A model to predict the immediate postoperative FEV1 following major lung resections.

OBJECTIVE: FEV1 measured on the first postoperative day has shown to be a better predictor of complications than traditional ppoFEV1. Therefore, its estimation before operation may enhance risk stratification. The objective of this study was to develop and validate a model to predict FEV1 on the first postoperative day after major lung resection. METHODS: FEV1 was prospectively measured on the first postoperative day in 272 patients submitted for lobectomy or pneumonectomy at two centers. A random sample of 136 patients was used to develop a model estimating the first day FEV1 by using multiple regression analysis including several preoperative and operative factors. The model was then validated by bootstrap analysis and tested on the other sample of 136 patients. RESULTS: Factors reliably associated with postoperative first day FEV1 were age (p=0.002), preoperative FEV1 (p<0.0001), the presence of epidural analgesia (p<0.0001), and the percentage of non-obstructed segments removed during operation (p=0.001). The following model estimating the first day postoperative FEV1 was derived: -2.648+0.295 x age+0.371 x FEV1+8.216 x epidural analgesia - 0.338 x percentage of non-obstructed segments removed during operation. In the validation set, the mean predicted first day postoperative FEV1 value did not differ from the observed one (42.6 vs 42.0, respectively; p=0.3) and the plot of the observed versus the predicted first day FEV1 showed a satisfactory calibration. CONCLUSIONS: We developed a model predicting the first day postoperative FEV1. If future analyses will prove its role in stratifying the early postoperative risk, it may be integrated in preoperative evaluation algorithms to refine risk stratification.     

Measured FEV1 in the first postoperative day, and not ppoFEV1, is the best predictor of cardio-respiratory morbidity after lung resection.

INTRODUCTION AND OBJECTIVE: There is a low correlation between predicted postoperative FEV1 (ppoFEV1) and FEV1 measured the days after pulmonary resection, when most complications are developed. The hypothesis of this investigation is that ppoFEV1 does not predict postoperative morbidity in patients undergoing lung resection when immediate postoperative FEV1 is considered in the predictive model. METHODS: One hundred ninety-eight consecutive patients undergoing lobectomy or pneumonectomy were included in a prospective, multiinstitutional study. Independent variables: age, body mass index, ppoFEV1, surgical approach (VATS or muscle-sparing thoracotomy), type of analgesia (epidural or intraveous), postoperative visual analogue pain score and FEV1 measured the day after the operation. Target variable: occurrence of postoperative cardio-respiratory complications. Method of analysis: classification tree (CART) dividing the population at random in two subsets and developing a bootstrap set of 100 trees resampling training data. The relative importance of each variable and the accuracy of both initial and committee trees to predict the outcome were presented. RESULTS: One hundred seventy-seven lobectomies and 21 pneumonectomies were included. Overall cardio-respiratory morbidity was 22%. According to CART results, first day FEV1 was the most important variable to classify cases as primary splitter and as a surrogate of each primary splitter (100% importance). Patient age followed (51%) and ppoFEV1 was third (43%) with a score similar to postoperative pain score (42%) and type of analgesia (36%). Sensitivity and specificity of the initial tree were, respectively, 0.5 and 0.7; values for committee tree were 0.5 sensitivity and 0.7 specificity. CONCLUSION: Postoperative cardio-respiratory complications are more related to FEV1 measured in the first postoperative day than to ppoFEV1 value.     

Post-thoracotomy analgesia--comparison epidural fentanyl to intravenous pethidine

BACKGROUND AND METHODS. To evaluate the efficacy of postthoracotomy analgesia with intermittent epidural fentanyl. 50 patients were allocated randomly into 2 groups. The first group received intermittent epidural fentanyl and the second group received intermittent intravenous analgesia using pethidine. The variables studied were: pain score; total amount of additional intravenous opioid analgesia, and ventilatory function parameters [forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) and FEV1/FVC ratio]. RESULTS. In the first postoperative day, pain scores were higher in the epidural group (P = 0.034), but there was no significant difference between mean pain scores in the second and third days (P = 0.61, P = 0.15, respectively). On all three days, significantly more additional analgesics were required in the epidural group. A difference was found between both groups in the post- to pre-operative FEV1, FVC and FEV1/FVC ratios, with the better preservation of the ventilatory function in the epidural group (P = 0.001, 0.013, <0.0001, respectively). CONCLUSION. The analgesic effect of intermittent epidural fentanyl is not adequate and postoperative pain relief has not any significant advantage over the more easily-applied intravenous analgesia. However, better preservation of ventilatory function makes epidural fentanyl a useful adjunct analgesia in reduction of post-thoracotomy pulmonary complications.     

Clinical parameters affecting prediction accuracy of postoperative lung function in non-small cell lung cancer

Despite significant development in chemotherapy and radiotherapy, surgery is still the cornerstone for curative lung cancer treatment. Accurate prediction of postoperative lung function is mandatory. The goal of this study was to identify important clinical factors affecting prediction accuracy of postoperative lung function for more careful patient selection. The medical records of non-small cell lung cancer patients undergoing pulmonary resection were reviewed. An accuracy index, apo/ppoFEV(1) was defined as the ratio of actual postoperative FEV(1) [apoFEV(1)] to predicted postoperative FEV(1) [ppoFEV(1)]. We used multivariate analysis to inspect the relationship between the accuracy index and seven tentative clinical factors: age, gender, preoperative FEV(1), time interval between operation and the first postoperative FEV(1), bronchodilator response (%), resected lung portion, and the number of resected lung segments. A total of 82 patients were analyzed. Accuracy index of quantitative perfusion lung scan-based prediction was better than that of simple calculation. Multivariate analysis identified the number of resected lung segments and preoperative FEV(1) as the significant clinical factors affecting the accuracy index (P=0.026 and 0.002, respectively). Preoperative FEV(1) and the number of resected lung segments are significant clinical factors affecting prediction accuracy of postoperative lung function.     

Postoperative Pain Treatment after Upper Abdominal Surgery with Epidural Morphine at Thoracic or Lumbar Level

Thirty patients undergoing upper laparotomy were entered into a randomized trial, comparing the effect of midthoracic (T) and lumbar (L) epidural morphine on postoperative pain and pulmonary function. Five mg morphine was injected through the catheter at the end of the operation, and subsequently three times a day. Six, 30 and 54 h postoperatively, the following tests were performed: linear analogue pain score, arterial gas tensions (PaO2, PaCO2 and pH), forced ventilatory capacity (FVC), forced expiratory volume in 1s (FEV1) and peak expiratory flow rate (PEF). The changes in pain score (increase of the median): T: 21, 6, 5, and L: 24, 15, 8 per cent of full scale), PaO2 (decrease of the tension: T: 1.7, 2.1, 2.4, and L: 2.0, 2.8, 2.0 kPa), PaCO2, pH, FVC (decrease of the volume: T: 1.3, 1.1, 0.9, and L: 1.3, 1.3, 1.21), FEV1 and PEF from the preoperative tests were not significantly different. It is concluded that the clinical effect of epidural morphine for postoperative pain treatment is the same or little different whether the administration takes place at the thoracic or lumbar level.     

Lobar volume reduction surgery: a method of increasing the lung cancer resection rate in patients with emphysema

BACKGROUND: Guidelines on patient selection for lung cancer resection identify a predicted postoperative forced expiratory volume in 1 second (ppoFEV(1)) of <40% as a predictor of high risk. Experience with lung volume reduction surgery suggests that ppoFEV(1) may be underestimated in those with concomitant emphysema. METHODS: Anatomical lobectomy was performed in 29 patients with a resectable lung cancer within a poorly perfused, hyperinflated emphysematous lobe identified by radionuclide perfusion scintigraphy and computed tomographic scanning. Perioperative changes in spirometric parameters at 3 months were compared in 14 patients (group A) of mean age 69 years (range 48-78) with ppoFEV(1) <40% (mean (SD) 31.4 (7)%) and 15 patients (group B) with ppoFEV(1) >40% (mean (SD) 47 (5)%). The correlation between predicted and actual postoperative FEV(1) was also assessed. RESULTS: In group B there was a significant perioperative reduction in FEV(1) (p=0.01) but in group A FEV(1) did not change significantly after lobectomy (p=0.87); mean difference in perioperative change between groups A and B 331 ml (95% CI 150 to 510). Despite the difference in ppoFEV(1) between the groups, there was no difference in actual FEV(1) at 3 months. In-hospital mortality was 14% in group A and zero in group B, but at a median follow up of 12 (range 6-40) months there was no difference in survival between the groups. CONCLUSIONS: Selection for lung cancer resection in patients with emphysema using standard calculations of ppoFEV(1) may be misleading. The effect of lobar volume reduction allows for an extension of the selection criteria.     

The effect of epidural injection with morphine on the post-thoracotomy respiratory function

Patients undergoing thoracotomy experience severe post-operative pain and marked respiratory impairment, which causes pulmonary atelectasis and pneumonia. The effects of epidural injection on postoperative pain and respiratory function were examined in this study. The group undergoing epidural injection of 3 mg morphine (at the end of operation, 09oo and 21oo for the next 3 days) included 37 patients, while the control group involved 16. The number of required analgesics on the operating day and next three days were compared between the two groups. And postoperative vital capacity (VC), forced expiratory volume in the first second (FEV1), maximum mean flow (MMF) were compared with preoperative value. Patients receiving epidural morphine required significantly less analgesics throughout the postoperative periods (p less than 0.01). The morphine injected group had significantly better value in VC and FEV1 in the first two postoperative day (p less than 0.01), while significance were seen only in the first postoperative day in MMF (p less than 0.01). It seems that epidural morphine is highly effective in alleviating pain and improving respiratory function in post-thoracotomy patients. These effects help the expectoration of sputum especially in senile patients. As the side-effects of epidural morphine, urinary retention, nausea, vomiting and itching were seen in few patients. No serious side effect such as hypotension or ventilatory depression were seen.     

Spirometry: predicting risk and outcome

Predicted postoperative FEV1 is certainly the most widely used parameter in preoperative risk stratification [54] and the measure recommend by BTS and ACCP functional guidelines as a first step in the screening of patients for lung resection surgery. Nevertheless, recent evidences have demonstrated that ppoFEV1 is not a reliable predictor of postoperative cardiopulmonary complications in patients with preoperative impaired pulmonary function. This may be because of the fact that the resection of a portion of lung in patients with obstructive disease determines only a minimal loss, or even an improvement, in overall respiratory function and exercise tolerance. This lung volume reduction effect takes place very early, since the first postoperative days, balancing what ever negative physiologic effects a thoracotomy and lung resection may entail. In addition to its poor predictive role in COPD patients, ppoFEV1 largely underestimate the actual loss in the very first days after operation, when most of the complications develop. The rationale to use a parameter which is poorly correlated with the pulmonary function at the moment the complications occur seems unwarranted. At the very best, ppoFEV1 appears a weak surrogate of the immediate postoperative FEV1. The FEV1 measured on the first postoperative day may be 30% less than predicted. Corrective equations have been published to correct this discrepancy with the aim to improve risk stratification.     

Exercise capacity after lobectomy in patients with chronic obstructive pulmonary disease

The aim of this study is to clarify whether patients with chronic obstructive pulmonary disease (COPD) lose less exercise capacity after lobectomy than do those without COPD, to the same extent as ventilatory capacity and lobectomy for selected patients with severe emphysema improve exercise capacity like ventilatory capacity. Seventy non-COPD patients (N group), 16 mild COPD patients (M group), and 14 moderate-to-severe COPD patients (S group) participated. Pulmonary function and exercise capacity tests were performed on the same day preoperatively and six months to one year after lobectomy. The S group lost significantly less FEV(1) (forced expiratory volume in 1 s) after lobectomy than did the N or M group (P<0.0001 and P<0.005). However, their loss of exercise capacity was equivalent to that for the N and M groups. For the S group, there was a significant, negative correlation between preoperative FEV(1) % of predicted and percentage change in FEV(1) and maximum oxygen consumption (VO2 max) after lobectomy (r=-0.93, P<0.0001 and r=-0.64, P=0.01). In moderate-to-severe COPD patients, patients with a lower preoperative FEV(1) % of predicted experienced a smaller decrease in FEV(1) and VO2 max after lobectomy.     

Long-term respiratory functional results after pneumonectomy.

INTRODUCTION: The aim of this study is to evaluate the long-term respiratory outcome of patients who underwent pneumonectomy for non-small cell lung cancer (NSCLC), analysing functional tests. MATERIALS AND METHODS: Twenty-seven consecutive patients who were candidates for pneumonectomy performed spirometry before and at least 24 months after surgery in the same laboratory. Diffusion of carbon monoxide and the most common dynamic and static lung volumes were evaluated in percentage of predicted and compared. RESULTS: A significant inverse correlation was observed between the preoperative FEV1 (%) and FVC (%) and their postoperative loss, respectively r=-641 (p<0.0001) and r=-789 (p<0.0001). Also the correlation between the RV/TLC ratio and the FEV1 loss confirmed a better postoperative outcome in patients with major airway obstruction (p=0.02). To investigate these data, the series were divided into two groups: group A included BPCO patients with a FEV1 lower than 80%, the others were considered group B. Group B showed a significant major postoperative FEV1 (%) and FVC (%) impairment, 31% versus 12%, p=0.005, and FVC (%) loss, 37% versus 16% (p=0.02), meanwhile group A showed a significant major postoperative RV (%) reduction, 43% versus 17%, p=0.03. Despite being significantly higher preoperatively in BPCO patients, the RV% becomes similar between the two groups in the postoperative. CONCLUSIONS: In our experience patients with major preoperative airway obstruction who underwent pneumonectomy had lower impairment in FEV1% at almost one year after surgery than those with normal respiratory function. The resection of a certain amount of non-functional parenchyma associated with the mediastinal shift, with an improvement of the chest cavity for the remaining lung, could give a reduction volume effect in BPCO/emphysematous patients.     

The efficacy of epidural analgesia after video-assisted thoracoscopic surgery: a randomized control study.

PURPOSE: Video-assisted thoracoscopic surgery (VATS) is known to reduce the severity of pain after surgery. However, it has not yet been established whether epidural anesthesia/analgesia (EA) is necessary after VATS. We therefore conducted a randomized control study to examine whether or not EA is necessary for pain control after VATS. PATIENTS AND METHODS: Forty-six patients undergoing VATS were randomly allocated to one of 2 groups: 24 who were given EA after the procedure (EA group) and 22 who were not (NEA group). Patients in the EA group received a continuous infusion of fentanyl and bupivacaine via an epidural catheter for 2 days after VATS. The degree of postoperative pain was assessed on the total dose of additional analgesics administered, a visual analog scale (VAS), a verbal pain score at rest (VPS-R) and on movement (VPS-M), from the day of surgery to the 2nd postoperative day (2 POD). RESULTS: Additional use of rectal diclofenac sodium and intramuscular pentazocine was more frequent in the NEA group than in the EA group (p<0.05). The VAS, VPS-R, and VPS-M scores were significantly lower in the EA group than in the NEA group at 0 POD, from 0 to 1 POD, and from 0 to 2 POD, respectively (p<0.0001-0.05). Stepwise regression analysis revealed that EA was a significant independent variable of VPS-R and VPS-M from 0 to 1 POD (p<0.05). However, the incidence of nausea/vomiting in the EA group was 29%, which was more frequent than in the NEA group (5%) (p<0.05). CONCLUSION: While EA causes nausea/vomiting in some patients, it is effective for pain control until 1 POD after VATS, especially for pain on movements.     

Comparison of magnesium sulfate with opioid and NSAIDs on postoperative pain management after coronary artery bypass surgery

OBJECTIVE: This study measured the effectiveness of magnesium sulfate during and after coronary artery bypass grafting (CABG) on postoperative pain and respiratory functions, and compared it with 2 other well-known and widely used analgesic agents: codeine and diclofenac, a nonsteroidal anti-inflammatory drug (NSAID). DESIGN: Prospective unblinded study. Setting: Single institution. PARTICIPANTS: Patients undergoing CABG. INTERVENTIONS: Patients were divided into 3 groups. In group A (n = 50), intraoperative magnesium sulfate, 2 g/70 kg, was infused intravenously and was continued during the first 3 days postoperatively. In group B (n = 50), codeine, 60 mg/70 kg, was given orally 4 times a day for 3 days. In group C (n = 50), diclofenac sodium, 75 mg, was given orally twice a day for 3 days. MAIN RESULTS: On the first postoperative day the visual analog scale (VAS) score was greater than 5 in all groups. On the second day the VAS score was greater than 5 in groups B and C, and was less than 5 in group A. On the third day the VAS score was less than 5 in all groups. During the first 2 postoperative days the need for morphine was significantly less in group A than in the other 2 groups. Preoperative respiratory function tests (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and FEV1/FVC) were similar in each group. The FEV1, FVC, and FEV1/FVC values on the postoperative first, second, and third days were significantly higher in group A. CONCLUSIONS: Magnesium sulfate can be a beneficial adjuvant therapy for pain after CABG. In this respect, especially in patients with respiratory problems or intolerance to NSAIDs, magnesium sulfate can be a better choice than NSAIDs and opioids.     

Changing pattern of the respiratory function associated with resected lung lobe

Respiratory function before and 2 months after lung lobectomy was analyzed associated with resected lobe. Post- or preoperative ratios of FEV1.0 or VC were compared among (1) predicted value by the number of subsegments using bronchofiberscopy, (2) predicted value by the lobar volume ratio using computed tomography (CT), and (3) actually measured value. Using subsegments method, post- or preoperative predicted VC ratios were 85 +/- 1% after right upper lobectomy (RU), 69 +/- 1% after right lower lobetomy (RL), 74 +/- 1% after left upper lobectomy (LU), and 75 +/- 1% after left lower lobectomy (LL). Using CT method, post- or preoperative predicted VC ratios were 80 +/- 2% after RU, 76 +/- 4% after RL, 74 +/- 2% after LU, and 79 +/- 3% after LL. Actually measured post- or preoperative FEV1.0 ratios were 82 +/- 3% after RU, 89 +/- 8% after RL, 73 +/- 3% after LU, and 86 +/- 5% after LL, and the VC ratios were 88 +/- 5% after RU, 79 +/- 3% after RL, 77 +/- 4% after LU, and 94 +/- 3% after LL. In the FEV1.0 analysis using both subsegments method and CT method, the predicted value was correlated with upper lobectomy but was overestimated in case of lower lobectomy. This phenomenon might be caused by the postoperative bronchial branching deformity after upper lobectomy. In the VC analysis using subsegments method, the predicted value was correlated with upper lobectomy but was overestimated in case of lower lobectomy. Meanwhile, in the VC analysis using CT method, the predicted value was correlated with RL or LU but was overestimated in case of RU or LL. This may due to the fact that RL and LU had large lobar volumes. In conclusion, postoperative predicted and actually measured values were different associated with resected lobe. In the FEV1.0 and VC analysis using subsegments method, the predicted value was strongly correlated with upper lobectomy but was overestimated (10%) in case of lower lobectomy.     

Utility of standardized exercise oximetry to predict cardiopulmonary morbidity after lung resection.

OBJECTIVES: To evaluate if desaturation, measured by finger oximetry on standardized exercise, accurately predicts cardiopulmonary morbidity after pulmonary resection. METHODS: A prospective observational clinical study was carried out on 81 consecutive lung carcinoma patients scheduled for pulmonary resection from February 1998 to March 1999. Finger oximetry was monitored during an incremental to exhaustion cycle exercise test. The presence or absence of desaturation (cut-off value 90%) during exercise was recorded. Other independent analyzed variables were: age of the patient (over 75th percentile), body-mass index (BMI) (over 75th percentile), presence of major cardiovascular co-morbidity, and calculated postoperative FEV1% (under 25th percentile) according to the number of resected segments (ppoFEV1%). Postoperative cardiopulmonary morbidity was the evaluated dependent outcome. Fisher's exact test and risk calculation on contingency tables were used for statistical analysis. RESULTS: A lobectomy was performed in 62 cases, a pneumonectomy was performed in 16 cases, and a segmentectomy was performed in three cases. The mean age of the patients was 63.6 years (SD 10.3, range 34-79 years, 75th percentile 72 years), the mean BMI was 25.9 (SD 4.9, range 16.9-38.1, 75th percentile 29.3), and the mean ppoFEV1% was 64.1 (SD 2016.1, range 29.5-98.6, 25th percentile 50.5). In 14 patients exercise desaturation was registered. Postoperative cardiopulmonary morbidity was presented in 32 cases (five deaths). No correlation was found between postoperative morbidity and any of the following variables: age of the patient, BMI, and co-morbidity. On univariate analysis only low ppoFEV1% (P<0.001) was associated with the outcome, so no multivariate analysis has been carried out. CONCLUSIONS: We have shown that desaturation during standardized exercise in this series adds no relevant information to predict postoperative cardiorespiratory morbidity after lung resection.     

Minimal alteration of pulmonary function after lobectomy in lung cancer patients with chronic obstructive pulmonary disease

BACKGROUND: The aim of this study was to evaluate the influence of chronic obstructive pulmonary diseases (COPD) on postoperative pulmonary function and to elucidate the factors for decreasing the reduction of pulmonary function after lobectomy. METHODS: We conducted a retrospective chart review of 521 patients who had undergone lobectomy for lung cancer at Chiba University Hospital between 1990 and 2000. Forty-eight patients were categorized as COPD, defined as percentage of predicted forced expiratory volume at 1 second (FEV1) less than or equal to 70% and percentage of FEV1 to forced vital capacity less than or equal to 70%. The remaining 473 patients were categorized as non-COPD. RESULTS: Although all preoperative pulmonary function test data and arterial oxygen tension were significantly lower in the COPD group, postoperative arterial oxygen tension and FEV1 were equivalent between the two groups, and the ratio of actual postoperative to predicted postoperative FEV1 was significantly better in the COPD group (p < 0.001). With multivariable analysis, COPD and pulmonary resection of the lower portion of the lung (lower or middle-lower lobectomies) were identified as independent factors for the minimal deterioration of FEV1. Actual postoperative FEV1 was 15% lower and higher than predicted, respectively, in the non-COPD patients with upper portion lobectomy and the COPD patients with lower portion lobectomy. Finally, we created a new equation for predicting postoperative FEV1, and it produced a higher coefficient of determination (R(2)) than the conventional one. CONCLUSIONS: The postoperative ventilatory function in patients with COPD who had lower or middle-lower lobectomies was better preserved than predicted.     

A case-matched study of anatomical segmentectomy versus lobectomy for stage I lung cancer in high-risk patients.

OBJECTIVE: Sublobar resections may offer a method of increasing resection rates in patients with lung cancer and poor lung function, but are thought to increase recurrence and therefore compromise survival for stage I non-small cell lung cancer (NSCLC). To test this hypothesis we have compared the long-term outcome from lobectomy and anatomical segmentectomy in high-risk cases as defined by predicted postoperative FEV1 (ppoFEV1) less than 40%. METHODS: Over a 7-year period 55 patients (27% of all resections for stage I NSCLC) with ppoFEV1<40% underwent resection of stage I NSCLC. The 17 patients who underwent anatomical segmentectomy were individually matched to 17 patients operated by lobectomy on the bases of gender, age, use of VATS, tumour location and respiratory function. We compared their perioperative course, tumour recurrence and survival. RESULTS: There were no significant differences in hospital mortality (one case in each group), complications or hospital stay. Overall 5-year survival was 69%. There were no differences in recurrence rates (18% in both groups) or survival (64% after lobectomy and 70% after segmentectomy). There was preservation of pulmonary function after segmentectomy (median gain of 12%) compared to lobectomy (median loss of 12%) (P=0.02). CONCLUSIONS: Anatomical segmentectomy allowed for surgical resection in patients with stage I NSCLC and impaired respiratory reserve without compromising oncological results but with preservation in respiratory function.     

Discordance between predicted postoperative forced expiratory volumes in one second (ppoFEV1) calculated before and after resection of bronchogenic carcinoma

The aim of this study is to evaluate the concordance between predicted postoperative forced expiratory volumes in 1s (ppoFEV1) calculated on the basis of data known before surgery with ppoFEV1 calculated after completing surgical procedure. We have prospectively studied 66 consecutive patients (55 cases scheduled for lobectomy and 11 for pneumonectomy) operated on for bronchial carcinoma. According to location, 33 tumours were classified as central and 33 as peripheral. In all cases, ppoFEV1 was calculated twice: first (ppoFEV1-A) according to the scheduled surgical procedure; second (ppoFEV1-B) according to the procedure eventually performed. At operation, 43 lobectomies (65.2%) and 23 pneumonectomies (34.8%) were performed. Differences between ppoFEV1 A and B were found in 18 cases (12 central tumours). In three of them (4.5% of 66 cases), ppoFEV1-B was under 40%. Pearson coefficient was 0.85 (P<0.001) for the whole series of cases; 0.83 (P<0.001) for central and 0.87 (P<0.001) for peripheral tumours. On multiple regression analysis, R2 was 0.76 and ppoFEV1-A had the highest influence on the dependent variable. We have found that: (1) there is no perfect correlation between ppoFEV1 calculated with data known before and after surgery; (2) discrepancies are most important in centrally located tumours and (3) in 4.5% of cases, discrepancies could have influenced the preoperative risk estimation.     

静脉和硬膜外自控镇痛对肺叶切除术后肺功能的影响

目的　比较静脉与硬膜外病人自控镇痛 (PCIA与PCEA)对肺叶切除术后肺功能的影响。方法　 44例择期行单肺叶切除病人 ,随机分成PCIA组和PCEA组。分别于术前、术后 2 4、48h用脉冲振荡肺功能测定仪 (IOS)测定肺功能。结果　PCEA组与PCIA组术前肺功能无统计学差异 ;术后 2 4h两组与术前比较用力肺活量 (FVC)、1秒用力呼气量 (FVE1 )降幅较大 (P <0 0 5) ,呼吸总阻抗 (Zrs)、共振频率(Fres)、35Hz时呼吸阻力 (R35)、5Hz时呼吸电阻 (X5)升高显著 (P <0 0 5) ;术后 48h两组FVC、FEV1 、Zrs、Fres、R35、X5较术后 2 4h有所恢复 ,但PCEA组恢复更好 (P <0 0 5)。结论　胸科手术后用PCEA、PCIA均能获得较好的镇痛效果 ,但PCEA对病人早期肺功能的恢复作用积极明显     

Pleural tent after upper lobectomy: a randomized study of efficacy and duration of effect

BACKGROUND: The object of this study was to assess the efficay and maximum duration of effect of the pleural tent in reducing the incidence of air leak after upper lobectomy. METHODS: Two hundred patients who underwent upper lobectomy were prospectively randomized into two groups: 100 patients who underwent an upper lobectomy and a pleural tent procedure (group 1; tented patients) and 100 patients who underwent only an upper lobectomy and not a pleural tent procedure (group 2; untented patients). The preoperative, operative, and postoperative characteristics of both groups were compared. Then multivariate analyses were used to identify factors predictive of prolonged air leaks and their duration. The reduction of incidences of air leak in the two groups was subsequently compared during successive postoperative periods. RESULTS: No differences were detected between the two groups in terms of preoperative and operative characteristics. A significant reduction occurred in group 1 patients for the mean duration of air leak in days (2.5 vs 7.2 days; p < 0001), the number of days a chest tube was required (7.0 vs 11.2 days; p < 0.0001), the length of postoperative hospital stay in days (8.2 vs 11.6 days; p < 0.0001), and the hospital stay cost per patient (4,110 dollars vs 5,805 dollars; p < 0.0001). Logistic regression analyses showed that not having undergone a pleural tent procedure was the most significant predictive factor of the occurrence and duration of prolonged air leaks. A greater reduction in the duration of air leaks was observed before postoperative day 4 in group 1, and logistic regression analysis showed that having undergone a pleural tent procedure was the most significant predictive factor of air leaks that persisted for less than 4 days. CONCLUSIONS: Pleural tenting after upper lobectomy was a safe procedure that reduced the duration of air leaks and the hospital stay costs. The benefit from that procedure was achieved before postoperative day 4.     

Effects of preoperative ketamine on postoperative pain in patients undergoing laparotomy

BACKGROUND: Effects of preoperative ketamine on postoperative pain in patients undergoing laparotomy have been controversial. METHODS: Fifty-two patients undergoing elective laparotomy were enrolled in this retrospective study. Patients were classified into 3 groups according to anesthetic management; patients received general anesthesia alone with preoperative ketamine (n = 20), patients received epidural blockade and general anesthesia with preoperative ketamine (n = 15), and patients received epidural blockade and general anesthesia without preoperative ketamine (n = 17). Among the three groups, we compared the parameters concerning postoperative pain managements; frequency of complaining about pain, opioid consumption, incidence of nausea and vomiting in the first 24 hours after laparotomy, and ability of ambulation on the first postoperative day. RESULTS: Among the three groups, there were no significant differences in all parameters concerning postoperative pain management described above. CONCLUSIONS: Results of this study imply that preoperative ketamine may elicit preemptive analgesic effects, and can be an efficient adjuvant to postoperative pain management for patients undergoing laparotomy.