Agreement of measured and calculated serum osmolality during the infusion of mannitol or hypertonic saline in patients after craniotomy: a prospective, double-blinded, randomised controlled trial.

BACKGROUND: Mannitol and hypertonic saline are used to ameliorate brain edema and intracranial hypertension during and after craniotomy. We hypothesized that the agreement of measured and calculated serum osmolality during the infusion of hypertonic saline would be better than mannitol. The objective was to determine the accuracy of serum osmolality estimation by different formulas during the administration of hyperosmolar agent. METHODS: A prospective, randomized, double-blinded, controlled trial was conducted in a 30-bed neurosurgical intensive care unit at a university hospital. Thirty-five adult patients requiring the use of hyperosmolar agents for prevention or treatment of brain edema after elective craniotomy were enrolled, and randomly assigned 1:1 to receive 125 mL of either 20 % mannitol (mannitol group) or 3.1 % sodium chloride solution (hypertonic saline group) in 15 min. Serum osmolality, serum sodium and potassium concentration, blood urea nitrogen and blood glucose concentration were measured during the study period. The primary outcome was the agreement of measured and estimated serum osmolality during the infusion of the two experimental agents. We used Bland and Altman's limits of agreement analysis to clarify the accuracy of estimated serum osmolality. Bias and upper and lower limits of agreement of bias were calculated. RESULTS: For each formula, the bias was statistically lower in hypertonic saline group than mannitol group (p < 0.001). Within group comparison showed that the lowest bias (6.0 [limits of agreement: -18.2 to 30.2] and 0.8 [-12.9 to 14.5] mOsml/kg in mannitol group and hypertonic saline group, respectively) was derived from the formula '2 × ([serum sodium] + [serum potassium]) + [blood urea nitrogen] + [blood glucose]'. CONCLUSIONS: Compared to mannitol, a better agreement between measured and estimated serum osmolality was found during the infusion of hypertonic saline. This result indicates that, if hypertonic saline is chosen to prevent or treat brain edema, calculated serum osmolality can be used as a reliable surrogate for osmolality measurement. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02037815.

Combination of extracorporeal membrane oxygenation and continuous renal replacement therapy in critically ill patients: a systematic review.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients presenting acute cardiac and/or pulmonary dysfunctions, who are at high risk of developing acute kidney injury and fluid overload. Continuous renal replacement therapy (CRRT) is commonly used in intensive care units (ICU) to provide renal replacement and fluid management. We conducted a review to assess the feasibility, efficacy and safety of the combination of ECMO and CRRT and to illustrate the indications and methodology of providing renal replacement therapy during the ECMO procedure. METHOD: We searched for all published reports of a randomized controlled trial (RCT), quasi-RCT, or other comparative study design, conducted in patients undergoing ECMO plus CRRT. Two reviewers independently selected potential studies and extracted data. We used the modified Jadad scale and the Newcastle-Ottawa for quality assessment of RCTs and non-RCTs, respectively. Statistical analyses were performed using RevMan 5.2. RESULTS: We identified 19 studies meeting the eligibility criteria (seven cohort, six case control, one historically controlled trial and five studies of technical aspects). There are three major methods for performing CRRT during ECMO: 'independent CRRT access', 'introduction of a hemofiltration filter into the ECMO circuit (in-line hemofilter)' and 'introduction of a CRRT device into the ECMO circuit'. We conducted a review with limited data synthesis rather than a formal meta-analysis because there could be greater heterogeneity in a systematic review of non-randomized studies than that of randomized trials. For ECMO survivors receiving CRRT, overall fluid balance was less than that in non-CRRT survivors. There was a higher mortality and a longer ECMO duration when CRRT was added, which may reflect a relatively higher severity of illness in patients who received ECMO plus CRRT. CONCLUSIONS: The combination of ECMO and CRRT in a variety of methods appears to be a safe and effective technique that improves fluid balance and electrolyte disturbances. Prospective studies would be beneficial in determining the potential of this technique to improve the outcome in critically ill patients.

Extracorporeal membrane oxygenation in curing a young man after modified Fontan operation: A case report.

BACKGROUND: The Fontan operation is the only treatment option to change the anatomy of the heart and help improve patients' hemodynamics. After successful operation, patients typically recover the ability to engage in general physical activity. As a better ventilatory strategy, extracorporeal membrane oxygenation (ECMO) provides gas exchange via an extracorporeal circuit, and is increasingly being used to improve respiratory and circulatory function. After the modified Fontan operation, circulation is different from that of patients who are not subjected to the procedure. This paper describe a successful case using ECMO in curing influenza A infection in a young man, who was diagnosed with Tausing-Bing syndrome and underwent Fontan operation 13 years ago. The special cardiac structure and circulatory characteristics are explored in this case. CASE SUMMARY: We report a successful case using ECMO in curing influenza A infection in a 23-year-old man, who was diagnosed with Tausing-Bing syndrome and underwent Fontan operation 13 years ago. The man was admitted to the intensive care unit with severe acute respiratory distress syndrome as a result of influenza A infection. He was initially treated by veno-venous (VV) ECMO, which was switched to veno-venous-arterial ECMO (VVA ECMO) 5 d later. As circulation and respiratory function gradually improved, the VVA ECMO equipment was removed on May 1, 2018. The patient was successfully withdrawn from artificial ventilation on May 28, 2018 and then discharged from hospital on May 30, 2018. CONCLUSION: After the modified Fontan operation, circulation is different compared with that of patients who are not subjected to the procedure. There are certainly many differences between them when they receive the treatment of ECMO. Due to the special cardiac structure and circulatory characteristics, an individualized liquid management strategy is necessary and it might be better for them to choose an active circulation support earlier.

Use of Dexmedetomidine for Prophylactic Analgesia and Sedation in Patients With Delayed Extubation After Craniotomy: A Randomized Controlled Trial.

BACKGROUND: We conducted a randomized trial to evaluate the efficacy and safety of dexmedetomidine for prophylactic analgesia and sedation in patients with delayed extubation after craniotomy. METHODS: From June 2012 to July 2014, 150 patients with delayed extubation after craniotomy were randomized 1:1 and were assigned to the dexmedetomidine group that received a continuous infusion of 0.6 µg/kg/h (10 µg/mL) or the control group that received a maintenance infusion of 0.9% sodium chloride for injection. The mean percentage of time under optimal sedation (SAS3-4), the percentage of patients who required rescue with propofol/fentanyl, and the total dose of propofol/fentanyl required throughout the course of drug infusion, as well as VAS, HR, MAP, and SpO2 were recorded. RESULTS: The percentage of time under optimal sedation was significantly higher in the dexmedetomidine group than in the control group (98.4%±6.7% vs. 93.0%±16.2%, P=0.008). The VAS was significantly lower in the dexmedetomidine group than in the control group (1.0 vs. 4.0, P=0.000). The HR and mean BP were significantly lower in the dexmedetomidine group than in the control group at all 3 time points (before endotracheal suctioning, immediately after extubation, and 30 min after extubation). No significant difference in SpO2 was observed between the 2 groups. For hemodynamic adverse events, patients in the dexmedetomidine group were more likely to develop bradycardia (5.3% vs. 0%, P=0.043) but had a lower likelihood of tachycardia (2.7% vs. 18.7%, P=0.002). CONCLUSIONS: Dexmedetomidine may be an effective prophylactic agent to induce sedation and analgesia in patients with delayed extubation after craniotomy. The use of dexmedetomidine (0.6 µg/kg/h) infusion does not produce respiratory depression, but may increase the incidence of bradycardia.

Real-time continuous glucose monitoring shows high accuracy within 6 hours after sensor calibration: a prospective study.

Accurate and timely glucose monitoring is essential in intensive care units. Real-time continuous glucose monitoring system (CGMS) has been advocated for many years to improve glycemic management in critically ill patients. In order to determine the effect of calibration time on the accuracy of CGMS, real-time subcutaneous CGMS was used in 18 critically ill patients. CGMS sensor was calibrated with blood glucose measurements by blood gas/glucose analyzer every 12 hours. Venous blood was sampled every 2 to 4 hours, and glucose concentration was measured by standard central laboratory device (CLD) and by blood gas/glucose analyzer. With CLD measurement as reference, relative absolute difference (mean±SD) in CGMS and blood gas/glucose analyzer were 14.4%±12.2% and 6.5%±6.2%, respectively. The percentage of matched points in Clarke error grid zone A was 74.8% in CGMS, and 98.4% in blood gas/glucose analyzer. The relative absolute difference of CGMS obtained within 6 hours after sensor calibration (8.8%±7.2%) was significantly less than that between 6 to 12 hours after calibration (20.1%±13.5%, p<0.0001). The percentage of matched points in Clarke error grid zone A was also significantly higher in data sets within 6 hours after calibration (92.4% versus 57.1%, p<0.0001). In conclusion, real-time subcutaneous CGMS is accurate in glucose monitoring in critically ill patients. CGMS sensor should be calibrated less than 6 hours, no matter what time interval recommended by manufacturer.

Use of dexmedetomidine for prophylactic analgesia and sedation in delayed extubation patients after craniotomy: a study protocol and statistical analysis plan for a randomized controlled trial.

BACKGROUND: Pain and agitation are common in patients after craniotomy. They can result in tachycardia, hypertension, immunosuppression, increased catecholamine production and increased oxygen consumption. Dexmedetomidine, an alpha-2 agonist, provides adequate sedation without respiratory depression, while facilitating frequent neurological evaluation. METHODS/DESIGN: The study is a prospective, randomized, double-blind, controlled, parallel-group design. Consecutive patients are randomly assigned to one of the two treatment study groups, labeled 'Dex group' or 'Saline group.' Dexmedetomidine group patients receive a continuous infusion of 0.6 µg/kg/h (10 ug/ml). Placebo group patients receive a maintenance infusion of 0.9% sodium chloride for injection at a volume and rate equal to that of dexmedetomidine. The mean percentages of time in optimal sedation, vital signs, various and adverse events, the percentage of patients requiring propofol for rescue to achieve/maintain targeted sedation (Sedation-Agitation Scale, SAS 3 to 4) and total dose of propofol required throughout the study drug infusion are collected. The percentage of patients requiring fentanyl for additional rescue to analgesia and total dose of fentanyl required are recorded. The effects of dexmedetomidine on hemodynamic and recovery responses during extubation are measured. Intensive care unit and hospital length of stay also are collected. Plasma levels of epinephrine, norepinephrine, dopamine, cortisol, neuron-specific enolase and S100-B are measured before infusion (T1), at two hours (T2), four hours (T3) and eight hours (T4) after infusion and at the end of infusion (T5) in 20 patients in each group. DISCUSSION: The study has been initiated as planned in July 2012. One interim analysis advised continuation of the trial. The study will be completed in July 2013. TRIAL REGISTRATION: ClinicalTrials (NCT): ChiCTR-PRC-12002903.

[Studies on nitrobacteria and nitrification in Liaohe estuary wetland sediments].

Nitrobacteria, nitrification and its impact factors were discussed based on the method of on-site incubation and laboratory simulation in Liaohe estuary wetland sediments in June and August 2009, respectively. The results showed that the number of ammonia-oxidizing bacteria (AOB) ranged from 0.54 x 10(4) to 5.69 x 10(4) cells x g(-1) with an average of (2.21 +/- 2.32) x 10(4) cells x g(-1) in June and ranged from 1.90 x 10(4) to 7.90 x 10(4) cells x g(-1) with an average of (3.61 +/- 2.87) x 10(4) cells x g(-1) in August. The potential nitrification rates ranged from 9.72 to 16.45 mmol x (m2 x h)(-1) with an average of (12.54 +/- 3.14) mmol x (m2 x h)(-1) in June and ranged from 14.66 to 24.62 mmol x (m2 x h)(-1) with an average of (18.71 +/- 4.21) mmol x (m2 x h)(-1) in August. The net nitrification rates were 0.41 mmol x (m2 x h)(-1) in June and ranged from 0.20 to 0.53 mmol x (m2 x h)(-1) with an average of (0.35 +/- 0.16) mmol x (m2 x h)(-1) in August. The potential nitrification rates were apparently higher than the net nitrification rates. The AOB abundance and nitrification rates were all higher in August than in June. Ammonia concentration in the overlying water, pH, organic matter, total nitrogen content, total phosphorus content, ammonia nitrogen content and the number of AOB in sediments were the main environmental impact factors on nitrification by SPSS 13.0 statistical analysis (p < 0.05), and it also showed ammonia concentration in the overlying water, total phosphorus content and ammonia nitrogen content in sediments were key impact factors on nitrification by partial correlation analysis. The flux of transformed ammonium into nitrate by nitrification process was 1.14 x 10(5) kg per day, suggesting that nitrification was important on nitrogen cycle in Liaohe estuary wetland sediments.