Mechanism-Based Modeling of Perioperative Variations in Hemoglobin Concentration in Patients Undergoing Laparoscopic Surgery.

BACKGROUND: Hemoglobin concentration ([Hb]) in the perioperative setting should be interpreted in the context of the variables and processes that may affect it to differentiate the dilution effects caused by changes in intravascular volume. However, it is unclear what variables and processes affect [Hb]. Here, we modeled the perioperative variations in [Hb] to identify the variables and processes that govern [Hb] and to describe their effects. METHODS: We first constructed a mechanistic framework based on the main variables and processes related to the perioperative [Hb] variations. We then prospectively studied patients undergoing laparoscopic surgery, divided into 2 consecutive cohorts for the development and validation of the model. The study protocol consisted of serial measurements of [Hb] along with recordings of hemoglobin mass loss, blood volume loss, fluid infusion, urine volume, and inflammatory biomarkers measurements, up to 96 hours postoperatively. Mathematical fitting was performed using nonlinear mixed-effects. Additionally, we performed simulations to explore the effects of blood loss and fluid therapy protocols on [Hb]. RESULTS: We studied 154 patients: 118 enrolled in the development group and 36 in the validation group. We characterized the perioperative course of [Hb] using a mass balance model that accounted for hemoglobin losses during surgery, and a 2-compartment model that estimated fluid kinetics and intravascular volume changes. During model development, we found that urinary fluid elimination represented only 24% of the total fluid elimination, and that total fluid elimination was inhibited after surgery in a time-dependent manner and influenced by age. Also, covariate evaluation showed a significant association between the type of surgery and proportion of fluid eliminated via urine. In contrast, neither the type of infused solution, blood volume loss nor inflammatory biomarkers were found to correlate with model parameters. In the validation analysis, the model demonstrated a considerable predictive capacity, with 95% of the predicted [Hb] within -4.4 and +5.5 g/L. Simulations demonstrated that hemoglobin mass loss determined most of the postoperative changes in [Hb], while intravascular volume changes due to fluid infusion, distribution, and elimination induced smaller but clinically relevant variations. Simulated patients receiving standard fluid therapy protocols exhibited a hemodilution effect that resulted in a [Hb] decrease between 7 and 15 g/L at the end of surgery, and which was responsible for the lowest [Hb] value during the perioperative period. CONCLUSIONS: Our model provides a mechanistic and quantitative understanding of the causes underlying the perioperative [Hb] variations.

Differential response to preoperative exercise training in patients candidates to cardiac valve replacement.

BACKGROUND: There is lack of evidence regarding safety, effectiveness and applicability of prehabilitation on cardiac surgery population, particularly in patients candidates to cardiac valve replacement. The aim of the study is to assess and compare the effect of a multimodal prehabilitation program on functional capacity in patients with severe aortic stenosis (AoS) and severe mitral regurgitation (MR) proposed for valve replacement surgery. METHODS: Secondary analysis from a randomised controlled trial whose main objective was to analyze the efficacy of a 4-6 weeks multimodal prehabilitation program in cardiac surgery on reducing postoperative complications. For this secondary analysis, only candidates for valve replacement surgery were selected. The primary outcome was the change in endurance time (ET) from baseline to preoperative assessment measured by a cycling constant work-rate cardiopulmonary exercise test. RESULTS: 68 patients were included in this secondary analysis, 34 (20 AoS and 14 MR) were allocated to the prehabilitation group and 34 (20 AoS and 14 MR) to control group. At baseline, patients with AoS had better left systolic ventricular function and lower prevalence of atrial fibrillation compared to MR (p = 0.022 and p = 0.035 respectively). After prehabilitation program, patients with MR showed greater improvement in ET than AoS patients (101% vs. 66% increase from baseline). No adverse events related to the prehabilitation program were observed. CONCLUSIONS: A 4-6 week exercise training program is safe and overall improves functional capacity in patients with severe AoS and MR. However, exercise response is different according to the cardiac valve type disfunction, and further studies are needed to know the factors that predispose some patients to have better training response. TRIAL REGISTRATION: The study has been registered on the Registry of National Institutes of Health ClinicalTrials.gov (NCT03466606) (05/03/2018).

European Association of Cardiothoracic Anesthesiology and Intensive Care Pediatric Cardiac Anesthesia Fellowship Curriculum: First Edition.

Pediatric cardiac anesthesia is a subspecialty of cardiac and pediatric anesthesiology dedicated to the perioperative care of patients with congenital heart disease. Members of the Congenital and Education Subcommittees of the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) agreed on the necessity to develop an EACTAIC pediatric cardiac anesthesia fellowship curriculum. This manuscript represents a consensus on the composition and the design of the EACTAIC Pediatric Cardiac Anesthesia Fellowship program. This curriculum provides a basis for the training of future pediatric cardiac anesthesiologists by clearly defining the theoretical and practical requirements for fellows and host centers.

Thoracic Anesthesia during the COVID-19 Pandemic: 2021 Updated Recommendations by the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) Thoracic Subspecialty Committee.

The novel coronavirus pandemic has radically changed the landscape of normal surgical practice. Lifesaving cancer surgery, however, remains a clinical priority, and there is an increasing need to fully define the optimal oncologic management of patients with varying stages of lung cancer, allowing prioritization of which thoracic procedures should be performed in the current era. Healthcare providers and managers should not ignore the risk of a bimodal peak of mortality in patients with lung cancer; an imminent spike due to mortality from acute coronavirus disease 2019 (COVID-19) infection, and a secondary peak reflecting an excess of cancer-related mortality among patients whose treatments were deemed less urgent, delayed, or cancelled. The European Association of Cardiothoracic Anaesthesiology and Intensive Care Thoracic Anesthesia Subspecialty group has considered these challenges and developed an updated set of expert recommendations concerning the infectious period, timing of surgery, vaccination, preoperative screening and evaluation, airway management, and ventilation of thoracic surgical patients during the COVID-19 pandemic.

Cost-effectiveness of a technology-supported multimodal prehabilitation program in moderate-to-high risk patients undergoing lung cancer resection: randomized controlled trial protocol.

BACKGROUND: Multimodal prehabilitation is a preoperative intervention with the objective to enhance cancer patients' functional status which has been showed to reduce both postoperative morbidity and hospital length of stay in digestive oncologic surgery. However, in lung cancer surgery patients further studies with higher methodological quality are needed to clarify the benefits of prehabilitation. The main aim of the current protocol is to evaluate the cost-effectiveness of a multimodal prehabilitation program supported by information and communication technologies in moderate-to-high risk lung cancer patients undergoing thoracic surgery. METHODS: A Quadruple Aim approach will be adopted, assessing the prehabilitation program at the following levels: i) Patients' and professionals' experience outcomes (by means of standardized questionnaires, focus groups and structured interviews); ii) Population health-based outcomes (e.g. hospital length of stay, number and severity of postoperative complications, peak oxygen uptake and levels of systemic inflammation); and, iii) Healthcare costs. DISCUSSION: This study protocol should contribute not only to increase the scientific basis on prehabilitation but also to detect the main factors modulating service adoption. TRIAL REGISTRATION: NCT04052100 (August 9, 2019).

Agreement of surgical blood loss estimation methods.

BACKGROUND: Surgical blood loss is usually estimated by different formulae in studies of strategies aimed at reducing perioperative bleeding. This study assessed and compared the agreement of the main blood loss estimation formulae using a direct measurement of blood loss as the reference method. STUDY DESIGN AND METHODS: Eighty consecutive patients undergoing urologic laparoscopic surgery were studied. Only optimal conditions for the direct measurement of surgical blood loss were considered. Surgical blood loss was estimated by six formulae at four different postoperative time points. The agreement of the formulae was evaluated by the Concordance correlation coefficient (CCC) and Bland-Altman analyses. An analysis of the agreement's variability regarding different magnitudes of blood loss was also performed. RESULTS: Directly measured blood loss ranged from 200 to 2200 mL. The formulae studied showed poor agreement with the direct measurement of blood loss; 95% limits of agreement widely exceeded the criterion of ±560 mL. Significant biases were found, which for most of the formulae led to an overestimation of blood loss. For all formulae, agreement remained constant regardless of the amount of blood loss, with limits between -40 and +120% approximately. Among the formulae, the best agreement was achieved by López-Picado's formula at 48 hours (CCC: 0.577), with a bias of +283 mL and 95% limits of agreement between -477 and +1043 mL. CONCLUSION: Formulae currently used to estimate surgical blood loss differ substantially from direct measurements; therefore, they may not be reliable methods of blood loss quantification in the surgical setting.

Cardiorespiratory impact of transesophageal endoscopic mediastinoscopy compared with cervical mediastinoscopy: a randomized experimental study.

BACKGROUND: Transesophageal natural-orifice transluminal endoscopic surgery (NOTES) mediastinoscopy has been described as a feasible, less-invasive alternative to video-assisted mediastinoscopy (VAM). We aimed to investigate hemodynamic and respiratory effects during transesophageal NOTES mediastinoscopy compared with VAM. PATIENTS AND METHODS: This was a short-survival experiment in 20 female pigs randomized to NOTES (n = 10) or VAM (n = 10) mediastinoscopy. In the NOTES group, an endoscopist accessed the mediastinum through a 5-cm submucosal tunnel in the esophageal wall, and CO2 was used to create the pneumomediastinum. Conventional VAM was carried out by thoracic surgeons. A 30-minute systematic exploration of the mediastinum was then performed, including invasive monitoring for hemodynamic and respiratory data. Blood samples were drawn for gas analyses. RESULTS: All experiments except 2 in the NOTES group (one because of technical difficulties, the other because of thoracic lymphatic duct lesion) were completed as planned, and animals survived 24 hours. Also, 3 animals in the NOTES group presented a tension pneumothorax that was immediately recognized and percutaneously drained. VAM and NOTES animals showed similar pulmonary and systemic hemodynamic behavior during mediastinoscopy. Pulmonary gas exchange pattern was mildly impaired during the NOTES procedure, showing lower partial arterial oxygen pressure associated with higher airway pressures (more important in animals that presented with pneumothorax). CONCLUSIONS: NOTES mediastinoscopy induces minimal deleterious respiratory effects and hemodynamic changes similar to conventional cervical VAM and could be feasible when performed under strict hemodynamic and respiratory surveillance. Notably, serious complications caused by the injury of pleura are more frequent in NOTES, which mandates an improvement in technique and suitable equipment.

Individualised, perioperative open-lung ventilation strategy during one-lung ventilation (iPROVE-OLV): a multicentre, randomised, controlled clinical trial.

BACKGROUND: It is uncertain whether individualisation of the perioperative open-lung approach (OLA) to ventilation reduces postoperative pulmonary complications in patients undergoing lung resection. We compared a perioperative individualised OLA (iOLA) ventilation strategy with standard lung-protective ventilation in patients undergoing thoracic surgery with one-lung ventilation. METHODS: This multicentre, randomised controlled trial enrolled patients scheduled for open or video-assisted thoracic surgery using one-lung ventilation in 25 participating hospitals in Spain, Italy, Turkey, Egypt, and Ecuador. Eligible adult patients (age ≥18 years) were randomly assigned to receive iOLA or standard lung-protective ventilation. Eligible patients (stratified by centre) were randomly assigned online by local principal investigators, with an allocation ratio of 1:1. Treatment with iOLA included an alveolar recruitment manoeuvre to 40 cm H2O of end-inspiratory pressure followed by individualised positive end-expiratory pressure (PEEP) titrated to best respiratory system compliance, and individualised postoperative respiratory support with high-flow oxygen therapy. Participants allocated to standard lung-protective ventilation received combined intraoperative 4 cm H2O of PEEP and postoperative conventional oxygen therapy. The primary outcome was a composite of severe postoperative pulmonary complications within the first 7 postoperative days, including atelectasis requiring bronchoscopy, severe respiratory failure, contralateral pneumothorax, early extubation failure (rescue with continuous positive airway pressure, non-invasive ventilation, invasive mechanical ventilation, or reintubation), acute respiratory distress syndrome, pulmonary infection, bronchopleural fistula, and pleural empyema. Due to trial setting, data obtained in the operating and postoperative rooms for routine monitoring were not blinded. At 24 h, data were acquired by an investigator blinded to group allocation. All analyses were performed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, NCT03182062, and is complete. FINDINGS: Between Sept 11, 2018, and June 14, 2022, we enrolled 1380 patients, of whom 1308 eligible patients (670 [434 male, 233 female, and three with missing data] assigned to iOLA and 638 [395 male, 237 female, and six with missing data] to standard lung-protective ventilation) were included in the final analysis. The proportion of patients with the composite outcome of severe postoperative pulmonary complications within the first 7 postoperative days was lower in the iOLA group compared with the standard lung-protective ventilation group (40 [6%] vs 97 [15%], relative risk 0·39 [95% CI 0·28 to 0·56]), with an absolute risk difference of -9·23 (95% CI -12·55 to -5·92). Recruitment manoeuvre-related adverse events were reported in five patients. INTERPRETATION: Among patients subjected to lung resection under one-lung ventilation, iOLA was associated with a reduced risk of severe postoperative pulmonary complications when compared with conventional lung-protective ventilation. FUNDING: Instituto de Salud Carlos III and the European Regional Development Funds.

Comparative study of NOTES alone versus NOTES guided by a new image registration system for navigation in the mediastinum: a study in a porcine model.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) mediastinoscopy (MED) through the esophagus has proved to be feasible in the animal model. However, injury of the adjacent pleura and pneumothorax has been reported as a frequent adverse event when using a blind access. OBJECTIVE: To assess the utility and safety of a CT-based image registration system (IRS) for navigation in the mediastinum. DESIGN: Prospective, randomized, controlled trial in 30 Yorkshire pigs. Thirty-minute MEDs were performed: 15 MEDs were performed with IRS guidance (MED-IRS), and 15 MEDs were performed with a blind access. SETTING: Animal research laboratory. INTERVENTIONS: In both groups, the mediastinum was accessed through a 10-cm submucosal tunnel in the esophageal wall. Timed exploration was performed with identification of 8 mediastinal structures. MAIN OUTCOME MEASUREMENTS: Technical feasibility, adverse events, and the number of mediastinal structures identified. RESULTS: Thirty animals weighing 31.5 ± 3.5 kg were included in this study. MED was not possible in 2 animals in the "MED with blind access" group but was possible in all MEDs performed with IRS. The mean number of identified organs was slightly higher in "with IRS-MED" (6.13 ± 1.3) than with MED with blind access (4.7 ± 2.3; P = .066). Moreover, the right atrium and vena cava were identified in more cases with IRS-MED than in MED with blind access (13 vs 3 and 15 vs 11, P = .000 and P = .03, respectively). There were 3 (23%) adverse events with IRS-MED and 4 (27%) with "MED with blind access" (P = not significant), with pneumothorax being the most frequent (2 and 3, respectively). LIMITATIONS: Nonsurvival animal study. CONCLUSIONS: This study demonstrates that the IRS system appears feasible in natural orifice transluminal endoscopic surgery MED and suggests that IRS guidance might be useful for selected procedures.

Difficult ventilation in a patient with a giant aortic aneurysm: A challenge for the anesthesiologist.

Patients with Marfan syndrome present anatomic variations that may increase the risk of a difficult airway. Moreover, they can present large aortic aneurysms, which may cause extrinsic airway compression. Therefore, difficult ventilation during general anesthesia poses a challenge in that the anesthesiologist has to promptly make a crucial differential diagnosis. Multidisciplinary preoperative assessment and planning of the airway and ventilation management are of utmost importance in such uncommon and highly complex clinical cases. Fiberoptic bronchoscopy is probably a really useful tool in order to assess the severity and extent of the airway compression, both preoperatively and intraoperatively. We present a clinical case where difficult ventilation occurred immediately after the induction of general anesthesia.

Multimodal Prehabilitation in Heart Transplant Recipients Improves Short-Term Post-Transplant Outcomes without Increasing Costs.

(1) Background and aim: This study aimed to investigate the impact of prehabilitation on the postoperative outcomes of heart transplantation and its cost-effectiveness. (2) Methods: This single-center, ambispective cohort study included forty-six candidates for elective heart transplantation from 2017 to 2021 attending a multimodal prehabilitation program consisting of supervised exercise training, physical activity promotion, nutritional optimization, and psychological support. The postoperative course was compared to a control cohort consisting of patients transplanted from 2014 to 2017 and those contemporaneously not involved in prehabilitation. (3) Results: A significant improvement was observed in preoperative functional capacity (endurance time 281 vs. 728 s, p < 0.001) and quality-of-life (Minnesota score 58 vs. 47, p = 0.046) after the program. No exercise-related events were registered. The prehabilitation cohort showed a lower rate and severity of postoperative complications (comprehensive complication index 37 vs. 31, p = 0.033), lower mechanical ventilation time (37 vs. 20 h, p = 0.032), ICU stay (7 vs. 5 days, p = 0.01), total hospitalization stay (23 vs. 18 days, p = 0.008) and less need for transfer to nursing/rehabilitation facilities after hospital discharge (31% vs. 3%, p = 0.009). A cost-consequence analysis showed that prehabilitation did not increase the total surgical process costs. (4) Conclusions: Multimodal prehabilitation before heart transplantation has benefits on short-term postoperative outcomes potentially attributable to enhancement of physical status, without cost-increasing.

On-demand endoscopic CO2 insufflation with feedback pressure regulation during natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy induces minimal hemodynamic and respiratory changes.

BACKGROUND: Endoscopic insufflation has been associated with marked increase in intra-abdominal pressure (IAP) and hemodynamic and respiratory changes during transgastric surgery. OBJECTIVE: To investigate the hemodynamic and respiratory effects during intraperitoneal cavity exploration through 3 different natural orifice transluminal endoscopic surgery (NOTES) access locations compared with laparoscopy. DESIGN AND SETTING: Survival experiments using 40 female pigs randomized to transgastric, transcolonic, transvaginal, and laparoscopic peritoneoscopy. INTERVENTIONS: On-demand endoscopic insufflation of CO(2) with feedback pressure regulation was used in NOTES with a maximum pressure of 14 mm Hg. In the laparoscopy group, the IAP was maintained at 14 mm Hg. NOTES procedures were performed by an endoscopist (with the assistance of a gynecologist in the transvaginal group and a second endoscopist in the transgastric and transrectal groups) and laparoscopy by 2 surgeons. MAIN OUTCOME MEASUREMENTS: Invasive hemodynamic and respiratory data. Blood samples were drawn for gas analyses. RESULTS: All experiments except one in the transrectal group were completed. The IAP was significantly lower in all NOTES groups compared with the laparoscopy group. A significant increase in mean systemic arterial blood pressure was observed in the laparoscopy group at 15 and 30 minutes of intraperitoneal cavity exploration, but it remained unchanged during all NOTES procedures. An increase in airway pressures was observed at 15 and 30 minutes of peritoneoscopy in the animals undergoing laparoscopy, whereas those parameters remained unchanged in the NOTES groups. The laparoscopy group showed a significant impairment in pulmonary gas exchange (decrease in Pao(2), increase in Paco(2), and decrease in arterial pH) after 30 minutes of peritoneoscopy, whereas only a slight increase in Paco(2) was observed in the transrectal and transvaginal groups. LIMITATIONS: Healthy animal model. CONCLUSION: On-demand endoscopic insufflation of CO(2) with feedback pressure regulation can minimize the risk of hemodynamic and respiratory compromise caused by acute changes in IAP.

Inflammatory impact of NOTES peritoneoscopy is not different from that of laparoscopy: a randomized comparative study in a survival porcine model.

BACKGROUND: Inflammatory changes of different NOTES approaches remain unknown. The aim of this study was to compare the inflammatory effects of NOTES and laparoscopy. METHODS: Forty female pigs were assigned to transgastric, transrectal, and transvaginal NOTES and laparoscopic peritoneoscopy groups. Antiseptic technique was utilized for NOTES whereas laparoscopy was performed sterile. Intraperitoneal pressures were monitored and maintained below 15 mmH(2)O. Pneumoperitoneum was maintained with CO(2) in all groups. Pre- and postoperative blood samples of IL-6, Il-1ß, and TNFα, and peritoneal fluid collected at surgery were analyzed. Animals were followed daily for 14 days. At necropsy, peritoneal fluid was collected for cytokine analysis. RESULTS: Thirty-nine peritoneoscopies were successfully completed. The median procedure time was longer in the NOTES groups (57 min, range = 33-109) than in the laparoscopy group (33 min, range 32-36; P < 0.001); this was related to longer incision time and closure time. All 39 completed follow-up. Severe bleeding in the post-transrectal approach required early sacrifice of the remaining animal. Besides this, complications were similar among groups. At necropsy, adhesions were seen in four animals in the gastric group, five in the rectal group, two in the vaginal group, and two in the laparoscopic group (P = ns). There were no statistical differences in serum levels of TNFα among the groups. When serum TNFα values were expressed as the difference from the baseline, in the transvaginal group they were significantly lower than in the transrectal at 2 h [0.5 pg/ml (range = -14 to 59) vs. 60 pg/ml (range = -8 to 303); P = 0.041] and at 8 h [-5.5 pg/ml (range = -86 to 55] vs. 37 pg/ml (range = -30 to 62); P = 0.031]. The limitations of this study were that the analyses of IL-6 and Il-1ß were not possible because most of the samples were below detectable levels, it was an animal model, and the sample size was small. CONCLUSION: Inflammatory parameters are similar between NOTES and laparoscopic peritoneoscopy despite longer surgery time in the NOTES group. The vaginal route seems to reduce the inflammatory stress.

Feasibility of a Multimodal Prehabilitation Programme in Patients Undergoing Cytoreductive Surgery for Advanced Ovarian Cancer: A Pilot Study.

INTRODUCTION: Treatment for advanced ovarian cancer (AOC) comprises cytoreductive surgery combined with chemotherapy. Multimodal prehabilitation programmes before surgery have demonstrated efficacy in postoperative outcomes in non-gynaecological surgeries. However, the viability and effects of these programmes on patients with AOC are unknown. We aimed to evaluate the feasibility and postoperative impact of a multimodal prehabilitation programme in AOC patients undergoing surgery. METHODS: This single-centre, before-and-after intervention pilot study included 34 patients in two cohorts: the prehabilitation cohort prospectively included 15 patients receiving supervised exercise, nutritional optimisation, and psychological preparation from December 2019 to January 2021; the control cohort included 19 consecutive patients between January 2018 and November 2019. Enhanced Recovery After Surgery guidelines were followed. RESULTS: The overall adherence to the multimodal prehabilitation programme was 80%, with 86.7% adherence to exercise training, 100% adherence to nutritional optimisation, and 80% adherence to psychological preparation. The median hospital stay was shorter in the prehabilitation cohort (5 (IQR, 4-6) vs. 7 days (IQR, 5-9) in the control cohort, p = 0.04). Differences in postoperative complications using the comprehensive complication index (CCI) were not significant (CCI score: 9.3 (SD 12.12) in the prehabilitation cohort vs. 16.61 (SD 16.89) in the control cohort, p = 0.08). The median time to starting chemotherapy was shorter in the prehabilitation cohort (25 (IQR, 23-25) vs. 35 days (IQR, 28-45) in the control cohort, p = 0.03). CONCLUSIONS: A multimodal prehabilitation programme before cytoreductive surgery is feasible in AOC patients with no major adverse effects, and results in significantly shorter hospital stays and time to starting chemotherapy.

Infection during natural orifice transluminal endoscopic surgery peritoneoscopy: a randomized comparative study in a survival porcine model.

BACKGROUND: Infection in natural orifice transluminal endoscopic surgery (NOTES) remains controversial. OBJECTIVE: To estimate the frequency of infection during NOTES peritoneoscopy with different routes of access and to compare with laparoscopy. DESIGN: Prospective randomized controlled study (Canadian Classification type I). METHODS: Forty female pigs were randomly assigned to 3 NOTES (transgastric, transrectal, and transvaginal) and laparoscopic groups. Antiseptic technique was used for NOTES, whereas laparoscopy was performed in a sterile environment. Preoperative and postoperative intravenous antibiotics were administered. Closure of the transluminal access site was performed in all animals. Peritoneal fluid was collected for culture at the end of surgery and at necropsy at day 14. RESULTS: Thirty-nine peritoneoscopies were successfully completed. Necropsy confirmed complete healing of NOTES incisions, but 2 animals in the laparoscopy group had small abscesses in the abdominal incisions. There were no statistical differences in the presence of peritoneal adhesions. Positive culture results were seen in all groups at the end of the procedure and in all animals at necropsy, but this did not lead to clinical signs of gross infection. The most common organisms that colonized the peritoneum were gram-positive cocci and gram-negative bacilli from the normal swine gastrointestinal flora. LIMITATIONS: Animal model and small sample size. CONCLUSIONS: In these small series of animals and with the careful lavage and preparation used, NOTES appeared to be comparable to laparoscopy in terms of peritoneal contamination and clinical infection. Despite the adherence to a strict antiseptic protocol, peritoneal contamination occurs but does not lead to septic complications in the swine.

Perioperative anaesthetic management of patients undergoing thoracic cytoreductive surgery and HITHOC.

Historically, patients with pleural malignant mesothelioma have had a poor prognosis and survival rate. Recently, new surgical approaches and chemotherapy delivery techniques have been developed. One of this treatment options is thoracic cytoreductive surgery and HITHOC (hyperthermic intrathoracic chemotherapy perfusion), a promising strategy in selected patients, offering significantly longer median survival length and tumour-free survival rate. However, there is little experience and little is known regarding the optimal perioperative management of this patients. Given that they usually present with poor preoperative status and the surgery is aggressive, prolonged and associated with significant hemodynamic repercussions, this procedure poses a true challenge to the anaesthesiologist. We will discuss optimal patient selection and optimization, as well as premedication, recommended monitoring aspects on top of the usual for any anaesthetic procedure, induction and anaesthetic agents, blood management and one lung ventilation. Also, we expose the importance of adequate pain control during the surgery and postoperatively, the hemodynamic disturbances that occur during the procedure and the potential complications that could occur afterwards. In a few words, this review intends to offer recommendations for the management of patients undergoing cytoreductive surgery and HITHOC for the perioperative care, based on the scarce evidence and our clinical experience.

Perioperative blood loss: estimation of blood volume loss or haemoglobin mass loss?

BACKGROUND: Perioperative blood loss is an essential parameter in research into Patient Blood Management. However, currently there is no "gold standard" method to quantify it. Direct measurements of blood loss are considered unreliable methods, and the formulae to estimate it have proven to be significantly inaccurate. Given the need for better research tools, this study evaluated an estimation of haemoglobin mass loss as an alternative approach to estimate perioperative blood loss, and compared it to estimations based on blood volume loss. MATERIAL AND METHODS: We studied one hundred consecutive patients undergoing urological laparoscopic surgery. Both haemoglobin mass loss and blood volume loss were directly measured during surgery, under highly controlled conditions for a reliable direct measurement of blood loss. Three formulae were studied: 1) a haemoglobin mass loss formula, which estimated blood loss in terms of haemoglobin mass loss, 2) the López-Picado's formula and 3) an empirical volume formula that estimated blood loss in terms of blood volume loss. The empirical volume formula was developed within the study with the aim of providing the best possible estimation of blood volume loss in the studied population. The formulae were evaluated and compared by assessing their agreements with their respective direct measurements of blood loss. RESULTS: The haemoglobin mass loss formula met the predefined agreement criterion of ±71 g, with 95% limits of agreement ranging from 0.6 to 44.1 g and a moderate overestimation of 22.4. In comparison to both blood volume loss formulae, the haemoglobin mass loss formula was superior in every agreement parameter evaluated. DISCUSSION: In this study, the estimation of haemoglobin mass loss was found to be a more accurate method to estimate perioperative blood loss. This estimation method could be a robust research tool, although more studies are needed to establish its reliability.

Multimodal prehabilitation as strategy for reduction of postoperative complications after cardiac surgery: a randomised controlled trial protocol.

INTRODUCTION: Prehabilitation programmes that combine exercise training, nutritional support and emotional reinforcement (multimodal prehabilitation) have demonstrated efficacy reducing postoperative complications in the context of abdominal surgery. However, such programmes have seldom been studied in cardiac surgery, one of the surgeries associated with higher postoperative morbidity and mortality. This trial will assess the feasibility and efficacy in terms of reduction of postoperative complications and cost-effectiveness of a multimodal prehabilitation programme comparing to the standard of care in cardiac surgical patients. METHODS AND ANALYSIS: This is a single-centre, randomised, open-label, controlled trial with a 1:1 ratio. Consecutive 160 elective valve replacement and/or coronary revascularisation surgical patients will be randomised to either standard of care or 4-6 weeks of multimodal prehabilitation that will consist in (1) two times/week supervised endurance and strength exercise training sessions, (2) promotion of physical activity and healthy lifestyle, (3) respiratory physiotherapy, (4) nutrition counselling and supplementation if needed, and (5) weekly mindfulness sessions. Baseline, preoperative and 3-month postoperative data will be collected by an independent blinded evaluator. The primary outcome of this study will be the incidence of postoperative complications. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of Clinical investigation of Hospital Clinic de Barcelona (HCB/2017/0708). The results will be disseminated in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03466606.

Prehabilitation in thoracic surgery.

Surgical resection remains the best treatment option for patients with early stage of non-small cell lung cancer (NSCLC). However, it may be responsible of postoperative complication and mortality, especially in patients with impaired pulmonary function. Enhanced recovery after surgery (ERAS) programs have been focused mainly in minimal invasive surgery approach during lung resection and respiratory rehabilitation after surgery. Preoperative exercise-based intervention (prehabilitation) has demonstrated reduction of morbi-mortality in other surgeries but in thoracic surgery continues to be under discussion. Cardio-pulmonary exercise test (CPET) is the gold standard technique to predict postoperative morbi-mortality. The implementation of a preoperative respiratory rehabilitation could optimize patient's physical capacity before surgery and improve outcomes and enhance recovery. The aim of this systematic review of the literature is to identify the effectiveness and safety of prehabilitation programs in thoracic surgery, the type of exercise and its duration, and the group of patients with best benefit. Prehabilitation is a safe intervention without side effects in patients. High-intensity interval training (HIT) with duration of 2 to 6 weeks seems to be the best exercise programme in a prehabilitation intervention but it exists heterogeneity in terms of intensity and duration. Prehabilitation increase exercise capacity and significantly enhances pulmonary function. But the reduction of postoperative complication and mortality has not been clearly demonstrated. Different criteria selection, type of intervention and small sample size, in addition to no randomization, could justify disparate results. It seems that not all patients can benefit from prehabilitation and it could be indicated only in patients with impaired lung function. Further randomized clinical trials with enough patients, correct duration of HIT (2 to 6 weeks) and focused in COPD patients are needed to clarify the suitability of prehabilitation. Meanwhile, safety of prehabilitation and good results of some studies support this intervention in high-risk patients.