Secondary migration of a pre-existing central venous catheter due to a Swan-Ganz catheter insertion – A case report –

The entanglement of multiple central venous catheters is a rare and seriouscomplication. The Swan-Ganz catheter is a responsible for various cases.Case: A 66-year-old male patient was under general anesthesia for a coronary artery bypassgraft surgery. As he had a pre-existing Perm catheter in the right subclavian vein, a SwanGanz catheter was inserted into the left internal jugular vein. Chest radiograph after catheterplacement revealed that the Perm catheter had migrated to the left brachiocephalic vein.The surgeon attempted to reposition it manually, but postoperative radiograph showed thatit had rolled into a loop. On postoperative day 1, radiological intervention was performed tountangle the loop, which was successful.Conclusions: After placing a Swan-Ganz catheter in patients with a pre-existing central venous catheter, the presence of entanglement should be assessed. In such cases, radiology-guided correction is recommended, as a blind attempt to disentangle can aggravate thecondition.

Numbness of the lower lip following urological surgery under general anesthesia – A case report –

Background@#Peripheral nerve injury is a complication that can occur after general anesthesia. It significantly impairs the patient’s quality of life and may lead to permanent disability. Nerves in several areas can be damaged during the perioperative period, but it is very rare that numbness of the lower lip is caused after general anesthesia. Case: A 73-year-old man with diabetes mellitus underwent urological surgery under general anesthesia. The day after surgery, he complained of numbness on the right lower lip caused by a mental nerve injury. Diabetic mononeuropathy or neurapraxia related to mechanical compression was considered a possible cause. The symptoms resolved spontaneously after six weeks. @*Conclusions@#Mental nerve injury is a rare perioperative complication in surgical patients under general anesthesia. In this case, patients should be reassured and advised to avoid injuries to the mouth and lips. However, specific treatment is not required.

Effect of single dose preoperative intravenous ibuprofen on postoperative pain and opioid consumption: a systematic review and meta-analysis / 대한마취과학회지

Background@#Ibuprofen, a well-known analgesic, is commonly used as a component of a multimodal analgesic approach for postoperative pain. This systematic review and meta-analysis aimed to investigate whether a single-dose preoperative intravenous ibuprofen can reduce postoperative pain and opioid consumption. @*Methods@#PubMed/MEDLINE, Embase, Cochrane Library (CENTRAL), and Web of Science databases were searched to identify relevant studies published up to May 2020. Randomized controlled trials comparing preoperative single-dose intravenous ibuprofen effect with the control group on postoperative pain and opioid consumption after surgery under general anesthesia were included. @*Results@#Six studies involving 366 participants were included. Single-dose administration of intravenous ibuprofen preoperatively significantly reduced postoperative pain score on a scale of 0-10 at 1 h (MD: -1.64, 95% CI [-2.56, -0.72], P < 0.001, I2 = 95%), at 4-6 h (MD: -1.17, 95% CI [-2.09, -0.26], P < 0.001, I2 = 94%), and 24 h (MD: -0.58, 95% CI [-0.99, -0.18], P < 0.001, I2 = 90%). Cumulative opioid consumption, presented as fentanyl equivalents, was also reduced significantly in the ibuprofen group compared to placebo group until postoperative 4-6 h (MD: -56.35 μg, 95% CI [-101.10, -11.60], P < 0.001, I2 = 91%) and 24 h (MD: -131.39 μg, 95% CI [-224.56, -38.21], P < 0.001, I2 = 95%). @*Conclusions@#Preoperative single-dose intravenous ibuprofen can reduce postoperative pain and opioid consumption until 24 h postoperatively. Considering the high heterogeneity and small number of studies included, care should be taken when generalizing these findings.

Effect of single dose preoperative intravenous ibuprofen on postoperative pain and opioid consumption: a systematic review and meta-analysis / 대한마취과학회지

Background@#Ibuprofen, a well-known analgesic, is commonly used as a component of a multimodal analgesic approach for postoperative pain. This systematic review and meta-analysis aimed to investigate whether a single-dose preoperative intravenous ibuprofen can reduce postoperative pain and opioid consumption. @*Methods@#PubMed/MEDLINE, Embase, Cochrane Library (CENTRAL), and Web of Science databases were searched to identify relevant studies published up to May 2020. Randomized controlled trials comparing preoperative single-dose intravenous ibuprofen effect with the control group on postoperative pain and opioid consumption after surgery under general anesthesia were included. @*Results@#Six studies involving 366 participants were included. Single-dose administration of intravenous ibuprofen preoperatively significantly reduced postoperative pain score on a scale of 0-10 at 1 h (MD: -1.64, 95% CI [-2.56, -0.72], P < 0.001, I2 = 95%), at 4-6 h (MD: -1.17, 95% CI [-2.09, -0.26], P < 0.001, I2 = 94%), and 24 h (MD: -0.58, 95% CI [-0.99, -0.18], P < 0.001, I2 = 90%). Cumulative opioid consumption, presented as fentanyl equivalents, was also reduced significantly in the ibuprofen group compared to placebo group until postoperative 4-6 h (MD: -56.35 μg, 95% CI [-101.10, -11.60], P < 0.001, I2 = 91%) and 24 h (MD: -131.39 μg, 95% CI [-224.56, -38.21], P < 0.001, I2 = 95%). @*Conclusions@#Preoperative single-dose intravenous ibuprofen can reduce postoperative pain and opioid consumption until 24 h postoperatively. Considering the high heterogeneity and small number of studies included, care should be taken when generalizing these findings.

Numbness of the lower lip following urological surgery under general anesthesia – A case report –

Background@#Peripheral nerve injury is a complication that can occur after general anesthesia. It significantly impairs the patient’s quality of life and may lead to permanent disability. Nerves in several areas can be damaged during the perioperative period, but it is very rare that numbness of the lower lip is caused after general anesthesia. Case: A 73-year-old man with diabetes mellitus underwent urological surgery under general anesthesia. The day after surgery, he complained of numbness on the right lower lip caused by a mental nerve injury. Diabetic mononeuropathy or neurapraxia related to mechanical compression was considered a possible cause. The symptoms resolved spontaneously after six weeks. @*Conclusions@#Mental nerve injury is a rare perioperative complication in surgical patients under general anesthesia. In this case, patients should be reassured and advised to avoid injuries to the mouth and lips. However, specific treatment is not required.

Effect of preoperative administration of systemic alpha-2 agonists on postoperative pain: a systematic review and meta-analysis

Background@#Alpha-2 agonists have sedative, analgesic, and opioid-sparing effects. Moreover, intraoperative or postoperative systemic administration of alpha-2 adrenergic agonists is known to reduce postoperative pain and opioid consumption. This meta-analysis investigated whether preoperative administration of alpha-2 agonists can affect postoperative pain and opioid consumption. @*Methods@#We searched the MEDLINE, EMBASE, Cochrane Library (CENTRAL), KoreaMed, and KMbase databases through March 2019 to identify relevant randomized controlled trials (RCTs) on the effect of preoperative systemic administration of alpha-2 agonists on postoperative pain and opioid consumption. We conducted a meta-analysis according to the Cochrane Collaboration guidelines. Standardized mean differences (SMDs) of postoperative pain intensity or dose of opioid consumption in the alpha-2 agonist group were extracted and combined using a random-effect model and were compared to those of the control group. @*Results@#Eleven RCTs involving 748 participants were included in this meta-analysis. Preoperative administration of systemic alpha-2 agonists significantly reduced cumulative opioid consumption up to 6 h (SMD, –0.52; 95% confidence interval [–0.90 to –0.14]) and 24 h (SMD, –0.68 [–1.27 to –0.09]) after surgery. Moreover, preoperative administration of alpha-2 agonists significantly reduced postoperative pain intensity at 6 h (SMD, –0.50 [–0.78 to –0.21]) and 24 h (SMD, –0.44 [–0.86 to –0.03]). @*Conclusions@#In this meta-analysis, high degree of heterogeneity limits the preoperative administration of alpha-2 agonists in reducing postoperative opioid consumption and pain intensity. Future powered large RCTs are required to increase the certainty of evidence on the effect in reducing postoperative opioid consumption and pain intensity.

Novel alternative for submental intubation - A case report -

Background@#Submental intubation is commonly used during general anesthesia for maxillofacial surgeries as it provides a safe unrestricted surgical access compared to tracheostomy. During submental intubation, soft tissues and blood clots can become lodged in the endotracheal tube. To overcome this problem, we used a laparoscopic trocar.Case: A 52-year-old man with maxillofacial injury was scheduled to undergo an open reduction and internal fixation. We performed submental intubation using laparoscopic trocar, which created sufficient space for the insertion of the endotracheal tube. Unlike conventional methods, our method did not require any blunt dissection and caused significantly less soft tissue damage and required significantly less time. @*Conclusions@#Submental intubation with laparoscopic trocar is a one-step method and is quick and easy-to-perform technique with less complications.

Risk factors of 30-day mortality following endovascular thoracic and abdominal aortic repair with general anesthesia

BACKGROUND: Recently, endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR), have been used for treatment of thoracic and abdominal aortic aneurysms. The purpose of this study was to analyze the outcome and predictors for 30-day mortality and complications, in patients that underwent EVAR and/or TEVAR under general anesthesia. METHODS: In this study, 151 cases of EVAR and/or TEVAR under general anesthesia in 140 patients during 2009–2017 were studied. The primary outcome was 30-day mortality after surgery. Multivariate logistic regression analysis was used, to clarify risk for postoperative 30-day mortality. RESULTS: Postoperative 30-day mortality rate was 9.9% in the study population (10.3% in EVAR, and 9.3% in TEVAR, respectively). Seventy-two cases (47.7%) experienced postoperative complications within 30 days. Elderly older than age 76.5 (odds ratio [ORs] = 48.89, 95% confidential interval [95% CI] 1.40–1,710.25, P = 0.032), technically expertness (OR = 0.01, 95% CI 0.00–0.40, P = 0.013), severity of systemic complications (OR = 23.24, 95% CI, 2.27–238.24, P = 0.008), and severity of local-vascular complications (OR = 31.87, 95% CI, 1.29–784.66, P = 0.034) were significantly associated with 30-day mortality. CONCLUSIONS: This study revealed that elderly, technically expertness, and severity of systemic and local-vascular complications were associated with 30-day mortality of EVAR and TEVAR in aortic aneurysm.

Effect of intravenous tranexamic acid on perioperative bleeding and transfusion in spine surgery: systematic review and meta-analysis of randomized controlled trials

BACKGROUND: This study aimed to systematically review the literature investigating the effect of intravenous (IV) tranexamic acid (TXA) on the perioperative blood loss and amount of transfused blood in patients who underwent spine surgery under general anesthesia. METHODS: MEDLINE, EMBASE, and CENTRAL databases were searched for studies published up to June 2017. Randomized controlled trials comparing the intervention of tranexamic acid use with a placebo in corrective spine fusion surgery were included. Outcome measures included intraoperative and postoperative blood loss and perioperative blood transfusion volume. We also conducted subgroup analyses according to the dose of administration of intervention drug. RESULTS: In total, 12 studies involving 875 patients were included in the final analysis. Blood loss decreased in patients treated with perioperative IV TXA by a mean volume of 189.58 ml intraoperatively (95% confidence interval [CI]: 135.82 to 243.34 ml, P < 0.001; I² = 74%), 121.04 ml postoperatively (95% CI: 84.92 to 157.17 ml, P < 0.001; I² = 0%), and 285.97 ml in total (95% CI: 190.70 to 381.23 ml, P < 0.001; I² = 0%). Perioperative transfusion volume also decreased by 162.10 ml in patients who received IV TXA (95% CI: 31.77 to 292.44 ml, P = 0.010; I² = 47%). CONCLUSIONS: Blood loss was reduced in patients who were administered TXA during spine surgery. Additionally, the perioperative volume of blood transfusion decreased in patients who received TXA. Further research is required to confirm the optimal dosage and timing of TXA usage.

Analysis of the characteristics of unplanned admission to the intensive care unit after general surgery

BACKGROUND: Unplanned intensive care unit admission (UIA) is associated with perioperative morbidity and mortality, and can be used as a surrogate marker for patient safety. This study aimed to compare the characteristics of planned and unplanned intensive care unit (ICU) admission groups. METHODS: We retrospectively reviewed the electronic medical records of adult patients admitted to the ICU after abdominal and thyroid surgery under general anesthesia between 2016 and 2017. Preoperative, intraoperative, and postoperative information of enrolled patients was recorded. We compared patients' characteristics and outcomes between the unplanned and planned admission groups. RESULTS: In the total cohort, the proportion of UIA was 82.8% (202/244). In the unplanned admission group, total hospital stay was significantly shorter and ICU stay longer than that in the planned admission group (19.0 and 3.0 days, respectively vs. 28.5 and 2.0 days, respectively). In-hospital mortality rates were 21.3% and 7.1% in the unplanned and planned groups, respectively (P = 0.055). Patients in the UIA group showed higher Acute Physiology And Chronic Health Evaluation II scores, higher American Society of Anesthesiologist physical status class, and more co-morbidities than those in the planned group. There were significant differences in the incidence of UIA among surgery types. CONCLUSIONS: The UIA group had a relatively high mortality rate and longer ICU stay. More critically ill patients tended to be admitted to the ICU without planning.

Risk factors for postoperative delirium following total knee arthroplasty in elderly patients

BACKGROUND: Postoperative delirium has been suggested as a significant predictor of postoperative morbidity and mortality in elderly patients. They usually have multiple comorbidities, including cardiovascular, respiratory, renal, and neurologic disease. We aimed to determine the incidence rate and modifiable risk factors of postoperative delirium following total knee arthroplasty in elderly. METHODS: We reviewed the medical records of 318 elderly patients (age >65 years) underwent unilateral total knee arthroplasty between 2009 and 2016. Patient demographics, American Society of Anesthesiologists physical status, preoperative comorbidities, type and duration of anesthesia and surgery, length of hospital stay, ambulation ability, frequency of intraoperative hypotension, frequency of hypothermia, whether the patient was transfused or heparinized, and perioperative laboratory results were evaluated. Univariate and multivariate logistic regression analyses were used to identify significant independent predictors of postoperative delirium. RESULTS: The incidence rate of postoperative delirium was 6% in this study. Univariate analysis showed that postoperative delirium was significantly associated with age, body mass index, general anesthesia, anesthesia time, preoperative dementia, intraoperative hypotension, preoperative hemoglobin, blood transfusion, and intraoperative hypothermia. Preoperative dementia (odds ratio [OR] = 8.80), intraoperative hypotension (OR = 1.06), and preoperative hemoglobin (OR = 0.66) were significant independent risk factors of postoperative delirium. CONCLUSIONS: Preoperative dementia is the most important risk factor of postoperative delirium. High-risk patients undergoing total knee arthroplasty should be thoroughly evaluated and their dementia should be managed preoperatively. Adequate management of preoperative hemoglobin and intraoperative hypotension might also be helpful in reducing the incidence of postoperative delirium in this population.

Beneficial aspect of dexmedetomidine as a postoperative sedative for cardiac surgery

BACKGROUND: The aim of this study was to compare the clinical outcomes of the sedative, analgesic, and hemodynamic effects of dexmedetomidine and midazolam for sedation after coronary artery bypass grafting (CABG). METHODS: The adult patients undergoing elective CABG surgery under general anesthesia were randomly assigned to the dexmedetomidine (DEX) and midazolam (MDZ) groups. From the time of the sternal closure, dexmedetomidine (0.5–0.7 μg/kg/h) was continuously administered (DEX group), and midazolam (0.03–0.1 mg/kg) was administered by bolus (MDZ group). To maintain the target sedation level (Richmond Agitation-Sedation Scale [RASS] range, −2 to −1) until extubation in the intensive care unit (ICU), continuous doses of dexmedetomidine were regulated and midazolam was administered intermittently. Sedation (RASS) and pain scores (visual analogue scale) and hemodynamic changes were recorded every two hours, until the end of the mechanical ventilation assistance after entering the ICU. RESULTS: The mean of the fraction within the target sedation level in each patient's total sedation time was 41.0% in the DEX group and 20.7% in the MDZ group (P = 0.026). In the DEX group, the RASS (P < 0.001) and cardiac index were lower (P = 0.047) than those in the MDZ group, but the other hemodynamic parameters and pain scores were not different. CONCLUSIONS: This study showed that post-operative infusion of dexmedetomidine maintained a stable sedation without side effects in patients who underwent CABG surgery.

The effect of pre-anesthetic administration of dexmedetomidine on the consumption of opioids in postoperative gynecologic patients

BACKGROUND: This study was designed to assess whether pre-anesthetic administration of dexmedetomidine reduces the postoperative consumption of opioids, in patients receiving patient-controlled fentanyl after gynecological laparotomy. METHODS: This was a prospective, randomized, double-blind, controlled study. Ten minutes before induction of anesthesia, 36 patients scheduled for elective gynecological laparotomy were assigned to receive either normal saline (group N) or dexmedetomidine 1 µg/kg (group D). A patient-controlled analgesia (PCA) device was used to administer fentanyl for the postoperative 24 h period. Cumulative fentanyl consumption and pain score were assessed at postoperative 30 min, 6 h and 24 h. Patient's satisfaction for pain control and other side effects (nausea, sedation score) were recorded for all corresponding time points. RESULTS: There was no significant difference between the groups in cumulative fentanyl consumption (Group N: 11.1 ± 3.2 µg/kg, Group D: 10.3 ± 2.9 µg/kg, P value: 0.706). The incidence of side-effects did not differ between the groups. Both groups showed similar blood pressure after anesthesia induction. However, 10 min after anesthesia induction, the heart rates in group D were significantly lower than group N (P = 0.0002). CONCLUSIONS: In patients undergoing gynecological laparotomy, the pre-anesthetic administration of single loading dose dexmedetomidine (1 µg/kg) given 10 min before anesthesia induction did not reduce the PCA consumption of postoperative fentanyl or the pain score.

The efficacy of warming blanket on reducing intraoperative hypothermia in patients undergoing transurethral resection of bladder tumor under general anesthesia

BACKGROUND: Perioperative hypothermia, defined as a core temperature under 36℃, increases the risk of cardiac complication, bleeding and infection. This study aimed to compare the hypothermia-preventing effects of a warming blanket (Ready-heat®) and one-layer cotton blanket in patients undergoing transurethral resection of the bladder (TURBT) under general anesthesia. METHODS: Patients undergoing TURBT under general anesthesia were allocated to the warming blanket (N = 23) or one-layer cotton blanket (N = 23) groups. Ten minutes before induction of anesthesia, warming blanket or one-layer cotton blanket was applied according to the assigned group. Tympanic temperature was measured just before induction of anesthesia. Esophageal temperature and tympanic temperature were measured from 20 min after induction of anesthesia at 10-min intervals. Tympanic temperature was measured at 10-min intervals over a 30-min period in the post-anesthesia care unit (PACU). In addition, the incidence and intensity of shivering and thermal comfort were also measured. RESULTS: The core temperature during general anesthesia showed no significant intergroup difference. The warming blanket group showed a lower incidence of hypothermia at 1 h after induction of anesthesia. Tympanic temperature, the incidence and intensity of shivering, and thermal comfort in the PACU showed no significant intergroup differences. CONCLUSIONS: Application of the warming blanket or one-layer cotton blanket for 10 min before induction of anesthesia showed no hypothermia-preventing effects. However, at one hour after induction of anesthesia, warming blanket application reduced the incidence of hypothermia to a greater degree than one-layer cotton blanket.

Analysis of the current state of postoperative patient-controlled analgesia in Korea

BACKGROUND: Patient-controlled analgesia (PCA) is a widely used method of postoperative analgesia with the advantage of tailored dosing for each individual. In spite of its popularity, there have been few reports on the current state of PCA in Korea. In this study, the data on PCA management and PCA regimens of medical institutions in Korea were collected and analyzed. METHODS: Members of the Korean Society for Anesthetic Pharmacology were questioned as to the state of postoperative PCA management, such as acute pain services (APS) and pain assessment. A list of PCA regimens for each institution was also requested and analyzed. RESULTS: Among 65 hospitals, APS was run in 30 and the severity of postoperative pain was assessed in 60. The safety and efficacy of PCA was evaluated only in 9 hospitals. A total 518 PCA regimens were reported (414, 95 and 9 regimens for intravenous, epidural and other routes, respectively). For intravenous PCA, fentanyl only and fentanyl-ketorolac regimens comprised 33.8 and 30.9% of treatments, respectively. In 95.9% of the regimens, background infusion was used. For epidural PCA, fentanyl-ropivacaine or fentanyl-levobupivacaine regimens made up the majority (47.4 and 13.7%, respectively). CONCLUSIONS: In Korea, APS was used in less than 50% of the hospitals and the evaluation of the safety and efficacy of PCA is not carried out in the majority. Background infusion, known to have little advantage in most cases, was widely used in intravenous PCA.

A comparative clinical study on the accuracy and efficacy of Accumate(R) 1100, an infusion pump for patient-controlled analgesia

BACKGROUND: The accuracy and efficacy of patient-controlled analgesia (PCA) devices are crucial because malfunction of the devices may lead to fatal outcomes. The aim of this study is to evaluate the accuracy and efficacy of Accumate(R) 1100, an electronic PCA pump, in comparison with GemStar(R) infusion system. METHODS: Fifty patients scheduled for gastrectomy or colon resection were assigned to the Accumate or GemStar group (n = 25 in each group). Intraoperatively, backflow, siphonage, autoclamp function, and lockout time were tested. Postoperatively, PCA using either Accumate(R) 1100 or GemStar(R) infusion system according to the assigned group was maintained for 48 hours. For PCA, fentanyl 1,500 ug and ketorolac 180 mg in 100 ml were used (demand bolus 1 ml, background infusion 1 ml/h, lockout time 15 minutes). The accuracy of the total infused dose and the level of satisfaction of the patients and users were assessed. The results were compared between the two groups. RESULTS: Although backflow and auto-clamp backflow were less with GemStar(R) infusion system, their extent was negligible in both groups. Siphonage was not different between both pumps. Autoclamp and lockout time worked without abnormalities. The relative error of total infused volume over 48 hours was -0.26 +/- 1.20% and -0.34 +/- 0.48% in the Accumate group and GemStar group, respectively. The Accumate group showed a higher level of satisfaction in terms of the ease of priming (P < 0.05). CONCLUSIONS: The accuracy and clinical efficacy of Accumate(R) 1100 were comparable to those of GemStar(R) infusion system.

Opioid pharmacogenetics in anesthesia and pain management

Opioids are the cornerstone for treating moderate to severe pain and are commonly used for anesthesia and pain management. However, large inter-individual variability exists in the analgesic and adverse effects. It would be very helpful to predict the opioid response of each patient, considering the serious outcomes related to insufficient pain control and fatal side effects. Pharmacogenetic data on opioids have accumulated; thus, the aim of this article is to review the pharmacogenetic studies related to opioids frequently used for anesthesia and pain management.

Predictive performance of a target controlled infusion of Aquafol(TM) by use of a PION TCI(R) pump

BACKGROUND: The performance of a target controlled infusion (TCI) system needs to be confirmed in a clinical setting. Aquafol(TM), a microemulsion propofol, can be used for TCI with its pharmacokinetic parameters. The aim of this study is to evaluate the predictive performance of Aquafol(TM) TCI by using a PION TCI(R) pump incorporating the previously established pharmacokinetic parameters and ke0. METHODS: Thirty adult patients were enrolled in the study. General anesthesia was maintained with TCI of Aquafol(TM) and remifentanil using a PION TCI(R) pump. During the maintenance of anesthesia with a constant target effect-site concentration of propofol for at least for 20 minutes, blood was drawn and the propofol plasma concentration was measured. The predictive performance of Aquafol(TM) TCI was evaluated by determining the median performance error (MDPE), median absolute performance error (MDAPE), divergence, and wobble from the intra-individual and pooled performance errors. The acceptability of the TCI system was determined based on the pooled predictive performance. RESULTS: A total of 153 propofol blood samples were analyzed. The estimates of pooled MDPE, MDAPE, divergence and wobble were 8.59% (1.61), 19.1% (1.12), -1.12%/h and 9.87% (1.01), respectively. The MDAPE indicating the accuracy of the TCI infusion system was within the clinically acceptable range (< 20-30%) and the bias (MDPE) was also acceptable (< 10-20%). CONCLUSIONS: The performance of Aquafol(TM) TCI using a PION TCI(R) pump was acceptable for the clinical use.

Risk factors associated with outcomes of hip fracture surgery in elderly patients / 대한마취과학회지

BACKGROUND: Hip fracture surgery on elderly patients is associated with a high incidence of morbidity and mortality. The aim of this study is to identify the risk factors related to the postoperative mortality and complications following hip fracture surgery on elderly patients. METHODS: In this retrospective study, the medical records of elderly patients (aged 65 years or older) who underwent hip fracture surgery from January 2011 to June 2014 were reviewed. A total of 464 patients were involved. Demographic data of the patients, American Society of Anesthesiologists physical status, preoperative comorbidities, type and duration of anesthesia and type of surgery were collected. Factors related to postoperative mortality and complications; as well as to intensive care unit admission were analyzed using logistic regression. RESULTS: The incidence of postoperative mortality, cardiovascular complications, respiratory complications and intensive care unit (ICU) admission were 1.7, 4.7, 19.6 and 7.1%, respectively. Postoperative mortality was associated with preoperative respiratory comorbidities, postoperative cardiovascular complications (P < 0.05). Postoperative cardiovascular complications were related to frequent intraoperative hypotension (P <0.05). Postoperative respiratory complications were related to age, preoperative renal failure, neurological comorbidities, and bedridden state (P < 0.05). ICU admission was associated with the time from injury to operation, preoperative neurological comorbidities and frequent intraoperative hypotension (P < 0.05). CONCLUSIONS: Adequate treatment of respiratory comorbidities and prevention of cardiovascular complications might be the critical factors in reducing postoperative mortality in elderly patients undergoing hip fracture surgery.

Effective dose of dexmedetomidine to induce adequate sedation in elderly patients under spinal anesthesia / 대한마취과학회지

BACKGROUND: During sedation with dexmedetomidine, a dose adjustment may be needed based on the invasiveness of the procedure, the patient's general condition, and their age. We aim here to determine the effective dose (ED) of dexmedetomidine to induce an adequate depth of sedation in elderly patients undergoing spinal anesthesia. METHODS: In this study, 47 patients aged 65 years or older, American Society of Anesthesiologists physical status I or II, undergoing spinal anesthesia were included. Patients were randomly allocated into group I, II, III, IV or V according to the dexmedetomidine loading dose of 0.1, 0.3, 0.5, 0.7 and 1.0 microg/kg, respectively. After spinal anesthesia, the assigned loading dose of dexmedetomidine was infused intravenously for 10 minutes, after which infusion was maintained at a rate of 0.3 microg/kg/h for the next 10 minutes in all groups. We assessed the depth of sedation with the Ramsay sedation scale every five minutes and measured vital signs and the oxygen saturation. The ED50 and ED95 of dexmedetomidine to obtain adequate sedation (Ramsay sedation score > or = 3) upon the completion of the loading dose were calculated with logistic regression. RESULTS: The ED50 and ED95 of dexmedetomidine for adequate sedation were 0.29 microg/kg (95% confidence intervals [CI] 0.14-0.44) and 0.86 microg/kg (95% CI 0.52-1.20), respectively. Hypotension was frequent in groups IV, V compared to groups I, II, III (31.6 vs. 3.6%, P = 0.013). CONCLUSIONS: ED95 of dexmedetomidine loading dose for adequate sedation is 0.86 microg/kg. However, dose higher than 0.5 microg/kg can lead to hemodynamic instability.