Stair climbing as an exercise test to predict the postoperative complications of lung resection. Two years' experience

The 6-minute stepper test and the sit-to-stand test predict complications after major pulmonary resection via minimally invasive surgery: a prospective inception cohort study

QUESTIONS

How well do the 6-minute stepper test (6MST) and sit-to-stand test (STST) predict complications after minimally invasive lung cancer resection? Do the 6MST and STST provide supplementary information on the risk of postoperative complications in addition to the prognostic variables that are currently used, such as age and the American Society of Anesthesiology (ASA) score?

DESIGN

Prospective inception cohort study with follow-up for 90 days.

PARTICIPANTS

Consecutive sample of adults undergoing major lung resection with video-assisted thoracic surgery (VATS) or robot-assisted thoracic surgery (RATS).

OUTCOME MEASURES

Patients had a preoperative functional evaluation with the 6MST and STST. The number of steps, heart rate change, saturation and dyspnoea during the 6MST and the number of lifts during the STST were recorded. Complications graded ≥ 2 on the Clavien-Dindo classification were recorded for 90 days after surgery.

RESULTS

Between November 2018 and November 2019, 118 patients with a mean age of 65 years (SD 9) were included and analysed. Their surgeries were via VATS in 88 (75%) and via RATS in 30 (25%). For predicting a postoperative complication graded ≥ 2 on the Clavien-Dindo classification, the area under the Receiver Operating Characteristic curve was: 0.82 (95% CI 0.75 to 0.90) for the number of steps during the 6MST, with an optimum cut-off of 140 steps; and 0.85 (95% CI 0.77 to 0.93) for the number of lifts during the STST, with an optimum cut-off of 20 lifts.

CONCLUSION

The 6MST and STST predicted morbidity and mortality after lung cancer resection via minimally invasive surgery. The preoperative use of these exercise tests in clinical practice may be useful for risk stratification.

REGISTRATION

NCT03824977.

The Predictive Value of Stair Climbing Test on Postoperative Complications in Lung Cancer Patients with Limited Pulmonary Function

PURPOSE

To evaluate the predictive value of stair climbing test (SCT) on postoperative complications in lung cancer patients with limited pulmonary function.

METHODS

A total of 727 hospitalized lung cancer patients with limited pulmonary function were retrospectively reviewed. Included in the cohort were 424 patients who underwent SCT preoperatively. Patients were grouped according to general condition, past medical history, surgical approach, pulmonary function test, and SCT results. Comparison of the postoperative cardiopulmonary complication rates was made and independent risk factors were identified.

RESULTS

A total of 89 cardiopulmonary-related complications occurred in 69 cases, accounting for 16.3% of the entire cohort. The postoperative cardiopulmonary complication rates were significantly different between groups stratified by smoking index, percentage of forced expiratory volume in one second, percentage of diffusion capacity for carbon monoxide, SCT results, excision extension, and anesthetic duration (p <0.05). Multivariate analysis showed that only height achieved (p <0.001), changes in heart rate (∆HR; p <0.001), and excision extension (p = 0.006) were independent risk factors for postoperative cardiopulmonary complications.

CONCLUSIONS

The SCT could be used as a preoperative screening method for lung cancer patients with limited pulmonary function. For those patients who could only climb less than 6 floors or had ∆HR >30 bpm in the test, sublobar resection should be selected to reduce the postoperative cardiopulmonary complication rate.

The 6-min walk test in the functional evaluation of patients with lung cancer qualified for lobectomy

OBJECTIVES

The American College of Chest Physicians guidelines recommend low-technology exercise tests in the functional evaluation of patients with lung cancer considered for resectional surgery. However, the 6-min walk test (6MWT) is not included, because the data on its clinical value are inconsistent. Our goal was to evaluate the 6MWT in assessing the risk of cardiopulmonary complications in candidates for lung resection.

METHODS

We performed a retrospective assessment of clinical data and pulmonary function test results in 947 patients, mean age 65.3 (standard deviation 9.5) years, who underwent a single lobectomy for lung cancer. In 555 patients with predicted postoperative values ≤60%, the 6MWT was performed. The 6-min walking distance (6MWD) and the distance-saturation product (DSP), which is the product of the 6MWD in metres, and the lowest oxygen saturation registered during the test were assessed.

RESULTS

A total of 363 patients with predicted postoperative values <60% and a 6MWT distance (6MWD) ≥400 m or DSP ≥ 350 m% had a lower rate of cardiopulmonary complications than patients with shorter 6MWD or lower DSP values [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.35-0.81] and 0.47 (95% CI 0.30-0.73), respectively. This result was also true for patients with predicted postoperative values <40%, ORs 0.33 (95% CI 0.14-0.79) and 0.25 (95% CI 0.10-0.61), respectively.

CONCLUSIONS

The 6MWT is useful in the assessment of operative risk in patients undergoing a single lobectomy for lung cancer. It helps to stratify the operative risk, which is lower in patients with 6MWD ≥400 m or DSP ≥350 m% than in patients with a shorter 6MWD or lower DSP values.

Performance at stair-climbing test is associated with postoperative complications after lung resection: a systematic review and meta-analysis

Background

Thoracic surgery is the optimal treatment for early-stage lung cancer, but there is a high risk of postoperative morbidity. Therefore, it is necessary to evaluate patients’ preoperative general condition and cardiorespiratory capacity to determine the risk of postoperative complications. The objective of this study was to assess whether the stair-climbing test could be used in the preoperative evaluation of lung resection patients to predict postoperative morbidity following thoracic surgery.

Methods

We performed a systematic review and a meta-analysis on the association between stair-climbing test result and morbidity/mortality after thoracic surgery. We analysed all articles published until May 2020 in the following databases: Pubmed/Medline, Pedro, The Cochrane library, Embase and CINAHL. The risk of bias was assessed using the Quality in Prognosis Studies tool. This meta-analysis is registered as PROSPERO CRD42019121348.

Results

13 articles were included in the systematic review for a total of 2038 patients and 6 in the meta-analysis. There were multiple test evaluation criteria: rise time, height, desaturation and heart rate change. For the meta-analysis, we were able to pool data on the height of rise at a variable threshold: risk ratio 2.34 (95% CI 1.59 to 3.43) with I²=53% (p=0.06). The threshold for occurrence of complications was estimated at a 10 m climb.

Conclusions

Our results indicate that the stair-climbing test could be used as a first-line functional screening test to predict postoperative morbidity following thoracic surgery and that patients with a poor test result (<10 m) should be referred to formal cardiopulmonary exercise testing.

Validation of the two-minute step test in obese with comorbibities and morbidly obese patients

Cardiopulmonary fitness assessment is a valuable resource to obtain quantitative indicators of an individual's physical performance. The cardiopulmonary exercise test (CPX), considered the gold standard test for this evaluation, is costly and difficult to be accessed by the general population. In order to make this evaluation more accessible, and to better reflect the performance of daily life activities, alternative tests were proposed. Morbidly obese patients present limitations that impair physical performance assessment and could benefit from a test of shorter duration, provided it is validated. This observational study aimed to validate the two-minute step test (2MST) as a tool to evaluate functional capacity (FC) in obese with comorbidities and morbidly obese patients, compared the 2MST with CPX as a measure of physical performance, and developed a predictive equation to estimate peak oxygen uptake (VO₂) in the 2MST. The CPX and the 2MST were performed and metabolic and ventilatory parameters were recorded in 31 obese individuals (BMI>35 kg/m²). Pearson correlation and multiple linear regression analyses were performed to evaluate the peak VO₂ best predictors. Bland-Altman analysis was performed to assess the agreement between the two methods. Peak VO₂ measured by CPX and 2MST showed a strong correlation (r=0.70, P<0.001) and there was a moderate correlation between peak VO₂ of the 2MST and the number of up-and-down step cycles (UDS) (r=0.55; P=0.01). The reference equation obtained was: VO₂ (mL·kg^-1·min^-1) = 13.341 + 0.138 × total UDS – (0.183 × BMI), with an estimated standard error of 1.3 mL·kg^-1·min^-1. The 2MST is a viable, practical, and easily accessible test for FC. UDS and BMI can predict peak VO₂ satisfactorily.

Desaturation during Six-Minute Walk Testing Predicts Major Morbidity Following Anatomic Lung Resection among Patients with COPD

Background: Pulmonary function testing (PFT) is commonly used to risk-stratify patients prior to lung resection. Guidelines recommend that patients with reduced lung function, due to chronic lung conditions such as Chronic Obstructive Pulmonary Disease (COPD), should receive additional physiologic testing to determine fitness for resection. We reviewed our experience with six-minute walk testing (SMWT) to determine the association of test results and post-operative complications. Methods: Consecutive adult patients undergoing segmentectomy, lobectomy, bilobectomy or pneumonectomy between 1 January, 2007 and 1 January, 2017 were identified in a prospectively maintained database. Patients with poor lung function, as defined by percent predicted forced expiratory volume in 1 s (FEV1) or diffusion capacity of carbon monoxide (DLCO) ≤60%, had results of SMWT extracted from their chart. Association of test result to post-operative events was performed. Results: 581 patients had anatomic lung resections with predicted post-operative FEV1 or DLCO values ≤60%, consistent with a diagnosis of COPD. Among them, 50 (8.6%) had preoperative SMWT performed. Patients who received SMWT were more likely to have a FEV1 or DLCO less than 40 percent predicted (24/50 (48.0%) vs 166/531 (31.3%), p = 0.016). Post-operatively, patients who had SMWT performed had higher rates of pneumonia, but similar rates of major morbidity. The post-exercise oxygen saturation and the amount of desaturation correlated with the occurrence of major morbidity. In multivariable regression, oxygen desaturation was an independent risk factor for the occurrence of major morbidity, and desaturation was an excellent predictor of major morbidity by receiver operating characteristic curves analsysis. Conclusions: Among patients with elevated risk, oxygen desaturation during SMWT was independently associated with the occurence of major morbidity in multivariable analysis, while pulmonary function testing was not. SMWT is an important tool for risk-stratification, and may be underutilized.

Association between Pulmonary Function and Stair-Climbing Test Results after Lung Resection: A Pilot Study

Background

The stair-climbing test was used to assess the exercise capacity before lung resection in subjects with lung cancer. However, few studies have systematically evaluated the role of this exercise methodology as a postoperative test. The aim of the present study was to assess whether the stair-climbing test findings reflect the postoperative decrease in pulmonary function.

Methods

Twenty subjects with non-small-cell lung cancer who underwent lung resection were enrolled in the study. Perioperative functional evaluation comprised the pulmonary function test, stair-climbing test, and 6-min walk distance test (6MWD). A correlation analysis was performed between the postoperative percentages of pulmonary function with respect to preoperative values and the exercise capacity.

Results

No correlation was noted between the percentage changes in pulmonary function and those in 6MWD. However, there was a significant correlation between the percentage changes in forced expiratory volume in 1 s and those in the altitude reached in the stair-climbing test (r=0.46, p < 0.05) and between the percentage changes in carbon monoxide lung diffusion capacity and those in the altitude (r=0.54, p < 0.05).

Conclusions

The stair-climbing test findings might be effective at detecting changes in exercise capacity induced by postoperative decrease in pulmonary function.

Preoperative functional workup for patients with advanced lung cancer

Locally advanced lung cancer remains a surgical indication in selected patients. This condition often demands larger resections. As a consequence preoperative functional workup is of paramount importance to stratify the risk and choose the most appropriate treatment. We reviewed the current evidence on functional evaluation with a special focus on specific aspects related to locally advanced lung cancer stages (i.e., risk after neoadjuvant treatment, pneumonectomy). Evidence is discussed to provide information that could assist clinicians in their preoperative workup of these challenging patients.

Common Pitfalls in Anesthesia for Noncardiac Thoracic Surgery

Over the past few decades, major surgical procedures involving the thorax have become commonplace at most larger medical facilities. Advances in perioperative care have allowed surgeons to perform increasingly complex procedures. These procedures are being performed on more seriously ill patients who are at increased risk for significant complications. Recent advances should help the anesthesiologist avoid some of the pitfalls in managing these complex patients. Preoperative assessment aids in the identification of patients at highest risk for intraoperative and postoperative events. Particular attention is given to myasthenia gravis, as thymectomy is among the most common surgical procedures that are performed in these patients. Aggressive pain control techniques, including neuraxial opioids and patient-controlled analgesia, where appropriate, not only improve patient comfort but can improve postoperative pulmonary function. Advances in techniques for providing one-lung ventilation allow the anesthesiologist more options to individualize management for each clinical scenario. Careful fluid management may help to minimize the risk of postoperative pulmonary complications. A basic understanding of video-assisted thoracic surgery should help the anesthesiologist provide optimal surgical conditions and perioperative care. Recent advances demand a greater role for the anesthesiologist if the best outcomes are to be achieved in patients undergoing thoracic procedures.

Prediction of Cardiorespiratory Fitness by the Six-Minute Step Test and Its Association with Muscle Strength and Power in Sedentary Obese and Lean Young Women: A Cross-Sectional Study

Impaired cardiorespiratory fitness (CRF) is a hallmark characteristic in obese and lean sedentary young women. Peak oxygen consumption (VO_2peak) prediction from the six-minute step test (6MST) has not been established for sedentary females. It is recognized that lower-limb muscle strength and power play a key role during functional activities. The aim of this study was to investigate cardiorespiratory responses during the 6MST and CPX and to develop a predictive equation to estimate VO_2peak in both lean and obese subjects. Additionally we aim to investigate how muscle function impacts functional performance. Lean (LN = 13) and obese (OB = 18) women, aged 20–45, underwent a CPX, two 6MSTs, and isokinetic and isometric knee extensor strength and power evaluations. Regression analysis assessed the ability to predict VO_2peak from the 6MST, age and body mass index (BMI). CPX and 6MST main outcomes were compared between LN and OB and correlated with strength and power variables. CRF, functional capacity, and muscle strength and power were lower in the OB compared to LN (<0.05). During the 6MST, LN and OB reached ~90% of predicted maximal heart rate and ~80% of the VO_2peak obtained during CPX. BMI, age and number of step cycles (NSC) explained 83% of the total variance in VO_2peak. Moderate to strong correlations between VO_2peak at CPX and VO_2peak at 6MST (r = 0.86), VO_2peak at CPX and NSC (r = 0.80), as well as between VO_2peak, NSC and muscle strength and power variables were found (p<0.05). These findings indicate the 6MST, BMI and age accurately predict VO_2peak in both lean and obese young sedentary women. Muscle strength and power were related to measures of aerobic and functional performance.

Pulmonary function tests in the preoperative evaluation of lung cancer surgery candidates. A review of guidelines

Before planned surgical treatment of lung cancer, the patient's respiratory system function should be evaluated. According to the current guidelines, the assessment should start with measurements of FEV₁ (forced expiratory volume in 1 second) and DLco (carbon monoxide lung diffusion capacity). Pneumonectomy is possible when FEV₁ and DLco are > 80% of the predicted value (p.v.). If either of these parameters is < 80%, an exercise test with VO₂ max (oxygen consumption during maximal exercise) measurement should be performed. When VO₂ max is < 35 % p.v. or < 10 ml/kg/min, resection is associated with high risk. If VO₂ max is in the range of 35-75% p.v. or 10-20 ml/kg/min, the postoperative values of FEV₁ and DLco (ppoFEV₁, ppoDLco) should be determined. The exercise test with VO₂ max measurement may be replaced with other tests such as the shuttle walk test and the stair climbing test. The distance covered during the shuttle walk test should be > 400 m. Patients considered for lobectomy should be able to climb 3 flights of stairs (12 m) and for pneumonectomy 5 flights of stairs (22 m).

Fixed-altitude stair-climbing test replacing the conventional symptom-limited test. A pilot study

INTRODUCTION

The objective of this study was to investigate whether a patient's maximum capacity is comparable in 2 different stair-climbing tests, allowing the simplest to be used in clinical practice.

METHOD

Prospective, observational study of repeated measures on 33 consecutive patients scheduled for lung resection. Stair-climbing tests were: the standard test (climb to 27 m) and the alternative fixed-altitude test (climb to 12 m). In both cases, heart rate and oxygen saturation were monitored before and after the test. The power output of stair-climbing for each test (Watt1 for the standard and Watt2 for the fixed-altitude test) was calculated using the following equation: Power (watt)=weight (kg)*9.8*height (m)/time (sec). Concordance between tests was evaluated using a regression model and the residuals were plotted against Watt1. Finally, power output values were analyzed using a Bland-Altman plot.

RESULTS

Twenty-one male and 12 female patients (mean age 63.2±11.2) completed both tests. Only 12 patients finished the standard test, while all finished the fixed-altitude test. Mean power output values were Watt1: 184.1±65 and Watt2: 214.5±75.1. The coefficient of determination (R(2)) in the linear regression was 0.67. No fixed bias was detected after plotting the residuals. The Bland-Altman plot showed that 32 out of 33 values were within 2 standard deviations of the differences between methods.

CONCLUSIONS

The results of this study show a reasonable level of concordance between both stair-climbing tests. The standard test can be replaced by the fixed-altitude test up to 12 m.

Outcomes of lobectomy in 'active' octogenarians with clinical stage I non-small-cell lung cancer

INTRODUCTION

In octogenarians with early stage of lung cancer, sublobar resection has been shown to be no inferior survival to lobectomy. However, some octogenarians remain physically and mentally active.

METHODS

We retrospectively studied 65 octogenarians who underwent curative resection for clinical stage I NSCLC (excluding adenocarcinoma in situ). All patients were assessed by cardiologists and underwent stair-climbing tests (five flights, 18 m) and cognitive function tests. Lobectomy was performed in patients who could climb 5 flights of stairs without stopping or oxygen desaturation of >4%.

RESULTS

The actuarial survival rate was 68.6% at 5 years, and the median survival time was 109.2 months. Forty-three patients met the criteria for lobectomy. As compared with sublobar resection, lobectomy was associated with significantly higher rates of overall survival (78.4% vs. 48.5%; p = 0.02) and disease-specific survival (88.4% vs. 61.7%; p = 0.02) at 5 years. On multivariate analysis, male sex (hazard ratio, 3.827; 1.382-10.596) and sublobar resection (2.261; 1.054-5.360) were independent risk factors for survival. Mental disorders occurred in 6 patients (9.2%), and their score on preoperative cognitive function tests was significantly lower than that of patients without mental disorders (22.7 vs. 26.0, p <0.01).

CONCLUSION

Outcomes of lobectomy are good in physically and mentally competent octogenarians.

Cardiopulmonary responses to robotic end-effector-based walking and stair climbing

BACKGROUND

A recently developed robotic end-effector device (G-EO system, Reha Technology AG) can simulate walking and stair climbing. This approach has the potential to promote cardiovascular exercise training during rehabilitation. The aim of this study was to characterise cardiopulmonary responses of end-effector-based exercise in able-bodied subjects and to evaluate the feasibility of intensity-guided exercise testing.

METHODS

Five healthy subjects aged 33.7 ± 8.8 years (mean ± SD) performed a constant load test and an intensity-guided incremental exercise test. The outcome measures were steady-state and peak cardiopulmonary performance parameters including oxygen uptake (VO2) and heart rate (HR).

RESULTS

Passive end-effector-based stair climbing (VO2=13.6 ± 4.5 mL/min/kg, HR=95 ± 23 beats/min) showed considerably lower cardiopulmonary responses compared to reference data (VO2=33.5 ± 4.8 mL/min/kg, HR=159 ± 15 beats/min). Peak performance parameters during intensity-guided incremental exercise testing were: VO2=35.8 ± 5.1 mL/min/kg and HR=161 ± 27 beats/min, corresponding to a relative VO2=76.0 ± 18.7% of predicted aerobic capacity and a relative HR=87.3 ± 14.5% of age-predicted HR maximum.

CONCLUSION

End-effector-based exercise is a promising method for the implementation of cardiovascular exercise. Although end-effector-based stair climbing evoked lower cardiopulmonary responses than conventional stair climbing, active contribution during exercise elicited substantial cardiopulmonary responses within recommended ranges for aerobic training.

Efeitos do estímulo verbal sobre o desempenho no teste de escada e ajustes cardiorrespiratórios em sujeitos saudáveis

Esta pesquisa teve o objetivo de avaliar os efeitos do estímulo verbal (EV) no tempo do teste de escada (TEsc) e nas variáveis cardiorrespiratórias de adultos saudáveis. Trinta e um adultos saudáveis realizaram dois TEsc (com EV e sem EV). Antes e depois de cada teste, foram avaliados os sinais vitais e a Escala de Borg. Os tempos nos TEsc foram comparados por meio do Teste t de Student para amostras pareadas e as diferenças, de acordo com a ordem de realização dos testes utilizando o Teste de Mann-Whitney. Os sinais vitais e a Escala de Borg foram comparados por meio do Teste de Friedman ou ANOVA com post hoc do Teste de Tukey. As variações foram comparadas utilizando o Teste t Student para amostras independentes ou Teste de Mann-Whitney (p<0,05). O tempo no TEsc sem EV foi de 23,48±8,28 segundos, significativamente maior que o teste com EV, que foi de 21,60±7,18 segundos (p<0,05). Todas as variáveis aumentaram após os testes, e a Escala de Borg foi a única que teve maior variação no TEsc com EV, variando 2,5±1,4 no teste sem estímulo e 3,0±1,8 pontos no com estímulo (p<0,05). O estímulo verbal melhora o desempenho no TEsc e leva à maior sensação de esforço.

Role of exercise in testing and in therapy of COPD

The stair-climbing test, 6MWT, and shuttle test are exercise tests that requires less technical support than the CPET and are more available to any physician. The 6MWT is the simplest and most likely to be cost effective, as it provides useful information regarding prognosis, ADLs, and health care use at a very low cost. In addition, the 6MWT can be used to evaluate response to several interventions, including physical rehabilitation, medications, lung volume reduction interventions, and transplantation. The 6MWT has also been useful in and has become an integral part of the evaluation and response to treatment in other medical conditions, including congestive heart failure, pulmonary hypertension, and pulmonary fibrosis. The stair-climbing test seems to be most useful for preoperative evaluations when a CPET is not available. We have also used it on patients unable to perform a good CPET because of lack of familiarity with bicycle pedaling. The shuttle walk test may be used to better determine a maximal exercise capacity when a CPET is not available and to measure the effects of pulmonary rehabilitation in patients unfamiliar with a CPET. The role of exercise as a therapeutic tool is central to the concept of pulmonary rehabilitation. Exercise training improves not only functional dyspnea and health-related quality of life, but also has been shown to decrease health care resource use. As part of a comprehensive pulmonary rehabilitation initiated after a hospitalization for exacerbation, it has been shown to decrease readmission rates.

Evaluation and treatment of high-risk patients with early-stage lung cancer

Standard therapy for early-stage non-small cell lung cancer is lobectomy for patients who are able to tolerate such surgery. However, the risk of postoperative morbidity is not trivial, with a 30% to 40% incidence of postoperative complications and a 1% to 5% incidence of operative mortality. Some patients, though technically resectable, refuse surgery or are considered medically inoperable because of insufficient respiratory reserve, cardiovascular disease, or general frailty. This group is considered either "high risk" or "medically inoperable."

Comparison between actual and predicted postoperative stair-climbing test, walk test and spirometric values in patients undergoing lung resection

PURPOSE

To assess whether the tests - Forced Expiratory Volume at one second (FEV₁), 6-minute walk test (6MWT) and stair-climbing test (SCT) showed proportional changes after the resection of functioning lung.

METHODS

Candidates for pulmonary resection were included. Spirometry, 6MWT and SCT were performed preoperatively (pre) and at least 3 months after surgery (pos). SCT was performed on a staircase with a total ascent height of 12.16m. The time taken to climb the total height the fastest possible was defined as stair-climbing time (SCt). Number of functioning segments lost, was used to calculated predicted postoperative (ppo) tests values. Pre, ppo and pos values for each test were compared. Data were analyzed by repeated-measure ANOVA with significance level set at 5%.

RESULTS

A total of 40 patients were enrolled. Pulmonary resection results ranged from gain of 2 functioning segments to loss of 9. Pre, ppo and pos values were the following: preFEV₁ = 2.6±0.8L, ppo FEV₁ =2.3±0.8L, and pos FEV₁=2.3±0.8L, (pre FEV₁ > ppo FEV₁ = pos FEV₁); pre6MWT = 604±63m, ppo6MWT= 529±103m, pos6MWT= 599±74m (pre6MWT = pos6MWT > ppo6MWT); preSCt = 32.9±7.6s, ppoSCt = 37.8±12.1s, posSCt = 33.7±8.5s (preSCt = posSCt < ppoSCt).

CONCLUSION

In our group of patients, pulmonary resection led to loss of lung function measured by spirometry, but not to exercise capacity measured by stair-climbing and walk tests.

Handheld Office-Based Spirometry versus Laboratory Spirometry in Low-Risk Patients Undergoing Lung Resection

Objective

To compare handheld office spirometry with laboratory spirometry in evaluation of low-risk patients undergoing pulmonary resection.

Methods

Low-risk patients evaluated for lung resection were enrolled in a prospective study and underwent office and laboratory spirometry. Standard laboratory spirometry values were considered the gold standard. Values of forced expiratory volume in 1 second (FEV1) <1.5 L or FEV1% <60% were determined in advance to signal high risk.

Results

Thirty patients with mean age 64 ± 12 years and median Karnofsky performance status 100 (80–100) were evaluated. The mean FEV1-office spirometry and mean FEV1-laboratory spirometry were comparable (2.14 L vs 2.36 L) as were the mean FEV1%-office spirometry and FEV1%-laboratory spirometry (78% vs 85%). The differences were within limits established a priori. Laboratory spirometry identified 3 of 30 (10%) patients as high risk and office spirometry identified 5 of 30 (16%) patients as high risk, including the 3 patients identified by laboratory spirometry. The sensitivity of office spirometry for detecting high risk was 100% (3/3) and specificity was 93% (25/27). The negative predictive value of office spirometry was 100% (25/25). Office spirometry added a median of 1 minute to the office visit, whereas laboratory spirometry added 42 minutes. Eventually, 25 of 30 (83%) patients underwent lung resection. There were 12 lobar and 13 sublobar resections. One patient developed postoperative respiratory morbidity. This patient was high risk by office spirometry but not by laboratory spirometry. This patient was discharged on home oxygen.

Conclusions

Office spirometry FEV1 and FEV1% are clinically comparable to formal laboratory spirometry values. Office Spirometry saves time and possibly expense in the preoperative workup of patients evaluated for lung resection.

Accuracy of six minute walk test, stair test and spirometry using maximal oxygen uptake as gold standard

PURPOSE: To assess the accuracy of the variables stair climbing time (SCt), stair climbing power (SCP), six-minute walk test distance (6MWT), and forced expiratory volume in 1 second (FEV1) using maximal oxygen uptake on exercise (VO2max) as the gold standard. METHODS: Tests were performed in 51 patients. FEV1 was measured by spirometry and 6MWT was performed in a flat 120-m corridor. Stair climbing test was performed on a 6-flight stairway to obtain SCt and SCP. VO2max was measured by ergospirometry, using the Balke protocol. Pearson's linear correlation and p values were calculated between VO2max and the other variables tested. For accuracy calculations, variable cutoff points were obtained through receiver operating characteristic (ROC) curves, dividing individuals into normal or unhealthy. Kappa statistic was used to calculate concordance. RESULTS: Accuracy was: SCt - 86%, 6MWT - 80%, SCP - 71%, FEV1(L) - 67%, FEV1(%) - 63%. SCt and 6MWT showed 93.5% sensitivity when combined in parallel, and 96.4% specificity in series. CONCLUSION: SCt presented the best accuracy. SCt and 6MWT combined showed nearly 100% sensitivity or specificity. Thus, these simple exercise tests should be more routinely used, especially when an ergospirometer is not available to measure VO2max.

Update on anesthetic management for pneumonectomy

PURPOSE OF REVIEW

Pneumonectomy has the highest perioperative risk among common pulmonary resections. The purpose of this review is to update clinicians on the importance of anesthetic management for these patients.

RECENT FINDINGS

Two complications associated with increased perioperative mortality are relevant to anesthetic management: postoperative arrhythmias and acute lung injury. The geriatric population is particularly at risk for arrhythmias. Adequate preoperative cardiac assessment and drug prophylaxis may decrease this risk. Patients with decreased respiratory function are at increased risk for acute lung injury. The use of large tidal-volume ventilation during anesthesia may increase this risk. There is a trend to better outcomes in centers with larger surgical volumes.

SUMMARY

Patients should have a preoperative assessment of their respiratory function in three areas: lung mechanical function, pulmonary parenchymal function and cardiopulmonary reserve. Interventions that have been shown to decrease the incidence of respiratory complications include cessation of smoking, physiotherapy and thoracic epidural analgesia. Extrapleural pneumonectomy and sleeve pneumonectomy are surgical variations that place specific increased demands on the anesthesiologist. The rare but treatable complication of cardiac herniation must always be remembered as a potential cause of life-threatening hemodynamic instability in the early postoperative period.

Performance at symptom-limited stair-climbing test is associated with increased cardiopulmonary complications, mortality, and costs after major lung resection

BACKGROUND

Exercise tests are increasingly used during preoperative evaluation before lung resection. This study assessed the association between performance at the symptom-limited stair-climbing test and postoperative cardiopulmonary morbidity, mortality, and costs after major lung resections.

METHODS

As part of their routine preoperative evaluation, 640 patients who had lobectomy (n = 533) or pneumonectomy (n = 107) for lung cancer from January 2000 through April 2007 performed a preoperative symptom-limited stair-climbing test. Sensitivity/specificity analysis was used to identify the best cutoff values of altitude climbed (number of steps x height of the step in m) associated with outcome. Univariate and multivariate regression analyses (validated by bootstrap) were used to test associations between preoperative and operative factors and postoperative cardiopulmonary complications, mortality, and postoperative costs.

RESULTS

The altitude reached at the stair-climbing test was reliably associated with increased cardiopulmonary complications (p = 0.04), mortality (p = 0.02), and costs (p < 0.0001). In patients who climbed less than 12 m, cardiopulmonary complications, mortality, and costs were 2-fold (p < 0.0001), 13-fold (p < 0.0001), and 2.5-fold higher, respectively, than in patients who climbed more than 22 m.

CONCLUSIONS

Performance at a maximal stair-climbing test was reliably associated with postoperative morbidity and mortality. We recommend the use of this simple and economic test in all lung resection candidates. Patients who perform poorly at the stair-climbing test should undergo a formal cardiopulmonary exercise test with measurement of oxygen consumption to optimize their perioperative management.

Use of the 15-steps climbing exercise oximetry test in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is often associated with exercise-induced hypoxemia. Although maximal oxygen consumption (VO2(max)) is considered the gold-standard index of functional capacity in IPF, its measurement requires sophisticated equipment and trained personnel. The aim of the present study was to investigate the value of the simple 15-steps climbing exercise oximetry test in patients with IPF. The 15-steps climbing test was administered to 51 patients with IPF. Pulmonary function tests (PFTs), cardiopulmonary exercise test (CPET), and the 6-min walk distance (6MWD) test were performed in the same session. Oxygen saturation in the 15-steps climbing test was measured by continuous oximetry, and quantified oxygen desaturation was determined by calculating the area under the curve of oxygen saturation from the beginning of exercise through the lowest desaturation point until recovery to baseline ("desaturation area"). There was a statistically significant correlation between all parameters of the 15-steps climbing test and both VO2(max)) on the CPET (lowest saturation, p=0.002, r=0.43; saturation difference, p=0.02, r=-0.33; recovery time, p=0.02, r=-0.32; and desaturation area, p=0.005, r=-0.39), and carbon dioxide diffusion in the lungs (DLCO) on the PFTs (lowest saturation, p=0.0001, r=0.52; saturation difference, p=0.0002, r=-0.50; recovery time, p=0.0001, r=-0.53; and desaturation area, p=0.0001, r=-0.53). On stepwise linear regression analysis, independent significant predictors of VO2(max) were lowest saturation on the 15-steps test and the 6MWD. We concluded that the 15-steps oximetry test is a simple and accurate bedside tool for the evaluation of functional capacity in patients with IPF.

Stairs climbing test with pulse oximetry as predictor of early postoperative complications in functionally impaired patients with lung cancer and elective lung surgery: prospective trial of consecutive series of patients

AIM

To test the predictive value of stairs climbing test for the development of postoperative complications in lung cancer patients with forced expiratory volume in one second (FEV1)<2 L, selected for an elective lung surgery.

METHODS

The prospective study was conducted in 101 consecutive patients with an FEV1<2 L selected for elective lung surgery for lung cancer. Preoperative examination included medical history and physical examination, lung function testing, electrocardiography, laboratory testing, and chest radiography. All patients underwent stairs climbing with pulse oximetry before the operation with the number of steps climbed and the time to complete the test recorded. Oxygen saturation and pulse rate were measured every 20 steps. Data on postoperative complications including oxygen use, prolonged mechanical ventilation, and early postoperative mortality were collected.

RESULTS

Eighty-seven of 101 patients (86%) had at least one postoperative complication. The type of surgery was significantly associated with postoperative complications (25.5% patients with lobectomy had no early postoperative complications), while age, gender, smoking status, postoperative oxygenation, and artificial ventilation were not. There were more postoperative complications in more extensive and serious types of surgery (P<0.001). The stairs climbing test produced a significant decrease in oxygen saturation (-1%) and increase in pulse rate (by 10/min) for every 20 steps climbed. The stairs climbing test was predictive for postoperative complications only in lobectomy group, with the best predictive parameter being the quotient of oxygen saturation after 40 steps and test duration (positive likelihood ratio [LR], 2.4; 95% confidence interval [CI], 1.71-3.38; negative LR, 0.53; 95% CI, 0.38-0.76). In patients with other types of surgery the only significant predictive parameter for incident severe postoperative complications was the number of days on artificial ventilation (P=0.006).

CONCLUSION

Stairs climbing test should be done in routine clinical practice as a standard test for risk assessment and prediction of the development of postoperative complications in lung cancer patients selected for elective surgery (lobectomy). Comparative to spirometry, it detects serious disorders in oxygen transport that are a baseline for a later development of cardiopulmonary postoperative complications and mortality in this subgroup of patients.

Stair climbing in the functional assessment of lung resection candidates

BACKGROUND

Algorithms for the pre-operative evaluation of lung resection candidates with impaired lung function invariably include maximum oxygen uptake (VO(2)MAX) as a critical parameter of functional reserves, with a VO(2)MAX >or=20 ml/kg/min generally considered sufficient for pneumonectomy. Stair climbing is a low-cost alternative to assess exercise capacity.

OBJECTIVES

As stair climbing is not standardised, we aimed to compare the altitude reached and the speed of ascent with VO(2)MAX measured by cycle ergometry.

METHODS

We prospectively enrolled 44 pulmonary resection candidates (mean age: 47.6 +/- 12.5 years) with an FEV(1) <80%. Patients were asked to climb as high and as fast as they could, to a maximum elevation of 20 m. The altitude reached and the average speed of ascent were compared to VO(2)MAX.

RESULTS

Forty-three patients reached a 20-metre elevation. Thirteen of them, as well as the patient who did not reach this height, had a VO(2)MAX <20 ml/kg/min. There was a linear correlation between speed of ascent and VO(2)MAX/kg (R(2) = 0.67), but not between altitude and VO(2)MAX/kg. All 24 patients with a speed >or=15 m/min had a VO(2)MAX >or=20 ml/kg/min. Thirty-nine of 40 patients with a speed >or=12 m/min had a VO(2)MAX >or=15 ml/kg/min.

CONCLUSIONS

The average speed of ascent during stair climbing was an accurate semiquantitative predictor of VO(2)MAX/kg, whereas altitude was not. We were able to identify potential cut-off values for lobectomy or pneumonectomy. Pending validation with clinical endpoints, stair climbing may replace formal exercise testing at much lower costs in a large proportion of lung resection candidates.

Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

This section of the guidelines is intended to provide an evidence-based approach to the preoperative physiologic assessment of a patient being considered for surgical resection of lung cancer.

METHODS

Current guidelines and medical literature applicable to this issue were identified by computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee.

RESULTS

The preoperative physiologic assessment should begin with a cardiovascular evaluation and spirometry to measure the FEV(1). If diffuse parenchymal lung disease is evident on radiographic studies or if there is dyspnea on exertion that is clinically out of proportion to the FEV(1), the diffusing capacity of the lung for carbon monoxide (Dlco) should also be measured. In patients with either an FEV(1) or Dlco < 80% predicted, the likely postoperative pulmonary reserve should be estimated by either the perfusion scan method for pneumonectomy or the anatomic method, based on counting the number of segments to be removed, for lobectomy. An estimated postoperative FEV(1) or Dlco < 40% predicted indicates an increased risk for perioperative complications, including death, from a standard lung cancer resection (lobectomy or greater removal of lung tissue). Cardiopulmonary exercise testing (CPET) to measure maximal oxygen consumption (Vo(2)max) should be performed to further define the perioperative risk of surgery; a Vo(2)max of < 15 mL/kg/min indicates an increased risk of perioperative complications. Alternative types of exercise testing, such as stair climbing, the shuttle walk, and the 6-min walk, should be considered if CPET is not available. Although often not performed in a standardized manner, patients who cannot climb one flight of stairs are expected to have a Vo(2)max of < 10 mL/kg/min. Data on the shuttle walk and 6-min walk are limited, but patients who cannot complete 25 shuttles on two occasions will likely have a Vo(2)max of < 10 mL/kg/min. Desaturation during an exercise test has not clearly been associated with an increased risk for perioperative complications. Lung volume reduction surgery (LVRS) improves survival in selected patients with severe emphysema. Accumulating experience suggests that patients with extremely poor lung function who are deemed inoperable by conventional criteria might tolerate combined LVRS and curative-intent resection of lung cancer with an acceptable mortality rate and good postoperative outcomes. Combining LVRS and lung cancer resection should be considered in patients with a cancer in an area of upper lobe emphysema, an FEV(1) of > 20% predicted, and a Dlco of > 20% predicted.

CONCLUSIONS

A careful preoperative physiologic assessment will be useful to identify those patients who are at increased risk with standard lung cancer resection and to enable an informed decision by the patient about the appropriate therapeutic approach to treating their lung cancer. This preoperative risk assessment must be placed in the context that surgery for early-stage lung cancer is the most effective currently available treatment for this disease.

Preoperative exercise Vo2 measurement for lung resection candidates: results of Cancer and Leukemia Group B Protocol 9238

INTRODUCTION

A stepwise approach to the functional assessment of lung resection candidates is widely accepted, and this approach incorporates the measurement of exercise peak Vo2 when spirometry and radionuclear studies suggest medical inoperability. A new functional operability (FO) algorithm incorporates peak exercise Vo2 earlier in the preoperative assessment to determine which patients require preoperative radionuclear studies. This algorithm has not been studied in a multicenter study.

METHODS

The CALGB (Cancer and Leukemia Group B) performed a prospective multi-institutional study to investigate the use of primary exercise Vo2 measurement for the prediction of surgical risk. Patients with known or suspected resectable non-small cell lung cancer (NSCLC) were eligible. Exercise testing including measurement of peak oxygen uptake (Vo2), spirometry, and single breath diffusion capacity (DLCO) was performed on each patient. Nuclear perfusion scans were obtained on selected high-risk patients. After surgery, morbidity and mortality data were collected and correlated with preoperative data. Mortality and morbidity were retrospectively compared by algorithm-based risk groups.

RESULTS

Three hundred forty-six patients with suspected lung cancer from nine institutions underwent thoracotomy with or without resection; 57 study patients did not undergo thoracotomy. Patients who underwent surgery had a median survival time of 30.9 months, whereas patients who did not undergo surgery had a median survival time of 15.6 months. Among the 346 patients who underwent thoracotomy, 15 patients died postoperatively (4%), and 138 patients (39%) exhibited at least one cardiorespiratory complication postoperatively. We found that patients who had a peak exercise Vo2 of <65% of predicted (or a peak Vo2/kg <16 ml/min/kg) were more likely to suffer complications (p = 0.0001) and were also more likely to have a poor outcome (respiratory failure or death) if the peak Vo2 was <15 ml/min/kg (p = 0.0356). We also found a subset of 58 patients who did not meet FO algorithm criteria for operability, but who still tolerated lung resection with a 2% mortality rate.

CONCLUSIONS

Our data provide multicenter validation for the use of exercise Vo2 for preoperative assessment of lung cancer patients, and we encourage an aggressive approach when evaluating these patients for surgery.

Acurácia do teste de escada utilizando o consumo máximo de oxigênio como padrão-ouro

OBJETIVO: Determinar a acurácia dos atributos do teste de escada (TE) de altura definida utilizando como padrão-ouro o consumo máximo de oxigênio (VO2 máx). MÉTODOS: O TE foi realizado com incentivo, em escada (6 lances; 72 degraus; 12,16 m de altura total), em 51 pacientes. O 'tempo' de subida foi cronometrado e o 'trabalho' e a 'potência' calculados. O VO2 máx foi obtido por ergoespirometria, utilizando-se o protocolo de Balke. Foram calculados a correlação linear de Pearson (r) e os valores de p entre as variáveis do TE e o VO2 máx. Para o cálculo da acurácia, o ponto de corte do VO2 máx foi estabelecido em 25 mL/kg/min, estratificando os indivíduos em normais ou alterados. Os pontos de corte para os atributos do TE foram obtidos através da curva receiver operating characteristic. A estatística Kappa (k) foi utilizada para estudo da concordância. RESULTADOS: Obtiveram-se os seguintes valores para a variável 'tempo': ponto de corte = 40 s; x= 41 ± 15,5 s; r = -0,707; p < 0,005; especificidade = 89%; sensibilidade = 83%; acurácia = 86% e k = 0,724. Para a variável 'potência', obteve-se ponto de corte = 200 w; x= 222,3 ± 95,2 w; r = 0,515; p < 0,005; especificidade = 67%; sensibilidade = 75%; acurácia = 71% e k = 0,414. A correlação de 'trabalho' com o VO2 máx não foi significativa, sendo esse atributo descartado. CONCLUSÃO: Dos atributos testados do TE, tendo como padrão-ouro o VO2 máx, a variável 'tempo' foi a que apresentou a melhor acurácia.

Evaluation of Expiratory Volume, Diffusion Capacity, and Exercise Tolerance Following Major Lung Resection

BACKGROUND

Lung resections determine a variable functional reduction depending on the extent of the resection and the time elapsed from the operation. The objectives of this study were to prospectively investigate the postoperative changes in FEV(1), carbon monoxide lung diffusion capacity (Dlco), and exercise tolerance after major lung resection at repeated evaluation times.

METHODS

FEV(1), Dlco, and peak oxygen consumption (Vo(2)peak) calculated using the stair climbing test were measured in 200 patients preoperatively, at discharge, and 1 month and 3 months after lobectomy or pneumonectomy. Preoperative and repeated postoperative measures were compared, and a time-series, cross-sectional regression analysis was performed to identify factors associated with postoperative Vo(2)peak.

RESULTS

One month after lobectomy, FEV(1), Dlco, and Vo(2)peak values were 79.5%, 81.5%, and 96% of preoperative values and recovered up to 84%, 88.5%, and 97% after 3 months, respectively. One month after pneumonectomy, FEV(1) percentage of predicted, Dlco percentage of predicted, and Vo(2)peak values were 65%, 75%, and 87% of preoperative values, and were 66%, 80%, and 89% after 3 months, respectively. Three months after lobectomy, 27% of patients with COPD had improved FEV(1), 34% had improved Dlco, and 43% had improved Vo(2)peak compared to preoperative values. The time-series, cross-sectional regression analysis showed that postoperative Vo(2)peak values were directly associated with preoperative values of Vo(2)peak, and postoperative values of FEV(1) and Dlco, and were inversely associated with age and body mass index.

CONCLUSIONS

Our findings may be used during preoperative counseling and for deciding eligibility for operation along with other more traditional measures of outcome.