Protective Lung Ventilation and Morbidity After Pulmonary Resection: A Propensity Score-Matched Analysis

Ventilation during Lung Resection and Critical Care: Comparative Clinical Outcomes

Recent evidence suggests that outcomes do not meaningfully differ between thoracic surgery patients who are ventilated with a low or higher tidal volume and the effects of low versus higher positive end-expiratory pressure are unclear.

Effect of pressure controlled volume guaranteed ventilation during pulmonary resection in children

The purpose of the study was to evaluate the effect of pressure controlled volume guaranteed ventilation in children requiring one lung ventilation during pulmonary resection. Patients were randomly assigned to the lung protective ventilation combined with pressure controlled volume guaranteed group (PCV-VG group) or the lung protective ventilation combined with volume controlled ventilation group (VCV group). Both groups received tidal-volume ventilation of 8 ml kg⁻¹ body weight during two lung ventilation and 6 ml kg⁻¹ during OLV, with sustained 5 cmH₂O positive end-expiratory pressure. Data collections were mainly performed at 10 min after induction of anaesthesia during TLV (T1), 5 min after OLV initiation (T2) and 5 min after complete CO2 insufflations (T3). In total, 63 patients were randomly assigned to the VCV (n = 31) and PCV-VG (n = 32) groups. The PCV-VG group exhibited lower PIP than the VCV group at T1 (16.8 ± 2.3 vs. 18.7 ± 2.7 cmH₂O, P = 0.001), T2 (20.2 ± 2.7 vs. 22.4 ± 3.3 cmH₂O, P = 0.001), and T3 (23.8 ± 3.2 vs. 26.36 ± 3.7 cmH₂O, P = 0.01). Static compliance was higher in the PCV-VG group at T1, T2, and T3 (P = 0.01). After anaesthesia induction, lung aeration deteriorated, but with no immediate postoperative difference in both groups. Postoperative lung aeration improved and returned to normal from 2.5 h postextubation in both groups. PH was lower and PaCO₂ was higher in VCV group than PCV-VG group during one lung ventilation. No differences were observed in PaO₂-FiO₂-ratio at T2 and T3, the incidence of postoperative pulmonary complications, intraoperative desaturation and the length of hospital stay. In paediatric patients, who underwent pulmonary resection requiring one lung ventilation, PCV-VG was superior to VCV in its ability to provide lower PIP, higher static compliance and lower PaCO₂ at one lung ventilation during pneumothorax. However, its beneficial effects on different pathological situations in pediatric patients need more investigation.

A Lower Tidal Volume Regimen during One-lung Ventilation for Lung Resection Surgery Is Not Associated with Reduced Postoperative Pulmonary Complications

BACKGROUND

Protective ventilation may improve outcomes after major surgery. However, in the context of one-lung ventilation, such a strategy is incompletely defined. The authors hypothesized that a putative one-lung protective ventilation regimen would be independently associated with decreased odds of pulmonary complications after thoracic surgery.

METHODS

The authors merged Society of Thoracic Surgeons Database and Multicenter Perioperative Outcomes Group intraoperative data for lung resection procedures using one-lung ventilation across five institutions from 2012 to 2016. They defined one-lung protective ventilation as the combination of both median tidal volume 5 ml/kg or lower predicted body weight and positive end-expiratory pressure 5 cm H2O or greater. The primary outcome was a composite of 30-day major postoperative pulmonary complications.

RESULTS

A total of 3,232 cases were available for analysis. Tidal volumes decreased modestly during the study period (6.7 to 6.0 ml/kg; P < 0.001), and positive end-expiratory pressure increased from 4 to 5 cm H2O (P < 0.001). Despite increasing adoption of a "protective ventilation" strategy (5.7% in 2012 vs. 17.9% in 2016), the prevalence of pulmonary complications did not change significantly (11.4 to 15.7%; P = 0.147). In a propensity score matched cohort (381 matched pairs), protective ventilation (mean tidal volume 6.4 vs. 4.4 ml/kg) was not associated with a reduction in pulmonary complications (adjusted odds ratio, 0.86; 95% CI, 0.56 to 1.32). In an unmatched cohort, the authors were unable to define a specific alternative combination of positive end-expiratory pressure and tidal volume that was associated with decreased risk of pulmonary complications.

CONCLUSIONS

In this multicenter retrospective observational analysis of patients undergoing one-lung ventilation during thoracic surgery, the authors did not detect an independent association between a low tidal volume lung-protective ventilation regimen and a composite of postoperative pulmonary complications.

EDITOR’S PERSPECTIVE

Guidelines on enhanced recovery after pulmonary lobectomy

OBJECTIVE

To establish recommendations for optimisation of the management of patients undergoing pulmonary lobectomy, particularly Enhanced Recovery After Surgery (ERAS).

DESIGN

A consensus committee of 13 experts from the French Society of Anaesthesia and Intensive Care Medicine (Soci,t, franOaise d'anesth,sie et de r,animation, SFAR) and the French Society of Thoracic and Cardiovascular Surgery (Soci,t, franOaise de chirurgie thoracique et cardiovasculaire, SFCTCV) was convened. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Five domains were defined: 1) patient pathway and patient information; 2) preoperative management and rehabilitation; 3) anaesthesia and analgesia for lobectomy; 4) surgical strategy for lobectomy; and 5) enhanced recovery after surgery. For each domain, the objective of the recommendations was to address a number of questions formulated according to the PICO model (Population, Intervention, Comparison, Outcome). An extensive literature search on these questions was carried out and analysed using the GRADE® methodology. Recommendations were formulated according to the GRADE® methodology, and were then voted by all experts according to the GRADE grid method.

RESULTS

The SFAR/SFCTCV guideline panel provided 32 recommendations on the management of patients undergoing pulmonary lobectomy. After two voting rounds and several amendments, a strong consensus was reached for 31 of the 32 recommendations and a moderate consensus was reached for the last recommendation. Seven of these recommendations present a high level of evidence (GRADE 1+), 23 have a moderate level of evidence (18 GRADE 2+ and 5 GRADE 2-), and 2 correspond to expert opinions. Finally, no recommendation was provided for 2 of the questions.

CONCLUSIONS

A strong consensus was expressed by the experts to provide recommendations to optimise the whole perioperative management of patients undergoing pulmonary lobectomy.

Minimizing postoperative pulmonary complications in thoracic surgery patients

PURPOSE OF REVIEW

Quantification and optimization of perioperative risk factors focusing on anesthesia-related strategies to reduce postoperative pulmonary complications (PPCs) after lung and esophageal surgery.

RECENT FINDINGS

There is an increasing amount of multimorbid patients undergoing thoracic surgery due to the demographic development and medical progress in perioperative medicine. Nevertheless, the rate of PPCs after thoracic surgery is still up to 30-50% with a significant influence on patients' outcome. PPCs are ranked first among the leading causes of early mortality after thoracic surgery. Although patients' risk factors are usually barely modifiable, current research focuses on procedural risk factors. From the surgical position, the minimal-invasive approach using video-assisted thoracoscopy and laparoscopy leads to a decreased rate of PPCs. The anesthesiological strategy to reduce the incidence of PPCs after thoracic surgery includes neuroaxial anesthesia, lung-protective ventilation, and goal-directed hemodynamic therapy.

SUMMARY

The main anesthesiological strategies to reduce PPCs after thoracic surgery include the use of epidural anesthesia, lung-protective ventilation: PEEP (positive end-expiratory pressure) of 5-8 mbar, tidal volume of 5 ml/kg BW (body weight) and goal-directed hemodynamics: CI (cardiac index) ≥ 2.5 l/min per m2, MAD (Mean arterial pressure) ≥ 70 mmHg, SVV (stroke volume variation) < 10% with a total amount of perioperative crystalloid fluids ≤ 6 ml/kg BW (body weight) per hour.

Tidal volume during 1-lung ventilation: A systematic review and meta-analysis

BACKGROUND

The selection of tidal volumes for 1-lung ventilation remains unclear, because there exists a trade-off between oxygenation and risk of lung injury. We conducted a systematic review and meta-analysis to determine how oxygenation, compliance, and clinical outcomes are affected by tidal volume during 1-lung ventilation.

METHODS

A systematic search of MEDLINE and EMBASE was performed. A systematic review and random-effects meta-analysis was conducted. Pooled mean difference estimated arterial oxygen tension, compliance, and length of stay; pooled odds ratio was calculated for composite postoperative pulmonary complications. Risk of bias was determined using the Cochrane risk of bias and Newcastle-Ottawa tools.

RESULTS

Eighteen studies were identified, comprising 3693 total patients. Low tidal volumes (5.6 [±0.9] mL/kg) were not associated with significant differences in partial pressure of oxygen (-15.64 [-88.53-57.26] mm Hg; P = .67), arterial oxygen tension to fractional intake of oxygen ratio (14.71 [-7.83-37.24]; P = .20), or compliance (2.03 [-5.22-9.27] mL/cmH2O; P = .58) versus conventional tidal volume ventilation (8.1 [±3.1] mL/kg). Low versus conventional tidal volume ventilation had no significant impact on hospital length of stay (-0.42 [-1.60-0.77] days; P = .49). Low tidal volumes are associated with significantly decreased odds of pulmonary complications (pooled odds ratio, 0.40 [0.29-0.57]; P < .0001).

CONCLUSIONS

Low tidal volumes during 1-lung ventilation do not worsen oxygenation or compliance. A low tidal volume ventilation strategy during 1-lung ventilation was associated with a significant reduction in postoperative pulmonary complications.

Anesthesiological considerations in emphysema surgery

In the last decades, developing thoracic surgery raised the demands for sophisticated anesthesiological management. Especially patients with end-stage thoracic emphysema challenge the anesthesiologist to make modern surgery possible and to provide a safe and effective perioperative management. The development and scientific work-up of single lung ventilation (SLV) laid the cornerstone for surgery of the non-ventilated lung and hemi-thorax. However, modern medicine extended surgical options to extensive tracheal surgery and to patients suffering from severely insufficient lung-capacity precluding single-lung ventilation or artificial ventilation in se. For those critically ill, different techniques were thus developed and evaluated in recent research, among others, non-intubated surgery and surgery under extracorporeal perfusion support that temporarily avoids pulmonary gas exchange and ventilation via the trachea in any way. To tackle postoperative pain with its successive problems of immobilization, insufficient respiration and airway-clearance, regional anesthesia offers great advantages. Thoracic epidural anesthesia (TEA) is considered as the gold standard; complementary, modern ultrasound techniques make regional anesthesia possible even when contraindications prohibit neuraxial blocks. Especially paravertebral block, musculus serratus anterior block, intercostal block and the musculus erector spinae block provide good postoperative pain relief and appear to influence chronic post-thoracotmy pain positively. Careful preoperative preparation, intraoperative monitoring and patient-tailored, individual perioperative management by a well-trained team ensure good results, a good survival and favorable quality of life. This article provides a brief overview over state-of-the-art techniques and future perspectives to provide anesthesia in emphysema surgery.

Pressure-Controlled Ventilation-Volume Guaranteed Mode Combined with an Open-Lung Approach Improves Lung Mechanics, Oxygenation Parameters, and the Inflammatory Response during One-Lung Ventilation: A Randomized Controlled Trial

We evaluated the effectiveness of pressure-controlled ventilation-volume guaranteed (PCV-VG) mode combined with open-lung approach (OLA) in patients during one-lung ventilation (OLV). First, 176 patients undergoing thoracoscopic surgery were allocated randomly to four groups: PCV+OLA (45 cases, PCV-VG mode plus OLA involving application of individualized positive end-expiratory pressure (PEEP) after a recruitment maneuver), PCV (44 cases, PCV-VG mode plus standard lung-protective ventilation with fixed PEEP of 5 cmH₂O), VCV+OLA (45 cases, volume-controlled ventilation (VCV) plus OLA), and VCV (42 cases, VCV plus standard lung-protective ventilation). Mean airway pressure (P_mean), dynamic compliance (Cdyn), PaO₂/FiO₂ ratio, intrapulmonary shunt ratio (Qs/Qt), dead space fraction (V_D/V_T), and plasma concentration of neutrophil elastase were obtained to assess the effects of four lung-protective ventilation strategies. At 45 min after OLV, the median (interquartile range (IQR)) P_mean was higher in the PCV+OLA group (13.00 (12.00, 13.00) cmH₂O) and the VCV+OLA group (12.00 (12.00, 14.00) cmH₂O) than in the PCV group (11.00 (10.00, 12.00) cmH₂O) and the VCV group (11.00 (10.00, 12.00) cmH₂O) (P < 0.05); the median (IQR) Cdyn was higher in the PCV+OLA group (27.00 (24.00, 32.00) mL/cmH₂O) and the VCV+OLA group (27.00 (22.00, 30.00) mL/cmH₂O) than in the PCV group (23.00 (21.00, 25.00) mL/cmH₂O) and the VCV group (20.00 (18.75, 21.00) mL/cmH₂O) (P < 0.05); the median (IQR) Qs/Qt in the PCV+OLA group (0.17 (0.16, 0.19)) was significantly lower than that in the PCV group (0.19 (0.18, 0.20)) and the VCV group (0.19 (0.17, 0.20)) (P < 0.05); V_D/V_T was lower in the PCV+OLA group (0.18 ± 0.05) and the VCV+OLA group (0.19 ± 0.07) than in the PCV group (0.21 ± 0.07) and the VCV group (0.22 ± 0.06) (P < 0.05). The concentration of neutrophil elastase was lower in the PCV+OLA group than in the PCV, VCV+OLA, and VCV groups at total-lung ventilation 10 min after OLV (162.47 ± 25.71, 198.58 ± 41.99, 200.84 ± 22.17, and 286.95 ± 21.10 ng/mL, resp.) (P < 0.05). In conclusion, PCV-VG mode combined with an OLA strategy leads to favorable effects upon lung mechanics, oxygenation parameters, and the inflammatory response during OLV.

Nonintubated Video-Assisted Thoracoscopic Surgery Lung Biopsy for Interstitial Lung Disease

Interstitial lung diseases are a heterogeneous group with diffuse parenchymal lung disease. Because most patients with interstitial lung diseases have impaired pulmonary function, the risks of thoracic surgery are an important issue when considering surgical lung biopsy. The nonintubated video-assisted thoracoscopic surgery lung biopsy for interstitial lung disease is a safe and feasible option in carefully selected patients with interstitial lung disease.

Protective ventilation during anaesthesia reduces major postoperative complications after lung cancer surgery: A double-blind randomised controlled trial

BACKGROUND

Thoracic surgery for lung resection is associated with a high incidence of postoperative pulmonary complications. Controlled ventilation with a large tidal volume has been documented to be a risk factor for postoperative respiratory complications after major abdominal surgery, whereas the use of low tidal volumes and positive end-expiratory pressure (PEEP) has a protective effect.

OBJECTIVE

To evaluate the effects of ventilation with low tidal volume and PEEP on major complications after thoracic surgery.

DESIGN

A double-blind, randomised controlled study.

SETTING

A multicentre trial from December 2008 to October 2011.

PATIENTS

A total of 346 patients undergoing lobectomy or pneumonectomy for lung cancer.

MAIN OUTCOME MEASURES

The primary outcome was the occurrence of major postoperative complications (pneumonia, acute lung injury, acute respiratory distress syndrome, pulmonary embolism, shock, myocardial infarction or death) within 30 days after surgery.

INTERVENTIONS

Patients were randomly assigned to receive either lung-protective ventilation (LPV group) [tidal volume 5 ml kg ideal body weight + PEEP between 5 and 8 cmH2O] or nonprotective ventilation (control group) (tidal volume 10 ml kg ideal body weight without PEEP) during anaesthesia.

RESULTS

The trial was stopped prematurely because of an insufficient inclusion rate. Major postoperative complications occurred in 23/172 patients in the LPV group (13.4%) vs. 38/171 (22.2%) in the control group (odds ratio 0.54, 95% confidence interval, 0.31 to 0.95, P = 0.03). The incidence of other complications (supraventricular cardiac arrhythmia, bronchial obstruction, pulmonary atelectasis, hypercapnia, bronchial fistula and persistent air leak) was also lower in the LPV group (37.2 vs. 49.4%, odds ratio 0.60, 95% confidence interval, 0.39 to 0.92, P = 0.02).The duration of hospital stay was shorter in the LPV group, 11 [interquartile range, 9 to 15] days vs. 12 [9 to 16] days, P = 0.048.

CONCLUSION

Compared with high tidal volume and no PEEP, LPV combining low tidal volume and PEEP during anaesthesia for lung cancer surgery seems to improve postoperative outcomes.

TRIALS REGISTRATION

ClinicalTrials.gov number: NCT00805077.

Ivor Lewis esophagectomy patients are particularly vulnerable to respiratory impairment - a comparison to major lung resection

Pulmonary complications and a poor clinical outcome are common in response to transthoracic esophagectomy, but their etiology is not well understood. Clinical observation suggests that patients undergoing pulmonary resection, a surgical intervention with similarities to the thoracic part of esophagectomy, fare much better, but this has not been investigated in detail. A retrospective single-center analysis of 181 consecutive patients after right-sided thoracotomy for either Ivor Lewis esophagectomy (n = 83) or major pulmonary resection (n = 98) was performed. An oxygenation index <300 mm Hg was used to indicate respiratory impairment. When starting surgery, respiratory impairment was seen more frequently in patients undergoing major pulmonary resection compared to esophagectomy patients (p = 0.009). On postoperative days one to ten, however, esophagectomy caused higher rates of respiratory impairment (p < 0.05) resulting in a higher cumulative incidence of postoperative respiratory impairment for patients after esophagectomy (p < 0.001). Accordingly, esophagectomy patients were characterized by longer ventilation times (p < 0.0001), intensive care unit and total postoperative hospital stays (both p < 0.0001). In conclusion, the postoperative clinical course including respiratory impairment after Ivor Lewis esophagectomy is significantly worse than that after major pulmonary resection. A detailed investigation of the underlying causes is required to improve the outcome of esophagectomy.

Anesthetic considerations for lung resection: preoperative assessment, intraoperative challenges and postoperative analgesia

This article is intended to provide a general overview of the anesthetic management for lung resection surgery including the preoperative evaluation of the patient, factors influencing the intraoperative anesthetic management and options for postoperative analgesia. Lung cancer is the leading cause of death among cancer patients in the United States. In patients undergoing lung resection, perioperative pulmonary complications are the major etiology of morbidity and mortality. Risk stratification of patients should be part of the preoperative assessment to predict their risk of short-term vs. long-term pulmonary complications. Improvements in surgical technique and equipment have made video assisted thoracoscopy and robotically assisted thoracoscopy the procedures of choice for thoracic surgeries. General anesthesia including lung isolation has become essential for optimizing visualization of the operative lung but may itself contribute to pulmonary complications. Protective lung ventilation strategies may not prevent acute lung injury from one-lung ventilation, but it may decrease the amount of overall lung injury by using small tidal volumes, positive end expiratory pressure, low peak and plateau airway pressures and low inspired oxygen fraction, as well as by keeping surgical time as short as possible. Because of the high incidence of chronic post-thoracotomy pain syndrome following thoracic surgery, which can impact a patient's normal daily activities for months to years after surgery, postoperative analgesia is a necessary part of the anesthetic plan. Multiple options such as thoracic epidural analgesia, intravenous narcotics and several nerve blocks can be considered in order to prevent or attenuate chronic pain syndromes. Enhanced recovery after thoracic surgery is a relatively new topic with many elements taken from the experience with colorectal surgery. The goal of enhanced recovery is to improve patient outcome by improving organ function and decreasing postoperative complications, and therefore decreasing length of hospital stay.

Acute Right Ventricular Dysfunction in Intensive Care Unit

The role of the left ventricle in ICU patients with circulatory shock has long been considered. However, acute right ventricle (RV) dysfunction causes and aggravates many common critical diseases (acute respiratory distress syndrome, pulmonary embolism, acute myocardial infarction, and postoperative cardiac surgery). Several supportive therapies, including mechanical ventilation and fluid management, can make RV dysfunction worse, potentially exacerbating shock. We briefly review the epidemiology, pathophysiology, diagnosis, and recommendations to guide management of acute RV dysfunction in ICU patients. Our aim is to clarify the complex effects of mechanical ventilation, fluid therapy, vasoactive drug infusions, and other therapies to resuscitate the critical patient optimally.