Continuous positive airway pressure (CPAP) during the postoperative period for prevention of postoperative morbidity and mortality following major abdominal surgery

Effects of driving pressure-guided ventilation by individualized positive end-expiratory pressure on oxygenation undergoing robot-assisted laparoscopic radical prostatectomy: a randomized controlled clinical trial

PURPOSE

Patients with robot-assisted laparoscopic radical prostatectomy (RALP) need to be placed in Trendelenburg position, which results in cranial displacement of the diaphragm and decreases functional residual capacity and pulmonary compliance. Positive end-expiratory pressure (PEEP) can increase ventilation in the dorsal area, reduce the occurrence of atelectasis and improve oxygenation. However, due to individual differences, inappropriate PEEP will cause lung injury and even hemodynamic instability. Therefore, our study is to evaluate the efficacy of individualized PEEP in RALP.

METHODS

We randomly recruited 48 patients and divided them into driving pressure-guided individualized PEEP group (P group, individualized PEEP) or traditional lung-protective ventilation strategy group (C group, tidal volume 8 mL/kg combined with PEEP of 5cmH2O). The primary outcome was the PaO2/FiO2 before extubation. The secondary outcomes included individualized PEEP values in the P group, the results of arterial blood gas analysis, respiratory mechanics parameters and vital sign parameters. Other measurements included intraoperative vasoactive drug dosage, length of stay, postoperative SpO2, leukocyte count, temperature, serum inflammatory factors and soluble receptor for advanced glycation end products (sRAGE).

RESULTS

Individualized PEEP improved the PaO2/FiO2 before extubation (P = 0.034) and decreased driving pressure (P = 0.011). The PEEP valued in the P group was 14 [10-14] cmH2O. The lung compliance of the P group was significantly higher than that in the C group (P = 0.013). There was no significant difference in other measurements.

CONCLUSIONS

Individualized PEEP could improve PaO2/FiO2 in patients who underwent RALP and do not increase the dosage of intraoperative vasoactive drug and the release of inflammatory factors.

TRIAL REGISTRATION

www.chictr.org.cn (registration no. ChiCTR2100047271).

Consensus Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS®) Society Recommendations Part 2-Emergency Laparotomy: Intra- and Postoperative Care

BACKGROUND

This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care.

METHODS

Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL.

RESULTS

Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process.

CONCLUSIONS

These guidelines are based on best available evidence for an ERAS® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

Impact of 1-week preoperative auto-CPAP treatment on postoperative outcomes in patients undergoing heart valve replacement surgery: a prospective randomized controlled trial

Background

Whether preoperative continuous positive airway pressure (CPAP) treatment improves postoperative outcomes in patients undergoing cardiac valve replacement (CVR) remains unknown.

Hypothesis

This study was to evaluate the effects of 1-week perioperative auto-continuous positive airway pressure (CPAP) treatment on postoperative heart and pulmonary outcomes in patients with obstructive sleep apnea (OSA) and valvular heart disease.

Methods

Thirty-two patients with OSA and valvular heart disease were randomly assigned to 1-week CPAP (n = 15) group and non-CPAP treatments (n = 17) group. After the treatment, all patients underwent CVR surgery. The length of ICU and hospital stays, postoperative cardiac and respiratory complications were assessed and compared between the 2 groups.

Results

The results showed there was no significant difference in the baseline characteristics between the CPAP and non-CPAP treatment groups. The length of postoperative ICU and hospital stays, as well as the duration of mechanical ventilation were significantly reduced in the CPAP treatment group compared to the non-CPAP treatment group; however, there were no significant differences in cardiac complications (postoperative arrhythmias, pacemaker use, first dose of dopamine in the ICU, and first dose of dobutamine in the ICU), and respiratory complications (reintubation and pneumonia).

Conclusion

We concluded that in patients underwent CVR, preoperative use of auto-CPAP for OSA significantly decreased the duration of mechanical ventilation, and postoperative stays in the ICU and hospital.Clinical Trial Registration: https://ClinicalTrials.gov, identifier NCT03398733.

The role of prophylactic administration of CPAP in general surgical wards after open visceral surgery in reducing postoperative pneumonia-a retrospective cohort study

BACKGROUND

Postoperative pneumonia is a main adverse event that causes increased postoperative morbidity and prolonged length of hospital stay leading to high postoperative mortality. Continuous positive airway pressure (CPAP) is a type of non-invasive ventilation for the delivery of a positive airway pressure during respiration. In this study, we evaluated the impact of postoperative prophylactic CPAP on prevention of pneumonia in patients after open visceral surgery.

METHODS

In this observational cohort study, we compared the rates of postoperative pneumonia in patients who underwent open major visceral surgery from January 2018 till August 2020 in the study and control group. The study group had postoperative prophylactic sessions of CPAP for 15 min, 3-5 times a day and a repeated spirometer training was also performed in the general surgical ward. The control group received only the postoperative spirometer training as a prophylactic measure against postoperative pneumonia. The chi-square test was used to measure the relationships between categorical variables, and a binary regression analysis determined the correlation between independent and dependent variables.

RESULTS

A total of 258 patients met the inclusion criteria who had open visceral surgery for various clinical illnesses. There were 146 men (56.6%) and 112 women with a mean age of 68.62 years. As many as 142 patients received prophylactic CPAP and they were grouped into the study group, whereas 116 patients without prophylactic CPAP were placed in the control group. Overall, the rate of postoperative pneumonia was significantly less in the study group (5.6% vs. 25.9% in the control group; p-value < 0.0001), which could be confirmed by the regression analysis (OR 0.118, CI 95% 0.047-0.295, p < 0.001).

CONCLUSION

Postoperative intermittent CPAP after open visceral surgery can be performed in a general surgical ward. Our study showed a significant association with a low rate of postoperative pneumonia, especially in high-risk patients. This leads to a significantly shorter postoperative hospital stay especially in high-risk patients after upper gastrointestinal surgery.

TRIAL REGISTRATION NUMBER

DRKS00028988, 04.05.2022, retrospectively registered.

Comparing the effects of continuous positive airway pressure via mask or helmet interface on oxygenation and pulmonary complications after major abdominal surgery: a randomized trial

The risk of pulmonary complications is high after major abdominal surgery but may be reduced by prophylactic postoperative noninvasive ventilation using continuous positive airway pressure (CPAP). This study compared the effects of intermittent mask CPAP (ICPAP) and continuous helmet CPAP (HCPAP) on oxygenation and the risk of pulmonary complications following major abdominal surgery. Patients undergoing open abdominal aortic aneurysm repair or pancreaticoduodenectomy were randomized (1:1) to either postoperative ICPAP or HCPAP. Oxygenation was evaluated as the partial pressure of oxygen in arterial blood fraction of inspired oxygen ratio (PaO₂/FIO₂) at 6 h, 12 h, and 18 h postoperatively. Pulmonary complications were defined as X-ray verified pneumonia/atelectasis, clinical signs of pneumonia, or supplementary oxygen beyond postoperative day 3. Patient-reported comfort during CPAP treatment was also evaluated. In total, 96 patients (ICPAP, n = 48; HCPAP, n = 48) were included, and the type of surgical procedure were evenly distributed between the groups. Oxygenation did not differ between the groups by 6 h, 12 h, or 18 h postoperatively (p = 0.1, 0.08, and 0.67, respectively). Nor was there any difference in X-ray verified pneumonia/atelectasis (p = 0.40) or supplementary oxygen beyond postoperative day 3 (p = 0.53). Clinical signs of pneumonia tended to be more frequent in the ICPAP group (p = 0.06), yet the difference was not statistically significant. Comfort scores were similar in both groups (p = 0.43), although a sensation of claustrophobia during treatment was only experienced in the HCPAP group (11% vs. 0%, p = 0.03). Compared with ICPAP, using HCPAP was associated with similar oxygenation (i.e., PaO₂/FIO₂ ratio) and a similar risk of pulmonary complications. However, HCPAP treatment was associated with a higher sensation of claustrophobia.

Perioperative oxygen therapy: a protocol for an overview of systematic reviews and meta-analyses

BACKGROUND

Oxygen is routinely given to patients during and after surgery. Perioperative oxygen administration has been proposed as a potential strategy to prevent and treat hypoxaemia and reduce complications, such as surgical site infections, pulmonary complications and mortality. However, uncertainty exists as to which strategies in terms of amount, delivery devices and timing are clinically effective. The aim of this overview of systematic reviews and meta-analyses is to answer the research question, 'For which types of surgery, at which stages of care, in which sub-groups of patients and delivered under what conditions are different types of perioperative oxygen therapy clinically effective?'.

METHODS

We will search key electronic databases (MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, CENTRAL, Epistemonikos, PROSPERO, the INAHTA International HTA Database and DARE archives) for systematic reviews and randomised controlled trials comparing perioperative oxygen strategies. Each review will be mapped according to type of surgery, surgical pathway timepoints and clinical comparison. The highest quality reviews with the most comprehensive and up-to-date coverage of relevant literature will be chosen as anchoring reviews. Standardised data will be extracted from each chosen review, including definition of oxygen therapy, summaries of interventions and comparators, patient population, surgical characteristics and assessment of overall certainty of evidence. For clinical outcomes and adverse events, the overall pooled findings and results of subgroup and sensitivity analyses (where available) will be extracted. Trial-level data will be extracted for surgical site infections, mortality, and potential trial-level effect modifiers such as risk of bias, outcome definition and type of surgery to facilitate quantitative data analysis. This analysis will adopt a multiple indication review approach with panoramic meta-analysis using review-level data and meta-regression using trial-level data. An evidence map will be produced to summarise our findings and highlight any research gaps.

DISCUSSION

There is a need to provide a panoramic overview of systematic reviews and meta-analyses describing peri-operative oxygen practice to both inform clinical practice and identify areas of ongoing uncertainty, where further research may be required. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021272361.

Risk factors for prolonged mechanical ventilation in neonates following gastrointestinal surgery

BACKGROUND

Prolonged mechanical ventilation (MV) should be avoided in neonates. Noninvasive ventilation (NIV) can facilitate weaning from MV but has risks for patients immediately following foregut surgery due to the potential risk of anastomotic leak. We evaluated the risk factors for prolonged MV following intestinal surgery in neonates.

METHODS

We retrospectively reviewed 253 neonates undergoing intestinal surgery in 2017-2018 to identify risk factors for prolonged MV, and determine the correlation between NIV and anastomotic leak in a tertiary neonatal intensive care unit that performs the greatest number of neonatal surgeries in Ontario.

RESULTS

The most common diagnoses were necrotizing enterocolitis/spontaneous intestinal perforation (NEC/SIP) 21%, intestinal atresia 16%, esophageal atresia/tracheoesophageal fistula 14%, ano-rectal malformation 13%, malrotation/volvulus 11%, gastroschisis 9% and omphalocele 4%. The median (IQR) duration of MV post-surgery was 3 (1-8) days with 25.7 % (n=65) of neonates on MV for >7 days. Compared to infants on MV post-surgery for ≤7 days, those with MV>7 days were of lower gestational age, birth weight and weight at surgery, but a higher proportion underwent stoma creation, had a longer duration of opioid administration and higher rates of moderate to severe bronchopulmonary dysplasia (BPD) and mortality (P<0.05). Generalized linear regression analysis showed lower gestational age (GA) and longer opioid administration were associated with longer duration of MV (P<0.001), but indication for surgery, weight at surgery and stoma creation didn't correlate with longer duration of MV (P>0.05). Of the 122 patients handled by one-stage resection with primary anastomosis, 22.1% (n=27) received NIV with 74.1% (n=20) commenced on NIV after 7 days post-surgery, anastomotic leak was detected in 2.5 % (3/122) patients and didn't correlate with NIV.

CONCLUSIONS

Lower GA and longer opioid administration were risk factors for prolonged MV in neonates following intestinal surgery. Further research is needed to investigate modifiable practices around pain assessment/ventilation in these patients, and the correlation between NIV and anastomotic leak.

Severe pulmonary complications after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are common and contribute to decreased overall survival

BACKGROUND AND OBJECTIVES

Extensive abdominal surgery is associated with the risk of postoperative pulmonary complications. This study aims to explore the incidence and risk factors for developing postoperative pulmonary complications after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy and to analyze how these complications affect overall survival.

METHODS

Data were collected on 417 patients undergoing surgery between 2007 and2017 at Uppsala University Hospital, Sweden. Postoperative pulmonary complications were graded according to the Clavien-Dindo classification system where Grade ≥ 3 was considered a severe complication. A logistic regression analysis was used to analyze risk factors for postoperative pulmonary complications and a Cox proportional hazards model to assess impact on survival.

RESULTS

Seventy-two patients (17%) developed severe postoperative pulmonary complications. Risk factors were full thickness diaphragmatic injury and/or diaphragmatic resection [OR 5.393, 95% CI 2.924-9.948, p = < 0.001]. Severe postoperative pulmonary complications, in combination with non-pulmonary complications, contributed to decreased overall survival [HR 2.285, 95% CI 1.232-4.241, p = 0.009].

CONCLUSIONS

Severe postoperative pulmonary complications were common and contributed to decreased overall survival. Full thickness diaphragmatic injury and/or diaphragmatic resection were the main risk factors. This finding emphasizes the need for further research on the mechanisms behind pulmonary complications and their association with mortality.

Perioperative Pulmonary Support of the Elderly

Purpose of Review

With the projected increase in the geriatric patient population, it is of the utmost importance to understand and optimize conditions in the perioperative period to ensure the best surgical outcome. Age-associated changes in respiratory physiology affect the surgical management of geriatric patients. This review focuses on perioperative pulmonary management of elderly individuals.

Recent Findings

The physiological changes associated with aging include both physical and biochemical alterations that are detrimental to pulmonary function. There is an increased prevalence of chronic lung disease such as COPD and interstitial lung disease which can predispose patients to postoperative pulmonary complications. Additionally, elderly patients, especially those with chronic lung disease, are at risk for frailty. Screening tools have been developed to evaluate risk and aid in the judicious selection of patients for surgical procedures. The concept of “prehabilitation” has been developed to best prepare patients for surgery and may be more influential in the reduction of postoperative pulmonary complications than postoperative rehabilitation. Understanding the age-associated changes in metabolism of drugs has led to dose adjustments in the intraoperative and postoperative periods, reducing respiratory depression and lung protective ventilation and minimally invasive procedures have yielded reductions in postoperative pulmonary complications.

Summary

The perioperative management of the geriatric population can be divided into three key areas: preoperative risk mitigation, intraoperative considerations, and postoperative management. Preoperative considerations include patient selection and thorough history and physical, along with smoking cessation and prehabilitation in a subset of patients. Operative aspects include careful selection of anesthetic agents, lung protective ventilation, and choice of surgical procedure. Postoperative management should focus on selective use of agents that may contribute to respiratory depression and encouragement of rehabilitation.

Obesity in women: anaesthetic implications for peri-operative and peripartum management

The prevalence, healthcare and socio-economic impact of obesity (defined as having a body mass index of ≥ 30 kg.m^-2 ) are disproportionately higher in women than men. A combination of biological and social factors, including the adaptation of energy homeostasis to the increased demands of pregnancy and lactation and poor access to healthy foods or exercise facilities, contribute to the increasing prevalence of obesity in women. Obesity-related physiological changes stem from mass loading and increased metabolism of adipose tissue, as well as secretion of bioactive substances from adipocytes leading to chronic low-grade inflammation. As a result, obesity is associated with increased risks of: infertility; malignancy; sleep-disordered breathing; cardiovascular disease; diabetes; and thromboembolism. Hence, obese women are at markedly increased risk of peri-operative morbidity and mortality and require comprehensive evaluation and targeted comorbidity optimisation by a multidisciplinary team. In addition to routine obstetric challenges, pregnancy in women with obesity further exacerbates the above risks, making multidisciplinary management starting at pre-conception even more important. Weight loss, lifestyle management and optimisation of comorbidity are the cornerstone of reducing obesity-related risks. The anaesthetist plays a vital role within the multidisciplinary team by emphasising weight loss as part of pre-operative comorbidity optimisation, formulation of individualised peri-operative management plans, supervising postoperative care in the high dependency or intensive care settings and providing safe labour analgesia and careful peripartum management for obese parturients.

Non-Invasive Ventilation in a Non-Standard Setting – Is it Safe to Ventilate Outside the ICU?

Non-invasive ventilation (NIV) is considered a fundamental method in treating patients with various disorders, requiring respiratory support. Often the lack of beds in the intensive care unit (ICU) and the concomitant medical conditions, which refer patients as unsuitable for aggressive treatment in the ICU, highlight the need of NIV application in general non-monitored wards and unusual settings – most commonly emergency departments, high-dependency units, pulmonary wards, and even ambulances. Recent studies suggest faster improvement of all physiological variables, reduced intubation rates, postoperative pulmonary complications and hospital mortality with better outcome and quality of life by early well-monitored ward-based NIV compared to standard medical therapy in patients with exacerbation of a chronic obstructive pulmonary disease, after a surgical procedure or acute hypoxemic respiratory failure in hematologic malignancies. NIV is a ceiling of treatment and a comfort measure in many patients with do-not-intubate orders due to terminal illnesses. NIV is beneficial only by proper administration with appropriate monitoring and screening for early NIV failure. Successful NIV application in a ward requires a well-equipped area and adequately trained multidisciplinary team. It could be initiated not only by attending physicians, respiratory technicians, and nurses but also by medical emergency teams. Ward-based NIV is supposed to be more cost-effective than NIV in the ICU, but further investigation is required to establish the safety and efficacy in hospital wards with a low nurse to patient ratio.

Scaling the Need, Benefits, and Risks Associated with COVID-19 Acute and Postacute Care Rehabilitation: A Review

Coronavirus is an RNA virus, which attacks the respiratory system causing complications including severe respiratory distress and pneumonia and many other symptoms. Recently, a novel coronavirus (COVID-19) outbreak emerged in Wuhan, which caused a significant number of infections in China and resulted in a global pandemic. The main aim of this study is to review and summarize the evidence regarding the supportive role of physical rehabilitation techniques in managing COVID-19-associated pneumonia. In this review, we also emphasize the use of rehabilitation techniques in the management of pneumonia in COVID-19-infected patients. Based on the evidence presented, we conclude that certain physical rehabilitation techniques and modalities could be of great support in the management of COVID-19-associated pneumonia. The safety of staff and patients when applying rehabilitation intervention requires attention. The combination of physical rehabilitation and medical treatment would result in improved treatment outcomes, faster recovery, and shorter hospital stay. Many rehabilitation techniques are safe and feasible and can be easily incorporated into the management protocol of COVID-19 victims. Decisions of early rehabilitation induction should be based on the patient's medical condition and tolerability.

Effect of oxygenation modalities among patients with postoperative respiratory failure: a pairwise and network meta-analysis of randomized controlled trials

Background

Postoperative respiratory failure is associated with increased perioperative complications. Our aim is to compare outcomes between non-invasive ventilation (NIV), high-flow nasal cannula (HFNC), and standard oxygen in patients at high-risk for or with established postoperative respiratory failure.

Methods

Electronic databases including PubMed, Embase, and the Cochrane Library were reviewed from inception to September 2019. We included only randomized controlled trials (RCTs) that compared NIV, HFNC, and standard oxygen in patients at high risk for or with established postoperative respiratory failure. We performed a Bayesian network meta-analysis to calculate the odds ratio (OR) and Bayesian 95% credible intervals (CrIs).

Results

Nine RCTs representing 1865 patients were included (the mean age was 61.6 ± 10.2 and 64.4% were males). In comparison with standard oxygen, NIV was associated with a significant reduction in intubation rate (OR 0.23; 95% Cr.I. 0.10–0.46), mortality (OR 0.45; 95% Cr.I. 0.27–0.71), and intensive care unit (ICU)-acquired infections (OR 0.43, 95% Cr.I. 0.25–0.70). Compared to standard oxygen, HFNC was associated with a significant reduction in intubation rate (OR 0.28, 95% Cr.I. 0.08–0.76) and ICU-acquired infections (OR 0.41; 95% Cr.I. 0.20–0.80), but not mortality (OR 0.58; 95% Cr.I. 0.26–1.22). There were no significant differences between HFNC and NIV regarding different outcomes. In a subgroup analysis, we observed a mortality benefit with NIV over standard oxygen in patients undergoing cardiothoracic surgeries but not in abdominal surgeries. Furthermore, in comparison with standard oxygen, NIV and HFNC were associated with lower intubation rates following cardiothoracic surgeries while only NIV reduced the intubation rates following abdominal surgeries.

Conclusions

Among patients with post-operative respiratory failure, HFNC and NIV were associated with significantly reduced rates of intubation and ICU-acquired infections compared with standard oxygen. Moreover, NIV was associated with reduced mortality in comparison with standard oxygen.

Impact of paravertebral blockade use in geriatric patients undergoing thoracic surgery on postoperative adverse outcomes

Background

While it is known that thoracic paravertebral blockade (TPVB) could reduce pain undergoing thoracic surgery, it has not been confirmed whether this reduction in pain reduces pulmonary complications in an elderly population.

Methods

We performed a monocentric retrospective analysis for a prospectively collected patients receiving thoracic surgery with or without intraoperative TPVB between November 7, 2018 and April 1, 2019, at Shanghai Chest Hospital. Whether or not to use TPVB depending on anesthesiologists' preference, the chances of harm and benefit of each patients after discussed with their anesthetist. Chest wall resection, bilateral lung resection, conversion to thoracotomy and ipsilateral reoperation were excluded. A total of 154 patients with lung operations were included in the final analysis, 34 of whom received general anesthesia combined with TPVB (GA-TPVB). The primary outcome was the incidence of postoperative pulmonary complications (PPCs). The secondary outcomes were the incidence of cardiovascular and other complications, required analgesia in post anesthesia care unit (PACU), patient controlled analgesia (PCA) pressing frequency in 24h, chest tube duration, ICU stay and the hospital length of stay (LOS).

Results

The incidence of PPCs undergoing thoracic surgery was about 21.4% (33/154). Compared with GA, GA-TPVB could reduce the incidence of PPCs (25% vs. 9%, P=0.042), mostly reduce postoperative atelectasis (19% vs. 3%, P=0.021). TPVB could reduce the rate of required analgesia in PACU, PCA pressing frequency in 24 h and chest tube duration. However, there were no significant differences on the rate of cardiovascular and other complications, ICU stay and LOS between the two groups (P>0.05). Multivariable logistic regression analysis identified preoperative DLCO% ≥92% (OR =0.293, P=0.006), duration of surgery <75 min (OR =0.278, P=0.008) and GA-TPVB (OR =0.270, P=0.048) was associated with fewer PPCs.

Conclusions

Our study shows that general anesthesia combined with TPVB may reduce PPCs by reducing postoperative pain in geriatric patients undergoing thoracic surgery compared with general anesthesia alone.

Trial registration

Chinese Clinical Trial Registry number, ChiCTR1800019526. Registered on Nov 7, 2018.

Perioperative anaesthetic management of patients with or at risk of acute distress respiratory syndrome undergoing emergency surgery

Patients undergoing emergency surgery may present with the acute respiratory distress syndrome (ARDS) or develop this syndrome postoperatively. The incidence of ARDS in the postoperative period is relatively low, but the impact of ARDS on patient outcomes and healthcare costs is relevant Aakre et.al (Mayo Clin Proc 89:181-9, 2014).The development of ARDS as a postoperative pulmonary complication (PPC) is associated with prolonged hospitalisation, longer duration of mechanical ventilation, increased intensive care unit length of stay and high morbidity and mortality Ball et.al (Curr Opin Crit Care 22:379-85, 2016). In order to mitigate the risk of ARDS after surgery, the anaesthetic management and protective mechanical ventilation strategies play an important role. In particular, a careful integration of general anaesthesia with neuraxial or locoregional techniques might promote faster recovery and reduce opioid consumption. In addition, the use of low tidal volume, minimising plateau pressure and titrating a low-moderate PEEP level based on the patient's need can improve outcome and reduce intraoperative adverse events. Moreover, perioperative management of ARDS patients includes specific anaesthesia and ventilator settings, hemodynamic monitoring, moderately restrictive fluid administration and pain control.The aim of this review is to provide an overview and evidence- and opinion-based recommendations concerning the management of patients at risk of and with ARDS who undergo emergency surgical procedures.

Enhanced recovery after surgical repair of incisional hernias

AIM

Enhanced recovery programmes (ERPs) were developed to improve the patient's post-operative comfort and reduce post-operative morbidity after several types of major surgery including the incisional hernia repair. The aim of this review was to describe the features of ERPs in the setting for incisional hernia repair.

METHODS

The literature review was conducted until March 2019, but retrieved very few papers (n = 4) on this topic. All studies were retrospective.

RESULTS

Setting and comorbidities of incisional hernia patients are of such importance in many cases that prehabilitation (including tobacco use cessation, management of obesity, diabetes or malnutrition) should play a greater role compared with other specialties. The other peri-operative measures are similar to other specialties but their implementation was very heterogeneous in the published studies.

CONCLUSIONS

Like in other surgeries, ERPs were feasible and probably efficient to improve the post-operative course of incisional hernia patients. But the level of evidence remains low.

Development of Postoperative Pneumonia After Endovascular Aortic Aneurysm Repair is Associated with an Increased Length of Intensive Care Unit Stay

Objective

Endovascular aortic aneurysm repair (EVAR) has increasingly replaced open aortic surgery for treatment of abdominal aortic aneurysms (AAA). One of the key advantages of EVAR is the reduced length of intensive care unit (ICU) stay and hospital stay. This study aimed to identify the risk factors associated with increased ICU length of stay (LOS) after EVAR.

Methods

The American College of Surgeons (ACS-NSQIP) database for the year 2013 was used. All patients who underwent EVAR were divided into two groups: ICU LOS <1 day vs. ≥1 day. Preoperative, intraoperative, and postoperative factors were compared between these two groups utilizing bivariate logistic regression analysis. Multivariable logistic regression analysis was then used to identify factors that were independently associated with ICU LOS ≥1 day after EVAR.

Results

A total of 2,468 patients (18.7% females, 81.3% males) were identified. Group 1 (ICU LOS <1 day) = 1,535 patients and Group 2 (ICU LOS ≥1 day) = 933 patients. Multivariable analysis identified the following factors to be associated with ICU LOS ≥1 day: ruptured AAA (OR 3.88, CI 1.97-7.65), the American Society of Anesthesiology (ASA) score of 4-5 (OR 2.82, CI 1.50-5.31), operative time ≥180 minutes (OR 2.10, CI 1.51-2.93), bilateral groin cut down (OR 1.37, CI 1.10-1.71), juxta-renal AAA (OR 1.65, CI 1.16-2.35), renal artery stent (OR 2.13, CI 1.42-3.21), aortic stent (OR 2.39, CI 1.60-3.55), emergency surgery (OR 2.56, CI 1.94-3.38), need for blood transfusion (OR 3.11, CI 2.08-4.65) and postoperative pneumonia (OR 7.04, CI 1.95-25.45).

Conclusion

Variables identified above can be used to predict the cohort of EVAR patients which will likely require ICU for ≥1 day. Development of postoperative pneumonia is associated with a 7.04 times increase in ICU LOS ≥1 day.

Non-Invasive Positive airway Pressure thErapy to Reduce Postoperative Lung complications following Upper abdominal Surgery (NIPPER PLUS): protocol for a single-centre, pilot, randomised controlled trial

INTRODUCTION

Postoperative pulmonary complications (PPCs) are a common serious complication following upper abdominal surgery leading to significant consequences including increased mortality, hospital costs and prolonged hospitalisation. The primary objective of this study is to detect whether there is a possible signal towards PPC reduction with the use of additional intermittent non-invasive ventilation (NIV) compared with continuous high-flow nasal oxygen therapy alone following high-risk elective upper abdominal surgery. Secondary objectives are to measure feasibility of: (1) trial conduct and design and (2) physiotherapy-led NIV and a high-flow nasal oxygen therapy protocol, safety of NIV and to provide preliminary costs of care information of NIV and high-flow nasal oxygen therapy.

METHODS AND ANALYSIS

This is a single-centre, parallel group, assessor blinded, pilot, randomised trial, with 130 high-risk upper abdominal surgery patients randomly assigned via concealed allocation to either (1) usual care of continuous high-flow nasal oxygen therapy for 48 hours following extubation or (2) usual care plus five additional 30 min physiotherapy-led NIV sessions within the first two postoperative days. Both groups receive standardised preoperative physiotherapy and postoperative early ambulation. No additional respiratory physiotherapy is provided to either group. Outcome measures will assess incidence of PPC within the first 14 postoperative days, recruitment ability, physiotherapy-led NIV and high-flow nasal oxygen therapy protocol adherence, adverse events relating to NIV delivery and costs of providing a physiotherapy-led NIV and a high-flow nasal oxygen therapy service following upper abdominal surgery.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the relevant institution and results will be published to inform future multicentre trials.

TRIAL REGISTRATION NUMBER

ACTRN12617000269336; Pre-results.

Prophylactic continuous positive airway pressure after pulmonary lobectomy: a randomized controlled trial

Background

Despite advances in perioperative care and surgical techniques, patients undergoing pulmonary lobectomy are still at high risk for postoperative complications. Among interventions expected to reduce complications, continuous positive airway pressure (CPAP) is a discussed option. This trial aims to test the hypothesis whether prophylactic application of CPAP following pulmonary lobectomy can reduce postoperative complications.

Methods

The study was designed as a prospective, randomized, controlled trial. Patients with clinical stage I non-small cell lung cancer scheduled for pulmonary lobectomy were eligible and were trained for the use of CPAP interface. The control group received standard postoperative pain management and physiotherapy; in addition, the study group received CPAP (PEEP 8-12 cmH₂O, 2 hours thrice daily for three days).

Results

After the appropriate selection, 163 patients were considered for the analysis: 82 patients constituted the control group, 81 the study group. The two groups were substantially comparable for preoperative parameters. The rate of postoperative complications was lower in the study group (24.7% vs. 43.9%; P=0.015) as well as the hospital stay (6 vs. 7 days; P=0.031). The stepwise logistic regression model identified: CPAP [odd ratio (OR): 0.3026, CI: 0.1389-0.6591], smoke habits [OR: 2.5835, confidence interval (CI): 1.0331-6.4610] and length of surgery in minutes (OR: 1.0102, CI: 1.0042-1.0163) as regressors on postoperative complications.

Conclusions

The present trial demonstrated that prophylactic application of CPAP during the postoperative period after pulmonary lobectomy for stage I non-small cell lung cancer was effective in prevent postoperative complications.

Prophylactic penehyclidine inhalation for prevention of postoperative pulmonary complications in high-risk patients: study protocol of a randomized controlled trial

Background

Postoperative pulmonary complications (PPCs) are major causes of morbidity, mortality, and prolonged hospital stay in patients after surgery. Using effective strategies to prevent its occurrence is essential to improve outcome. However, despite various efforts, the incidence of PPCs remains elevated in high-risk patients. Anticholinergic inhalation is used to reduce high airway resistance and improve pulmonary function; it may be helpful to decrease the risk of PPCs. Penehyclidine is a long-acting anticholinergic agent which selectively blocks M1 and M3 receptors. We hypothesize that, in high-risk patients, prophylactic penehyclidine inhalation may decrease the incidence of PPCs.

Methods

This is a randomized, double-blind, placebo-controlled trial with two parallel arms. A total of 864 patients at high risk of PPCs will be enrolled and randomized to receive prophylactic inhalation of either penehyclidine or placebo (water for injection). Study drug inhalation will be administered from the night (7 pm) before surgery until the second day after surgery, in an interval of every 12 hours. The primary outcome is the incidence of PPCs within 30 days after surgery. Secondary outcomes include the time to onset of PPCs (from end of surgery to first diagnosis of PPCs), the number of PPCs (indicates the number of diagnosed individual PPCs), the incidence of postoperative extrapulmonary complications, the length of stay in hospital after surgery, and the 30-day all-cause mortality.

Discussion

Results of the present study will provide evidence to guide clinical practice in using prophylactic inhalation of an anticholinergic to prevent PPCs in high-risk patients.

Trial registration

The study was registered prospectively in Chinese Clinical Trial Registry (www.chictr.org.cn, ChiCTR-IPC-15006603) on 14 May 2015 and retrospectively in ClinicalTrials.gov (NCT02644876) on 30 December 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2315-7) contains supplementary material, which is available to authorized users.

Noninvasive Mechanical Ventilation in Acute Ventilatory Failure: Rationale and Current Applications

Noninvasive ventilation plays a pivotal role in acute ventilator failure and has been shown, in certain disease processes such as acute exacerbation of chronic obstructive pulmonary disease, to prevent and shorten the duration of invasive mechanical ventilation, reducing the risks and complications associated with it. The application of noninvasive ventilation is relatively simple and well tolerated by patients and in the right setting can change the course of their illness.

Physiotherapy in upper abdominal surgery - what is current practice in Australia?

Background

Upper abdominal surgery (UAS) has the potential to cause post-operative pulmonary complications (PPCs). In the absence of high-quality research regarding post-operative physiotherapy management, consensus-based best practice guidelines formulated by Hanekom et al. (2012) are available to clinicians providing recommendations for post-UAS treatment. Such best practice guidelines have recommended that physiotherapists should be using early mobilisation and respiratory intervention to minimise risk of PPCs. However, recent evidence supports the implementation of mobilisation as a standalone treatment in PPC prevention, though the diversity in literature poses questions regarding ideal current practice. This project aimed to document and report the assessment measures and interventions physiotherapists are utilising following UAS, establishing whether current management is reflective of best practice guidelines and recent evidence.

Results

An online survey was completed by 57 experienced Australian physiotherapists working with patients following UAS (35% survey response rate, 63% completion rate). On day one following UAS, when a patient’s condition is not medically limited, most physiotherapists routinely mobilise. Additionally, routine chest treatment continues to be implemented, with only 23% (n = 11/47) of physiotherapists mobilising patients without accompanying specific respiratory intervention. Variability of screening tools used to identify post-operative patients at high risk of PPC development was evident. Patient-dependent factors such as ‘fatigue’ and ‘non-compliance’ were among those identified as barriers to treatment, all influencing the commencement of treatment.

Conclusions

Physiotherapists indicated that early mobilisation away from the bedside was the preferred post-operative treatment within the UAS patient population. Many continue to perform routine respiratory interventions despite recent literature suggesting it may provide no additional benefit to preventing PPCs. Current intervention choice is reflective of guidelines [1], however, recent literature has called this into question and more research needs to be done to establish if these recommendations are the most effective at reducing PPCs. Continued research is necessary to promote translation of knowledge to ensure physiotherapists are mobilising patients day one post-UAS. Likewise, future work should focus on identification of barriers, the strategies used to overcome limitations and the creation of a reliable and validated screening tool to ensure appropriate prioritisation and allocation of physiotherapy resources within the UAS patient population.

Electronic supplementary material

The online version of this article (doi:10.1186/s40945-017-0039-3) contains supplementary material, which is available to authorized users.

Efficacy of continuous positive airway pressure and incentive spirometry on respiratory functions during the postoperative period following supratentorial craniotomy: A prospective randomized controlled study

STUDY OBJECTIVE

Volume controlled ventilation with low PEEP is used in neuro-anesthesia to provide constant PaCO₂ levels and prevent raised intracranial pressure. Therefore, neurosurgery patients prone to atelectasis formation, however, we could not find any study that evaluates prevention of postoperative pulmonary complications in neurosurgery.

DESIGN

A prospective, randomized controlled study.

SETTING

Intensive care unit in a university hospital in Istanbul.

PATIENTS

Seventy-nine ASAI-II patients aged between 18 and 70years scheduled for elective supratentorial craniotomy were included in the study.

INTERVENTIONS

Patients randomized into 3 groups after surgery. The Group IS (n=20) was treated with incentive spirometry 5 times in 1min and 5min per hour, the Group CPAP (n=20) with continuous positive airway pressure 10 cmH₂O pressure and 0.4 F_iO₂ via an oronasal mask 5min per hour, and the Group Control (n=20) 4L·min^-1O₂ via mask; all during the first 6h postoperatively. Respiratory functions tests and arterial blood gases analysis were performed before the induction of anesthesia (Baseline), 30min, 6h, 24h postoperatively.

MAIN RESULTS

The IS and CPAP applications have similar effects with respect to FVC values. The postoperative 30min FEV₁ values were statistically significantly reduced compared to the Baseline in all groups (p<0.0001). FEV₁ values were statistically significantly increased at the postoperative 24h compared to the postoperative 30min in the Groups IS and CPAP (p<0.0001). This increase, however, was not observed in the Group Control, and the postoperative 24h FEV₁ values were statistically significantly lower in the Group Control compared to the Group IS (p=0.015).

CONCLUSION

Although this study is underpowered to detect differences in FEV₁ values, the postoperative 24h FEV₁ values were significantly higher in the IS group than the Control group and this difference was not observed between the CPAP and Control groups. It might be evaluate a favorable effect of IS in neurosurgery patients. But larger studies are needed to make a certain conclusion.

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients With Obstructive Sleep Apnea

Supplemental Digital Content is available in the text.

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

The accuracy of postoperative, non-invasive Air-Test to diagnose atelectasis in healthy patients after surgery: a prospective, diagnostic pilot study

OBJECTIVE

To assess the diagnostic accuracy of peripheral capillary oxygen saturation (SpO₂) while breathing room air for 5 min (the 'Air-Test') in detecting postoperative atelectasis.

DESIGN

Prospective cohort study. Diagnostic accuracy was assessed by measuring the agreement between the index test and the reference standard CT scan images.

SETTING

Postanaesthetic care unit in a tertiary hospital in Spain.

PARTICIPANTS

Three hundred and fifty patients from 12 January to 7 February 2015; 170 patients scheduled for surgery under general anaesthesia who were admitted into the postsurgical unit were included.

INTERVENTION

The Air-Test was performed in conscious extubated patients after a 30 min stabilisation period during which they received supplemental oxygen therapy via a venturi mask. The Air-Test was defined as positive when SpO₂ was ≤96% and negative when SpO₂ was ≥97%. Arterial blood gases were measured in all patients at the end of the Air-Test. In the subsequent 25 min, the presence of atelectasis was evaluated by performing a CT scan in 59 randomly selected patients.

MAIN OUTCOME MEASURES

The primary study outcome was assessment of the accuracy of the Air-Test for detecting postoperative atelectasis compared with the reference standard. The secondary outcome was the incidence of positive Air-Test results.

RESULTS

The Air-Test diagnosed postoperative atelectasis with an area under the receiver operating characteristic curve of 0.90 (95% CI 0.82 to 0.98) with a sensitivity of 82.6% and a specificity of 87.8%. The presence of atelectasis was confirmed by CT scans in all patients (30/30) with positive and in 5 patients (17%) with negative Air-Test results. Based on the Air-Test, postoperative atelectasis was present in 36% of the patients (62 out of 170).

CONCLUSION

The Air-Test may represent an accurate, simple, inexpensive and non-invasive method for diagnosing postoperative atelectasis.

TRIAL REGISTRATION

NCT02650037.

The effects of respiratory physiotherapy after lung resection: Protocol for a systematic review

•

To investigate the effects of respiratory physiotherapy after lung resection surgery on mortality rate within 30 days after surgery.

•

Postoperative pulmonary complications within 30 days after surgery.

•

Length of stay in hospital postoperatively.

Background

The main treatment of lung cancer (stage 1 and 2) is lung resection surgery. The risk of postoperative pulmonary complications is high and therefore standard postoperative care involves respiratory physiotherapy. The purpose of this systematic review is to create an overview of the evidence on respiratory physiotherapy after lung resection surgery on mortality rate (within 30 days) and postoperative pulmonary complications.

Methods and analysis

The review will include randomized or quasi-randomized controlled studies investigating the effect of all types of respiratory physiotherapy on mortality and postoperative pulmonary complications after lung resection surgery. Furthermore, the effect of respiratory physiotherapy is evaluated on secondary outcomes such as length of hospital stay, lung volumes and function, and adverse events. The method of the planned review is described in this paper. The literature search will include the databases PubMed, Cochrane (Central), Embase, Cinahl and PEDro. The literature search is being performed in 2017. If meta-analyses are not undertaken, a narrative synthesis of the available data will be provided. The protocol was registered in PROSPERO on the 10th of October 2016 (registration number CRD42016048956).

Ethics and dissemination

Conclusion of this systematic review is expected available in the second half of 2017.

Do Changes in Perioperative and Postoperative Treatment Protocol Influence the Frequency of Pulmonary Complications? A Retrospective Analysis of Four Different Bariatric Groups

The current understanding of prophylaxis of pulmonary complications in bariatric surgery is weak.

PURPOSE

The aim of this study was to observe how changes in perioperative and postoperative treatments affect the incidence of pulmonary complications in bariatric patients.

MATERIALS

This is a retrospective clinical study of 400 consecutive bariatric patients. The patients, who either underwent a sleeve gastrectomy or a Roux-en-Y gastric bypass, were divided consecutively into four subgroups with different approaches to perioperative treatment.

METHODS

The first group (patients 0-100) was recovered in the intensive care unit with minimal mobilization (ICU). They had a urinary catheter and a drain. The second group (patients 101-200) was similar to the first group, but the patients used a continuous positive airway pressure (CPAP) device intermittently (ICU-CPAP). The third group (patients 201-300) was recovered on a normal ward without a urinary catheter or a drain and used a CPAP device (ward-slow). The fourth group (patients 301-400) walked to the operating theater and was mobilized in the recovery room during the first 2 h after the operation (ward-fast). CPAP was also used. Primary endpoints were pulmonary complications, pneumonia, and infection, non-ultra descriptus (NUD).

RESULTS

The number of pulmonary complications among the groups was significantly different. A long operation time increased the risk for infection (p < 0.001 95 % CI from 2.02 to 6.59 %).

CONCLUSIONS

Operation time increases the risk for pulmonary complications. Changes in perioperative care toward the ERAS protocol may have a positive effect on the number of pulmonary complications.

Early warning and prevention of pneumonia in acute leukemia by patient education, spirometry, and positive expiratory pressure: A randomized controlled trial

Long‐lasting neutropenia associated with acute myeloid leukemia (AML) and its treatment gives rise to a high risk of pneumonia. The use of broad‐spectrum antibiotic prophylaxis during outpatient management has not completely protected patients against admission due to infections and neutropenic fever, emphasizing the need to approach infection protection with complementary efforts. In a randomized controlled design, we examined the applicability of patient‐performed daily spirometry [forced expiratory volume in one second (FEV1)] as an early warning tool and explored the effectiveness of positive expiratory pressure (PEP) in preventing pneumonia among 80 AML patients. Twenty‐five incidences of pneumonia were detected among 23 patients (6 interventions, 17 controls), giving a prevalence of 28.75% during 5420 days of observation. We found a significant difference in incidence between intervention versus control group (2.17 per 1000 days vs. 6.52 per 1000 days, P = 0.021, respectively). A cross point at 80‐76% of the personal FEV1 reference value showed high sensitivity and specificity on pneumonia development. Our data demonstrate the feasibility of educating AML patients in their continuous daily measurement of FEV1 and use of PEP. Daily measures of FEV1 may be an important early warning tool for assessment of pulmonary deterioration during critical phases of neutropenia. We suggest that strategic patient education in the use of spirometry and PEP should be part of standard of care for AML patients undergoing induction chemotherapy. Am. J. Hematol. 91:271–276, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.

The LIPPSMAck POP (Lung Infection Prevention Post Surgery - Major Abdominal - with Pre-Operative Physiotherapy) trial: study protocol for a multi-centre randomised controlled trial

Background

Post-operative pulmonary complications are a significant problem following open upper abdominal surgery. Preliminary evidence suggests that a single pre-operative physiotherapy education and preparatory lung expansion training session alone may prevent respiratory complications more effectively than supervised post-operative breathing and coughing exercises. However, the evidence is inconclusive due to methodological limitations. No well-designed, adequately powered, randomised controlled trial has investigated the effect of pre-operative education and training on post-operative respiratory complications, hospital length of stay, and health-related quality of life following upper abdominal surgery.

Methods/design

The Lung Infection Prevention Post Surgery - Major Abdominal- with Pre-Operative Physiotherapy (LIPPSMAck POP) trial is a pragmatic, investigator-initiated, bi-national, multi-centre, patient- and assessor-blinded, parallel group, randomised controlled trial, powered for superiority. Four hundred and forty-one patients scheduled for elective open upper abdominal surgery at two Australian and one New Zealand hospital will be randomised using concealed allocation to receive either i) an information booklet or ii) an information booklet, plus one additional pre-operative physiotherapy education and training session. The primary outcome is respiratory complication incidence using standardised diagnostic criteria. Secondary outcomes include hospital length of stay and costs, pneumonia diagnosis, intensive care unit readmission and length of stay, days/h to mobilise >1 min and >10 min, and, at 6 weeks post-surgery, patient reported complications, health-related quality of life, and physical capacity.

Discussion

The LIPPSMAck POP trial is a multi-centre randomised controlled trial powered and designed to investigate whether a single pre-operative physiotherapy session prevents post-operative respiratory complications. This trial standardises post-operative assisted ambulation and physiotherapy, measures many known confounders, and includes a post-discharge follow-up of complication rates, functional capacity, and health-related quality of life. This trial is currently recruiting.

Trial registration

Australian New Zealand Clinical Trials Registry number: ACTRN12613000664741, 19 June 2013.

Clinical analysis of perioperative nursing of aortic coarctation

BACKGROUND

The aim of this study is to explore the treatment experience of the perioperative nursing of coarctation of the aorta.

METHODS

From June 2012 to December 2013, a total of 15 children diagnosed with coarctation of the aorta were retrospectively studied and sorted into the observation group in our hospital. Also, 12 children admitted between January 2010 and December 2012 was sorted into control group. Combined intravenous anesthesia and cardiopulmonary bypass were conducted on all the children. Children in observation group underwent perioperative nursing, including preoperative nursing (evaluating disease conditions, improving preoperative preparation and preoperative discussion) and postoperative nursing (transferred into ICU, respiratory management, circulation system management, nutrition support nursing, using intravenous drugs). Children in the control group were treated with common nursing. Clinical effects of both groups were compared.

RESULTS

Fourteen of 15 cases in the treatment group were cured and discharged from the hospital after a 6~12-month follow-up. All patients had good prognosis, except one case quit the treatment and left hospital for obstinate low output syndrome.

CONCLUSIONS

With the improvement in the skills of a repair operation, extracorporeal circulation and monitoring as well as nursing, the restenosis incident rate and morality rate were effectively reduced. Meanwhile, taking an initiative for comprehensive prevention nursing measures during peri-operation is an important guarantee to a successful operation and prognosis.

Obesity: physiologic changes and implications for preoperative management

The proportion of patients defined as obese continues to grow in many westernized nations, particularly the United States (USA). This trend has shifted the perioperative management of obese patients into the realm of routine care. As obese patients present for all types of procedures, it is crucial for anesthesiologists, surgeons, internists, and perioperative health care providers alike to have a firm understanding of their altered multi-organ physiology in order to safely prepare the obese patient for an operation. A careful preoperative evaluation may also serve to identify risk factors for postoperative adverse events. Subsequently, preoperative measures may be implemented to mitigate these complications. In this manuscript we address the major considerations for the preoperative evaluation of the severely obese patient.

Respiratory management of the obese patient undergoing surgery

As a reflection of the increasing global incidence of obesity, there has been a corresponding rise in the proportion of obese patients undergoing major surgery. This review reports the physiological effect of these changes in body composition on the respiratory system and discusses the clinical approach required to maximize safety and minimize the risk to the patient. The changes in respiratory system compliance and lung volumes, which can adversely affect pulmonary gas exchange, combined with upper airways obstruction and sleep-disordered breathing need to be considered carefully in the peri-operative period. Indeed, these challenges in the obese patient have led to a clear focus on the clinical management strategy and development of peri-operative pathways, including pre-operative risk assessment, patient positioning at induction and under anesthesia, modified approach to intraoperative ventilation and the peri-operative use of non-invasive ventilation (NIV) and continuous positive airways pressure.

Rationale and study design for an individualized perioperative open lung ventilatory strategy (iPROVE): study protocol for a randomized controlled trial

BACKGROUND

Postoperative pulmonary and non-pulmonary complications are common problems that increase morbidity and mortality in surgical patients, even though the incidence has decreased with the increased use of protective lung ventilation strategies. Previous trials have focused on standard strategies in the intraoperative or postoperative period, but without personalizing these strategies to suit the needs of each individual patient and without considering both these periods as a global perioperative lung-protective approach. The trial presented here aims at comparing postoperative complications when using an individualized ventilatory management strategy in the intraoperative and immediate postoperative periods with those when using a standard protective ventilation strategy in patients scheduled for major abdominal surgery.

METHODS

This is a comparative, prospective, multicenter, randomized, and controlled, four-arm trial that will include 1012 patients with an intermediate or high risk for postoperative pulmonary complications. The patients will be divided into four groups: (1) individualized perioperative group: intra- and postoperative individualized strategy; (2) intraoperative individualized strategy + postoperative continuous positive airway pressure (CPAP); (3) intraoperative standard ventilation + postoperative CPAP; (4) intra- and postoperative standard strategy (conventional strategy). The primary outcome is a composite analysis of postoperative complications.

DISCUSSION

The Individualized Perioperative Open-lung Ventilatory Strategy (iPROVE) is the first multicenter, randomized, and controlled trial to investigate whether an individualized perioperative approach prevents postoperative pulmonary complications.

TRIAL REGISTRATION

Registered on 5 June 2014 with identification no. NCT02158923 .

Noninvasive positive pressure ventilation for acute respiratory failure following oesophagectomy: Is it safe? A systematic review of the literature

OBJECTIVE

To find, critically appraise and synthesise all published studies so as to determine the safety and spectrum of use of noninvasive positive pressure ventilation for acute respiratory failure following oesophagectomy.

DESIGN

Systematic review.

METHODS

The MEDLINE and EMBASE databases were searched and the quality of the studies and any bias or confounding were rated according to established protocols. Outcomes extracted included re-intubation, anastomotic leakage, length of intensive care unit stay and mortality. The data were analysed quantitatively and qualitatively. Pooling of outcomes was considered if appropriate.

RESULTS

The search identified four papers, demonstrating the understudying/underreporting of the topic. Three were case-series and one was a conference abstract. The overall methodological quality was low. Design-specific biases and confounding were high. Despite this, the included studies conclude that noninvasive positive pressure ventilation is safe and effective and that re-intubation rates, intensive care unit length of stay, mortality and anastomotic dehiscence is lower when it is used. Meta-analysis was deemed to be inappropriate.

CONCLUSIONS

Despite the conclusions and consensus of the included studies, there is no evidence to definitively conclude that noninvasive positive pressure ventilation is either safe or dangerous following oesophagectomy and the current literary evidence is inadequate. Current practice varies and is based on opinion and consensus. As such, randomised controlled studies are urgently required as current practice may cause undue harm to patients. The incidence of anastomotic leakage with noninvasive positive pressure ventilation use needs to be determined.

Strategies for managing oxygenation in obese patients undergoing laparoscopic surgery

The worldwide trend toward increasing body mass index (BMI) has caused the anesthetic management of overweight, obese, and severely obese patients to become common. The increase in oxygen demand coupled with the anatomic and physiologic changes associated with excess adipose tissue make maintenance of oxygenation a major challenge during induction, maintenance and recovery from general anesthesia. It is crucial for anesthesiologists, surgeons and perioperative healthcare providers alike to have a thorough understanding of the impact of airway management and mechanical ventilation on the respiratory care of the obese in the immediate perioperative setting. In this manuscript we aim to discuss the consequences of obesity, particularly abdominal obesity, on respiratory physiology and provide suggestions on intraoperative ventilatory strategies to maintain oxygenation in the severely obese patient undergoing pneumoperitoneum.

Continuous positive airway pressure (CPAP) during the postoperative period for prevention of postoperative morbidity and mortality following major abdominal surgery

BACKGROUND

Major abdominal surgery can be associated with a number of serious complications that may impair patient recovery. In particular, postoperative pulmonary complications (PPCs), including respiratory complications such as atelectasis and pneumonia, are a major contributor to postoperative morbidity and may even contribute to increased mortality. Continuous positive airway pressure (CPAP) is a type of therapy that uses a high-pressure gas source to deliver constant positive pressure to the airways throughout both inspiration and expiration. This approach is expected to prevent some pulmonary complications, thus reducing mortality.

OBJECTIVES

To determine whether any difference can be found in the rate of mortality and adverse events following major abdominal surgery in patients treated postoperatively with CPAP versus standard care, which may include traditional oxygen delivery systems, physiotherapy and incentive spirometry.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 9; Ovid MEDLINE (1966 to 15 September 2013); EMBASE (1988 to 15 September 2013); Web of Science (to September 2013) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (to September 2013).

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) in which CPAP was compared with standard care for prevention of postoperative mortality and adverse events following major abdominal surgery. We included all adults (adults as defined by individual studies) of both sexes. The intervention of CPAP was applied during the postoperative period. We excluded studies in which participants had received PEEP during surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies that met the selection criteria from all studies identified by the search strategy. Two review authors extracted the data and assessed risk of bias separately, using a data extraction form. Data entry into RevMan was performed by one review author and was checked by another for accuracy. We performed a limited meta-analysis and constructed a summary of findings table.

MAIN RESULTS

We selected 10 studies for inclusion in the review from 5236 studies identified in the search. These 10 studies included a total of 709 participants. Risk of bias for the included studies was assessed as high in six studies and as unclear in four studies.Two RCTs reported all-cause mortality. Among 413 participants, there was no clear evidence of a difference in mortality between CPAP and control groups, and considerable heterogeneity between trials was noted (risk ratio (RR) 1.28, 95% confidence interval (CI) 0.35 to 4.66; I(2) = 75%).Six studies reported demonstrable atelectasis in the study population. A reduction in atelectasis was observed in the CPAP group, although heterogeneity between studies was substantial (RR 0.62, 95% CI 0.45 to 0.86; I(2) = 61%). Pneumonia was reported in five studies, including 563 participants; CPAP reduced the rate of pneumonia, and no important heterogeneity was noted (RR 0.43, 95% CI 0.21 to 0.84; I(2) = 0%). The number of participants identified as having serious hypoxia was reported in two studies, with no clear difference between CPAP and control groups, given imprecise results and substantial heterogeneity between trials (RR 0.48, 95% CI 0.22 to 1.02; I(2) = 67%). A reduced rate of reintubation was reported in the CPAP group compared with the control group in two studies, and no important heterogeneity was identified (RR 0.14, 95% CI 0.03 to 0.58; I(2) = 0%). Admission into the intensive care unit (ICU) for invasive ventilation and supportive care was reduced in the CPAP group, but this finding did not reach statistical significance (RR 0.45, 95% CI 0.18 to 1.14; I(2) = 0).Secondary outcomes such as length of hospital stay and adverse effects were only minimally reported.A summary of findings table was constructed using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) principle. The quality of evidence was determined to be very low.

AUTHORS' CONCLUSIONS

Very low-quality evidence from this review suggests that CPAP initiated during the postoperative period might reduce postoperative atelectasis, pneumonia and reintubation, but its effects on mortality, hypoxia or invasive ventilation are uncertain. Evidence is not sufficiently strong to confirm the benefits or harms of CPAP during the postoperative period in those undergoing major abdominal surgery. Most of the included studies did not report on adverse effects attributed to CPAP.New, high-quality research is much needed to evaluate the use of CPAP in preventing mortality and morbidity following major abdominal surgery. With increasing availability of CPAP to our surgical patients and its potential to improve outcomes (possibly in conjunction with intraoperative lung protective ventilation strategies), unanswered questions regarding its efficacy and safety need to be addressed. Any future study must report on the adverse effects of CPAP.