How to Prevent Ventilator-Induced Lung Injury in Intraoperative Mechanical Ventilation? A Randomized Prospective Study.

Objective: Intraoperative mechanical ventilation practices can lead to ventilator-induced lung injury (VILI) and postoperative pulmonary complications in healthy lungs. Mechanical power (MP) has been developed as a new concept in reducing the risk of postoperative pulmonary complications as it considers all respiratory mechanics that cause VILI. The most commonly used intraoperative modes are volume control ventilation (VCV) and pressure control ventilation (PCV). In this study, VCV and PCV modes were compared in terms of respiratory mechanics in patients operated in the supine and prone positions. Methods: The patients were divided into 4 groups (80 patients), volume control supine and prone, pressure control supine and prone with 20 patients each. MP, respiratory rate, positive end-expiratory pressure, tidal volume, peak pressure, plato pressure, driving pressure, inspiratory time, height, age, gender, body mass index, and predictive body weight data of the patients included in the groups have been obtained from "electronic data pool" with Structured Query Language queries. Results: The supine and prone MP values of the VCV group were statistically significantly lower than the PCV group (P values were 0.010 and 0.001, respectively). Conclusion: Supine and prone MP values of the VCV group were calculated significantly lower than the PCV group. Intraoperative PCV may be considered disadvantageous regarding the risk of VILI in the supine and prone positions.

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.

Sepsis Prediction by Using a Hybrid Metaheuristic Algorithm: A Novel Approach for Optimizing Deep Neural Networks.

The early diagnosis of sepsis reduces the risk of the patient's death. Gradient-based algorithms are applied to the neural network models used in the estimation of sepsis in the literature. However, these algorithms become stuck at the local minimum in solution space. In recent years, swarm intelligence and an evolutionary approach have shown proper results. In this study, a novel hybrid metaheuristic algorithm was proposed for optimization with regard to the weights of the deep neural network and applied for the early diagnosis of sepsis. The proposed algorithm aims to reach the global minimum with a local search strategy capable of exploring and exploiting particles in Particle Swarm Optimization (PSO) and using the mental search operator of the Human Mental Search algorithm (HMS). The benchmark functions utilized to compare the performance of HMS, PSO, and HMS-PSO revealed that the proposed approach is more reliable, durable, and adjustable than other applied algorithms. HMS-PSO is integrated with a deep neural network (HMS-PSO-DNN). The study focused on predicting sepsis with HMS-PSO-DNN, utilizing a dataset of 640 patients aged 18 to 60. The HMS-PSO-DNN model gave a better mean squared error (MSE) result than other algorithms in terms of accuracy, robustness, and performance. We obtained the MSE value of 0.22 with 30 independent runs.

The power of mechanical ventilation may predict mortality in critically ill patients.

BACKGROUND: Mechanical power (MP) is the amount of energy transferred from the ventilator to the patient within a unit of time. It has been emphasized in ventilation-induced lung injury (VILI) and mortality. However, its measurement and use in clinical practice are challenging. "Electronic recording systems (ERS)" using mechanical ventilation parameters provided by the ventilator can be helpful to measure and record the MP. The MP (J/minutes) formula is 0.098 x tidal volume x respiratory rate x (Ppeak - ½ ∆P), in which ∆P is the driving pressure and Ppeak is the peak pressure. We aimed to define the association between MP values and ICU mortality, mechanical ventilation days, and intensive care unit length of stay (ICU-LOS). The secondary outcome was to determine the most potent or essential component of power in the equation that has a role in mortality. METHODS: This retrospective study was performed in two centers (VKV American Hospital and Bakirköy Sadi Konuk Hospital ICUs) that used ERS (Metavision IMDsoft) between 2014 and 2018. We uploaded the power formula (MP (J/minutes)=0.098×VT×RR×(Ppeak - ½ ∆P) to ERS (METAvision, iMDsoft, and Consult Orion Health) and calculated the MP value by using MV parameters automatically sent from the ventilator. (∆P; driving pressure, VT; tidal volume, RR; respiratory rate and Ppeak; peak pressure). RESULTS: A total of 3042 patients were included in the study. The median value of MP was 11.3 J/min. Mortality in MP<11.3 J/min was 35.4%, and 49.1% in MP>11.3J/min.; P<0.001. Mechanical ventilation days and ICU-LOS were also statistically longer in the MVP>11.3 J/min group. CONCLUSIONS: The first 24 h MP maybe a predictive value for the ICU patients' prognosis. This implies that MP may be used as a decision-making system to define the clinical approach and as a scoring system to predict patient prognosis.

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.

Association between Acute Pancreatitis and COVID-19: Could Pancreatitis Be the Missing Piece of the Puzzle about Increased Mortality Rates?

BACKGROUND: The COVID-19 pandemic caused by SARS-CoV-2 commenced in Wuhan China in 2019 and soon spread worldwide. SARS-CoV-2 enters the cell by binding to the ACE II receptor and begins viral replication. The effects and clinical findings of SARS-CoV-2 on the liver, kidney, heart, gastrointestinal (GI) system and especially lungs have been widely discussed. However, the effects on the pancreas-another organ that also expresses ACE II-have not been studied. METHODS: This work prospectively evaluated data from 316 patients who were admitted with a diagnosis of COVID-19 pneumonia. The patients were categorized into three according to the severity of pneumonia (mild, severe, critical). Demographic data, rate of pancreatitis, biochemical parameters, and radiological images from each group were analyzed. The patients were divided into two groups and outcomes were compared: COVID-19 patients with acute pancreatitis (Group P) and without acute pancreatitis (Group C). RESULTS: The median age was 54 (18-87), and the median age for patients with acute pancreatitis was 55 (26-84). As an expected finding, we found a positive correlation between advanced age and mortality (p = 0.0003). 12.6% of the patients had acute pancreatitis. While pancreatitis was not seen in patients on mild status, the rate of pancreatitis was 32.5% in critical patients. Hospitalization and mortality rates were higher in patients with COVID-19 accompanied by acute pancreatitis (p = 0.0038 and p < 0.0001, respectively). C-Reactive Protein (CRP) and ferritin were significantly higher in those who had pancreatitis (p < 0.0001). D-Dimer and procalcitonin levels had only a small difference (p = 0.1127 and p = 0.3403, respectively). CONCLUSION: Acute pancreatitis alone is a clinical condition that can lead to mortality and may be one of the reasons for the exaggerated immune response developing in the progression of COVID-19. Our results point out that the presence of pancreatic damage triggered by SARS-CoV-2 can deteriorate the clinical condition of patients and the mortality rate may increase in these patients.

Efficacy of erector spinae plane block on postoperative pain in patients undergoing lumbar spine surgery.

BACKGROUND: Major lumbar spine surgery causes severe pain in the postoperative period. There are few studies regarding the effect of erector spinae plane block (ESPB) effect on lumbar surgery and its effect is still controversial. Therefore, the study aimed to investigate the effect of ultrasound-guided low thoracic ESPB on opioid consumption and postoperative pain score. MATERIAL AND METHODS: Seventy-eight patients undergoing elective open lumbar spine surgery were randomized into two groups. In ESPB group (n = 35) received ultrasound-guided ESPB and in the control group (n = 35), there was no block. Postoperative opioid consumption as morphine equivalent dose, numerical rating scale, mobilization time, discharge time and side effects, bolus deliveries, rescue analgesia doses were evaluated. RESULTS: Total opioid consumption as morphine equivalent was higher in the control group than the ESPB group (p = 0.000). Compare with the control group, the numeric rating scale scores were lower in the ESPB group at the 6th, 12th, and 24th hours (p < 0.05). The patient-controlled analgesia button pressing number in the postoperative 24-h period was lower in the ESPB group (p = 0.000). In the postoperative 24-h period, the need for paracetamol in the ESPB group was lower and the difference between the groups was statistically significant (p = 0.008). Rescue analgesia (diclofenac) doses were higher in the control group (p < 0.05). There was no statistically significant difference in terms of side effects and mobilization times. CONCLUSION: ESPB is adequate for postoperative analgesia in patients undergoing lumbar spine surgery and can reduce opioid consumption compared with standard analgesia.

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 effect of body mass index on the development of acute kidney injury and mortality in intensive care unit: is obesity paradox valid?

BACKGROUND: The conflicting results of studies on intensive care unit (ICU) mortality of obese patients and obese patients with acute kidney injury (AKI) reveal a paradox within a paradox. The aim of this study was to determine the effects of body mass index and obesity on AKI development and ICU mortality. METHODS: The 4,459 patients treated between January 2015 and December 2019 in the ICU at a Tertiary Care Center in Turkey were analyzed retrospectively. RESULTS: AKI developed more in obese patients with 69.8% (620). AKI development rates were similar in normal-weight (65.1%; 1172) and overweight patients (64.9%; 1149). The development of AKI in patients who presented with cerebrovascular diseases was higher in obese patients (81; 76.4%) than in normal-weight (158; 62.7%) and overweight (174; 60.8%) patients (p < 0.05). The risk of developing AKI was approximately 1.4 times (CI 95% = 1.177-1.662) higher in obese patients than in normal-weight patients. Dialysis was used more frequently in obese patients (24.3%, p < 0.001), who stayed longer in the ICU (p < 0.05). It was determined that the development of AKI in normal-weight and overweight patients increased mortality (p < 0.001) and that there was not a difference in mortality rates between obese patients with and without AKI. CONCLUSION: The risk of AKI development was higher in obese patients but not in those who were in serious conditions. Another paradox was that the development of AKI was associated with a higher mortality rate in normal-weight and overweight patients, but not in obese patients. Cerebrovascular diseases as a cause of admission pose additional risks for AKI.

In silico identification of widely used and well-tolerated drugs as potential SARS-CoV-2 3C-like protease and viral RNA-dependent RNA polymerase inhibitors for direct use in clinical trials.

Despite strict measures taken by many countries, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be an issue of global concern. Currently, there are no clinically proven pharmacotherapies for coronavirus disease 2019, despite promising initial results obtained from drugs such as azithromycin and hydroxychloroquine. Therefore, the repurposing of clinically approved drugs for use against SARS-CoV-2 has become a viable strategy. Here, we searched for drugs that target SARS-CoV-2 3C-like protease (3CLpro) and viral RNA-dependent RNA polymerase (RdRp) by in silico screening of the U.S. Food and Drug Administration approved drug library. Well-tolerated and widely used drugs were selected for molecular dynamics (MD) simulations to evaluate drug-protein interactions and their persistence under physiological conditions. Tetracycline, dihydroergotamine, ergotamine, dutasteride, nelfinavir, and paliperidone formed stable interactions with 3CLpro based on MD simulation results. Similar analysis with RdRp showed that eltrombopag, tipranavir, ergotamine, and conivaptan bound to the enzyme with high binding free energies. Docking results suggest that ergotamine, dihydroergotamine, bromocriptine, dutasteride, conivaptan, paliperidone, and tipranavir can bind to both enzymes with high affinity. As these drugs are well tolerated, cost-effective, and widely used, our study suggests that they could potentially to be used in clinical trials for the treatment of SARS-CoV-2-infected patients.Communicated by Ramaswamy H. Sarma.

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.

Atrial septal defect closure via mini-thoracotomy in pediatric patients: Postoperative analgesic effect of intercostal nerve block.

BACKGROUND: In this study, we evaluated the efficacy of intercostal nerve block for postoperative pain management in pediatric patients undergoing atrial septal defect closure through a right lateral mini-thoracotomy. METHODS: Between January 2016 and January 2019, a total of 63 pediatric patients (37 males, 26 females; mean age 34.8±26.8 months; range, 2 to 96 months) who underwent corrective congenital heart surgery for atrial septal defect closure through a right lateral mini-thoracotomy were retrospectively reviewed. The patients were divided into two groups as those (Group 1, n=33) receiving intercostal nerve block and general anesthesia and those (Group 2, n=30) receiving general anesthesia alone. Intravenous morphine at a dose of 0.03 mg/kg was applied as rescue analgesia to the patients with a Ramsay Sedation Scale score of >4 and Children"s Hospital of Eastern Ontario Pain Scale score of >7. The total analgesic requirement, adverse effects, duration of mechanical ventilation and length of stay in the intensive care unit were recorded. RESULTS: The mean duration of mechanical ventilation and intensive care unit stay was shorter in Group 1 compared to Group 2 (3.6±1.3 vs. 9.4±2.1 h; 23±2.6 vs. 30±7.2 h, respectively) (p<0.0001). The need for postoperative rescue analgesia was statistically significantly lower in Group 1 compared to Group 2 (0.3±0.5 mg vs. 1.1±0.9 mg, respectively) (p=0.003). The mean total morphine consumption was also lower in Group 1 compared to Group 2 (4.0±2.2 mg vs. 9.0±3.4 mg, respectively) (p<0.0001). CONCLUSION: Intercostal nerve block before thoracotomy closure in pediatric patients undergoing atrial septal defect repair under mini-thoracotomy provides early extubation, shorter mechanical ventilation duration and intensive care unit stay, and reduced analgesic requirements.