Yin-Yi Han

Impact of timing of renal replacement therapy initiation on outcome of septic acute kidney injury

IntroductionSepsis is the leading cause of acute kidney injury (AKI) in critical patients. The optimal timing of initiating renal replacement therapy (RRT) in septic AKI patients remains controversial. The objective of this study is to determine the impact of early or late initiation of RRT, as defined using the simplified RIFLE (risk, injury, failure, loss of kidney function, and end-stage renal failure) classification (sRIFLE), on hospital mortality among septic AKI patients.MethodsPatient with sepsis and AKI requiring RRT in surgical intensive care units were enrolled between January 2002 and October 2009. The patients were divided into early (sRIFLE-0 or -Risk) or late (sRIFLE-Injury or -Failure) initiation of RRT by sRIFLE criteria. Cox proportional hazard ratios for in hospital mortality were determined to assess the impact of timing of RRT.ResultsAmong the 370 patients, 192 (51.9%) underwent early RRT and 259 (70.0%) died during hospitalization. The mortality rate in early and late RRT groups were 70.8% and 69.7% respectively (P > 0.05). Early dialysis did not relate to hospital mortality by Cox proportional hazard model (P > 0.05). Patients with heart failure, male gender, higher admission creatinine, and operation were more likely to be in the late RRT group. Cox proportional hazard model, after adjustment with propensity score including all patients based on the probability of late RRT, showed early dialysis was not related to hospital mortality. Further model matched patients by 1:1 fashion according to each patients propensity to late RRT showed no differences in hospital mortality according to head-to-head comparison of demographic data (P > 0.05).ConclusionsUse of sRIFLE classification as a marker poorly predicted the benefits of early or late RRT in the context of septic AKI. In the future, more physiologically meaningful markers with which to determine the optimal timing of RRT initiation should be identified.

Successful resuscitation of acute massive pulmonary embolism with extracorporeal membrane oxygenation and open embolectomy

Acute massive pulmonary embolism is usually fatal if not treated aggressively, but the management is not standardized. Open pulmonary embolectomy retains a role in the treatment of this disastrous disease. Extracorporeal membrane oxygenation has been used for cardiopulmonary support in some patients with life-threatening pulmonary embolism. This article details our experience of a 58-year-old woman suffering from acute cardiopulmonary collapse caused by massive pulmonary embolism. Under extracorporeal membrane oxygenation support, the patient received pulmonary angiography and underwent open embolectomy for a definitive treatment.

Effects of Fish Oil on Inflammatory Modulation in Surgical Intensive Care Unit Patients

BACKGROUND The benefit of ω-3 fatty acids in fat emulsion remains controversial. This study evaluated the effect of ω-3 fatty acids on immune and inflammatory modulation in surgical intensive care unit (SICU) patients. METHODS Thirty-eight patients admitted to the SICU after major surgery were enrolled in this prospective controlled study and randomized to receive parenteral nutrition (PN) with equal volume and calories from glucose, nitrogen, and fat but different lipid components for 7 postoperative days. Group A (n = 12) received a mixture of soybean and medium-chain triglyceride oils; group B (n = 18) received a fat emulsion with part of the lipid replaced by fish oil. Blood tests, including lipid profile, routine biochemistry, inflammatory cytokines, and lymphocyte subpopulations, were evaluated preoperatively and on postoperative days 4 and 7. RESULTS Both lipid regimens were well tolerated. There was a trend toward reduced serum inflammatory cytokines in group B vs group A with significant differences regarding interleukin (IL)-1, IL-8, and interferon (IFN)-γ on postoperative day 4 (P < .05) and IL-1, IL-8, IFN-γ, IL-6, and tumor necrosis factor-α on postoperative day 7 (P < .05). There was a reduction in postoperative liver dysfunction (A vs B: 50% vs 33.3%) and infection rate (A vs B: 41.7% vs 27.8%) in group B, although this was not statistically significant. There was no mortality in either group. CONCLUSION This study suggests that supplementation of parenteral ω-3 fatty acids in PN is safe and may improve immune and hyperinflammatory response for SICU patients after major surgery.

Rescue for acute myocarditis with shock by extracorporeal membrane oxygenation.

BACKGROUND Acute myocarditis (AM) complicated with refractory cardiogenic shock carries a very high mortality. We report our experience in treating these patients, who were rescued by extracorporeal membrane oxygenation (ECMO) and intravenous immunoglobulin. METHODS Over a 5-year period, 5 patients with AM were rescued with ECMO in our hospital. Femoral venoarterial ECMO was performed in 4 patients, and right atrium-left atrium-aorta ECMO in the other 1 due to ventricular dysfunction. Hemofiltration was applied to 3 patients. Marked elevated creatine kinase, its MB form, and troponin T (TnT) were found before ECMO. RESULTS All the patients could be weaned off the ECMO after 140.0+/-57.7 hours of ECMO support. One patient died of multiple organ failure 10 days later after removal of ECMO, resulting in a 20% mortality. Renal function returned to normal in all survivors. The 4 survivors were discharged uneventfully in 23.3+/-8.3 days and resumed functional class I status. The TnT level declined to the low level within 3 days (slope -4.94+/-1.18 ng/mL/day), and might be an indicator of good recovery of myocardium. CONCLUSIONS ECMO can provide an effective and simple treatment for critical AM with a satisfactory result and reduce the possibility of progressive cardiomyopathy.

Clinical outcome of severe head injury using three different ICP and CPP protocol-driven therapies

In the past 5 years, cerebral perfusion pressure (CPP) management has become the standard in the treatment of severe head injuries. Guidelines published in 2000 suggest that CPP should be at least 70 mmHg; however, there is still debate about the optimal CPP. The purpose of the present study was to evaluate the effectiveness of these three widely used therapies: (i) intracranial pressure (ICP) targeted; (ii) CPP-targeted with CPP >70 mmHg; and (iii) modified CPP-targeted (mCPP) therapy with CPP >60 mmHg. The clinical procedures, complications and outcomes of patients in the different groups were compared. Data, including patient age, sex, initial Glasgow Coma Scale, ICP, CPP, fluid status, amount of mannitol and vasopressor used, daily fluid intake and output, complications and clinical results, were collected from 213 patients with severe head injuries over a 12-year period. Patients were categorized into three groups (ICP, CPP, mCPP) according to the treatment protocol used. Retrospective data collection was performed by chart review. The mortality rate was 28.6%, 14.3% and 13.5% in the ICP, CPP, and mCPP groups, respectively. Highest intake/output ratio, amount of vasopressor used and pulmonary complications were seen in the CPP patients. The mCPP patients showed the best clinical outcome and lowest complication rate. Although CPP-targeted therapy is the most recommended therapeutic protocol, our data show that patients treated with modified CPP-target therapy with CPP >60 mmHg have better clinical outcomes and fewer complications.

DETRENDED FLUCTUATION ANALYSES OF SHORT-TERM HEART RATE VARIABILITY IN SURGICAL INTENSIVE CARE UNITS

We examine the dynamics of complex physiologic fluctuations using methods developed very recently in statistical physics. The method based on detrended fluctuation analysis (DFA) has been used to investigate the profile of different types of physiologic states under long term (i.e., 24 hr) analysis of heart rate variability (HRV). In this paper, this method to investigate the output of central physiologic control system under short term (i.e., 1 hr) of HRV in surgical intensive care units (SICU). Electrocardiograph (ECG) signals lasting around 1 hr were collected from ten college student volunteers as group A. Ten computes-generates white noise signals as group B also provided ECG signals lasting around 1 hr. Finally, seventeen patients representing 37 cases undergoing different types of neurosurgery were studied as group C. From this group, 25 cases were selected from 15 patients with brain injury and 12 cases were selected from 2 patients with septicemia. Group A and B were used as high and low limits of baseline for comparison with pathologic states in the SICU. The a values of DFA of groups A, B, and C were 0.958 ± 0.034, 0.521 ± 0.010, and 0.815 ± 0.183, respectively. It was found that the α value of patients in the SICU was significantly lower (P < 0.05) than that of healthy volunteers and significantly higher (P < 0.05) than white noise signals. Hence, it can be concluded that α values based on the DFA statistical concept can clearly distinguish pathologic states in SICU patients from the healthy group and from white noise signals.

Rapid bacterial antibiotic susceptibility test based on simple surface-enhanced Raman spectroscopic biomarkers

Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.

Clinical outcome of severe head injury in different protocol-driven therapies

In the past 5 years cerebral perfusion pressure (CPP) management has become mainstream in the treatment of severe head injuries. The American Association of Neurological Surgeons guidelines (2000) suggest that CPP should be maintained at least 70 mmHg; however, there is still debate about optimal CPP level. The purpose of this study is to evaluate the effectiveness of three widely used therapies: intracranial pressure (ICP)-targeted therapy, CPP-targeted therapy with CPP > 70 mmHg, and modified CPP-targeted therapy with CPP > 60 mmHg. The clinical procedures, complications, and patient outcomes are compared. Data including patient age, sex, initial Glasgow Coma Score (GCS), ICP, CPP, fluid status, amount of mannitol and vasopressor used, daily intake and output, complications, and clinical results were collected from 213 patients with severe head injuries over a 12-year period. Patients were categorized into three groups (ICP, CPP, modified CPP [mCPP]) according to treatment protocol used. Retrospective data collection was by chart review. The mortality rate was 28.6%, 14.3%, and 13.5% in groups ICP, CPP, and mCPP, respectively. Highest intake/output ratio, amount of vasopressor used, and pulmonary complication rates were seen in group CPP patients. Group mCPP patients showed the best clinical outcome and lowest complication rate. Though CPP-targeted therapy is the most recommended therapeutic protocol, our data showed that the outcome is as good in the mCPP-targeted group with CPP > 60 mmHg as in the CPP-targeted group, but complications are fewer in the mCPP group.

Preoperative Proteinuria Is Associated with Long-Term Progression to Chronic Dialysis and Mortality after Coronary Artery Bypass Grafting Surgery

Aims Preoperative proteinuria is associated with post-operative acute kidney injury (AKI), but whether it is also associated with increased long- term mortality and end -stage renal disease (ESRD) is unknown. Methods and Results We studied 925 consecutive patients undergoing CABG. Demographic and clinical data were collected prospectively, and patients were followed for a median of 4.71 years after surgery. Proteinuria, according to dipstick tests, was defined as mild (trace to 1+) or heavy (2+ to 4+) according to the results of the dipstick test. A total of 276 (29.8%) patients had mild proteinuria before surgery and 119 (12.9%) patients had heavy proteinuria. During the follow-up, the Cox proportional hazards model demonstrated that heavy proteinuria (hazard ratio [HR], 27.17) was an independent predictor of long-term ESRD. There was a progressive increased risk for mild proteinuria ([HR], 1.88) and heavy proteinuria ([HR], 2.28) to predict all–cause mortality compared to no proteinuria. Mild ([HR], 2.57) and heavy proteinuria ([HR], 2.70) exhibited a stepwise increased ratio compared to patients without proteinuria for long–term composite catastrophic outcomes (mortality and ESRD), which were independent of the baseline GFR and postoperative acute kidney injury (AKI). Conclusion Our study demonstrated that proteinuria is a powerful independent risk factor of long-term all-cause mortality and ESRD after CABG in addition to preoperative GFR and postoperative AKI. Our study demonstrated that proteinuria should be integrated into clinical risk prediction models for long-term outcomes after CABG. These results provide a high priority for future renal protective strategies and methods for post-operative CABG patients.

Effect of Diuretic Use on 30-Day Postdialysis Mortality in Critically Ill Patients Receiving Acute Dialysis

Background The impact of diuretic usage and dosage on the mortality of critically ill patients with acute kidney injury is still unclear. Methods and Results In this prospective, multicenter, observational study, 572 patients with postsurgical acute kidney injury receiving hemodialysis were recruited and followed daily. Thirty-day postdialysis mortality was analyzed using Coxs proportional hazards model with time-dependent covariates. The mean age of the 572 patients was 60.8±16.6 years. Patients with lower serum creatinine (p = 0.031) and blood lactate (p = 0.033) at ICU admission, lower predialysis urine output (p = 0.001) and PaO2/FiO2 (p = 0.039), as well as diabetes (p = 0.037) and heart failure (p = 0.049) were more likely to receive diuretics. A total of 280 (49.0%) patients died within 30 days after acute dialysis initiation. The analysis of 30-day postdialysis mortality by fitting propensity score-adjusted Coxs proportional hazards models with time-dependent covariates showed that higher 3-day accumulated diuretic doses after dialysis initiation (HR = 1.449, p = 0.021) could increase the hazard rate of death. Moreover, higher time-varying 3-day accumulative diuretic doses were associated with hypotension (p<0.001) and less intense hemodialysis (p<0.001) during the acute dialysis period. Background and Significance Higher time-varying 3-day accumulative diuretic dose predicts mortality in postsurgical critically ill patients requiring acute dialysis. Higher diuretic doses are associated with hypotension and a lower intensity of dialysis. Caution should be employed before loop diuretics are administered to postsurgical patients during the acute dialysis period.