Novel Oxygenation and Saturation Indices for Mortality Prediction in COVID-19 ARDS Patients: The Impact of Driving Pressure and Mechanical Power.

Background: The oxygenation index (OI) and oxygen saturation index (OSI) are proven mortality predictors in pediatric and adult patients, traditionally using mean airway pressure (Pmean). We introduce novel indices, replacing Pmean with DP (ΔPinsp), MPdyn, and MPtot, assessing their potential for predicting COVID-19 acute respiratory distress syndrome (ARDS) mortality, comparing them to traditional indices. Methods: We studied 361 adult COVID-19 ARDS patients for 7 days, collecting ΔPinsp, MPdyn, and MPtot, OI-ΔPinsp, OI-MPdyn, OI-MPtot, OSI-ΔPinsp, OSI-MPdyn, and OSI-MPtot. We compared these in surviving and non-surviving patients over the first 7 intensive care unit (ICU) days using Mann-Whitney U test. Logistic regression receiver operating characteristic (ROC) analysis assessed AUC and CI values for ICU mortality on day three. We determined cut-off values using Youden's method and conducted multivariate Cox regression on parameter limits. Results: All indices showed significant differences between surviving and non-surviving patients on the third day of ICU care. The AUC values of OI-ΔPinsp were significantly higher than those of P/F and OI-Pmean (P values .0002 and <.0001, respectively). Similarly, AUC and CI values of OSI-ΔPinsp and OSI-MPdyn were significantly higher than those of SpO2/FiO2 and OSI-Pmean values (OSI-ΔPinsp: P < .0001, OSI-MPdyn: P values .047 and .028, respectively). OI-ΔPinsp, OSI-ΔPinsp, OI-MPdyn, OSI-MPdyn, OI-MPtot, and OSI-MPtot had AUC values of 0.72, 0.71, 0.69, 0.68, 0.66, and 0.64, respectively, with cut-off values associated with hazard ratios and P values of 7.06 (HR = 1.84, P = .002), 8.04 (HR = 2.00, P ≤ .0001), 7.12 (HR = 1.68, P = .001), 5.76 (HR = 1.70, P ≤ .0001), 10.43 (HR = 1.52, P = .006), and 10.68 (HR = 1.66, P = .001), respectively. Conclusions: Critical values of all indices were associated to higher ICU mortality rates and extended mechanical ventilation durations. The OI-ΔPinsp, OSI-ΔPinsp, and OSI-MPdyn indices displayed the strongest predictive capabilities for ICU mortality. These novel indices offer valuable insights for intensivists in the clinical management and decision-making process for ARDS patients.

The effect of inspiratory rise time on mechanical power calculations in pressure control ventilation: dynamic approach.

BACKGROUND: Mechanical power may serve as a valuable parameter for predicting ventilation-induced injury in mechanically ventilated patients. Over time, several equations have been developed to calculate power in both volume control ventilation (VCV) and pressure control ventilation (PCV). Among these equations, the linear model mechanical power equation (MPLM) closely approximates the reference method when applied in PCV. The dynamic mechanical power equation (MPdyn) computes power by utilizing the ventilatory work of breathing parameter (WOBv), which is automatically measured by the mechanical ventilator. In our study, conducted in patients with Covid-19 Acute Respiratory Distress Syndrome (C-ARDS), we calculated mechanical power using both the MPLM and MPdyn equations, employing different inspiratory rise times (Tslope) at intervals of 5%, ranging from 5 to 20% and compared the obtained results. RESULTS: In our analysis, we used univariate linear regression at both I:E ratios of 1:2 and 1:1, considering all Tslope values. These analyses revealed that the MPdyn and MPLM equations exhibited strong correlations, with R2 values exceeding 0.96. Furthermore, our Bland-Altman analysis, which compared the power values derived from the MPdyn and MPLM equations for patient averages and all measurements, revealed a mean difference of -0.42 ± 0.41 J/min (equivalent to 2.6% ± 2.3%, p < 0.0001) and -0.39 ± 0.57 J/min (equivalent to 3.6% ± 3.5%, p < 0.0001), respectively. While there was a statistically significant difference between the equations in both absolute value and relative proportion, this difference was not considered clinically relevant. Additionally, we observed that each 5% increase in Tslope time corresponded to a decrease in mechanical power values by approximately 1 J/min. CONCLUSIONS: The differences between mechanical power values calculated using the MPdyn and MPLM equations at various Tslope durations were determined to lack clinical significance. Consequently, for practical and continuous mechanical power estimation in Pressure-Controlled Ventilation (PCV) mode, the MPdyn equation presents itself as a viable option. It is important to note that as Tslope times increased, the calculated mechanical power exhibited a clinically relevant decrease.

Simplified calculation of mechanical power for pressure controlled ventilation in Covid-19 ARDS patients.

BACKGROUND: Mechanical power (MP) is a promising tool for guidance of lung protective ventilation. Different equations have been proposed to calculate MP in pressure control ventilation (PCV). The aim of this study is to introduce an easy to use MP equation MPpcv(m-simpl) and compare it to an equation proposed by Van der Meijden et al. (MPpcv) which considered as the reference equation in PCV. METHODS: Ventilatory parameters of 206 Covid-19 ARDS patients recorded between 24-72 hours after admission to intensive care unit. The PCV data from these patients were retrospectively investigated. MP in PCV was calculated with a modified equation (MPpcv(m-simpl)) derived from the equation (MPpcv) of Van der Meijden et al.: 0.098xRRx∆Vx(PEEP+∆Pinsp - 1). The results from MPpcv(slope), MPpcv(simpl), and MPpcv(m-simpl) were compared to MPpcv at 15 cmH2O ∙ s/L inspiratory resistance levels by univariable regression and Bland-Altman analysis. RESULTS: Inspiratory resistance levels at 15 cmH2O s/L was found to be correlated between the power values calculated by MPpcv(simpl)/MPpcv(m-simpl) and the MPpcv(slope)/MPpcv based on univariable logistic regression (R2≥98) analyses. In the comparison of all patients average MP values computed by the MPpcv(m-simpl) equation and the MPpcv reference equation. Bland-Altman analysis mean difference and p values at 15 cmH2O s/L inspiratory resistance values (J/min) were found to be MPpcv(m-simpl) vs MPpcv=-0,04 (P=0.014); MPpcv(slope) vs. MPpcv=0.63 (P<0.0001); MPpcv(simpl) vs. MPpcv=0.64 J/min (P<0.0001), respectively. CONCLUSIONS: The results of this study confirmed that the MPpcv(m-simpl) equation can be used easily to calculate MP at bedside in pressure control ventilated COVID-19 ARDS patients.

Comparison of Respiratory and Hemodynamic Parameters of COVID-19 and Non-COVID-19 ARDS Patients.

BACKGROUND: COVID-19 can cause a clinical spectrum from asymptomatic disease to life-threatening respiratory failure and acute respiratory distress syndrome (ARDS). There is an ongoing discussion whether the clinical presentation and ventilatory parameters are the same as typical ARDS or not. There is no clear understanding of how the hemodynamic parameters have been affected in COVID-19 ARDS patients. We aimed to compare hemodynamic and respiratory parameters of moderate and severe COVID-19 and non-COVID-19 ARDS patients. These patients were monitored with an advanced hemodynamic measurement system by the transpulmonary thermodilution method in prone and supine positions. PATIENTS AND METHODS: Data of 17 patients diagnosed with COVID-19 and 16 patients diagnosed with other types of diseases with moderate and severe ARDS, mechanically ventilated, placed in a prone position, had advanced hemodynamic measurements with PiCCO, and stayed in the intensive care unit for more than a week were analyzed retrospectively. Patient characteristics and arterial blood gases analysis recorded at admission and respiratory and advanced hemodynamic parameters during the first week were compared in prone and supine positions. RESULTS: No difference was observed in the respiratory parameters including respiratory system compliance between COVID-19 and non-COVD-19 patients in prone and supine positions. In comparison of advanced hemodynamic parameters in the first week of intensive care, the extravascular lung water and pulmonary vascular permeability indexes measured in supine position of COVID-19 ARDS patients were found to be significantly higher than non-COVID-19 patients. Duration of prone position was significantly longer in patients diagnosed with COVID-19 ARDS. CONCLUSIONS: The results of this study suggested that COVID-19 ARDS is a variant of typical ARDS with a different pathophysiology. HOW TO CITE THIS ARTICLE: Asar S, Acicbe Ö, Sabaz MS, Tontu F, Canan E, Cukurova Z, et al. Comparison of Respiratory and Hemodynamic Parameters of COVID-19 and Non-COVID-19 ARDS Patients. Indian J Crit Care Med 2021;25(6):704-708.

The relationship between serum erythropoietin, hepcidin, and haptoglobin levels with disease severity and other biochemical values in patients with COVID-19.

INTRODUCTION: Studies have shown that iron metabolism is affected by coronavirus disease 19 (COVID-19), which has spread worldwide and has become a global health problem. Our study aimed to evaluate the relationship between COVID-19 and serum erythropoietin (EPO), hepcidin, and haptoglobin (Hpt) levels with disease severity, and other biochemical values. METHODS: Fifty nine COVID-19 patients hospitalized in the intensive care unit (ICU) and wards in our hospital between March and June 2020 and 19 healthy volunteers were included in the study. Participants were divided into mild, severe, and critical disease severity groups. Group mean values were analyzed with SPSS according to disease severity, mortality, and intubation status. RESULTS: Hemoglobin (Hb) levels were significantly lower in the critical patient group (P < .0001) and deceased group (P < .0001). The red blood cell distribution width-coefficient of variation (RDW-CV) and ferritin values were significantly higher in the intubated (P = .001, P = .005) and deceased (P = .014, P = .003) groups. Ferritin values were positively correlated with disease severity (P < .0001). Serum iron levels were lower in the patient group compared with the reference range. (P < .0001). It was found that the transferrin saturation (TfSat) was lower in the patient group compared with the control group (P < .0001). It was found that the mean EPO of the deceased was lower than the control group and the survived patient group (P = .035). Hepcidin levels were found to be significantly lower in the patient group (P < .0001). Hpt values were found to be significantly lower in the intubated group (P = .004) and the deceased group (P = .042). CONCLUSION: In our study, while serum iron and hepcidin levels decreased in patients diagnosed with COVID-19, we found that EPO and Hpt levels were significantly lower in critical and deceased patient groups. Our study is the first study examining EPO and Hpt levels in patients diagnosed with COVID-19.

Bedside dynamic calculation of mechanical power: A validation study.

PURPOSE: To develop an equation to calculate the bedside dynamic mechanical power (MPdyn) for modern ventilators using the Work of Breathing ventilator (WOBv) parameter. MATERIALS AND METHODS: We developed an equation based on mechanical power values, which is equal to WOBv x minute volume. To measure mechanical power with this equation forty adult patients, hospitalized with the diagnosis of Acute Respiratory Distress Syndrome and underwent invasive mechanical ventilation, were used. To be able compare our results with Gattinoni's standart mechanical power equation (MPstd) the contribution of the PEEP was included in our equation. Then results obtained from MPdyn and MPstd were compared using univariable regression and Bland-Altman analysis. This comparison was performed at different I:E ratios, PEEP levels and tidal volumes. RESULTS: Analysis of the results for each condition showed that MPdyn and MPstd equation correlated with R2 ≥ 0.98. Additionally, there was no statistically significant difference between MPdyn and MPstd for patient power means were 0.04 J/min (p = .42) using Bland-Altman analysis. CONCLUSIONS: Physicians can easily calculate mechanical power by using MPdyn at the bedside of patients on volume control mode.

Dengue fever: Report from the task force on tropical diseases by the World Federation of Societies of Intensive and Critical Care Medicine.

Dengue is an arbovirus affecting humans and spread by mosquitoes. Severe dengue follows a secondary infection with a different virus serotype. The problem is truly global as it is endemic in over 100 countries. Severe dengue can be a life-threatening because of increased vascular permeability, resulting in leakage of fluid from the intravascular compartment to the extravascular space. When major bleeding does occur, it is almost invariably combined with profound shock since this, in combination with thrombocytopenia, hypoxia, and acidosis, can lead to multiple organ failure and disseminated intravascular coagulation. Dengue hemorrhagic fever and dengue shock syndrome are among the leading causes of morbidity and mortality in patients suffering from Dengue. Commercial rapid tests and ELISA kits are freely available, ensuring early diagnosis. The basis of management of severe dengue is effective fluid replacement. Future directions in management will involve vector control and development of effective vaccination.

Critical care of tropical disease in low income countries: Report from the Task Force on Tropical Diseases by the World Federation of Societies of Intensive and Critical Care Medicine.

Tropical disease results in a great burden of critical illness. The same life-saving and supportive therapies to maintain vital organ functions that comprise critical care are required by these patients as for all other diseases. In low income countries, the little available data points towards high mortality rates and big challenges in the provision of critical care. Improving critical care in low income countries requires a focus on hospital design, training, triage, monitoring & treatment modifications, the basic principles of critical care, hygiene and the involvement of multi-disciplinary teams. As a large proportion of critical illness from tropical disease is in low income countries, the impact and reductions in mortality rates of improved critical care in such settings could be substantial.

Risk factors for occupational brucellosis among veterinary personnel in Turkey.

Veterinarians and veterinary technicians are at risk for occupational brucellosis. We described the risk factors of occupational brucellosis among veterinary personnel in Turkey. A multicenter retrospective survey was performed among veterinary personnel who were actively working in the field. Of 712 veterinary personnel, 84 (11.8%) had occupational brucellosis. The median number of years since graduation was 7 (interquartile ranges [IQR], 4-11) years in the occupational brucellosis group, whereas this number was 9 (IQR, 4-16) years in the non-brucellosis group (p<0.001). In multivariable analysis, working in the private sector (odds ratio [OR], 2.8; 95% confidence interval [95% CI], 1.55-5.28, p=0.001), being male (OR, 4.5; 95% CI, 1.05-18.84, p=0.041), number of performed deliveries (OR, 1.01; 95% CI, 1.002-1.02, p=0.014), and injury during Brucella vaccine administration (OR, 5.4; 95% CI, 3.16-9.3, p<0.001) were found to be risk factors for occupational brucellosis. We suggest that all veterinary personnel should be trained on brucellosis and the importance of using personal protective equipment in order to avoid this infection.

[In Vitro Effect of Ankaferd Blood Stopper®, a Plant Extract Against Mycobacterium tuberculosis Isolates]. / Bir Bitki Ekstresi Olan Ankaferd Blood Stopper®'in Mycobacterium tuberculosis Izolatlarina Karsi In Vitro Etkinligi.

Treatment of drug-resistant Mycobacterium tuberculosis infections requires combination of anti-tuberculosis drugs which have several toxic side effects. Thus there is a need for safer and effective new drugs. Ankaferd Blood Stopper® (ABS), which is a mixture of plant extracts prepared from Alpinia officinarum, Glycyrrhiza glabra, Thymus vulgaris, Urtica dioica and Vitis vinifera, has homeostatic and antibacterial effects. Standard solutions of ABS are already being used topically for post-traumatic and post-operative bleeding control in our country. This study was aimed to evaluate the in vitro activity of ABS against M.tuberculosis isolates. A total of 57 clinical isolates [17 multidrug resistant (MDR), 11 resistant to only isoniazid (INH), one resistant to INH and streptomycin (STR), two resistant only to STR, two resistant only to ETM, and 24 susceptible to all drugs] and three standard strains [H37Rv (susceptible to all drugs), ATCC 35822 (INH-resistant), ATCC 35820 (STR-resistant)] were included in the study. Agar dilution method was used to detect the MIC values of ABS. In the study, ABS MIC value was determined as 10.94 µg/ml for M.tuberculosis H37Rv strain which was susceptible to all anti-tuberculosis drugs, whereas it was determined as 21.88 µg/ml for INH-resistant ATCC 35822 and STR-resistant ATCC 35820 strains. The MIC values for 24 susceptible clinical isolates were as follows; 10.94 µg/ml (n= 17), 21.88 µg/ml (n= 6) and < 1.37 µg/ml (n= 1). When evaluating 17 MDR clinical isolates, MIC values were determined as 5.47 µg/ml (n= 1), 10.94 µg/ml (n= 5) and 21.88 µg/ml (n= 11). MIC values were ranging between < 1.37-21.88 µg/ml among 11 INH-resistant isolates. These isolates were susceptible to other first line anti-tuberculosis drugs. MIC value of one isolate resistant to both of INH and STR was determined as 21.88 µg/ml. MIC value of the two sole STR-resistant isolates was 21.88 µg/ml. MIC values of the two sole ETM-resistant isolates were determined as 21.88 µg/ml and 10.94 µg/ml. MIC50 and MIC90 values for the tested bacteria were 10.94 µg/ml and 21.88 µg/ml, respectively. It was concluded that 16 fold diluted concentration of the topically used ABS solution was found to be active against tuberculosis bacilli in vitro. Thus ABS might be used as a supportive agent together with anti-tuberculous drugs during debridement of multiple drug-resistant M.tuberculosis caused osteomyelitis and lymphadenitis lesions.

In vitro effects of sulbactam combinations with different antibiotic groups against clinical Acinetobacter baumannii isolates.

Treatment of multidrug resistant (MDR) Acinetobacter baumannii infections causes some problems as a result of possessing various antibacterial resistance mechanisms against available antibiotics. Combination of antibiotics, acting by different mechanisms, is used for the treatment of MDR bacterial infections. It is an important factor to determine synergy or antagonism between agents in the combination for the constitution of effective therapy. The study aimed to determine In vitro interactions interpreted according to calculated fractional inhibitory concentration (FIC) index between sulbactam and ceftazidime, ceftriaxone, cefepime, ciprofloxacin, gentamicin, meropenem, tigecycline, and colistin. Ten clinical isolates of A. baumannii were tested for determination of synergistic effects of sulbactam with different antimicrobial combinations. Minimal inhibitory concentration (MIC) values of both sulbactam and combined antibiotics decreased 2- to 128-fold. Synergy and partial synergy were determined in combination of sulbactam with ceftazidime and gentamicin (FIC index: ≤ 0.5 or >0.5 to <1) and MIC values of both ceftazidime and gentamicin for five isolates fell down below the susceptibility break point. Similarly, MIC value of ciprofloxacin for six ciprofloxacin resistant isolates was determined as below the susceptibility break point in combination. However, all isolates were susceptible to colistin and tigecycline, MIC values of both were decreased in combination with sulbactam. Although synergistic and partial synergistic effects were observed in the combination of sulbactam and ceftriaxone, all isolates remained resistant to ceftriaxone. The effect of cefepime-sulbactam combination was synergy in five, partial synergy in one and indifferent in four isolates. Meropenem and sulbactam showed a partial synergistic effect (FIC index: >0.5 to <1) in three, an additive effect (FIC index: 1) in one and an indifferent effect (FIC index: >1-2) in six isolates. Antagonism was not determined in any combination for clinical A. baumannii isolates in the study. In conclusion, sulbactam is a good candidate for combination treatment regimes for MDR A. baumannii infections.