Hyperoxemia post thoracic surgery - Does it matter?

Introduction: Post-operative oxygen therapy is used to prevent hypoxemia and surgical site infection. However, with improvements of anesthesia techniques, post-operative hypoxemia incidence is declining and the benefits of oxygen on surgical site infection have been questioned. Moreover, hyperoxemia might have adverse effects on the pulmonary and cardiovascular systems. We hypothesized hyperoxemia post thoracic surgery is associated with post-operative pulmonary and cardiovascular complications. Methods: Consecutive lung resection patients were included in this post-hoc analysis. Post-operative pulmonary and cardiovascular complications were prospectively assessed during the first 30 post-operative days, or hospital stay. Arterial blood gases were analyzed at 1, 6 and 12 h after surgery. Hyperoxemia was defined as arterial partial pressure of oxygen (PaO2)>100 mmHg. Patients with hyperoxemia duration in at least two adjacent time points were considered as hyperoxemic. Student t-test, Mann-Whitney U test and two-tailed Fisher exact test were used for group comparison. P values < 0.05 were considered statistically significant. Results: Three hundred sixty-three consecutive patients were included in this post-hoc analysis. Two hundred five patients (57%), were considered hyperoxemic and included in the hyperoxemia group. Patients in the hyperoxemia group had significantly higher PaO2 at 1, 6 and 12 h after surgery (p < 0.05). Otherwise, there was no significant difference in age, sex, comorbidities, pulmonary function tests parameters, lung surgery procedure, incidence of post-operative pulmonary and cardiovascular complications, intensive care unit and hospital length of stay and 30-day mortality. Conclusion: Hyperoxemia after lung resection surgery is common and not associated with post-operative complications or 30-day mortality.

The risk of post-operative pulmonary complications in lung resection candidates with normal forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide: a prospective multicentre study.

Introduction: According to the guidelines for preoperative assessment of lung resection candidates, patients with normal forced expiratory volume in 1 s (FEV1) and diffusing capacity of the lung for carbon monoxide (D LCO) are at low risk for post-operative pulmonary complications (PPC). However, PPC affect hospital length of stay and related healthcare costs. We aimed to assess risk of PPC for lung resection candidates with normal FEV1 and D LCO (>80% predicted) and identify factors associated with PPC. Methods: 398 patients were prospectively studied at two centres between 2017 and 2021. PPC were recorded from the first 30 post-operative days. Subgroups of patients with and without PPC were compared and factors with significant difference were analysed by uni- and multivariate logistic regression. Results: 188 subjects had normal FEV1 and D LCO. Of these, 17 patients (9%) developed PPC. Patients with PPC had significantly lower pressure of end-tidal carbon dioxide (P ETCO2 ) at rest (27.7 versus 29.9; p=0.033) and higher ventilatory efficiency (V'E/V'CO2 ) slope (31.1 versus 28; p=0.016) compared to those without PPC. Multivariate models showed association between resting P ETCO2 (OR 0.872; p=0.035) and V'E/V'CO2 slope (OR 1.116; p=0.03) and PPC. In both models, thoracotomy was strongly associated with PPC (OR 6.419; p=0.005 and OR 5.884; p=0.007, respectively). Peak oxygen consumption failed to predict PPC (p=0.917). Conclusions: Resting P ETCO2 adds incremental information for risk prediction of PPC in patients with normal FEV1 and D LCO. We propose resting P ETCO2 be an additional parameter to FEV1 and D LCO for preoperative risk stratification.

Prediction of Postoperative Complications: Ventilatory Efficiency and Rest End-tidal Carbon Dioxide.

BACKGROUND: Cardiopulmonary exercise testing parameters including ventilatory efficiency (VE/VCO2 slope) are used for risk assessment of lung resection candidates. However, many patients are unable or unwilling to undergo exercise. VE/VCO2 slope is closely related to the partial pressure of end-tidal carbon dioxide (PETCO2). We hypothesized PETCO2 at rest predicts postoperative pulmonary complications. METHODS: Consecutive lung resection candidates were included in this prospective multicenter study. Postoperative respiratory complications were assessed from the first 30 postoperative days or from the hospital stay. Student t test or Mann-Whitney U test was used for comparison. Multivariate stepwise logistic regression analysis was used to analyze association with the development of postoperative pulmonary complications. The De Long test was used to compare area under the curve (AUC). Data are summarized as median (interquartile range). RESULTS: Three hundred fifty-three patients were analyzed, of which 59 (17%) developed postoperative pulmonary complications. PETCO2 at rest was significantly lower (27 [24-30] vs 29 [26-32] mm Hg; P < .01) and VE/VCO2 slope during exercise significantly higher (35 [30-40] vs 29 [25-33]; P < .01) in patients who developed postoperative pulmonary complications. Both rest PETCO2 with odds ratio 0.90 (95% confidence interval [CI] 0.83-0.97); P = .01 and VE/VCO2 slope with odds ratio 1.10 (95% CI 1.05-1.16); P < .01 were independently associated with postoperative pulmonary complications by multivariate stepwise logistic regression analysis. There was no significant difference between AUC of both models (rest PETCO2: AUC = 0.79 (95% CI 0.74-0.85); VE/VCO2 slope: AUC = 0.81 (95% CI 0.75-0.86); P = .48). CONCLUSIONS: PETCO2 at rest has similar prognostic utility as VE/VCO2 slope, suggesting rest PETCO2 may be used for postoperative pulmonary complications prediction in lung resection candidates.

Poor ventilatory efficiency during exercise may predict prolonged air leak after pulmonary lobectomy.

Poor ventilatory efficiency, defined as the increase in minute ventilation relative to carbon dioxide production during exercise (VE/VCO2 slope), may be associated with dynamic hyperinflation and thereby promote the development of prolonged air leak (PAL) after lung resection. Consecutive lung lobectomy candidates (n = 96) were recruited for this prospective two-centre study. All subjects underwent pulmonary function tests and cardiopulmonary exercise testing prior to surgery. PAL was defined as the presence of air leaks from the chest tube on the 5th postoperative day and developed in 28 (29%) subjects. Subjects with PAL were not different in terms of age, sex, American Society of Anesthesiologists class, type of surgery (thoracotomy/video-assisted thoracoscopic surgery) and site of surgery (right/left lung; upper/lower lobes). Subjects with PAL had more frequent pleural adhesions (50% vs 21%; P = 0.006) and steeper VE/VCO2 slope (35 ± 7 vs 30 ± 5; P = 0.001). Stepwise logistic regression showed that only the presence of pleural adhesions [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.4-10.9; P = 0.008] and VE/VCO2 slope (OR 1.1, 95% CI 1.0-1.2; P = 0.003) were independently associated with PAL (AUC 0.74, 95% CI 0.62-0.86). We conclude that a high VE/VCO2 slope during exercise may be helpful in identifying patients at greater risk for the development of PAL after lung lobectomy. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT03498352.

The Influence of Microscopic Inflammation at Resection Margins on Early Postoperative Endoscopic Recurrence After Ileocaecal Resection for Crohn's Disease.

BACKGROUND AND AIMS: The pathogenesis and risk factors for early postoperative endoscopic recurrence of Crohn's disease [CD] remain unclear. Thus, this study aimed to identify whether histological inflammation at the resection margins after an ileocaecal resection influences endoscopic recurrence. METHODS: We have prospectively followed up patients with CD who underwent ileocaecal resection at our hospital between January 2012 and January 2018. The specimens were histologically analysed for inflammation at both of the resection margins [ileal and colonic]. We evaluated whether histological results of the resection margins are correlated with endoscopic recurrence of CD based on colonoscopy 6 months after ileocaecal resection. Second, we assessed the influence of known risk factors and preoperative therapy on endoscopic recurrence of CD. RESULTS: A total of 107 patients were included in our study. Six months after ileocaecal resection, 23 patients [21.5%] had an endoscopic recurrence of CD. The histological signs of CD at the resection margins were associated with a higher endoscopic recurrence [56.5% versus 4.8%, p < 0.001]. Disease duration from diagnosis to surgery [p = 0.006] and the length of the resected bowel [p = 0.019] were significantly longer in patients with endoscopic recurrence. Smoking was also proved to be a risk factor for endoscopic recurrence [p = 0.028]. CONCLUSIONS: Histological inflammation at the resection margins was significantly associated with a higher risk of early postoperative endoscopic recurrence after an ileocaecal resection for CD.

Impact of surgery on quality of life in Crohn´s disease patients: final results of Czech cohort.

INTRODUCTION: Crohns disease (CD) belongs to chronic diseases that highly affect the patient´s quality of life (QoL). The effect of the disease and impairment of QoL in CD patients is already known. The aim was to assess how surgical treatment influences the patients QoL and determine factors that can affect postoperative QoL. METHODS AND PATIENTS: We compared the QoL before and after surgery in patients who had undergone a bowel resection at our department due to CD between 2010-2016. The patients filled in a standardized QLQ-CR29 questionnaire to assess QoL in the preoperative period and the postoperative period after a 2-month interval. The control groups were CD patients who had not undergone surgical treatment (bowel resection) and a healthy cohort. In the QoL evaluation, 132 patients with CD who had undergone surgery (bowel resection), 83 patients with CD without an operation and 104 healthy subjects were enrolled. RESULTS: 104 of the operated patients experienced a postoperative improvement of the overall QoL (78.8 %), 2 patients did not register any changes in QoL (1.5 %) and 26 patients (19.7 %) experienced a worsening of their postoperative QoL. The results were statistically significant (p < 0.001). CONCLUSION: We detected a significant improvement of the overall QoL after surgical resection in CD patients (measured 2 months after surgery). Gender was identified as the only statistically relevant factor with influence on postoperative QoL.Key words: bowel resection - Crohn´s disease - Czech cohort - inflammatory bowel disease - quality of life - surgical treatment.

Self-expandable biodegradable biliary stents in porcine model.

BACKGROUND: Treatment or prevention of a benign biliary tree stricture is an unresolved problem. A novel self-expandable biodegradable polydioxanon biliary stent in a porcine model was studied. MATERIALS AND METHODS: This new stent was used in 23 pigs. Feasibility and safety of surgical stenting, time of biodegradation, and histologic reaction in 2, 8, 13, and 20 wk of a follow-up were studied. All stents were inserted into a common bile duct through a duodenal papilla following small dilatation. After surgical evaluation of abdominal cavities, the pigs were sacrificed to remove common bile ducts with the stents. All bile ducts were assessed by macroscopic and histopathologic examination. RESULTS: Self-expansion was correct in all cases. Neither bile duct obstruction nor postsurgical complications were observed. Macroscopic evaluation indicated lightening of the stent color in 2 wk, a partial disintegration in 8 wk, and a complete absorption in 13 and 20 wk. Histologic evaluation in general substantiated a mild-to-moderate inflammatory reaction in the lamina propria during the whole follow up and had no clinical consequences. No cholangitis, necrosis, abscess, or excessive fibroplasia was found in a hepatoduodenal ligament. CONCLUSIONS: Our results suggest that polydioxanon biodegradable self-expanding stents seem to be useful for biliary system implantation, offer a good biocompatibility, and completely degrade within 13 wk.

Surgical treatment of Clostridium colitides.

INTRODUCTION: Infection with Clostridium difficile (CDI) is the most frequent cause of nosocomial diarrhoeas. Most cases are successfully treated by antibiotic therapy, but nearly 10% may progress to the fulminative form of this condition. The objective of the work is retrospective evaluation of the results of surgical treatment in patients with the fulminative form of Clostridium colitis with revealing of risk factors leading to serious post-operative morbidity and mortality. PATIENTS AND METHODOLOGY: Retrospective evaluation of the results of surgical treatment in patients with the fulminative form of Clostridium colitis between 2008 and 4/2012. RESULTS: Between 2008 and 4/2012 Clostridium toxins were positively detected in 1,088 patients in total, 21 of whom underwent operations due to the fulminative form of Clostridium colitis. The operations included 4 total colectomies with terminal ileostomy, 15 subtotal colectomies with terminal ileostomy, 1 caecostomy and 1 axial ileostomy. The 30-day mortality was 23.8%, and morbidity reached 66.6%. High leukocytosis is a statistically significant predictor of post-operative mortality and morbidity (p = 0.008). CONCLUSION: Early indication for a colectomy operation with terminal ileostomy in patients with the fulminative form of Clostridium colitis leads to lower morbidity and mortality.