Mean Peak Inspiratory Pressure Research Articles

Risk factors affecting the development of pneumothorax in patients followed up in intensive care with a diagnosis of COVID-19

BackgroundPneumothorax is a little known and reported complication of COVID-19. These patients have poorer general outcomes and greater respiratory support requirements, longer hospitalization times, and higher mortality rates. The purpose of this study was to determine which factors predict mortality in patients with tube thoracostomy diagnosed with COVID-19, admitted to the COVID-19 intensive care unit (ICU), and developing pneumothorax.MethodsThis respective, observational study was conducted in all COVID-19 ICUs at the Marmara University Pendik Training and Research Hospital, Türkiye. Patients admitted to the ICU with diagnoses of COVID-19 pneumonia and with chest tubes inserted due to pneumothorax were investigated retrospectively.ResultsOne hundred patients with tube thoracostomy were included in the study. Their median age was 68 (57–78), and 63% were men. The median follow-up time was 20 [10–29] days, and the median time from initial reverse transcriptase polymerase chain reaction (RT-PCR) results to tube thoracostomy was 17 [9–23] days. Initial RT-PCR results were positive in 90% of the patients, while 8% were negative, and 2% were unknown. Half the patients exhibited pulmonary involvement at thoracic computed tomography (CT) (n = 50), while 22 patients had COVID-19 reporting and data system (CO-RADS) scores of 5 (22%). Sixty-two patients underwent right tube thoracostomy, 24 left side placement, and 14 bilateral placement. The patients’ mean positive end expiratory pressure (PEEP) level was 10.31 (4.48) cm H2O, with a mean peak inspiratory pressure (PIP) level of 26.69 (5.95) cm H2O, a mean fraction of inspired oxygen (FiO2) level of 80.06 (21.11) %, a mean respiratory rate of 23.71 (5.62) breaths/min, and a mean high flow nasal cannula (HFNC) flow rate of 70 (8.17) L/min. Eighty-seven patients were intubated (87%), six used non-rebreathable reservoir masks, four HFNC, two non-invasive mechanical ventilation (NIV), and one a simple face mask. Comorbidity was present in 70 patients, 25 had no comorbidity, and the comorbidity status of five was unknown. Comorbidities included hypertension (38%), diabetes mellitus (23%), cardiovascular disease (12%), chronic obstructive pulmonary disease (5%), malignancy (3%), rheumatological diseases (3%), dementia (2%) and other diseases (9%). Twelve of the 100 patients survived. The median survival time was 20 (17.82–22.18) days, and the median 28-day overall survival rate was 29% (20-38%). The multivariate Cox proportional hazards model indicated that age over 68 (HR = 2.23 [95% CI: 1.39–3.56]; p = 0.001), oxygenation status other than by intubation (HR = 2.24 [95% CI: 1.11–4.52]; p = 0.024), and HCO3- below 22 compared with a normal range of 22 to 26 (HR = 1.95 [95% CI: 1.08–3.50]; p = 0.026) were risk factors associated with mortality in patients in the ICU.ConclusionsAge over 68, receipt of oxygenation other than by intubation, and HCO3- values lower than 22 in patients with COVID-19 pneumonia emerged as prognostic factors associated with mortality in terms of pneumothorax.

Effects of Dexmedetomidine in Improving Oxygenation and Reducing Pulmonary Shunt in High-Risk Pediatric Patients Undergoing One-Lung Ventilation for Thoracic Surgery: A Double-Blind Randomized Controlled Trial.

Background and objectives Pediatric thoracic surgery has unique considerations due to the immaturity of the respiratory system anatomically and physiologically, which presents technical and pharmacological considerations, including the very common technique of one-lung ventilation (OLV), which causes serious complications in children. Therefore, we investigated the effects of dexmedetomidine on oxygenation and pulmonary shunt fraction (Qs/Qt) in high-risk pediatric patients undergoing OLV for thoracic surgery. This randomized controlled trial aimed to investigate dexmedetomidine's effect on the partial pressure of arterial oxygen (PaO2) and pulmonary shunt fraction (Qs/Qt). Methods A total of 63 children underwent thoracic surgery with OLV and were divided into two groups. The dexmedetomidine group (group Dex, n = 32) received dexmedetomidine (0.4 μg/kg/hour), and the placebo group (group placebo, n = 31) received normal saline. Two arterial and central venous blood samples were taken for arterial and venous blood gas analysis at four time points: T1 (10 minutes after mechanical ventilation of total lung ventilation), T2 (10 minutes after OLV), T3 (60 minutes after OLV), and T4 (20 minutes after the end of OLV). At these intervals, the following parameters were measured: PaO2, Qs/Qt, mean arterial pressure (MAP), heart rate (HR), and peak inspiratory pressure (PIP). Results The two groups had no significant differences in FEV1/FVC and baseline pulmonary shunt fraction (Qs/Qt). Dexmedetomidine significantly improved PaO2 compared with placebo during OLV (T2 and T3). There was a significant decrease in Qs/Qt compared with placebo during OLV (T2, T3, and T4). There was a decrease in PIP compared with placebo during OLV (T2 and T3). No statistically significant differences in MAP or HR were observed between the groups. Conclusion Infusion of dexmedetomidine during OLV in high-risk pediatric thoracic surgery reduces shunt and pulmonary shunt fraction Qs/Qt, improves PaO2 and body oxygenation, reduces PIP and pressure load, and maintains hemodynamic stability (MAP, HR).

Current State of Ventilator Setting and Their Relationship with Mortality Rate in Patients under Mechanical Ventilation: A Cross-Sectional Study

Background: Given the importance of implementing lung protective strategies to prevent lung injury caused by ventilators and death of patients, it is necessary to monitor the current condition of hospitals and examine the relationship between the parameters set on the ventilators and patient mortality. This study conducted to determine the current state of ventilator setting and their relationship with mortality rate in patients under mechanical ventilation: a cross-sectional study. Methods: This is a cross-sectional study that was conducted between June to December 2020 in one of the hospitals affiliated to Tehran University of Medical Sciences. The initial tidal volume set on the ventilator was recorded for 304 patients under mechanical ventilation and then, their heights were measured and their tidal volumes were determined based on the standard formula. Other parameters set on the ventilator as well as systolic and diastolic blood pressures of patients were also recorded and their survival rate was investigated. The data was analyzed by SPSS software, using descriptive statistics and logistic regression model. Results: Among patients, who were under mechanical ventilation, 77.6% were hospitalized in intensive care units and the rest were hospitalized in general wards. The mean adjusted tidal volume for patients was 472.91 ± 32.13 ml. The mean peak inspiratory pressure and plateau pressure were 28.00±6.98 and 13.88±4.93 CmH2O, respectively. Also, 37.2% of patients died during the hospitalization. The results of adjusted odds ratio based on multivariate logistic regression model for predictors of mortality rate showed that the variables of patients' age [OR=1.040 (1.019-1.062)], the hospital’s general ward in comparison with the ICU [OR=11.379 (5.130-25.240)] and the peak inspiratory pressure [OR=1.072 (1.007-1.141)] had a direct and significant relationship with mortality rate (in all cases P<0.05). Meanwhile, the plateau pressure [OR=0.886 (0.808 -0.972)] had an inverse and significant relationship with mortality rate (P<0.05). Conclusion: Despite the recommendations regarding lung protective strategies, in some cases, some parameters set in the ventilator are outside the recommended levels, which can effect on patients mortality. So monitoring and controlling the implementation of lung protective strategies and paying attention to controlling pressures set on the ventilator are among measures that should be taken in medical centers in order to prevent lung injuries and maintain patient safety.

Effect of Dexmedetomidine on Oxygen and Intrapulmonary Shunt (Qs/Qt) During One-Lung Ventilation in Pediatric Surgery: A Randomized Controlled Trial.

Background One-lung ventilation (OLV) is a common ventilation technique used during thoracic surgery. It can cause serious complications in children, and hypoxic pulmonary vasoconstriction (HPV) is a protective mechanism against the resulting hypoxia.Dexmedetomidine does not affect HPV, so we will investigate its impact on the partial pressure of oxygen in arterial blood (PaO2) and pulmonary shunt fraction (Qs/Qt). Methods Children who underwent OLV were divided into two equal groups. The Dex group received 0.4 μg/kg/h of dexmedetomidine intravenously. The placebo group received normal saline. Two blood samples were taken to analyze arterial and central venous blood gasses during four time periods: T1, 10 minutes after anesthesia; T2, 10 minutes after OLV; T3, 60 minutes after OLV; and T4, 20 minutes after the end of OLV. Heart rate, mean arterial pressure (MAP), PaO2, Qs/Qt, and peak inspiratory pressure (PIP) values were recordedat these time points. Results Regarding heart rate, the Dex group remained relatively stable, whereas the placebo group showed a slight increase in T3 and T4. Concerning MAP, theDex group had a reduction at T1 compared with the placebo group and remained similar for other points. PaO2 decreased with OLV. However, the Dex group consistently maintained higher PaO2 values than the placebo, especially in T3 and T4. Concerning Qs/Qt, the Dex group maintained lower time values than the placebo group at OLV. Regarding PIP, the Dex group had significantly lower T2 and T3 than the placebo group. Conclusion Administration ofdexmedetomidine inchildren with OLV improves PaO2 and reduces pulmonary shunt fraction (Qs/Qt), thereby improving oxygen transport. It reduces the maximum PIP values, thereby reducing pressure-related complications.

Comparison of nasal and face mask ventilation in anaesthetised obese adults: A randomised controlled study.

The use of a face mask while inducing general anaesthesia (GA) in obese patients is often ineffective in providing adequate ventilation. Although nasal mask ventilation has demonstrated effectiveness for continuous positive airway pressure (CPAP) in obese patients with obstructive sleep apnoea (OSA), it has not yet been applied to the induction of anaesthesia. This study evaluated the efficacy of nasal mask ventilation against standard face mask ventilation in anaesthetised obese patients with body mass index (BMI)>25 kg/m2. Ninety adult patients with BMI >25 kg/m2 were randomly assigned to receive either facemask (Group FM) or nasal-mask (Group NM) ventilation during induction of GA. Expired tidal volume (VtE), air leak, peak inspiratory pressure (PIP), plateau pressure (PPLAT), oxygen saturation (SpO2), and end-tidal carbon dioxide (EtCO2) were recorded for10 breaths, and their mean was analysed. The mean (standard deviation) VtE measured was not significantly higher in Group NM [455.98 (55.64) versus 436.90 (49.50) mL, P = 0.08, degree of freedom (df):88, mean difference (95% confidence interval [CI]) -19.08 (-41.14, 2.98) mL]. Mean air-leak [16.44 (22.16) versus 31.63 (21.56) mL, P = 0.001, df: 88, mean difference 95%CI: 15.19 (6.03,24.35)], mean PIP [14.79 (1.39) versus 19.94 (3.05) cmH2O, P = 0.001, df: 88, mean difference, 95%CI: 5.15 (4.16, 6.14)], and mean PPLAT [12.04 (1.21) versus 16.66 (2.56) cmH2O, P = 0.001, df: 88, mean difference 95% CI: 4.62 (3.78, 5.45)] were significantly lower in Group NM. EtCO2, SpO2, and haemodynamic measurements were similar between the two groups. Nasal mask ventilation is an effective ventilation method and can be used as an alternative to face mask ventilation in anaesthetised obese adults with BMI>25 kg/m2.

Clinical Efficacy of Ambu AuraGainTM and i-gel® in Patients Undergoing Elective Gynaecological Laparoscopic Surgeries Under General Anaesthesia: A Randomised Clinical Study

Introduction: Second-generation supraglottic airway devices that provide high seal pressures are found to be suitable for patients undergoing laparoscopic surgery, as they have a separate port for gastric tube insertion, effectively separating the airway and the oesophagus. The present study compares the usage of two such second-generation supraglottic devices-AuraGain™ and i-gel® in patients undergoing gynaecological laparoscopic surgeries. Aim: To compare the Oropharyngeal Leak Pressure (OLP) and airway pressures achieved by the i-gel® and Ambu AuraGain™ after insertion in the supine position and during laparoscopic carbon dioxide peritoneum in the Trendelenburg position. Materials and Methods: This randomised clinical, singleblinded study conducted at the Department of Anaesthesiology, Narayana Medical College, Nellore, Andhra pradesh, India involved 100 female patients undergoing elective gynaecological laparoscopic surgeries under general anaesthesia with controlled ventilation. The primary objective was to compare the clinical performance of Ambu AuraGain™ (Group-A) and i-gel® (Group-I) concerning their oropharyngeal seal pressures and airway pressures in gynaecological laparoscopic surgeries. The secondary outcomes measured included the time taken for insertion, ease of insertion of the device, effects on postinsertion haemodynamic parameters like heart rate, blood pressure, oxygen saturation, ease of gastric tube insertion, and fibreoptic bronchoscopic grading of the visualised glottic structures after device placement, as well as postoperative side effects like blood staining upon removal of the device and sore throat. Data were analysed using Student’s t-test and chi-square test. Results: The mean age in Group-A was 39.62±4.085 years, and in Group-I, it was 39.48±2.468 years. The mean peak inspiratory pressures after device insertion were 14.34 mmHg in Group-A and 16.66 mmHg in Group-I. Haemodynamic parameters postinsertion were similar in both groups {Group-A: Mean Heart Rate (HR) 87.22 bpm, Mean Arterial Pressure (MAP) 89.72 mmHg, Oxygen Saturation (SpO2 ) 99.58%; Group-I: Mean HR 87.50 bpm, MAP 89.72 mmHg, SpO2 99.72%). Fibreoptic bronchoscopic grading in Group-A was 0/0/9/41, and in Group-I, it was 0/0/11/39. Blood staining upon removal was noted in four patients (8%) in Group-A and in 3 patients (6%) in Group-I. Sore throat in the postoperative period was noted in 14% of patients in Group-A and 8% in Group-I. Conclusion: Ambu AuraGain™ was found to provide a better seal and higher OLP compared to the i-gel® in gynaecological laparoscopic surgeries and therefore provide safer and more effective ventilation for patients undergoing such surgeries. I-gel® was found to be easier and quicker to insert than the AuraGain™.

The effect of APRV-LTV mechanical ventilation mode on SpO2 and ventilation indices in patients with COVID-19

Background & Aim: Mechanical ventilation is a life-saving method for acute respiratory distress syndrome. The present study aimed to investigate the impact of airway pressure release ventilation-low tidal volume mode on COVID-19 patients’ peripheral capillary oxygen saturation and ventilation indices.
 Methods & Materials: This clinical trial was conducted on 70 COVID-19 patients hospitalized in the Intensive care unit in Qom, Iran. Patients were selected using convenience sampling and randomly allocated to intervention and control groups. In the control group, patients were ventilated using synchronized intermittent mandatory ventilation mode, and in the intervention group, patients were ventilated using airway pressure release ventilation-low tidal volume mode. Patients’ peripheral capillary oxygen saturation and ventilation indices were checked and recorded before and after the intervention. The data were analyzed using SPSS 11.5.
 Results: According to the results of the repeated-measures ANOVA test before the intervention and the 2 and 4 hours after the intervention, there were no significant differences between the intervention and control groups regarding the fraction of inspired oxygen, volume minute per minute, and peripheral capillary oxygen saturation (P>0.05). However, in the intervention group compared to the control group, the mean of PIP was significantly reduced (P<0.05).
 Conclusion: In patients with COVID-19, the two modes of mechanical ventilation, APRV, and control, had no significant differences in the fraction of inspired oxygen, volume minute per minute, and peripheral capillary oxygen saturation. However, the mean peak inspiratory pressure reduction in the intervention group was greater than that in the control group. Considering that several factors can affect peripheral capillary oxygen saturation and ventilation indices, these results should be considered with caution.

A pilot study to evaluate the safety and efficacy of automated mechanical respiratory aid device

Background: High burden of morbidity and mortality due to respiratory illnesses was witnessed during the COVID-19 pandemic. We developed a portable automated mechanical respiratory assist device (RespirAID R20) that delivers Intermittent Positive Pressure Ventilation by mechanically compressing a Bag Valve Mask. The objective of the study is to evaluate the safety and efficacy of the RespirAID R20, a mechanical ventilation device in post-operative care patients. Method: This pilot study enrolled five subjects at Yenepoya Medical College Hospital, India. Post-operative subjects were transferred from the Mindray Synovent E3 (standard ventilator) to the RespirAID R20 for 3 hours. Ventilator and physiologic parameters were recorded and compared. Result: All patients maintained normal blood pressure, heart rate, and heart rhythm. The delivered mean tidal volume (VT) and peak inspiratory pressure (PIP) was 419.64 +/- 11 ml and 20 +/- 2 cmH2O, which remained within the initial set range of 428 +/- 12 ml and 24 +/- 2 cmH2O throughout the study duration. Arterial blood gas (ABG) parameters during RespirAID R20, except PaO2, were within the normal range. PaO2 levels were greater than 300 mm Hg during the first four hours (323 +/- 163 mmHg and 344 +/- 97 mmHg). Conclusion: The findings of this study suggests that RespirAID R20 may be an alternative device in providing respiratory assistance to sedated and intubated adult patients in the postoperative period. Additional studies are required to evaluate other possible applications of the RespirAID R20. Keywords: RespirAID R20, ABG parameters, mechanical ventilation, respiratory assist

Endotracheal Tube Size in Critically Ill Patients

Many patients who survive critical illness are left with laryngeal functional impairment from endotracheal intubation that permanently limits their recovery and quality of life. Although the risk for laryngeal injury increases with larger endotracheal tube sizes, there are no data delineating the association of smaller endotracheal tube sizes with survival or acute recovery from critical illness. To determine if smaller endotracheal tubes are noninferior to larger endotracheal tubes with respect to critical illness outcomes. This propensity score-matched retrospective cohort study included all adult patients who underwent endotracheal intubation in the emergency department or intensive care unit and received mechanical ventilation for at least 12 hours from June 2020 to November 2020 at a single tertiary referral academic medical center. Endotracheal intubation. Propensity score-matched analyses were performed with respect to the primary end point of 30-day all-cause in-hospital survival as well as the secondary end points of duration of invasive mechanical ventilation, length of hospital stay, mean peak inspiratory pressure, 30-day readmission, need for reintubation, and need for tracheostomy or gastrostomy tube placement. Overall, 523 participants (64%) were men and 291 (36%) were women. Of these, 814 patients were categorized into 3 endotracheal tube groups: small for height (n = 182), appropriate for height (n = 408), and large for height (n = 224). There was not a significant difference in 30-day all-cause in-hospital survival between groups ([HR, 1.1; 95% CI, 0.7-1.7] for small vs appropriate; [HR, 1.1; 95% CI, 0.7-1.6] for large vs appropriate). Patients with small-for-height endotracheal tubes had longer intubation durations (mean difference, 32.5 hrs [95% CI, 6.4-58.6 hrs]) compared with patients with appropriate-for-height tubes. Despite differences in intubation duration, the results of this cohort study suggest that smaller endotracheal tube sizes are not associated with impaired survival or recovery from critical illness. They support future prospective exploration of the association of smaller endotracheal tube sizes with recovery from critical illness.

Review of Outcomes of Low Verses Standard Pressure Pneumoperitoneum in Laparoscopic Surgery.

Carbon dioxide pneumoperitoneum during laparoscopy changes cardiorespiratory physiology and contributes to post-op pain. We studied outcomes before and after implementing low-pressure pneumoperitoneum QI project. Forty-two patients were insufflated at standard pressures (15mmHg) while 41 were insufflated using low (8-12mmHg) during laparoscopic procedures. These variables were obtained from the patient chart: pain scores, intravenous morphine milligram equivalents (MME), peak inspiratory pressures (PIP), end-tidal CO2 (EtCO2), surgery duration, and patient demographics. The study was conducted after IRB approval. Low-pressure pneumoperitoneum is feasible and the surgeon can increase to 10-12mmHg as needed. The mean post-op IV MME was significantly decreased in the low-pressure group (11.75 ± 10.41) compared to the standard pressure group (17.36 ± 18.1) (t-test, P = .047). Mean peak inspiratory pressures during insufflation were significantly higher for procedures conducted at standard pressure (31.40 ± 4.82) compared to the 8mmHg (24.68 ± 4.19) and 12mmHg (27.33± 3.85) low pressure groups (one-way ANOVA, P < .0001). During insufflation, there was a significant increase in the average EtCO2 in the standard pressure group (42.07 ± 5.60) compared to the 8mmHg low pressure group (37.59 ± 5.05) (ANOVA, P = .0096). Constant flow insufflation was more likely to be performed at low pressure than demand mode (58% v. 33%). Low pressure pneumoperitoneum decreases PIP pressure and CO2 absorption evidenced by lower ETCO2 intra-operatively. Patients have significant improvement in postoperative pain evidenced by decreased narcotics needed. Low pressure pneumoperitoneum using a constant flow insufflator is safe and results in improved patient outcomes.

Outcome, Clinical Profile and Risk Factors for Mortality of Neonates Necessitating Mechanical Ventilation

Background: Assisted ventilation has turn out to be an essential part of the neonatal intensive care unit (NICU). It is one of the main methods of support in the ICU and undoubtedly influences the survival of sick newborns. Aims: 1. To investigate common indications for mechanical ventilation in newborns 2. To investigate factors influencing the outcome. Method: It is a descriptive study of 60 infants admitted to the Department of Pediatric Medicine in the ICU over a one-year period in the department of Paediatrics, Abbasi Shaheed Hospital. The information was gathered and analysed in a pre-designed format. Results: Of a total of 60 infants, 46 survived, 14 died, and one infant was discharged despite medical advice. 36 children were born vaginally, 20 were born via LSCS, and 4 via assisted delivery. Postnatal asphyxia was the most common ventilation indication in full-term newborns, while HMD was present in preterm infants. The best results were obtained in ventilated infants with MAS, with 100% survival, followed by apnoea in premature infants, perinatal asphyxia, and HMD. Pulmonary haemorrhage (48.3%) was the most common complication among deceased infants, followed by sepsis (28.3%) and shock (23.4%) with a significant p &lt;0.05. There were no complications in 76.7% of the surviving infants. Conclusions: Among the many widely available variables studied in this study, maximum and mean peak inspiratory pressure (PIP or (PEEP), maximum respiratory rate, maximum mean airway pressure (MAP) and average ventilation demand was much greater among non-survivals in comparison to the survivors. Bicarbonate, PH and excess base have been found to be important determinants of mortality in ventilated newborns. Keywords: Indications, mechanical ventilation and Results

Neurally adjusted ventilatory assist in ventilated very preterm infants: A crossover study

To assess the effects of neurally adjusted ventilatory assist (NAVA) ventilation on oxygenation and respiratory parameters in preterm infants. An observational crossover study with a convenience sample of 19 infants born before 30 gestational weeks. Study parameters were recorded during 3-h periods of both NAVA and conventional ventilation. The proportion of time peripheral oxygen saturation (SpO2 ) and cerebral regional oxygen saturation (cRSO2 ) were within their target ranges, plus the number and severity of desaturation episodes were analyzed. In addition, electrical activity of the diaphragm (Edi), neural respiratory rates, and peak inspiratory pressures (PIPs) were recorded. Infants were born at a median age of 264/7 gestational weeks (range: 230/7 -293/7 ); the study was performed at a median age of 20 days (range: 1-82). The proportion of time SpO2 was within the target range, the number of peripheral desaturations or cRSO2 did not differ between the modes. However, the desaturation severity index was lower (131 vs. 152; p = .03) and fewer manual supplemental oxygen adjustments (1.3 vs. 2.2/h; p = .006) were needed during the period of NAVA ventilation following conventional ventilation. The mean Edi (8.1 vs. 11.4 µV; p < .006) and PIP values (14.9 vs. 19.1; p < .001) were lower during the NAVA mode. Although NAVA ventilation did not increase the proportion of time with optimal saturation, it was associated with decreased diaphragmatic activity, lower PIPs, less severe hypoxemic events, and fewer manual oxygen adjustments in very preterm infants.

Second generation laryngeal mask airway during laparoscopic living liver donor hepatectomy: a randomized controlled trial

The second-generation laryngeal mask airway (LMA) provides a higher sealing pressure than classical LMA and can insert the gastric drainage tube. We investigated the difference in respiratory variables according to the use of second-generation LMA and endotracheal tube (ETT) in laparoscopic living liver donor hepatectomy (LLDH). In this single-blind randomized controlled trial, intraoperative arterial carbon dioxide partial pressure at 2 h after the airway devices insertion (PaCO2_2h) was compared as a primary outcome. Participants were randomly assigned to the following groups: Group LMA (n = 45, used Protector LMA), or Group ETT (n = 43, used cuffed ETT). Intraoperative hemodynamic and respiratory variables including mean blood pressure (MBP), heart rate (HR), and peak inspiratory pressure (PIP) were compared. Postoperative sore throat, hoarseness, postoperative nausea and vomiting (PONV), and pulmonary aspiration were recorded. The PaCO2_2h were equally effective between two groups (mean difference: 0.99 mmHg, P = 0.003; 90% confidence limits: − 0.22, 2.19). The intraoperative change in MBP, HR, and PIP were differed over time between two groups (P < 0.001, P = 0.015, and P = 0.039, respectively). There were no differences of the incidence of postoperative complications at 24 h following LLDH (sore throat and hoarseness: P > 0.99, PONV: P > 0.99, and P = 0.65, respectively). No case showed pulmonary aspiration in both groups. Compared with endotracheal tube, second-generation LMA is equally efficient during LLDH. The second-generation LMA can be considered as the effective airway devices for securing airway in patients undergoing prolonged laparoscopic surgery.Trial Registration This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CRiS No. KCT0003711).

Feasibility of manual ventilation replacing mechanical ventilation

BackgroundDuring the COVID-19 pandemic it is anticipated that there will be a shortage of mechanical ventilators available for patients in critical condition. This has sparked many discussions about rationing resources...

Impact of human behavior on inspiratory flow profiles in patients with pulmonary arterial hypertension using AOS™ dry powder inhaler device.

Relative to healthy subjects, patients with pulmonary arterial hypertension often present with decreased respiratory muscle strength, resulting in decreased maximum inspiratory pressure. Little is known about the impact of reduced respiratory muscle strength on the ability to achieve the peak inspiratory pressures needed for effective drug delivery when using portable dry powder inhalers (≥1.0 kPa). The objective of this study was to assess the impact of inhaler resistance and patient instruction on the inspiratory flow profiles of pulmonary arterial hypertension patients when using breath-actuated dry powder inhalers. The inspiratory flow profiles of 35 patients with pulmonary arterial hypertension were measured with variants of the RS01 dry powder inhaler. Profiles were determined with a custom inspiratory flow profile recorder. Results showed that going from the low resistance RS01 dry powder inhaler to the high resistance AOS® dry powder inhaler led to increases in mean peak inspiratory pressures for pulmonary arterial hypertension subjects from 3.7 kPa to 6.5 kPa. Instructions that ask pulmonary arterial hypertension subjects to inhale with maximal effort until their lungs are full led to a mean peak inspiratory pressures of 6.0 kPa versus 2.1 kPa when the same subjects are asked to inhale comfortably. Significant decreases in mean peak inspiratory pressures are also observed with decreases in lung function, with a mean peak inspiratory pressures of 7.2 kPa for subjects with FEV1 > 60% predicted, versus 3.3 kPa for those subjects with FEV1 < 50% predicted. In conclusion, despite having reduced respiratory muscle strength, subjects with pulmonary arterial hypertension can effectively use a breath-actuated dry powder inhaler. The probability of achieving effective dose delivery may be increased by using dry powder inhalers with increased device resistance, particularly when subjects do not follow the prescribed instructions and inhale comfortably.

EMPROVING outcomes: Evaluating the effect of an ultralung protective strategy for patients with ARDS treated with ECMO.

Since the initiation of an adult extracorporeal membrane oxygenation (ECMO) program at our institution, the program has managed well over 200 patients with ECMO in a 3-year time frame. While there is a plethora of research evaluating ECMO for acute respiratory distress syndrome (ARDS), few studies have evaluated the impact that ventilator management after cannulation might have on outcomes. We hypothesized that failure to properly protect the lungs after cannulation would lead to higher mortality. This was a retrospective observational study performed from 1 January 2014 to 8 July 2018. A total of 196 patients were treated with ECMO, 57 of whom were diagnosed with ARDS and treated with venovenous ECMO. The univariable analysis revealed a statistically higher total serum bilirubin and lower total days on ECMO in those who died vs those who lived. During ECMO, higher mean peak inspiratory pressures (PIP) and higher FiO2 were found in those who died vs those who lived. In multivariable analysis, increasing age (odds ratio [OR] = 1.2; confidence interval [CI] = 1.04-1.39, P = .02), increasing mean PIP, and increasing mean FiO2 concentration during ECMO (PIP: OR = 1.40, CI = 1.03-1.89, P = .03; FiO2 : OR = 1.16, CI = 1.02-1.32, P = .02) were all associated with increased mortality. Failing to protect the lungs with a lung protective strategy such as the EMPROVE protocol after ECMO cannulation was associated with mortality. For every 1 mm Hg increase in the mean PIP, the odds of dying increased 1.4 times, and for every 1% increase in the mean FiO2 , the odds of dying increased 1.16 times. For lung rest to truly be effective, the lungs must be relieved of the burden of gas exchange.

Ventilator-associated Events in Children: Controversies and Research Needs.

Ventilator-associated Events in Children: Controversies and Research Needs.

Airway Pressure Release Ventilation as a Rescue Therapy in Pediatric Acute Respiratory Distress Syndrome.

ObjectivesTo describe experience with airway pressure release ventilation (APRV) in children with severe acute respiratory distress syndrome (ARDS) refractory to conventional low tidal volume ventilation.MethodsThis retrospective observational study was performed in an 11-bed, level 3 pediatric intensive care unit. Evaluation was made of 30 pediatric patients receiving airway pressure release ventilation as rescue therapy for severe ARDS.ResultsPatients were switched to APRV on an average 3.2 ± 2.6 d following intubation. When changed from conventional mechanical ventilation (CMV) to APRV, there was an expected increase in the SpO2/FiO2 ratio (165.1 ± 13.6 vs. 131.7 ± 10.2; p = 0.035). Mean peak inspiratory pressure was significantly lower during APRV (25.4 ± 1.26 vs. 29.8 ± 0.60, p < 0.001) compared to CMV prior to APRV but mean airway pressure (Paw) was significantly higher during APRV (19.1 ± 0.9 vs. 15.3 ± 1.3, p < 0.001). Hospital mortality in this study group was 16.6%.ConclusionsThe results of this study support the hypothesis that APRV may offer potential clinical advantages for ventilatory management and may be considered as an alternative rescue mechanical ventilation mode in pediatric ARDS patients refractory to conventional ventilation.

Association of Perioperative Variables and the Acute Respiratory Distress Syndrome in Liver Transplant Recipients.

The assessment of perioperative risk factors for the development of acute respiratory distress syndrome (ARDS) has been described in various surgical populations. However, there are only limited data among patients undergoing liver transplantation (LT), particularly regarding the influence of intraoperative ventilation parameters. We sought to identify the perioperative risk factors associated with the development of ARDS in LT recipients. This is a single-center, retrospective cohort study of adult patients who underwent LT at a tertiary academic medical center between January 1, 2006, and January 31, 2016. Postoperative ARDS was identified using the Berlin definition. Multivariable logistic regression analysis was used to identify perioperative risk factors for ARDS. Of 817 eligible patients who underwent an LT during the study period, 20 (2.45%) developed postoperative ARDS. In the preoperative model, ongoing dialysis (odds ratio, 6.41; P < 0.01) was identified as an independent risk factor of ARDS post-LT. A higher mean peak inspiratory pressure per increase of 1 cm H2O (odds ratio, 1.31; P < 0.01) was the only independent risk factor in the intraoperative model. Patients who developed ARDS postoperatively had significantly greater intensive care unit and hospital stay compared to non-ARDS patients (P < 0.001). There were no significant differences in the 30-day (P = 0.16) and 1-year (P = 0.51) mortality between the groups. Dialysis at the time of transplant and elevated intraoperative mean peak inspiratory pressure were associated with the development of ARDS. ARDS post LT was associated with increased intensive care unit and hospital length of stay, but not increased mortality.

EMPROVING Outcomes: Evaluating the Effect of an Ultra-Lung Protective Strategy for Patients with ARDS Treated with ECMO

Purpose While there is much discussion about selection of patients for ECLS for acute respiratory distress syndrome (ARDS), little is said about the impact that ventilator management after cannulation might have on outcomes. We hypothesized that failure to properly protect the lungs after cannulation would lead to higher mortality. Methods A retrospective chart review was performed on all patients undergoing venovenous (VV) ECLS at a single center from Jan 2014 to July 2018. We evaluated the impact of ventilator management during ECLS on mortality by evaluating three variables obtained during ECLS support: the mean peak inspiratory pressure (PIP), FiO2, and respiratory rate. Results 54 patients underwent VV ECLS for ARDS . Bivariate analysis (Table) revealed a significant association with higher total bilirubin , lower mean arterial pressure & higher total days on ECLS in those who died vs. those who lived. During ECLS higher mean PIP & higher FiO2 were found in those who died. In multivariate analysis increasing age was predictive of mortality (OR 1.2; CI 1.04-1.39, p=0.02) while higher pre-cannulation serum hemoglobin was protective (OR = 0.42, CI 0.18-0.98, p=0.04). The mean PIP & the mean FiO2 during ECLS were both predictive of increased risk of mortality (PIP; OR 1.40, CI 1.03-1.89, p=0.03;FiO2; OR 1.16, CI 1.02-1.32, p =0.02). Conclusion The use of the EMPROVE protocol is significantly associated with survival in this study. As our patients’ PIP & FiO2 during ECLS more closely approximated the EMPROVE protocol criteria, survival increased. For every 1 mmHg increase in the mean peak pressure the risk of dying increased 1.4x, and for every 1% increase in the mean FiO2 during ECLS the risk of dying increased 1.16x. For lung rest to truly be effective, the lungs must be relieved of the burden of gas exchange. If gas exchange is not adequate with simple VV configuration, alternatives for gas exchange should be sought such as switching to venoarterial, rather than increasing the burden on the lungs.