Nonventilatory strategies to prevent postoperative pulmonary complications

Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement in Lower-Surgical-Risk Patients With Chronic Obstructive Pulmonary Disease

Respiratory complications are a major factor contributing to postoperative morbidity and mortality, especially in patients with chronic obstructive pulmonary disease (COPD). Our objective was to compare the rate of respiratory complications in patients with COPD with severe aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR). Low-to-intermediate surgical-risk patients with moderate or severe COPD who underwent TAVI or SAVR at 2 tertiary centers were included in this study. COPD was defined by the Global Initiative for Chronic Lung Disease classification. The primary end point was the 30-day composite of respiratory mortality, prolonged ventilation (>24 hours), the need for reintubation for respiratory causes, tracheostomy, acute respiratory distress syndrome, pneumonia, or pneumothorax. The inverse probability of treatment weighting was determined to reduce baseline imbalance between the 2 groups. A total of 321 patients (mean age 72.4 ± 9.3 years old, 74.5% male, mean Society of Thoracic Surgeons predicted risk of mortality 3.8 ± 1.9%, mean forced expiratory volume 1: 59 ± 13%) were included in the analysis. TAVI was performed in 122 patients, whereas 199 underwent SAVR. There were no differences between the 2 groups regarding the composite respiratory primary end point (SAVR 10.6%, TAVR 7.4%, adjusted odds ratio 0.57, 95% confidence interval 0.20 to 1.65, p = 0.30). Transfemoral TAVI without general anesthesia (28 patients) was associated with the lowest rate of respiratory complications (3.6%). Among patients with moderate or severe COPD at low-to-intermediate surgical risk, TAVI patients had a similar rate of 30-day major pulmonary complications compared with SAVR patients despite a higher baseline risk profile. Future studies should further investigate whether TAVI is associated with reduced respiratory complications, comparing transfemoral TAVI recipients treated with local anesthesia with their SAVR counterparts.

A Clinical Experimental Model to Evaluate Analgesic Effect of Remote Ischemic Preconditioning in Acute Postoperative Pain

This study aims to evaluate the viability of a clinical model of remote ischemic preconditioning (RIPC) and its analgesic effects. It is a prospective study with twenty (20) patients randomly divided into two groups: control group and RIPC group. The opioid analgesics consumption in the postoperative period, the presence of secondary mechanical hyperalgesia, the scores of postoperative pain by visual analog scale, and the plasma levels interleukins (IL-6) were evaluated. The tourniquet applying after spinal anesthetic block was safe, producing no pain for all patients in the tourniquet group. The total dose of morphine consumption in 24 hours was significantly lower in RIPC group than in the control group (p = 0.0156). The intensity analysis of rest pain, pain during coughing and pain in deep breathing, showed that visual analogue scale (VAS) scores were significantly lower in RIPC group compared to the control group: p = 0.0087, 0.0119, and 0.0015, respectively. There were no differences between groups in the analysis of presence or absence of mechanical hyperalgesia (p = 0.0704) and in the serum levels of IL-6 dosage over time (p < 0.0001). This clinical model of remote ischemic preconditioning promoted satisfactory analgesia in patients undergoing conventional cholecystectomy, without changing serum levels of IL-6.

Non-ventilatory approaches to prevent postoperative pulmonary complications

This educational narrative review provides a summary of non-ventilatory strategies to prevent postoperative pulmonary complications (PPCs). It highlights patient- and procedure-related risk factors for PPCs that are non-modifiable, potentially modifiable, or well modifiable. Non-ventilatory strategies, mainly based on the modification of risk factors, play a key role in reducing PPCs. Non-modifiable risk factors, most importantly age, American Society of Anesthesiologists (ASA) class, and risk of the procedure, should be recognized and patients intensively screened for the potential to optimize other, potentially or well-modifiable, risk factors. Potentially modifiable risk factors, mainly comorbidities and the surgical approach, increase the risk of PPCs. Patient-related factors can be improved while procedure-related factors may be adapted in high-risk patients. Well-modifiable risk factors, mainly certain anesthesia techniques, for example, general anesthesia, intravenous opioids or liberal fluid management, and smoking or alcohol abuse, should be avoided as far as possible in order to prevent PPCs.

Postoperative respiratory failure: pathogenesis, prediction, and prevention

PURPOSE OF REVIEW

This review discusses our present understanding of postoperative respiratory failure (PRF) pathogenesis, risk factors, and perioperative-risk reduction strategies.

RECENT FINDINGS

PRF, the most frequent postoperative pulmonary complication, is defined by impaired blood gas exchange appearing after surgery. PRF leads to longer hospital stays and higher mortality. The time frame for recognizing when respiratory failure is related to the surgical-anesthetic insult remains imprecise, however, and researchers have used different clinical events instead of blood gas measures to define the outcome. Still, studies in specific surgical populations or large patient samples have identified a range of predictors of PRF risk: type of surgery and comorbidity, mechanical ventilation, and multiple hits to the lung have been found to be relevant in most of these studies. Recently, risk-scoring systems for PRF have been developed and are being applied in new controlled trials of PRF-risk reduction measures. Current evidence favors carefully managing intraoperative ventilator use and fluids, reducing surgical aggression, and preventing wound infection and pain.

SUMMARY

PRF is a life-threatening event that is challenging for the surgical team. Risk prediction scales based on large population studies are being developed and validated. We need high-quality trials of preventive measures, particularly those related to ventilator use in both high risk and general populations.