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BackgroundDuring 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.MethodsIn 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 µg/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 µg/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 ≥ 3) upon the completion of the loading dose were calculated with logistic regression.ResultsThe ED50 and ED95 of dexmedetomidine for adequate sedation were 0.29 µg/kg (95% confidence intervals [CI] 0.14-0.44) and 0.86 µg/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).ConclusionsED95 of dexmedetomidine loading dose for adequate sedation is 0.86 µg/kg. However, dose higher than 0.5 µg/kg can lead to hemodynamic instability.

Background: Perioperative patients are potentially at risk for pressure injuries due to anesthetic agents and surgical positioning. Pressure injury increases discomfort and pain in patients and causes complications, which lead to an increase in mortality and hospitalization duration. Most previous studies did not focus on specific types of surgery or surgical positioning. We tried to identify the incidence of perioperative pressure injury during spinal surgery and perioperative risk factors that contribute to pressure injury.Methods: We retrospectively analyzed electronic medical records of 663 patients who underwent spinal surgery between March 2016 and May 2018. The primary outcome was occurrence of pressure injury. Potential risk factors of pressure injury were selected based on previous studies and expert opinion, and divided into two sub-categories: preoperative and intraoperative risk factors. We compared the clinical characteristics of patients in the pressure injury and non-injury groups. Perioperative risk factors for pressure injury were analyzed by logistic regression.Results: Among 663 patients, the incidence of all stages of pressure injury was 5.9%. The face and inguinal regions were the most injured sites (both 28.6%). The pressure injury group showed a 13% longer hospitalization period. Preoperative plasma concentration of protein was associated with 0.5-fold lower pressure injury (OR: 0.50; 95% CI: 0.27 to 0.95; P = 0.034).Conclusions: The incidence of pressure injury was similar to that previously reported and occurred in the direct weight-bearing areas, which led to longer hospitalization. We found that a lower preoperative serum protein level is significantly associated with intraoperative pressure injury occurrence during spinal surgery.

BackgroundHip 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.MethodsIn 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.ResultsThe 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).ConclusionsAdequate 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.

BackgroundIn this retrospective study, we measured the frequency of unexpected antibodies in the blood. Specific considerations for preoperative preparations were kept in mind for the patients undergoing surgery positive for these antibodies.MethodsAfter reviewing the results of antibody screening tests lasted for 2 years, the frequency of unexpected antibodies was determined. Surgical patients who were positive for unexpected antibodies were selected and divided into two groups based on their potential need for an intra-operative transfusion (groups with high versus low possibility of transfusion). Blood for the high possibility group was prepared before surgery. For the low possibility group for which preoperative blood preparation was not performed, cases of this group were reviewed whether a blood preparation was delayed or not in case of transfusion.ResultsAmong a total 22,463 cases, 340 (1.52%) had positive results for antibody screening tests. Among the 243 patients who were positive for unexpected antibodies, Lewis, Rh, Xga, and mixed antibodies were found in 85, 25, five, and eight cases, respectively. Out of 243 patients, 117 patients, specificities of the unexpected antibodies were not determined and 125 (51.4%) had a history of pregnancy and delivery, and 49 (20.2%) had a history of transfusion. In the low probability group, transfusions were administered for nine patients; transfusion was delayed for two patients due to difficulties with obtaining matched blood.ConclusionsPatients with unexpected blood antibodies may be at increased risk for delayed transfusion. For rapid transfusion, it might be helpful to keep a record about blood antibodies and introduce a notification system such as medical alert cards. Preoperative blood preparation is needed for timely intraoperative transfusion.