Intraoperative Ventilation/Perfusion Mismatch and Postoperative Pulmonary Complications after Major non-cardiac surgery: a prospective cohort study.

BACKGROUND: Postoperative pulmonary complications (PPCs) can increase hospital length of stay, postoperative morbidity and mortality. Despite many factors can increase the risk of PPCs, it is not known whether intraoperative ventilation/perfusion (V/Q) mismatch can be associated with an increased risk of PPCs after major non-cardiac surgery. METHODS: We enrolled patients undergoing general anesthesia for non-cardiac surgery and evaluated intraoperative V/Q distribution using the Automatic Lung Parameter Estimator technique. The assessment was done after anesthesia induction (T1), after 1 hour from surgery start (T2) and at the end of surgery (T3). We collected demographic and procedural information and measured intraoperative ventilatory and hemodynamic parameters at each time-point. Patients were followed up for 7 days after surgery and assessed daily for PPCs occurrence. RESULTS: We enrolled 101 patients with a median age of 71 [62-77] years, a BMI of 25 [22.4-27.9] kg/m 2 and a preoperative ARISCAT score of 41 [34-47]. Of them, 29 (29%) developed PPCs, mainly acute respiratory failure (23%) and pleural effusion (11%). Patients with and without PPCs did not differ in levels of shunt at T1 (PPCs:22.4[10.4-35.9] % vs No PPCs:19.3[9.4-24.1] %, p=0.18) or during the protocol, while significantly different levels of high V/Q were found during surgery (PPCs:13[11-15] mmHg vs No PPCs:10[8-13.5] mmHg, p=0.007) and before extubation (PPCs:13[11-14]mmHg vs No PPCs:10[8-12] mmHg, p=0.006). After adjusting for age, ARISCAT, BMI, smoking, fluid balance, anesthesia type, laparoscopic procedure and surgery duration, high V/Q before extubation was independently associated with the development of PPCs (OR 1.147, CI 95% [1.021-1.289], p=0.02). The sensitivity analysis showed an E-value of 1.35 (CI=1.11). CONCLUSIONS: In patients with intermediate/high risk of PPCs undergoing major non-cardiac surgery, intraoperative V/Q mismatch is associated with the development of PPCs. Increased high V/Q before extubation is independently associated with the occurrence of PPCs in the first 7 days after surgery.

Markers of endothelial and epithelial pulmonary injury in mechanically ventilated COVID-19 ICU patients.

BACKGROUND: Biomarkers can be used to detect the presence of endothelial and/or alveolar epithelial injuries in case of ARDS. Angiopoietin-2 (Ang-2), soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1), P-selectin and E-selectin are biomarkers of endothelial injury, whereas the receptor for advanced glycation end-products (RAGE) reflects alveolar epithelial injury. The aims of this study were to evaluate whether the plasma concentration of the above-mentioned biomarkers was different 1) in survivors and non-survivors of COVID-19-related ARDS and 2) in COVID-19-related and classical ARDS. METHODS: This prospective study was performed in two COVID-19-dedicated Intensive Care Units (ICU) and one non-COVID-19 ICU at Ferrara University Hospital. A cohort of 31 mechanically ventilated patients with COVID-19 ARDS and a cohort of 11 patients with classical ARDS were enrolled. Ang-2, ICAM-1, VCAM-1, P-selectin, E-selectin and RAGE were determined with a bead-based multiplex immunoassay at three time points: inclusion in the study (T1), after 7 ± 2 days (T2) and 14 ± 2 days (T3). The primary outcome was to evaluate the plasma trend of the biomarker levels in survivors and non-survivors. The secondary outcome was to evaluate the differences in respiratory mechanics variables and gas exchanges between survivors and non-survivors. Furthermore, we compared the plasma levels of the biomarkers at T1 in patients with COVID-19-related ARDS and classical ARDS. RESULTS: In COVID-19-related ARDS, the plasma levels of Ang-2 and ICAM-1 at T1 were statistically higher in non-survivors than survivors, (p = 0.04 and p = 0.03, respectively), whereas those of P-selectin, E-selectin and RAGE did not differ. Ang-2 and ICAM-1 at T1 were predictors of mortality (AUROC 0.650 and 0.717, respectively). At T1, RAGE and P-selectin levels were higher in classical ARDS than in COVID-19-related ARDS. Ang-2, ICAM-1 and E-selectin were lower in classical ARDS than in COVID-19-related ARDS (all p < 0.001). CONCLUSIONS: COVID-19 ARDS is characterized by an early pulmonary endothelial injury, as detected by Ang-2 and ICAM-1. COVID-19 ARDS and classical ARDS exhibited a different expression of biomarkers, suggesting different pathological pathways. Trial registration NCT04343053 , Date of registration: April 13, 2020.

Over time relationship between platelet reactivity, myocardial injury and mortality in patients with SARS-CoV-2-associated respiratory failure.

The aim of this study (NCT04343053) is to investigate the relationship between platelet activation, myocardial injury, and mortality in patients affected by Coronavirus disease 2019 (COVID-19). Fifty-four patients with respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were enrolled as cases. Eleven patients with the same clinical presentation, but negative for SARS-CoV-2 infection, were included as controls. Blood samples were collected at three different time points (inclusion [T1], after 7 ± 2 days [T2] and 14 ± 2 days [T3]). Platelet aggregation by light transmittance aggregometry and the circulating levels of soluble CD40 ligand (sCD40L) and P-selectin were measured. Platelet biomarkers did not differ between cases and controls, except for sCD40L which was higher in COVID-19 patients (p = .003). In COVID-19 patients, P-selectin and sCD40L levels decreased from T1 to T3 and were higher in cases requiring admission to intensive care unit (p = .004 and p = .008, respectively). Patients with myocardial injury (37%), as well as those who died (30%), had higher values of all biomarkers of platelet activation (p < .05 for all). Myocardial injury was an independent predictor of mortality. In COVID-19 patients admitted to hospital for respiratory failure, heightened platelet activation is associated with severity of illness, myocardial injury, and mortality.ClinicalTrials.gov number: NCT04343053.

Enhanced Recovery Program in Laparoscopic Colorectal Surgery: An Observational Controlled Trial.

Background: Most of the evidence for enhanced recovery programs (ERPs) in colorectal surgery relies on nonrandomized studies with control groups either historical or operated on at different facilities. The aim of this study was to investigate ERP in coeval groups admitted in different wards at the same hospital. Materials and Methods: A prospective cohort of consecutive patients (n = 100) undergoing elective laparoscopic colorectal resection completing a standardized ERP (ERP group) was compared with patients (n = 100) operated with traditional perioperative care in the same period at the same institution (non-ERP group). The two groups were located in separate wards and shared the same anesthesiologists. The exclusion criteria were: >80 years old, American Society of Anesthesia (ASA) IV, metastatic disease, and inflammatory bowel disease. The primary outcome was hospital length of stay (LoS), used as a proxy of functional recovery. Secondary outcomes included: postoperative complications, readmission rate, mortality, and protocol adherence. Results: The ERP group protocol adherence was 81%. The LoS was significantly reduced in the ERP group (4 versus 7 days). The number of 30-day postoperative complications was lower in the ERP group (P < .001). No increase was found in 30-day readmission or mortality. Conventional perioperative protocol was the only predictor of any postoperative complication and, together with male sex and age 65-74 years old, was the only factor associated with prolonged LoS. Conclusion: Implementing a colorectal ERP is feasible, safe, and efficient for functional recovery, but high protocol adherence is needed. Following traditional perioperative care is associated with more postoperative complications and prolonged LoS.

Impact of a colorectal enhanced recovery program implementation on clinical outcomes and institutional costs: A prospective cohort study with retrospective control.

BACKGROUND: The enhanced recovery program for perioperative care of the surgical patient reduces postoperative metabolic response and organ dysfunction, accelerating functional recovery. The aim of this study was to determine the impact on postoperative recovery and cost-effectiveness of implementing a colorectal enhanced recovery program in an Italian academic centre. MATERIALS AND METHODS: A prospective series of consecutive patients (N = 100) undergoing elective colorectal resection completing a standardized enhanced recovery program in 2013-2015 (ERP group) was compared to patients (N = 100) operated at the same institution in 2010-2011 (Pre-ERP group) before introducing the program. The exclusion criteria were: >80 years old, ASA score of IV, a stage IV TNM, and diagnosis of inflammatory bowel disease. The primary outcome was hospital length of stay which was used as a proxy of functional recovery. Secondary outcomes included: postoperative complications, 30-day readmission and mortality, protocol adherence, nursing workload, cost-effectiveness, and factors predicting prolonged hospital stay. The ERP group patient satisfaction was also evaluated. RESULTS: Hospital stay was significantly reduced in the ERP versus the Pre-ERP group (4 versus 8 days) as well as nursing workload, with no increase in postoperative complications, 30-day readmission or mortality. ERP group protocol adherence (81%) and patient satisfaction were high. Conventional perioperative protocol was the only independent predictor of prolonged hospital stay. Total mean direct costs per patient were significantly higher in the Pre-ERP versus the ERP group (6796.76 versus 5339.05 euros). CONCLUSIONS: Implementing a colorectal enhanced recovery program is feasible, efficient for functional recovery and hospital stay reduction, safe, and cost-effective. High patient satisfaction and nursing workload reduction may also be expected, but high protocol adherence is necessary.

Physiologic Evaluation of Ventilation Perfusion Mismatch and Respiratory Mechanics at Different Positive End-expiratory Pressure in Patients Undergoing Protective One-lung Ventilation.

BACKGROUND: Arterial oxygenation is often impaired during one-lung ventilation, due to both pulmonary shunt and atelectasis. The use of low tidal volume (VT) (5 ml/kg predicted body weight) in the context of a lung-protective approach exacerbates atelectasis. This study sought to determine the combined physiologic effects of positive end-expiratory pressure and low VT during one-lung ventilation. METHODS: Data from 41 patients studied during general anesthesia for thoracic surgery were collected and analyzed. Shunt fraction, high V/Q and respiratory mechanics were measured at positive end-expiratory pressure 0 cm H2O during bilateral lung ventilation and one-lung ventilation and, subsequently, during one-lung ventilation at 5 or 10 cm H2O of positive end-expiratory pressure. Shunt fraction and high V/Q were measured using variation of inspired oxygen fraction and measurement of respiratory gas concentration and arterial blood gas. The level of positive end-expiratory pressure was applied in random order and maintained for 15 min before measurements. RESULTS: During one-lung ventilation, increasing positive end-expiratory pressure from 0 cm H2O to 5 cm H2O and 10 cm H2O resulted in a shunt fraction decrease of 5% (0 to 11) and 11% (5 to 16), respectively (P < 0.001). The PaO2/FIO2 ratio increased significantly only at a positive end-expiratory pressure of 10 cm H2O (P < 0.001). Driving pressure decreased from 16 ± 3 cm H2O at a positive end-expiratory pressure of 0 cm H2O to 12 ± 3 cm H2O at a positive end-expiratory pressure of 10 cm H2O (P < 0.001). The high V/Q ratio did not change. CONCLUSIONS: During low VT one-lung ventilation, high positive end-expiratory pressure levels improve pulmonary function without increasing high V/Q and reduce driving pressure.

The effects of storage of red blood cells on the development of postoperative infections after noncardiac surgery.

BACKGROUND: Prolonged storage of red blood cells (RBCs) is a potential risk factor for postoperative infections. The objective of this study was to examine the effect of age of RBCs transfused on development of postoperative infection. STUDY DESIGN AND METHODS: In this prospective, double-blind randomized trial, 199 patients undergoing elective noncardiac surgery and requiring RBC transfusion were assigned to receive nonleukoreduced RBCs stored for not more than 14 days ("fresh blood" group, n = 101) or for more than 14 days ("old blood" group, n = 98). The primary outcome was occurrence of infection within 28 days after surgery; secondary outcomes were postoperative acute kidney injury (AKI), in-hospital and 90-day mortality, admission to intensive care unit, and hospital length of stay (LOS). As older blood was not always available, an "as-treated" (AT) analysis was also performed according to actual age of the RBCs transfused. RESULTS: The median [interquartile range] storage time of RBCs was 6 [5-10] and 15 [11-20] days in fresh blood and in old blood groups, respectively. The occurrence of postoperative infection did not differ between groups (fresh blood 22% vs. old blood 25%; relative risk [RR], 1.17; confidence interval [CI], 0.71-1.93), although wound infections occurred more frequently in old blood (15% vs. 5%; RR, 3.09; CI, 1.17- 8.18). Patients receiving older units had a higher rate of AKI (24% vs. 6%; p < 0.001) and, according to AT analysis, longer LOS (mean difference, 3.6 days; CI, 0.6-7.5). CONCLUSION: Prolonged RBC storage time did not increase the risk of postoperative infection. However, old blood transfusion increased wound infections rate and incidence of AKI.

The effect of an Enhanced Recovery Program in elective retroperitoneal abdominal aortic aneurysm repair.

OBJECTIVE: Enhanced Recovery Programs (ERPs) have been introduced to accelerate postoperative recovery and are mainly focused on decreasing the surgical stress response. Limited data are available regarding the implementation of ERPs in patients who undergo abdominal aortic aneurysm (AAA) repair using the retroperitoneal approach. The aims of this study were: (1) to evaluate the implementation of an ERP in patients who underwent elective retroperitoneal AAA repair; and (2) to define independent predictors of prolonged hospital length of stay (LOS) in these patients. METHODS: This was a retrospective cohort study on 221 patients who underwent elective AAA repair via a retroperitoneal approach from 2005 through 2013 at an Italian university hospital. Patients who received surgery from 2008 through 2013 and enrolled in an ERP (n = 130) were compared with those who received surgery from 2005 through 2007 and managed with traditional perioperative care (n = 91). RESULTS: Patient characteristics were comparable between groups. Intensive care unit admissions were prevalent among patients who received traditional care vs patients in the ERP (P < .01). ERP patients had fewer major (P < .01) and minor (P = .019) complications, and mortality was similar between groups. Complete functional recovery was achieved earlier in ERP patients vs controls (P < .01). Patients in the ERP group left the hospital earlier than controls (P < .01). No readmission ≤30 days were reported in the ERP group. Age ≥65 years and being in a conventional care protocol were found to be independent predictors of prolonged hospital LOS. CONCLUSIONS: The implementation of an ERP after elective AAA repair using a retroperitoneal approach reduced postoperative intensive care unit admission, accelerated functional recovery, and decreased morbidity and LOS with no readmission ≤30 days. Age ≥65 years and conventional perioperative care were the only independent predictors of prolonged LOS.

Successful nasal intubation with a laryngeal nerve monitoring tube using bronchoscopy in a patient with plunging goiter: a case report.

BACKGROUND: The appropriate positioning of nerve integrity monitoring during thyroid surgery is of relevance. In this case report we describe our experience with accurate placement of a nerve integrity monitoring endotracheal tube, obtained by fiberoptic control, in a patient with expected difficult airway management. CASE PRESENTATION: We report the case of a 70-year-old obese woman scheduled for elective total thyroidectomy due to plunging intrathoracic goiter. The preoperative indirect laryngoscopy pointed out a massive bombè of the hypopharyngeal wall to the right and right vocal cord paralysis. The epiglottis was oedematous and the glottis could not be identified. On physical examination, the tongue was large and a Mallampati's score of 3 was determined. Hence, due to an expected difficult airway management, a nasal intubation with an electromyographic nerve integrity monitoring endotracheal tube trough fiberoptic bronchoscopy was successfully performed. CONCLUSION: Our experience suggests that nasal intubation can be safely performed by using a nerve integrity monitoring tube with the help of fiberoptic bronchoscopy.

Acute effects of hyperoxemia on dyspnoea and respiratory variables during pressure support ventilation.

OBJECTIVE: To evaluate the acute effect of hyperoxemia on the comfort and the respiratory variables in patients undergoing pressure support ventilation (PSV) for acute respiratory failure (ARF). DESIGN AND SETTING: Prospective, observational study performed in the intensive care unit of a university hospital. PATIENTS: Thirteen semirecumbent patients were ventilated in PSV mode, the setting of which was established by the treating physician who was blinded to the study. MEASUREMENTS: The variables measured at different levels (21-80%) of FiO(2) randomly applied were: minute volume (V (E)), respiratory frequency (f) and the pressure develing during the first 100 ms of an occluded breath (P(0.1)). These variables were firstly measured at the level of FiO(2) chosen by the treating physician. Severity of dyspnea was rated using the visual analogue scale 15' after each FiO(2) variation. RESULTS: Modulation of FiO(2) was able to vary significantly the respiratory variables, since a FiO(2) increase was associated with a decrease in dyspnea, P(0.1), f, and V (E). While valuable variations were detected at both lower and higher values of FiO(2) than those established by the treating physician, a significant improvement in the respiratory variables was detected at FiO(2) 60%. The reduction in respiratory drive was statistically related to an amelioration of dyspnea (R(2)=0.89) even at values of FiO(2) higher than 60%. CONCLUSIONS: During PSV the respiratory drive can be heavily modulated by varying the FiO(2) since even at FiO(2) greater than 0.6 dyspnea and respiratory variables continued to improve.

Reporting of unintended events in an intensive care unit: comparison between staff and observer.

BACKGROUND: In order to identify relevant targets for change, it is essential to know the reliability of incident staff reporting. The aim of this study is to compare the incidence and type of unintended events (UE) reported by facilitated Intensive Care Unit (ICU) staff with those recorded concurrently by an observer. METHODS: The study is a prospective data collection performed in two 4-bed multidisciplinary ICUs of a teaching hospital. The format of the UE reporting system was voluntary, facilitated and not necessarily anonymous, and used a structured form with a predetermined list of items. UEs were reported by ICU staff over a period of 4 weeks. The reporting incidence during the first fourteen days was compared with that during the second fourteen. During morning shifts in the second fourteen days, one observer in each ICU recorded any UE seen. The staff was not aware of the observers' study. The incidence of UEs reported by staff was compared with that recorded by the observers. RESULTS: The staff reported 36 UEs in the first fourteen days and 31 in the second.. The incidence of UE detection during morning shifts was significantly higher than during afternoon or night shifts (p < 0.001). Considering only working day morning shifts, the rate of UE reporting by the staff per 100 patient days was 26.9 (CI 95% 16.9-37.0) in the first fourteen day period and 20.3 (CI 95% 10.3-30.4) in the second. The rate of UE detection by the observers was 53.1 per 100 patient days (CI 95% 40.6-65.6), significantly higher (p < 0.001) than that reported concurrently by the staff. There was excellent agreement between staff and observers about the severity of the UEs recorded (Intraclass Correlation Coefficient 0.869). The observers recorded mainly UEs involving Airway/mechanical ventilation and Patient management, and the staff Catheter/Drain/Probe and Medication errors (p = 0.025). CONCLUSION: UE incidence is strongly underreported by staff in comparison with observers. Also the types of UEs reported are different. Invaluable information about incidents in ICU can be obtained in a few days by observer monitoring.

Respiratory function after aortic aneurysm repair: a comparison between retroperitoneal and transperitoneal approaches.

OBJECTIVE: Elective abdominal aneurysm repair can be performed by using the transperitoneal or the retroperitoneal approach. The latter has been described as having a better outcome, reducing the impairment of respiratory function or the incidence of lung complications. Hence, the retroperitoneal approach has been proposed for treatment of medically high-risk patients. However, the superiority of one technique or the other in preserving pulmonary function has not been conclusively demonstrated. The aim of this study was to ascertain whether the retroperitoneal and the transperitoneal approaches affect respiratory function differently. DESIGN: A prospective randomized study. SETTING: Two four-bed surgical-medical ICUs of a University hospital. PATIENTS: Twenty-three consecutive patients undergoing abdominal aortic aneurysm repair were randomized to the retroperitoneal (12 patients) and transperitoneal approach (11 patients). They were studied: a). within 30 min the end of surgery; b). 8 h after the end of surgery; and c). during a T-piece tube-weaning trial. MEASUREMENTS: The comparison between the two groups was based on respiratory mechanics, partitioned between lung and chest wall components, basic spirometry, tension-time index of the inspiratory muscle, weaning indexes, and length of stay both in ICU and hospital. RESULTS: The two surgical techniques do not differ in their impact on either respiratory mechanics or inspiratory muscle function or weaning indexes. However, there was a tendency for retroperitoneal patients to stay for less time both in ICU and in the hospital. CONCLUSIONS: During the first 24 h after surgery, the postoperative impairment of respiratory function is independent of the surgical approach.