Performance in the 6-minute walk test and postoperative pulmonary complications in pulmonary surgery: an observational study

A review of perioperative immune-modulating and metabolic-modulating nutrition strategies for bowel resection surgery

Focused perioperative nutrition strategies have proven benefits on the outcomes for patients undergoing major abdominal surgery. In this brief article, we will review these strategies and the evidence to support them with a focus on gastrointestinal anastomotic healing. We will elaborate the risks and benefits of enteral feeds, immune- and metabolic-modulating formulas, prebiotics and probiotics, and prehabilitation in preparation for surgery. Additionally, we will discuss the role of fish oils (eicosapentaenoic acid and docosahexaenoic acid) in the surgical patient and new data on specialized proresolving mediators in inflammation resolution. Finally, this article will consider the harmful impact surgical trauma has on the microbiome and the potential for perioperative dietary modulation to attenuate these negative effects.

Preoperative 6-minute walk distance is associated with postoperative complications in patients undergoing laparoscopic gastrointestinal cancer surgery

OBJECTIVE

The 6-min walk test (6MWT) is a simple and valid method to evaluate cardiopulmonary function. We performed this prospective study in patients undergoing laparoscopic gastrointestinal cancer surgery to explore the association between preoperative 6MWT performance and overall postoperative complications.

METHODS

This study was registered at clinicaltrials.gov (NCT03711526). The study consecutively enrolled patients receiving laparoscopic gastrointestinal cancer surgery in our institution. All patients performed the 6MWT upon recruitment and received 30 days of postoperative follow-up. The primary outcome was overall complications, defined by ≥ grade I Clavien-Dindo (CD) classification (2004) complications. Multivariable logistic regression was used to test the association of 6-min walk distance (6MWD) with the outcome.

RESULTS

A total of 184 patients were included in the final analyses. In the 37 (20.1 %) patients with overall complications, the mean (standard deviation) preoperative 6MWD was 469.1 (86.8) m. In patients with no complications, the 6MWD was 502.6 (90.2) m. The mean difference was 33.5 m (95 % confidence interval, 1.3, 65.7; P = 0.042). A longer preoperative 6MWD was associated with a lower odds of developing postoperative complications (odds ratio, 0.994 per meter increase; 95 % confidence interval, 0.989, 0.999; p = 0.023).

CONCLUSION

This study indicated an association between the preoperative 6MWD and postoperative complications in patients undergoing laparoscopic gastrointestinal cancer surgery.

Functional capacity in smoking patients after coronary artery bypass grafting surgery: a quasi-experimental study

Coronary artery bypass grafting surgery (CABG) is an important approach to treating coronary heart disease. However, patients undergoing open heart surgery are at risk of postoperative complications. Cigarette smoking is one of the preoperative risk factors that may increase postoperative complications. Studies show that early mobilization intervention may reduce these complications and improve functional capacity, but the impact of smoking on early outcomes after CABG has been controversial for the past two decades. This quasi-experimental study explored the effects of early mobilization on functional capacity among patients with different smoking histories undergoing CABG. The study involved 51 participants who underwent CABG surgery, divided into three groups: current smokers, former smokers, and non-smokers (n=17 each). A day before surgery, all groups underwent a six-minute walking test (6MWT). Every participant received the same intervention after surgery, including deep breathing exercises, an upper limb range of motion assessment, an incentive spirometer, and walking with and without assistance. Five days postoperatively, all outcomes - including the 6MWT, length of stay (LOS) in the ICU, and postoperative pulmonary complications - were assessed, and the 6MWT was repeated. There was a reduced functional capacity after CABG in ex-smokers (215.8±102 m) and current smokers (272.7±97m) compared to non-smokers (298.5±97.1m) in terms of 6MWT (p<0.05). Current smokers were more likely to have atelectasis after CABG than ex-smokers (76.5% vs. 52.9%), with non-smokers being the least likely to have atelectasis among the three groups (29.4%, p<0.05). Additionally, current smokers required longer ventilator support post-CABG (11.9±7.3 hours) compared to ex-smokers (8.3±4.3 hours) and non-smokers (7±2.5 hours, p<0.01). Smoking status significantly impacts functional capacity reduction after CABG, with current smokers being more susceptible to prolonged ventilator use and atelectasis.

Impact of preoperative 6-minute walk distance on long-term prognosis after esophagectomy in patients with esophageal cancer

BACKGROUND

The 6-minute walk distance (6MWD) is a simple way of assessing exercise capacity. The purpose of this study was to investigate the relationship between preoperative 6MWD and long-term prognosis after esophagectomy.

METHODS

This retrospective cohort study involved 108 patients who underwent radical esophagectomy for esophageal cancer between 2013 and 2020. The patients were classified into the short group (SG: 6MWD < 480 m) or the long group (LG: 6MWD  ≥  480 m). To adjust for the background characteristics of both groups, propensity score matching (PSM) analysis was performed and 32 patients were matched from each group. Five-year overall survival (OS) and relapse-free survival (RFS) were analyzed by the Kaplan-Meier method. The log-rank test was used to evaluate differences in survival between the groups. After adjusting for other prognostic factors, the Cox proportional hazards model was used to investigate the impact of preoperative 6MWD on long-term prognosis.

RESULTS

The median follow-up period was 923 days. Thirty-three deaths were recorded during the study period. After PSM, 5-year OS following surgery was 29.2 and 66.1% (p = 0.003) and 5-year RFS was 27.9 and 58.6% (p  =  0.021) in the SG and LG, respectively. In Cox proportional hazards analysis, the SG was a significant independent risk factor for OS (hazard ratio 3.33; 95% confidence interval 1.37-8.11, p = 0.008) and RFS (hazard ratio 2.30; 95% confidence interval 1.08-4.88, p = 0.030).

CONCLUSION

The preoperative 6MWD is useful for evaluating exercise capacity and predicting the long-term outcome in patients undergoing esophagectomy.

Analysis of exercise tolerance on the basis of six-minute walk test - 6MWT and Borg RPE scale in men with inguinal hernia before and after Lichtenstein repair

&lt;b&gt;Introduction:&lt;/b&gt; Assessment of exercise tolerance (ET) plays an important role in qualifications for treatment and rehabilitation. &lt;br&gt;&lt;b&gt;Aim: &lt;/b&gt;The aim of the study was to assess ET in patients before and after inguinal hernia operations with Lichtenstein method. &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; The cohort study included men with inguinal hernia divided into the study group (SG) (n = 50) and control (CG) (n = 50) undergone the Lichtenstein surgery. Patients from the SG met the criterion of coexistence of cardiovascular and respiratory diseases. Day before and on the second day after surgery, patients performed 6MWT and subjectively rate the exertion according to Borg- RPE- Scale (before, immediately after and 10 minutes after the test). 6MWT distance, Borg scale ratings were analysed. On the second day after surgery 66% of patients from the SG and 58% from the CG did not complete the test. Patients from the SG before (500,07 ± 40,38 m) and on the second day after surgery (243,46 ± 18,18 m) achieved shorter distances compared to the CG (565,93 ± 20,41 m; 249,47 ± 26,66 m), p &lt; 0,001 i p = 0,481. A statistically significant negative correlation between 6MWT distance before surgery and age of the patients was confirmed. Patients who did not develop complications achieved significantly longer distances on admission (p = 0,003 for SG, p = 0,004 for CG). For 6MWT before surgery and 2 days after surgery, patients from the SG showed a significantly higher level of fatigue compared to the CG after the test (before: p = 0,001, after: p = 0,001). Patients form the SG often discontinued 6MWT and less tolerated effort compared to the CG. Hence, 6MWT is useful tool for ascertaining physical capacity and ET.

500 Meters Is a Result of 6-Minute Walk Test Which Differentiates Patients with High and Low Risk of Postoperative Complications after Lobectomy-A Validation Study

The 6-min walk test (6MWT) is a simple method of identifying patients with a high risk of postoperative complications. In this study, we internally validated the previously obtained threshold value of 500 m in the 6MWT as differentiating populations with a high and a low risk of postoperative complications after a lobectomy. Between November 2011 and November 2016, 624 patients who underwent a lobectomy and performed the 6MWT preoperatively entered this study. We compared the complication rates of two groups of patients—those who walked more than and those who walked less than 500 m. The patients who did not reach the distance of 500 m in the 6MWT were older (70 vs. 63 years p < 0.001), had worse pulmonary function tests (FEV1% 84 vs. 88 p = 0.041) and had a higher Charlson Comorbidity Index (p < 0.001). The patients who had a worse result in the 6MWT had a higher complication rate (52% vs. 42% p = 0.019; OR: 1.501 95% CI: 1.066–2.114) and a longer median postoperative hospital stay (7 vs. 6 days p = 0.010). In a multivariate analysis, the result of the 6MWT and pack-years proved to independently influence the risk of postoperative complications. This internal validation study confirms that 500 m is a result of the 6MWT which differentiates patients with a higher risk of postoperative complications and a prolonged hospital stay after a lobectomy.

Physiological Biomarkers Assessed by Low-Tech Exercise Tests Predict Complications and Overall Survival in Patients Undergoing Pneumonectomy Due to Lung Cancer

Due to its debilitating character pneumonectomy this is last-resort procedure. Preoperative results of the 6-min walking test (6MWT) help to identify high risk of postoperative complications and increased mortality in patients undergoing lobectomy for lung cancer. The aim of the study was to validate the value of 500 m in 6MWT as an indicator, which differentiates risk of complications in patients undergoing pneumonectomy. 125 patients who underwent pneumonectomy at Thoracic Surgery Department between 2009 and 2018. On the day preceding the surgery, patients underwent 6MWT. The patients were in median age of 63 years. The cut-off value of 500 m identified patients with increased 90-day mortality [17.9% vs. 3.5%, odds ratio (OR) 6.271, 95% confidence interval (CI) 1.528-25.739], first-year mortality (30.7% vs. 11.6%, OR 3.378, 95%CI 1.310-8.709), and overall survival (p = 0.02). Patients who covered a distance ≤ 500 m had an increased risk of atrial fibrillation (35.9% vs. 16.3%, OR 2.880, 95%CI 1.207-6.870) and cardiac complications (38.4% vs. 19.8%, OR 2.537, 95%CI 1.100-5.849). Patients unable to reach 500 m in 6MWT are in a high risk of postoperative death after pneumonectomy, what may be a result of increased frequency of postoperative cardiac complications. Poor result of 6MWT is a predictor of worse overall survival.

Preserving pulmonary function and functional capacity in children undergoing open abdominal surgery: A one group pretest-posttest, quasiexperimental pilot trial

PURPOSE

The aim of this trial was to determine the effects of Preoperative physiotherapy education (POPE) and Postoperative physiotherapy (POP) maintaining pulmonary function and functional capacity in children undergoing open abdominal surgery.

METHODS

A total of eight children aged, 5-17 years old posted for open abdominal surgery received POPE and POP. Spirometry, 10 m walk test (10mWT), timed up and go test (TUGT) and chest expansion were taken preoperatively and postoperatively on day one and five. Six minute walk test (6MWT), and Nine stair climbing test (9SCT) were taken preoperatively and postoperatively on day five.

RESULTS

No statistical significant difference were noted in FVC, FEV1, PEFR, FEV1/FVC Ratio, chest expansion levels and Borg scale but in TUGT, 10mWT, 6MWT and 9SCT significant difference was noted. Effect size were calculated and post hoc power analysis revealed that the power of the study is >90%.

CONCLUSION

POPE might have positive effects in preserving pulmonary function and functional capacity.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level II.

Performance in 6-min walk test in prediction of post-operative pulmonary complication in major oncosurgeries: A prospective observational study

Background and Aims

Post-operative pulmonary complications (PPC) contribute to increased morbidity and mortality, necessitating pre-operative functional assessment. Six-minute walk test (6MWT) is a simple option for functional assessment.

Methods

This is a prospective observational study conducted in 75 patients who underwent elective abdominal or thoracic oncosurgery under general anaesthesia with either age above 60 years or with cardiopulmonary diseases or obstructive sleep apnoea or low serum albumin or smoking. Patients with history of acute coronary syndrome in past 6 months, dyspnoea at rest, severe pain, inability to walk or interpret instructions and haemodynamic instability were excluded. Preoperatively 6MWT was conducted according to the American Thoracic Society guidelines and patients were observed for PPC. Patients were divided into two groups: group 1-no PPC and group 2-developed PPC. Statistical analysis was done using SPSS software (version 11.0.1). Categorical variables were assessed using Chi-square/Fisher's exact test and continuous variables using student's t-test/Mann-Whitney U test. Association was tested using logistic regression.

Results

Out of the 75 patients, 40 patients had no PPC (group 1) and 35 patients had PPC (group 2) including a death. The 6MWD of group with PPCs was significantly less (344 ± 61.927 m) compared to the group without PPCs (442.28 ± 83.194 m, P value = 0.001). The cut-off 6MWD obtained was 390 m, which correlated with longer duration of hospital stay and ICU stay (P = 0.001).

Conclusion

Six-minute walk test is a reliable predictor of post-operative pulmonary complications with a cut-off 6MWD of 390 m in the studied oncosurgery patients.

Association between early pulmonary complications after abdominal surgery and preoperative physical capacity

Objective: To investigate whether early postoperative pulmonary complications after abdominal surgery are associated with a lower performance in preoperative six-minute walk test.Methods: A cross-sectional cohort study of 50 participants who underwent elective abdominal surgery and performed the six-minute walk test within 48 hours prior to surgery were conducted. Postoperative pulmonary complications up to the seventh postoperative day were obtained from medical records.Results: Overall, 25 participants developed postoperative pulmonary complications. The mean (standard deviation) preoperative walked distances of the participants with and without postoperative pulmonary complications were, respectively, 444.8 (81.3) meters and 498.3 (63.7) meters (p = .013). The incidence of postoperative pulmonary complications was greater in the participants with walked distance < 400 meters. The multivariable logistic regression model revealed a significant association between postoperative pulmonary complications and preoperative walked distance (Odds ratio = 0.978, p = .010) in participants who underwent intestinal, stomach, or bile tract resection. Conclusions: This study found a high incidence of postoperative pulmonary complications in abdominal surgery participants and an association between lower preoperative physical capacity and the risk of postoperative pulmonary complications in participants who underwent intestinal, stomach, and biliary tract resection.

Predictive validity analysis of six reference equations for the 6-minute walk test in healthy Brazilian men: a cross-sectional study

BACKGROUND

The six-minute walk test (6MWT) is an important tool for evaluating functional capacity and exercise tolerance. The reference equations for the 6MWT in healthy subjects were established on the basis of American and European populations, but reference equations have been proposed with different variables for the Brazilian population.

OBJECTIVE

To analyze the predictive validity of six reference equations for the six-minute walking distance (6MWD) in healthy adult men.

METHODS

We evaluated 103 individuals in relation to level of physical activity (IPAQ), respiratory symptoms (MRC), handgrip strength, and 6MWD test. The data were submitted to a normality test, then the Bland-Altman agreement test was used to compare individual 6MWD values with that expected for each equation.

RESULTS

The subjects were active, with a mean age of 34.12 (SD=8.88) years and no respiratory symptoms. The mean of the 6MWD was 663.43 (SD=93.01)m. The 6MWD's predicted values came closest to the walked distance covered by Britto et al.'s equation (using BMI) of 647.62 (SD=38.62)m.

CONCLUSIONS

The equation proposed by Britto et al. using body mass index (BMI) was the closest to the 6MWD for the individuals studied and could be widely used as a reference tool during the 6MWT in healthy Brazilian men.

Functional electrical stimulation improves muscle strength and endurance in patients after cardiac surgery: a randomized controlled trial

BACKGROUND

Functional electrical stimulation (FES) has shown benefits in patients with chronic heart failure. Therefore, it is possible that FES can benefit patients similarly after cardiac surgery.

OBJECTIVE

This randomized placebo-controlled trial aimed to evaluate the effects of FES on lower limb functional capacity, strength, endurance, and muscle mass after discharge from cardiac surgery.

METHODS

Twenty patients were allocated (1:1) to the group receiving FES to the quadriceps (FESG) or FES placebo (FESPG). FES was applied at a frequency of 15Hz, with 0.5ms pulse width, 5s contraction time, and 10s resting time, twice a week for 40min over a period of eight weeks. Functional capacity was assessed using the six-minute walk test (6MWT), lower limb muscle strength using the one repetition maximum test (1RM), endurance using the sit-and-stand test (SST), and muscle using the perimeter of the thighs.

RESULTS

Both groups increased the distance covered in the 6MWT (FESG: 49.6m, 95% CI 15.9-83.3; FESPG: 41.5m, 95% CI 7.8-75.2), but without a difference between groups. There were significant between-group differences for quadriceps muscle strength (7.2kg, 95% CI 0.2-14.2) and muscle endurance (2.2 repetitions, 95% CI 1.0-3.4) in favor of the FESG.

CONCLUSION

FES improves lower limb muscle strength and endurance in patients after cardiac surgery. Larger trials are needed to confirm our findings.

Safety of early performance of the six-minute walk test following acute myocardial infarction: a cross-sectional study

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Coronary artery disease (CAD) is one of the main causes of death.

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The stress test is indispensable before cardiac rehabilitation.

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The 6MWT is a simple, low-cost, valid, and reliable method.

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The 6MWT can be used safely in the hospital after an AMI.

Background

The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated.

Objective

To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event.

Methods

Following discharge from the Coronary Care Unit, 152 stable asymptomatic patients diagnosed with uncomplicated AMI performed the 6MWT. During the test, in addition to the distance walked, heart rate (HR), blood pressure (BP), and adverse events were also recorded. Electrocardiography was recorded using a Holter monitor in 105 patients. Patients were allocated considering two groups according to the number of days since AMI: Up to 4 Days Group and After 4 Days Group.

Results

All patients completed the 6MWT, 66 in the Up to 4 Days Group and 86 in the After 4 Days Group. The walking distance was similar in both groups (85% of the predicted value), as well as the physiological responses (increase in systolic BP and HR), reaching 63% (median) of maximum HR. Only 3.9% of patients had major complications (angina, drop in BP, or ventricular tachycardia), with no difference between the groups. None of the complications regarded as severe led to truly significant complications or death.

Conclusion

The 6MWT was proven to be safe and feasible for early functional evaluation following uncomplicated AMI.