) and severity of EA did not differ between groups. The intraoperative requirement for desflurane, changes in mean blood pressure and heart rate during emergence, and adverse events were also similar between groups. Conclusions: Chlorpheniramine was not associated with a decrease in EA incidence or severity in patients who underwent ureteroscopic stone surgery

Choice of neuromuscular block reversal agent to reduce postoperative pulmonary complications

The definition of postoperative pulmonary complications (PPCs) is inconsistent in literature; however, PPCs include pulmonary abnormalities that adversely affect patient outcomes, such as respiratory failure, atelectasis, pneumonia, pleural effusion, and exacerbation of underlying lung conditions. Furthermore, although the incidence of PPCs varies according to its definition, surgery type, and patient population, they can lead to increased morbidity, mortality, duration of hospitalization, and medical costs; thus, efforts to identify and reduce the risk factors are important to improve patient outcomes. Among the risk factors for PPCs, residual neuromuscular block is a representative and preventable anesthesia-related risk factor that is affected by the choice of the reversal agent. However, it is not clear whether the chosen reversal agent, i.e., sugammadex, reduces PPCs better when compared to anticholinesterases. Additionally, the effects of the reversal agents on PPCs in high-risk patients, such as elderly patients, pediatric patients, those with end-stage renal disease, obesity, obstructive sleep apnea, or those undergoing specific surgeries, are diverse. To reduce the PPCs associated with the use of neuromuscular blocking agents, it is important to confirm complete reversal of the neuromuscular block under neuromuscular monitoring. Additionally, efforts to reduce the incidence of PPCs through interdisciplinary communication are required.

Effects of dexamethasone on catheter-related bladder discomfort and emergence agitation: a prospective, randomized, controlled trial / 대한마취과학회지

Background@#Catheter-related bladder discomfort (CRBD) is common in patients with a urinary catheter and is a risk factor for emergence agitation (EA). The mainstay of CRBD management is anticholinergics. Dexamethasone inhibits acetylcholine release. This study aimed to evaluate the effects of dexamethasone on postoperative CRBD and EA. @*Methods@#In this prospective study, 90 patients undergoing urological surgery requiring urinary catheterization were allocated randomly to one of two groups (each n = 45). Before induction of anesthesia, the dexamethasone group received 10 mg (2 ml) of dexamethasone intravenously, while the control group received 2 ml of saline in the same manner. The incidence and severity of CRBD were assessed 0, 1, 2, and 6 h after the patient arrived in the post-anesthesia care unit (PACU) as the primary outcomes. The incidence and severity of EA were also compared during emergence and recovery from anesthesia as secondary outcomes. @*Results@#The incidences of CRBD in the control group and dexamethasone group at 0, 1, 2, and 6 h postoperatively were 28.9% and 15.6%, 55.6% and 55.6%, 57.8% and 46.7%, and 53.3% and 51.1%, respectively. The incidence and severity of CRBD assessed at 0, 1, 2, and 6 h postoperatively did not show intergroup differences. The incidence and severity of EA in the operating room and PACU also showed no difference between the groups. @*Conclusions@#Dexamethasone (10 mg) administered before induction of anesthesia did not further reduce the incidence or severity of CRBD or EA in patients undergoing urological surgery.

Comparison of the effect of general and spinal anesthesia for elective cesarean section on maternal and fetal outcomes: a retrospective cohort study

Background@#Anesthesia is needed to ensure both maternal and fetal safety during cesarean sections. This retrospective cohort study compared maternal and fetal outcomes between general and spinal anesthesia for cesarean section based on perioperative hemodynamic parameters (pre- and postoperative systolic blood pressure, heart rate), mean difference of hematocrit and estimated blood loss, and neonatal Apgar scores at 1 and 5 min. @*Methods@#Data from electronic medical records of 331 singleton pregnancies between January 2016 and December 2018 were analyzed retrospectively; 44 cases were excluded, and 287 cases were assigned to the general group (n = 141) or spinal group (n = 146). @*Results@#Postoperative hemodynamic parameters were significantly higher in the general group than the spinal group (systolic blood pressure: 136.8 ± 16.7 vs. 119.3 ± 12.7 mmHg, heart rate: 93.2 ± 16.8 vs. 71.0 ± 12.7 beats/min, respectively, P < 0.001). The mean difference between the pre- and postoperative hematocrit was also significantly greater in the general than spinal group (4.8 ± 3.4% vs. 2.3 ± 3.9%, respectively, P < 0.001). The estimated blood loss was significantly lower in the spinal than general group (819.9 ± 81.9 vs. 856.7 ± 117.9 ml, P < 0.001). There was a significantly larger proportion of newborns with 5-min Apgar scores < 7 in the general than spinal group (6/141 [4.3%] vs. 0/146 [0%], respectively, P = 0.012). @*Conclusions@#General group is associated with more maternal blood loss and a larger proportion of newborns with 5-min Apgar scores < 7 than spinal group during cesarean sections.

Remifentanil-based propofol-supplemented vs. balanced sevoflurane-sufentanil anesthesia regimens on bispectral index recovery after cardiac surgery: a randomized controlled study

Background@#The present study was to compare the potential impact of remifentanil-based propofol-supplemented anesthesia regimen vs. conventional sevoflurane-sufentanil balanced anesthesia on postoperative recovery of consciousness indicated by c) values in patients undergoing cardiac surgery. @*Methods@#Patients undergoing cardiac surgery were randomly allocated to get the remifentanil-based propofol-supplemented anesthesia employing target-controlled infusion (TCI) of remifentanil and propofol (Group-PR, n = 15) or a balanced-anesthesia employing sevoflurane-inhalation and TCI-sufentanil (Group-C, n = 19). In Group-PR, plasma concentration (Cp) of TCI-remifentanil was fixed at 20 ng/ml, and the effect-site concentration of TCI-propofol was adjusted within 0.8–2.0 μg/ml to maintain BIS value of 40–60. In Group-C, sevoflurane dosage was adjusted within 1–1.5 minimum alveolar concentration to maintain BIS of 40–60, and Cp of TCI-sufentanil was fixed at 0.4 ng/ml. The inter-group difference in the time for achieving postoperative BIS > 80 (T-BIS80) in the intensive care unit was determined as the primary outcome. The inter-group difference in the extubation time was determined as the secondary outcome. @*Results@#T-BIS80, was shorter in Group-PR than Group-C (121.4 ± 64.9 min vs. 182.9 ± 85.1 min, respectively; the difference of means –61.5 min; 95% CI –115.7 to –7.4 min; effect size 0.812; P = 0.027). The extubation time was shorter in Group-PR than in Group-C (434.7 ± 131.3 min vs. 946.6 ± 393.3 min, respectively, P < 0.001). @*Conclusions@#Compared with the conventional sevoflurane-sufentanil balanced anesthesia, the remifentanil-based propofol-supplemented anesthesia showed significantly faster postoperative conscious recovery in patients undergoing cardiac surgery.

Emergence agitation: current knowledge and unresolved questions / 대한마취과학회지

Emergence agitation (EA), also referred to as emergence delirium, can have clinically significant consequences. The mechanism of EA remains unclear. The proposed risk factors of EA include age, male sex, type of surgery, emergency operation, use of inhalational anesthetics with low blood–gas partition coefficients, long duration of surgery, anticholinergics, premedication with benzodiazepines, voiding urgency, postoperative pain, and the presence of invasive devices. If preoperative or intraoperative objective monitoring could predict the occurrence of agitation during emergence, this would help to reduce its adverse consequences. Several tools are available for assessing EA.However, there are no standardized clinical research practice guidelines and its incidence varies considerably with the assessment tool or definition used. Total intravenous anesthesia, propofol, μ-opioid agonists, N-methyl-D-aspartate receptor antagonists, nefopam, α2-adrenoreceptor agonists, regional analgesia, multimodal analgesia, parent-present induction, and preoperative education for surgery may help in preventing of EA. However, it is difficult to identify patients at high risk and apply preventive measures in various clinical situations.The risk factors and outcomes of preventive strategies vary with the methodologies of studies and patients assessed.This review discusses important outcomes of research on EA and directions for future research.

Emergence agitation: current knowledge and unresolved questions / 대한마취과학회지

Emergence agitation (EA), also referred to as emergence delirium, can have clinically significant consequences. The mechanism of EA remains unclear. The proposed risk factors of EA include age, male sex, type of surgery, emergency operation, use of inhalational anesthetics with low blood–gas partition coefficients, long duration of surgery, anticholinergics, premedication with benzodiazepines, voiding urgency, postoperative pain, and the presence of invasive devices. If preoperative or intraoperative objective monitoring could predict the occurrence of agitation during emergence, this would help to reduce its adverse consequences. Several tools are available for assessing EA.However, there are no standardized clinical research practice guidelines and its incidence varies considerably with the assessment tool or definition used. Total intravenous anesthesia, propofol, μ-opioid agonists, N-methyl-D-aspartate receptor antagonists, nefopam, α2-adrenoreceptor agonists, regional analgesia, multimodal analgesia, parent-present induction, and preoperative education for surgery may help in preventing of EA. However, it is difficult to identify patients at high risk and apply preventive measures in various clinical situations.The risk factors and outcomes of preventive strategies vary with the methodologies of studies and patients assessed.This review discusses important outcomes of research on EA and directions for future research.

Transfusion-related acute lung injury in a parturient diagnosed with myelodysplastic syndrome: A case report

Transfusion-related acute lung injury (TRALI) is defined as a new episode of acute lung injury that occurs during or within 6 hours of a completed transfusion, which is one of the leading causes of transfusion-related morbidity and mortality. We present a case of TRALI in a 29-year-old parturient with myelodysplastic syndrome scheduled for cesarean section. The parturient developed hypoxemia and dyspnea after preoperative transfusion of platelets following apheresis to eliminate a unit of leucocyte in order to correct thrombocytopenia. She underwent emergent caesarean section for fetal distress. After surgery, the chest radiograph showed diffuse haziness of both lung fields. Direct and indirect antiglobulin tests were negative, and hemolytic transfusion reaction was ruled out. Pro-BNP 347.3 pg/ml also excluded transfusion-associated circulatory overload. The parturient completely recovered after oxygen support for 2 days. It is important to recognize TRALI as soon as possible to minimize perioperative morbidity and mortality.

A clinical retrospective study comparing thoracic epidural catheterization between awake and anesthetized patients

BACKGROUND: The clinical outcomes and safety of thoracic epidural catheterization in anesthetized adult patients has not yet been established. The purpose of this study was to compare clinical differences between epidural catheterization performed before and after anesthesia for postoperative pain control. METHODS: The medical records of 549 patients who received thoracic epidural catheterization before (awake group, n = 303) or after (anesthetized group, n = 246) induction of anesthesia for major abdominal surgery were reviewed retrospectively. RESULTS: The catheter insertion time (1.6 ± 1.5 vs. 1.1 ± 1.2 min; 95% confidence interval [95% CI], 0.3–0.8; effect size, 0.368; P < 0.001) and number of attempts required for successful epidural catheterization (1 [1, 3] vs. 1 [1, 2], P = 0.003) were increased in the awake group. The incidence rates of dural puncture, vascular injury and postoperative paresthesia were similar between the two groups. The median surgical site numerical rating scale pain score (0 = no pain, 10 = worst pain imaginable) was lower in the awake group than in the anesthetized group (3 vs. 4 on postoperative day 1, P < 0.001; and 2 vs. 3 on postoperative day 3, P = 0.002). Serious complications, including meningitis, epidural abscess, epidural hematoma, spinal cord injury, and paraplegia, were not observed in either group. CONCLUSIONS: Successful epidural catheterization before induction of anesthesia required more attempts versus after anesthesia. Overall complication rates of thoracic epidural catheterization were similar regardless of the timing of the procedure.

Comparison of the clinical performance of airway management with the i-gel® and laryngeal mask airway Supremeâ„¢ in geriatric patients: a prospective and randomized study / 대한마취과학회지

BACKGROUND@#Geriatric patients are susceptible to respiratory and hemodynamic adverse events during endotracheal intubation and extubation due to anatomic and physiological changes with aging. Supraglottic airway devices (SADs) provide reduced airway morbidity and increased hemodynamic stability in adults. However, studies that have compared the clinical performance of SADs in geriatric patients are limited. Therefore, we evaluated the clinical performance of airway management with i-gel® and laryngeal mask airway Supreme (LMA Supreme™) in geriatric patients.@*METHODS@#The subjects were American Society of Anesthesiologists physical status classification I–III geriatric (65–85 years) patients who underwent elective surgery with general anesthesia and were randomly allocated into the i-gel® group and the LMA Supreme™ group. We compared the time for successful insertion on a first attempt as a primary outcome, and the secondary outcomes were success rate, ease of insertion, maneuver for successful ventilation, oropharyngeal leak pressure, gastric insufflation, fiberoptic view grades, ventilator problems, and adverse events.@*RESULTS@#Insertion time was significantly shorter for the i-gel® than the LMA Supreme™ (21.4 ± 6.8 vs. 29.3 ± 9.9 s; P = 0.011). The i-gel® was also easier to insert than the LMA Supreme™ (P = 0.014). Gastric insufflation was less frequent with the i-gel® than the LMA Supreme™ (0% vs. 31.3%; P = 0.013). Other measurements were comparable between groups.@*CONCLUSIONS@#Both devices can be safely applied to geriatric patients with similar success rates and oropharyngeal leak pressures. However, inserting the i-gel® was faster and easier compared to the LMA Supreme™ in geriatric patients.

Current use of neuromuscular blocking agents and antagonists in Korea: a 2018 survey

BACKGROUND: Neuromuscular blocking agents (NMBAs) and neuromuscular monitoring in anesthetic management are integral for endotracheal intubation, better visualization of the surgical field, and prevention of residual neuromuscular blockade and pulmonary complications. Sugammadex is a drug that reduces risk of residual neuromuscular blockade, with more rapid recovery compared to anticholinesterase. The purpose of this study was to investigate current usage status of NMBAs and antagonist with neuromuscular monitoring, among anesthesiologists in Korea.METHODS: Anesthesiologists working in Korea were invited to participate in an online survey via email January 2–February 28, 2018. The questionnaire consisted of 45 items, including preferred NMBAs, antagonists, neuromuscular monitoring, and complications related to the use sugammadex. A total of 174 responses were analyzed.RESULTS: Rocuronium was a commonly used NMBA for endotracheal intubation (98%) of hospitals, and maintenance of anesthesia (83.3%) in of hospitals. Sugammadex, pyridostigmine, and neostigmine were used in 89.1%, 87.9%, and 45.4% of hospitals. Neuromuscular monitoring was employed in 79.3% of hospitals; however only 39.7% of hospitals used neuromuscular monitoring before antagonist administration. Usual dosage range of sugammadex was 2.1–4 mg/kg in 35.1% of hospitals, within 2 mg/kg in 34.5% of hospitals, and 1 vial regardless of body weight in 22.4% of hospitals. Sugammadex-related complications were encountered by 14.9% of respondents.CONCLUSIONS: This survey indicates several minor problems associated with the use of antagonists and neuromuscular monitoring. However, most anesthesiologists appear to have appropriate information regarding the usage of NMBAs and sugammadex.

Comparison of the clinical performance of airway management with the i-gel® and laryngeal mask airway Supreme™ in geriatric patients: a prospective and randomized study / 대한마취과학회지

BACKGROUND: Geriatric patients are susceptible to respiratory and hemodynamic adverse events during endotracheal intubation and extubation due to anatomic and physiological changes with aging. Supraglottic airway devices (SADs) provide reduced airway morbidity and increased hemodynamic stability in adults. However, studies that have compared the clinical performance of SADs in geriatric patients are limited. Therefore, we evaluated the clinical performance of airway management with i-gel® and laryngeal mask airway Supreme (LMA Supreme™) in geriatric patients. METHODS: The subjects were American Society of Anesthesiologists physical status classification I–III geriatric (65–85 years) patients who underwent elective surgery with general anesthesia and were randomly allocated into the i-gel® group and the LMA Supreme™ group. We compared the time for successful insertion on a first attempt as a primary outcome, and the secondary outcomes were success rate, ease of insertion, maneuver for successful ventilation, oropharyngeal leak pressure, gastric insufflation, fiberoptic view grades, ventilator problems, and adverse events. RESULTS: Insertion time was significantly shorter for the i-gel® than the LMA Supreme™ (21.4 ± 6.8 vs. 29.3 ± 9.9 s; P = 0.011). The i-gel® was also easier to insert than the LMA Supreme™ (P = 0.014). Gastric insufflation was less frequent with the i-gel® than the LMA Supreme™ (0% vs. 31.3%; P = 0.013). Other measurements were comparable between groups. CONCLUSIONS: Both devices can be safely applied to geriatric patients with similar success rates and oropharyngeal leak pressures. However, inserting the i-gel® was faster and easier compared to the LMA Supreme™ in geriatric patients.

Thoracic Scoliosis in Patients with Primary Spontaneous Pneumothorax

BACKGROUND: Primary spontaneous pneumothorax (PSP) affects patients without clinically apparent lung disorder found in tall and thin young male. Scoliosis refers to curves exceeding 10° Cobb angle observed through chest X-ray and affects 2% to 4% of adolescents. Both conditions are commonly encountered in primary health care setting. The aim of this study is to access the correlation of thoracic scoliosis and PSP in adolescent. METHODS: A retrospective analysis was conducted for patients diagnosed for PSP in Konyang University Hospital between January 2010 and March 2017. Chest X-rays of 222 patients and 155 normal control (NC) cases were reviewed to measure the Cobb angle. Greater than 10° of Cobb angle is diagnosed as scoliosis. RESULTS: Scoliosis in patient with PSP has higher incidence than that of NC group (p < 0.001). Median value of Cobb angle is 12.9° in PSP group and 14.7° in NC group. Directional relationship between scoliosis and pneumothorax in PSP group is also observed; 40.5% cases are ipsilateral and 59.5% are contralateral. CONCLUSION: PSP patients tend to have thoracic scoliosis more commonly compared with normal healthy adolescent. Scoliosis may contribute to heterogeneity of alveolar pressure which exacerbates subpleural bleb formation that can cause pneumothorax. The causal relationship is unclear and further studies are needed in the future.

The effect of magnesium sulfate concentration on the effective concentration of rocuronium, and sugammadex-mediated reversal, in isolated left phrenic nerve hemi-diaphragm preparations from the rat / 대한마취과학회지

BACKGROUND: Perioperative magnesium sulfate (MgSO4) is used for analgesic, anti-arrhythmic, and obstetric purposes. The effects of MgSO4 on the neuromuscular blockade (NMB) induced by rocuronium, and the sugammadex reversal thereof, have not been clearly quantified. We investigated the effect of various MgSO4 concentrations on the NMB by rocuronium, and sugammadex reversal, in isolated left phrenic nerve hemi-diaphragm (PNHD) preparations from the rat. METHODS: Rat PNHD preparations were randomly allocated to one of four groups varying in terms of MgSO4 concentration (1, 2, 3, and 4 mM, each n = 10, in Krebs solution). The train-of-four (TOF) and twitch height responses were recorded mechanomyographically. The preparations were treated with incrementally increasing doses of rocuronium and each group’s effective concentration (EC)50, EC90, and EC95 of rocuronium were calculated via nonlinear regression. Then, sugammadex was administered in doses equimolar to rocuronium. The recovery index, time to T1 height > 95% of control, and the time to a TOF ratio > 0.9 after sugammadex administration were measured. RESULTS: The EC50, EC90, and EC95 of rocuronium fell significantly as the magnesium level increased. The EC50, EC90, and EC95 of rocuronium did not differ between the 3 and 4 mM groups. The recovery index, time to T1 height > 95% of control, and time to a TOF ratio > 0.9 after sugammadex administration did not differ among the four groups. CONCLUSIONS: Increases in the magnesium concentration in rat PNHD preparations proportionally enhanced the NMB induced by rocuronium but did not affect reversal by equimolar amounts of sugammadex.

Optimal propofol dosage for i-gel® insertion in healthy paralyzed patients / 대한마취과학회지

BACKGROUND@#Propofol is used for supraglottic airway device insertion, often with the i-gel. However, the propofol requirement for i-gel insertion has not been explored in paralyzed patients. This study was performed to explore hemodynamic changes and sedation level with different propofol doses in healthy paralyzed patients when the i-gel was inserted.@*METHODS@#A total of 141 patients undergoing a urologic operation were randomly allocated to three groups depending on the propofol dose (1.5, 2, and 2.5 mg/kg; Groups P1.5, P2, and P2.5, respectively). After patients had been administered each propofol dose and rocuronium, the i-gel was inserted and changes in hemodynamic parameters and bispectral index were evaluated.@*RESULTS@#Group P2 showed a lower incidence of complications (17%) such as hemodynamic instability and inadequate sedation than Group P1.5 (55.3%, P < 0.001) or Group P2.5 (40.4%, P = 0.012). The incidence and dose of additional propofol increased in Group P1.5 (51%, median [range]; 20 [0–50]) compared with those in the other groups (0%, 0 [0–0] in Group P2 and 8.5%, 0 [0–50] in Group P2.5, all P < 0.001), and the incidence and dose of additional ephedrine were significantly higher in Group P2.5 (31.9%; 0 [0–20]) than in Group P1.5 (10.6%, P = 0.012; 0 [0–5], P = 0.007, respectively).@*CONCLUSIONS@#For the stable maintenance of hemodynamic parameters and proper sedation level during i-gel insertion, 2 mg/kg propofol has an advantage over 1.5 mg/kg or 2.5 mg/kg propofol in healthy paralyzed patients.

Isoflurane's Effect on Intraoperative Systolic Left Ventricular Performance in Cardiac Valve Surgery Patients

BACKGROUND: Isoflurane, a common anesthetic for cardiac surgery, reduced myocardial contractility in many experimental studies, few studies have determined isoflurane's direct impact on the left ventricular (LV) contractile function during cardiac surgery. We determined whether isoflurane dose-dependently reduces the peak systolic velocity of the lateral mitral annulus in tissue Doppler imaging (S′) in patients undergoing cardiac surgery. METHODS: During isoflurane-supplemented remifentanil-based anesthesia for patients undergoing cardiac surgery with preoperative LV ejection fraction greater than 50% (n = 20), we analyzed the changes of S′ at each isoflurane dose increment (1.0, 1.5, and 2.0 minimum alveolar concentration [MAC]: T1, T2, and T3, respectively) with a fixed remifentanil dosage (1.0 μg/min/kg) by using transesophageal echocardiography. RESULTS: Mean S′ values (95% confidence interval [CI]) at T1, T2, and T3 were 10.5 (8.8–12.2), 9.5 (8.3–10.8), and 8.4 (7.3–9.5) cm/s, respectively (P < 0.001 in multivariate analysis of variance test). Their mean differences at T1 vs. T2, T2 vs. T3, and T1 vs. T3 were −1.0 (−1.6, −0.3), −1.1 (−1.7, −0.6), and −2.1 (−3.1, −1.1) cm/s, respectively. Phenylephrine infusion rates were significantly increased (0.26, 0.22, and 0.47 μg/kg/min at T1, T2, and T3, respectively, P < 0.001). CONCLUSION: Isoflurane increments (1.0–2.0 MAC) dose-dependently reduced LV systolic long-axis performance during cardiac surgeries with a preserved preoperative systolic function.

Optimal propofol dosage for i-gel® insertion in healthy paralyzed patients / 대한마취과학회지

BACKGROUND: Propofol is used for supraglottic airway device insertion, often with the i-gel. However, the propofol requirement for i-gel insertion has not been explored in paralyzed patients. This study was performed to explore hemodynamic changes and sedation level with different propofol doses in healthy paralyzed patients when the i-gel was inserted. METHODS: A total of 141 patients undergoing a urologic operation were randomly allocated to three groups depending on the propofol dose (1.5, 2, and 2.5 mg/kg; Groups P1.5, P2, and P2.5, respectively). After patients had been administered each propofol dose and rocuronium, the i-gel was inserted and changes in hemodynamic parameters and bispectral index were evaluated. RESULTS: Group P2 showed a lower incidence of complications (17%) such as hemodynamic instability and inadequate sedation than Group P1.5 (55.3%, P < 0.001) or Group P2.5 (40.4%, P = 0.012). The incidence and dose of additional propofol increased in Group P1.5 (51%, median [range]; 20 [0–50]) compared with those in the other groups (0%, 0 [0–0] in Group P2 and 8.5%, 0 [0–50] in Group P2.5, all P < 0.001), and the incidence and dose of additional ephedrine were significantly higher in Group P2.5 (31.9%; 0 [0–20]) than in Group P1.5 (10.6%, P = 0.012; 0 [0–5], P = 0.007, respectively). CONCLUSIONS: For the stable maintenance of hemodynamic parameters and proper sedation level during i-gel insertion, 2 mg/kg propofol has an advantage over 1.5 mg/kg or 2.5 mg/kg propofol in healthy paralyzed patients.

Transient visual loss after lung surgery in a healthy patient: posterior reversible encephalopathy syndrome: A case report

Postoperative visual loss is a rare complication of general anesthesia in patients undergoing lung surgery. If the visual complication is permanent, it can greatly affect the patient's quality of life. Posterior reversible encephalopathy syndrome (PRES) leads to visual disturbances and may be associated with hypertension, renal disease, eclampsia, and chemotherapy. Although PRES is usually reversible, delayed diagnosis and treatment can result in permanent damage. We herein report a case of PRES in a patient with no medical history. The patient's symptoms included somnolence, visual loss, and headache. He was treated with conservative therapy, and his vision abruptly recovered three days after surgery. He was discharged from the hospital without neurologic complications 13 days after surgery.

Preoperative assessment of geriatric patients

Geriatric patients are vulnerable to stress associated with surgery. The preoperative assessment of elderly patients plays an important role in their perioperative care, in terms of risk identification, preoperative optimization, and the avoidance of postoperative complications. The preoperative assessment of geriatric patients may require multidisciplinary consultation and include a consideration of neurocognitive function, functional status, frailty, nutrition, substance abuse, polypharmacy, and decision-making capacity, as well as a meticulous evaluation of comorbidities. Preoperative laboratory tests should be ordered after a review of the medical charts, history, and physical examination. Any abnormal findings should be well documented. Cardiac and pulmonary complications are common in elderly patients. Risk identification according to surgical invasiveness, the continuation or cessation of medication, and preoperative risk-reduction strategies should be considered. Renal function should be evaluated and the dosage of medications should be adjusted based on the glomerular filtration rate, not serum levels of creatinine alone. Postoperative cognitive dysfunction, delirium, frailty, functional dependence, malnutrition, and polypharmacy are associated with poor postoperative outcomes; risk factors should be screened for and corrected preoperatively, if possible. Delays in the operation and prolonged operative times increase morbidity. Despite its importance, there are still no standardized preoperative assessment guidelines for Korean geriatric patients. Further studies should evaluate the clinical impact and cost-effectiveness of a preoperative geriatric assessment targeting the actual medical environment of Korea. Medical conditions should be optimized and proactive risk-reduction strategies should be used as part of a comprehensive preoperative assessment to improve surgical outcomes while avoiding a functional decline after surgery.