Evaluation of a recruitment maneuver with positive inspiratory pressure and high PEEP in patients with severe ARDS

BACKGROUND: To evaluate the effect of a recruitment maneuver (RM) with constant positive inspiratory pressure and high positive end-expiratory pressure (PEEP) on oxygenation and static compliance (Cs) in patients with severe acute respiratory distress syndrome (ARDS). METHODS: Eight patients with ARDS ventilated with lung-protective strategy and an arterial partial pressure of oxygen to inspired oxygen fraction ratio (PaO2/FIO2) < or =100 mmHg regardless of PEEP were prospectively studied. The RM was performed in pressure-controlled ventilation at FIO2 of 1.0 until PaO2 reached 250 mmHg or a maximal plateau pressure/PEEP of 60/45 cmH2O was achieved. The RM was performed with stepwise increases of 5 cmH2O of PEEP every 2 min and thereafter with stepwise decreases of 2 cmH2O of PEEP every 2 min until a drop in PaO2 >10% below the recruitment PEEP level. Data was collected before (preRM), during and after 30 min (posRM). RESULTS: The PaO2/FIO2 increased from 83 +/- 22 mmHg preRM to 118 +/- 32 mmHg posRM (P = 0.001). The Cs increased from 28 +/- 10 ml cmH2O(-1) preRM to 35 +/- 12 ml cmH2O(-1) posRM (P = 0.025). The PEEP was 12 +/- 3 cmH2O preRM and was set at 15 +/- 4 cmH2O posRM (P = 0.025). The PEEP of recruitment was 36 +/- 9 cmH2O and the collapsing PEEP was 13 +/- 4 cmH2O. The PaO2 of recruitment was 225 +/- 105 mmHg, with five patients reaching a PaO2 > or = 250 mmHg. The FIO2 decreased from 0.76 +/- 0.16 preRM to 0.63 +/- 0.15 posRM (P = 0.001). No major complications were detected. CONCLUSION: Recruitment maneuver was safe and useful to improve oxygenation and Cs in patients with severe ARDS ventilated with lung-protective strategy.     

Respiratory and haemodynamic effects of conventional volume controlled PEEP ventilation, pressure regulated volume controlled ventilation and low frequency positive pressure ventilation with extracorporeal carbon dioxide removal in pigs with acute ARDS

The purpose of this study was to evaluate whether any benefit of low frequency positive pressure ventilation with extracorporeal carbon dioxide removal (LFPPV–ECCO₂R) existed over either volume controlled ventilation (VCV) with measured best–PEEP or pressure regulated volume controlled ventilation (PRVCV) with an inspiration/expiration (I/E) ratio of 4:1, with respect to arterial oxygenation, lung mechanics and haemodynamics, in acute respiratory failure.
Fifteen adult pigs were used for the study. Respiratory failure was induced by surfactant depletion by repeated lung lavage. The different therapeutic approaches were applied randomly to each pig for 1 h. Measurements of gas exchange, airway pressures and haemodynamics were performed during ventilatory and haemodynamic steady state. Paco₂ was kept constant in all modes.
At almost similar total–PEEP, Pao₂ values were significantly higher with LFPPV–ECCO₂R comared to VCV with best–PEEP. Peak inspiratory pressure (PIP) and intrapulmonary pressure amplitude defined as the difference between PIP and total–PEEP were significantly lower with PRVCV and LFPPV–ECCO₂R compared to VCV with best–PEEP. There was no significant difference between the modes concerning cardiocircu–latory parameters.
PRVCV with I/E ratio of 4:1 and LFPPV–ECCO₂R proved to be better modes to achieve better gas exchange and lower PIP at lower intrapulmonary pressure amplitudes. It is concluded that PRVCV is an adequate form of treatment under these experimental conditions imitating acute respiratory failure, without necessitating other invasive measures.     

A systematic review of continuous renal replacement therapy and intermittent haemodialysis in management of patients with acute renal failure

Background: Acute renal failure (ARF) still bears a poor prognosis with mortality rates up to 70% and the ideal form of renal replacement therapy (RRT) remains controversial. The purpose of this study was to conduct a systematic review and meta-analysis of all randomized controlled trials (RCT) to examine the effect of dialysis modality (IHD: Intermittent haemodialysis; CRRT: continuous renal replacement therapy) on survival of patients with ARF and to also study the effect of each modality on dialysis dependence (DD). Methods: Using and combining two comprehensive search themes (ARF and RRT), we searched electronic databases from 1969 through September of 2007, supplemented by a manual review of abstracts from nephrology meetings and reference lists of review articles. All RCT comparing IHD with CRRT in adult patients with ARF and with explicit reporting of mortality were included. The primary outcome was the pooled estimate of the odds ratio (OR) of mortality for patients with ARF treated with CRRT versus IHD. The secondary outcome was OR of DD at time of discharge for surviving patients. Results: A total of 587 studies were identified, 554 of which were excluded on initial screening. Analysis of the nine RCT (1635 patients) showed an OR of 0.89 (0.63–1.24) for survival in patients on CRRT. Limiting the analysis to the seven RCT published after the year 2000, revealed an OR of 0.72 (0.58–0.90). The OR of all the studies before 2000 was 1.06 (95% CI 0.67–1.68), as compared with OR of 0.61 (95% CI 0.50–0.74) for studies post-2000. Four studies showed a significantly lower risk of DD among the CRRT group and none showed higher OR for DD. When analysis was limited to the RCT, the OR for DD was 1.07 (0.47–2.39), suggesting no difference in DD between the modalities. Conclusions: Similar to previously reported meta-analyses, we did not find a significant effect of CRRT on the OR of survival. The progressive reduction in the OR of survival with CRRT relative to IHD might reflect progressive improvements in IHD. The OR of DD was not affected by mode of RRT. In conclusion, compared with IHD, CRRT does not offer an advantage with regards to survival or DD in ARF. Considering its cost and potential disadvantages, it is imperative to identify the subset of patients with ARF that would potentially derive maximum benefit from CRRT. This will require large, adequately powered studies with sufficient follow-up.     

Mortality and renal prognosis in isolated metformin-associated lactic acidosis treated with continuous renal replacement therapy and citrate-calcium-anticoagulation

Introduction

Use of metformin increases plasma lactate concentration and may lead to metformin-associated lactic acidosis (MALA). Previous studies have suggested severe MALA to have a mortality of 17%-21%, but have included patients with other coincident conditions such as sepsis. The treatment of choice is continuous renal replacement therapy (CRRT), which has been performed using heparin analogues or no anticoagulation in former studies.

Materials and Methods

Patients admitted to the Intensive Care Unit of Turku University Hospital Finland with lactic acidosis without any other recognizable etiology than concomitant metformin treatment who required CRRT between years 2010 and 2019 were included. CRRT was performed using regional citrate-calcium-anticoagulation. Data extracted included patient demographics, comorbidities, and clinical parameters at 6-hour intervals about 72 hours from admission. Creatinine and estimated glomerular filtration rate (eGFR) were measured at 1 year after MALA.

Results

A total of 23 patients with isolated MALA were included in the study. Median (IQR) pH was 6.88 (6.81-7.07) and lactate 16.1 (11.9-23.0) mmol/L on admission. Median (IQR) duration of CRRT was 62 (41-70) hours. Seven patients (30%) required mechanical ventilation with a mean duration of 6.0 ± 3.0 days. 90-day mortality was 4.3% and 1-year mortality 13.0%. Creatinine (P = .02) and eGFR (P = .03) remained significantly altered at 1 year of follow-up compared to baseline.

Conclusions

MALA can be treated effectively and safely with CRRT and citrate-calcium-anticoagulation, usually required for 2-3 days. Mortality of patients with MALA treated with CRRT is low when other conditions inducing lactic acidosis are excluded. MALA episode may be associated with long-lasting kidney injury.

     

Outcome in critically ill medical patients treated with renal replacement therapy for acute renal failure: comparison between patients with and those without haematological malignancies.

BACKGROUND: Starting renal replacement therapy (RRT) for acute renal failure in critically ill patients with haematological malignancies is controversial because of the poor outcome and high costs. The aim of this study was to compare the outcome between critically ill medical patients with and without haematological malignancies who received RRT for acute renal failure. METHODS: We retrospectively collected data on all consecutive patients who received RRT for acute renal failure at the Medical Intensive Care Unit (ICU) of a University Hospital between 1997 and 2002, and assessed the impact of the presence of a haematological malignancy on the survival within 6 months after ICU admission by Cox proportional hazard models. RESULTS: Fifty of the 222 (22.5%) consecutive patients with haematological malignancies admitted to the ICU over the study period received RRT for acute renal failure compared with 248 of the 4293 (5.8%) patients without haematological malignancies (P<0.001). Among patients who received RRT, those with haematological malignancies had higher crude ICU (79.6 vs 55.7%, P=0.002) and in-hospital (83.7 vs 66.1%, P=0.016) mortality rates, and a higher mortality at 6 months (86 vs 72%, P=0.018) by Kaplan-Meier estimates compared with those without haematological malignancies. However, after adjustment for the severity of illness and the duration of hospitalization before ICU admission, haematological malignancy by itself was no longer associated with a higher risk of death (hazard ratio 1.04; 95% confidence interval, 0.73-1.54, P=0.78). CONCLUSIONS: Medical ICU patients with haematological malignancies have a higher rate of occurrence of acute renal failure treated with RRT and a higher mortality, compared with those without haematological malignancies. However, the presence of a haematological malignancy by itself is not a reason to withhold RRT in medical ICU patients with acute renal failure.     

Alveolar recruitment strategy and PEEP improve oxygenation,dynamic compliance of respiratory system and end‐expiratory lung volume in pediatric patients undergoing cardiac surgery for congenital heart disease

Objective: Optimizing alveolar recruitment by alveolar recruitment strategy (ARS) and maintaining lung volume with adequate positive end‐expiratory pressure (PEEP) allow preventing ventilator‐induced lung injury (VILI). Knowing that PEEP has its most beneficial effects when dynamic compliance of respiratory system (Crs) is maximized, we hypothesize that the use of 8 cm H₂O PEEP with ARS results in an increase in Crs and end‐expiratory lung volume (EELV) compared to 8 cm H₂O PEEP without ARS and to zero PEEP in pediatric patients undergoing cardiac surgery for congenital heart disease. Methods: Twenty consecutive children were studied. Three different ventilation strategies were applied to each patient in the following order: 0 cm H₂O PEEP, 8 cm H₂O PEEP without an ARS, and 8 cm H₂O PEEP with a standardized ARS. At the end of each ventilation strategy, Crs, EELV, and arterial blood gases were measured. Results: EELV, Crs, and P_aO₂/FiO₂ ratio changed significantly (P < 0.001) with the application of 8 cm H2O + ARS. Mean P_aCO₂– PETCO₂ difference between 0 PEEP and 8 cm H2O PEEP + ARS was also significant (P < 0.05). Conclusion: An alveolar recruitment strategy with relative high PEEP significantly improves Crs, oxygenation, P_aCO₂– PETCO₂ difference, and EELV in pediatric patients undergoing cardiac surgery for congenital heart disease.     

Prolongation of acute renal failure in two patients with hemolytic-uremic syndrome due to excessive plasma infusion therapy

Two children with prototypic hemolytic-uremic syndrome had prolonged acute dialysis-dependent renal failure (74 and 84 days) associated with a state of hyperproteinemia induced by extensive infusion of fresh frozen plasma (283 and 307 units). We believe that the hyperproteinemia prolonged the duration of renal failure. Following cessation of plasma therapy, the hyperproteinemic state reversed, the degree of proteinuria decreased and renal function quickly recovered. Although the pathophysiological mechanism requires further evaluation, we speculate that an alteration in the colloid oncotic pressure and/or aggravation of tubulointerstitial injury due to overload-proteinuria may have increased the duration of renal failure.     

Candidaemia in patients with dialysis-dependent acute renal failure: aetiology, predisposing and prognostic factors.

BACKGROUND: Infections remain the major cause of death among patients with acute renal failure (ARF), especially in severe ARF necessitating dialysis therapy (ARF(d)). Although the clinical features and outcomes of candidaemia in various patient populations have been described, data concerning candidaemic episodes among patients with ARF(d) are scarce. This study investigated the aetiology, predisposing, and prognostic factors for candidaemia in the ARF(d) patient population. Three patient groups were investigated in this study. METHODS: During an 8-year study period from January 1992 to December 1999, 37 candidaemic episodes that developed among 653 ARF(d) patients were assigned to ARF(d) candidaemic group, and 170 candidaemic episodes developing in patients without ARF(d) or chronic uraemia as the non-ARF(d) candidaemic group, and 28 matched ARF(d) patients without candidaemia were assigned to the ARF(d) control group. Among these groups, clinical characteristics in ARF(d) candidaemia patients, predisposing factors, and outcomes were compared. Four management strategies including central catheter removal, anti-fungal therapy, both, or neither were applied. The prognostic factors for attributable death were evaluated by univariate analysis followed by the multivariate logistic regression analysis. RESULTS: The proportion of ARF(d) patients with candidaemia was significantly higher than in patients who had no ARF(d) or chronic uraemia (5.7% vs 0.15%, P<0.001). Compared with the non-ARF(d) candidaemic group, systemic lupus erythematosus (SLE), administration of corticosteroid, and central venous catheter-associated candidaemia were more common in the ARF(d) candidaemic group (P<0.05). In matched case-control study, multiple antibiotic usage was shown to be a predisposing factor for developing candidaemia in patients with ARF(d), and corticosteroid therapy has a marginal significance (P=0.059). The occurrence of candidaemia increased the mortality rate of ARF(d) (71% vs 39.2% in ARF(d) control group, P<0.05). By multivariate logistic analysis, the variables associated with attributable death in ARF(d) candidaemic group were identified to be an APACHE II score of >or=18, and anti-fungal therapy for >48 h. Central venous catheters were removed in 32 (86.5%) of the 37 ARF(d) candidaemic patients, among whom the 18 patients who had received anti-fungal therapy for >48 h had a lower attributable death rate than those patients who had not (27.8% vs 64.3%, P<0.05). Of the remaining five patients who did not have their catheter removed, three patients subsequently died and two patients improved only after catheter removal. CONCLUSIONS: The higher prevalence of candidaemia in ARF(d) patients is due to their underlying illnesses and multiplicity of predisposing factors, rather than ARF and dialysis therapy per se. Predisposing factors include SLE, indwelling central venous catheter, multiple antibiotic usage, and corticosteroid therapy. Prompt anti-fungal therapy and catheter removal should be mandatory for ARF(d) patients with candidaemia.     

连续性肾脏替代治疗与间歇性血液透析治疗多器官功能障碍综合征的疗效比较

目的比较连续性肾脏替代治疗(CRRT)与间歇性血液透析(IHD)治疗伴急性肾功能衰竭(ARF)的多器官功能障碍综合征(MODS)患者的疗效.方法49例伴ARF的MODS患者,23例接受CRRT,26例接受每周3次或隔日1次的IHD.所有患者血液净化治疗前及治疗后记录液体摄人量,每日晨检查血肌酐、尿素氮、血钾、血碳酸氢根浓度,动脉血pH值.结果CRRT组和IHD组每日液体摄入量分别为(5128±103)ml、(2207±97)ml(P＜0.05).IHD组21例次出现透析相关低血压、17例次透析间期发生容量依赖性心功能衰竭,高于CRRT组的3例次及2例次(P＜0.05).IHD组每日晨血尿素氮、血肌酐、碳酸氢根、pH值组内比较差异有显著性意义(P＜0.05),而CRRT组组内比较差异没有显著性意义(P＞0.05);IHD组每日晨平均血肌酐、尿素氮高于CRRT组(P＜0.05);IHD组和CRRT组存活率分别为65.4%(17/26)、34.8%(8/23),但在APACHEⅡ评分27以上、衰竭器官数在3个以上的患者中,CRRT组和IHD组存活率分别为26.7%、14.3%(P＞005).结论CRRT控制伴ARF的MODS患者酸碱平衡、液体平衡及氮质血症优于IHD.     

No early respiratory benefit with CVVHDF in patients with acute renal failure and acute lung injury.

BACKGROUND: There is debate as to whether, in patients with acute lung injury, continuous renal replacement therapy has beneficial effects on pulmonary gas exchange by mechanisms other than fluid removal. Because continuous renal replacement therapy is associated with potential morbidity and mortality, it seems unethical to perform a randomized trial in patients with acute lung injury without renal failure. Therefore, the effects of continuous venovenous haemodiafiltration with zero volume balance on gas exchange were evaluated in patients with acute renal failure and acute lung injury. Because haemofilter conditions should be comparable between patients, we opted for an evaluation of the effects during a 24-h period. Results of this trial can guide future studies in non-renal patients with acute lung injury. METHODS: In all 37 patients with acute renal failure and acute lung injury, treated with continuous venovenous haemodiafiltration with zero fluid balance during a 1 year period, ventilatory and haemodynamic parameters were measured every 8 h during the 24 h preceding therapy and during the first 24 h of therapy. RESULTS: We found a slight, although not statistically significant, increase in the PaO(2)/FIO(2) ratio and the oxygenation index, in the total group of patients, and in the subgroups of patients with acute lung injury of extrapulmonary and pulmonary causes. CONCLUSIONS: During the first 24 h of treatment, continuous venovenous haemodiafiltration with zero volume balance did not result in a significant improvement of the respiratory status in patients with acute renal failure and acute lung injury, nor in the subgroups of patients with acute lung injury with extrapulmonary causes.     

心血管手术相关急性肾损伤患者行连续性肾脏替代治疗后的预后因素分析

目的探讨心血管手术相关急性肾损伤患者行连续性肾脏替代治疗后不同预后的相关因素。 方法本研究纳入2015年1月至2018年12月在南京医科大学第一附属医院住院行心血管手术治疗且接受连续性肾脏替代治疗的患者,按90 d是否死亡和90 d内RRT治疗天数(≤14 d,15～90 d,>90 d)将患者分为4组,分析90 d死亡、90 d透析依赖、90 d延迟摆脱透析的相关影响因素。 结果本研究共纳入210例患者,平均随访400 d。其中90 d死亡114例,90 d生存且14 d内摆脱透析37例,90 d生存15～90 d内摆脱透析46例,90 d生存且透析依赖13例。多因素Cox回归显示：90 d死亡的独立危险因素包括高龄(HR＝1.029,95%CI: 1.013～1.045,P<0.001)、术前血清肌酐低(HR＝0.993,95%CI: 0.987～0.998,P＝0.008)、CRRT前APACHE Ⅱ高评分(HR＝1.043, 95%CI: 1.004～1.084,P＝0.028)、CRRT前SOFA评分高(HR＝1.130, 95%CI: 1.052～1.213,P<0.001)、CRRT前脓毒症(HR＝2.327, 95%CI: 1.591～3.403,P<0.001)、CRRT前过低的舒张压(HR＝0.979,95%CI: 0.963～0.996,P＝0.013)。90 d存活患者透析依赖的独立危险因素包括术前较低的eGFR(HR＝0.962,95%CI: 0.940～0.984,P<0.001)。90 d存活患者中延迟摆脱透析的危险因素有血清白蛋白低(OR＝0.837,95%CI: 0.717～0.977,P＝0.024)、机械通气时间长(OR＝1.434,95%CI: 1.175～1.749,P<0.001)、CRRT前尿量少(OR＝0.739,95%CI: 0.623～0.876,P<0.001)。 结论心血管手术相关急性肾损伤并行连续性肾脏替代治疗患者中,90 d死亡与高龄、CRRT前疾病的严重程度、脓毒症和过低的舒张压有关;90 d存活患者透析依赖与患者术前较差的肾功能有关;90 d存活患者延迟摆脱透析与血清白蛋白低、机械通气时间长、CRRT前尿量少有关。     

Serum creatine kinase levels are not associated with an increased need for continuous renal replacement therapy in patients with acute kidney injury following rhabdomyolysis

Severe rhabdomyolysis can lead to acute kidney injury (AKI). Previous studies have reported a benefit from continuous renal replacement therapy (CRRT) for rhabdomyolysis-associated AKI. Here, we investigated the potential for serum creatine kinase (CK) levels to be used as a marker for CRRT termination in patients with AKI following rhabdomyolysis. We compared different CK levels in patients after CRRT termination and observed their clinical outcomes. We retrospectively collected 86 cases with confirmed rhabdomyolysis-associated AKI, who were receiving CRRT in Tongji Hospital. Patients’ renal functions were assessed within 24 h of intermission, patients with urine output ≥ 1,000 mL and serum creatinine ≤ 265 umol/L were considered for CRRT termination. After termination, 33 patients with a CK > 5,000 U/L were included in an experimental group, and 53 patients with a CK < 5,000 U/L were included in a control group. Clinical outcomes were compared between the two groups. Higher CK levels, as well as worse renal functions, predicted the necessity of CRRT. After CRRT termination, the in-hospital mortality (p = 0.389) and Multiple Organ Dysfunction Syndrome (MODS) incidence (p = 0.064) were similar between the two groups, while the experimental group showed a significantly shorter in-hospital length of stay (p = 0.026) and Intensive Care Unit (ICU) length of stay (p = 0.038). CRRT termination may be independent of CK levels for patients with rhabdomyolysis-associated AKI, and this is contingent on their renal functions having recovered to an appropriate level.     

Incidence and risk factors of acute kidney injury in COVID-19 patients with and without acute respiratory distress syndrome (ARDS) during the first wave of COVID-19: a systematic review and Meta-Analysis

BackgroundAcute kidney injury (AKI) is common among patients with COVID-19. However, AKI incidence may increase when COVID-19 patients develop acute respiratory distress syndrome (ARDS). Thus, this systematic review and meta-analysis aimed to assess the incidence and risk factors of AKI, need for kidney replacement therapy (KRT), and mortality rate among COVID-19 patients with and without ARDS from the first wave of COVID-19.MethodsThe databases MEDLINE and EMBASE were searched using relevant keywords. Only articles available in English published between December 1, 2019, and November 1, 2020, were included. Studies that included AKI in COVID-19 patients with or without ARDS were included. Meta-analyses were conducted using random-effects models.ResultsOut of 618 studies identified and screened, 31 studies met the inclusion criteria. A total of 27,500 patients with confirmed COVID-19 were included. The overall incidence of AKI in patients with COVID-19 was 26% (95% CI 19% to 33%). The incidence of AKI was significantly higher among COVID-19 patients with ARDS than COVID-19 patients without ARDS (59% vs. 6%, p < 0.001). Comparing ARDS with non-ARDS COVID-19 cohorts, the need for KRT was also higher in ARDS cohorts (20% vs. 1%). The mortality among COVID-19 patients with AKI was significantly higher (Risk ratio = 4.46; 95% CI 3.31–6; p < 0.00001) than patients without AKI.ConclusionThis study shows that ARDS development in COVID-19-patients leads to a higher incidence of AKI and increased mortality rate. Therefore, healthcare providers should be aware of kidney dysfunction, especially among elderly patients with multiple comorbidities. Early kidney function assessment and treatments are vital in COVID-19 patients with ARDS.     

Initiation time of renal replacement therapy on patients with acute kidney injury: A systematic review and meta‐analysis of 8179 participants

The early initiation of renal replacement therapy has been recommended for patients with acute renal failure by some studies, but its effects on mortality and renal recovery are unknown. We conducted an updated meta‐analysis to provide quantitative evaluations of the association between the early initiation of renal replacement therapy and mortality for patients with acute kidney injury. After applying inclusion/exclusion criteria, 51 studies, including 10 randomized controlled trials, with a total of 8179 patients were analyzed. Analysis of the included trials showed that patients receiving early renal replacement therapy had a 25% reduction in all‐cause mortality compared to those receiving late renal replacement therapy (risk ratio [RR] 0.75, 95% CI [0.69, 0.82]). We also noted a 30% increase in renal recovery (RR 1.30, 95% CI [1.07, 1.56]), a reduction in hospitalization of 5.84 days (mean difference [MD], 95% CI [–10.27, –1.41]) and a reduction in the duration of mechanical ventilation of 2.33 days (MD, 95% CI [–3.40, –1.26]) in patients assigned to early renal replacement therapy. The early initiation of renal replacement therapy was associated with a decreased risk of all‐cause mortality compared with the late initiation of RRT in patients with acute kidney injury. These findings should be interpreted with caution given the heterogeneity between studies. Further studies are needed to identify the causes of mortality and to assess whether mortality differs by dialysis dose.     

慢性阻塞性肺疾病急性加重机械通气患者序贯HFNC与NPPV的疗效比较

目的:比较慢性阻塞性肺疾病急性加重（acute exacerbation of chronic obstructive pulmonary disease, AECOPD）患者以肺部感染控制窗（pulmonary infection control window, PIC-W）为切换点序贯经鼻高流量湿化氧疗（high-...