The effect of thoracic epidural analgesia on respiratory function after cholecystectomy

To assess the effect of thoracic epidural analgesia (TEA) on postoperative respiratory function and pulmonary complications, a prospective randomized trial was conducted in patients undergoing cholecystectomy. One hundred patients were allocated to TEA (n = 30), TEA + general anesthesia (TEA + GA) (n = 30), or general anaesthesia (GA) (n = 40) groups. Respiratory function was analysed by measuring forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), total lung capacity (TLC), peak expiratory flow (PEF) in the supine and sitting postures, and arterial blood gases. Postoperative pulmonary complications were carefully documented. TEA significantly prevented the postoperative deterioration of respiratory function as compared with general anaesthesia. FVC, FEV1 and PEF decreased by 20% in patients receiving TEA, in contrast to 55% in patients after GA on the day of operation. This improvement continued until the 2nd day after operation, when FVC, FEV1 and PEF and their recovery rates were equal in all groups. In the sitting posture the preoperative FVC, FEV1 and PEF were about 10% greater than in the supine position. After operation, this difference was further increased. The preoperative difference of 27% in FRC between the sitting and supine postures was maintained after operation. PaO2 decreased by 0.8 kPa after TEA, by 1.5 kPa after TEA + GA with the lowest value on the 2nd postoperative day and by 1.5 kPa after GA, with the lowest value immediately after operation. Simultaneous hypercarbia indicated hypoventilation, which may have contributed to impaired respiratory function on the following days.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of different abdominal pressures on pulmonary function test results in laparoscopic cholecystectomy

This study aimed to examine the effects of differing intra-abdominal pressures on pulmonary function test results in laparoscopic cholecystectomy. Forty-five patients were operated on under 3 different intra-abdominal pressures: group A (8 mm Hg), group B (12 mm Hg), and group C (15 mm Hg). On the first day before and after the operation, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC rate, peak expiratory flow speed (PEF), and maximal middle expiration speed (FEF25-75) values were measured using Vmax 229 spirometry. No significant differences were observed among the 3 groups regarding preoperative and postoperative FVC, FEV1, FEV1/FVC, PEF, and FEF25-75 values (P=0.96, P=0.73, P=0.48, P=0.34, and P=0.33, respectively). When the groups' preoperative and postoperative values were compared, FVC, FEV1, and PEF values significantly decreased in each group. The FEF25-75 values statistically significantly decreased in groups B and C when compared with their preoperative values; however, the decrease in group A was not significant. In conclusion, different intra-abdominal pressures during laparoscopic cholecystectomy had similar effects on pulmonary function test results. However, lower intra-abdominal pressures were associated with slightly more negative effects on FEF25-75 values.     

Postoperative pulmonary function after laparoscopic and open cholecystectomy

In this prospective, randomized study, we compared 42 patients undergoing laparoscopic cholecystectomy and 40 undergoing open cholecystectomy to determine if laparoscopic cholecystectomy results in less respiratory impairment and fewer respiratory complications. Pulmonary function tests, arterial blood-gas analysis and chest radiographs were obtained in both groups before operation and on the second day after operation. Postoperative pain scores and analgesic requirements were also recorded. After operation, a significant reduction in total lung capacity, functional residual capacity (FRC), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and mid-expiratory flow (FEF25-75%) occurred after both laparoscopic and open cholecystectomy. The reductions in FRC, FEV1, FVC and FEF25-75% were smaller after laparoscopic (7%, 22%, 19% and 23%, respectively) than after open (21%, 38%, 32% and 34%, respectively) cholecystectomy. Laparoscopic cholecystectomy was also associated with a significantly lower incidence (28.6% vs 62.5%) and less severe atelectasis, better oxygenation and reduced postoperative pain and analgesia use compared with open cholecystectomy. We conclude that postoperative pulmonary function was impaired less after laparoscopic than after open cholecystectomy.      

腹腔镜上腹部与下腹部手术后肺功能的比较研究

目的:比较上腹部腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)、下腹部腹腔镜阑尾切除术(laparoscopic appendectomy,LA)、腹腔镜经腹腔腹膜前疝修补术(transabdominal preperitoneal,TAPP)对患者术后肺功能改变的影响。方法:将50例患者根据疾病分为3组,A组行LC(n=20),B组行LA(n=14),C组行TAPP(n=16)。分别于术后6 h、12 h、24 h、48 h检查一次肺功能。结果:A组患者术后肺功能明显改变,用力肺活量(forced vital capacity,FVC)、一秒用力呼气容积(forced expiratory volume in one second,FEV1)、最大呼气中段流量(maximal midexpiratory flow curve,MMF)等肺功能指标均明显下降,B、C组患者术后当天肺功能仅有轻微改变。3组间,术后6 h、12 h、24 h、48 h痛觉评分(visual analogue scale,VAS)差异无统计学意义。结论:腹腔镜下腹部手术(LA、TAPP)后肺功能的改变小于上腹部腹腔镜手术(LC),腹腔镜手术部位对肺功能的改变情况有重要作用。     

Impact of laryngeal mask airway and tracheal tube on pulmonary function during the early postoperative period

BACKGROUND: The tracheal tube (TT) produces reversible bronchoconstriction and increases pulmonary airway resistance compared to the laryngeal mask airway (LMA). The possible persistence of this effect in the postoperative period has not been studied. The aim of this study was to compare the early postoperative pulmonary function in healthy patients undergoing minor surgical procedures with the LMA or with the TT. METHODS: Sixty patients scheduled for saphenous vein stripping under general anaesthesia were randomised to receive the LMA or the TT. Before anaesthesia and 20 min after LMA or TT removal, pulse oxymetry values (SpO(2)) were recorded and patients performed forced spirometry in the supine position. RESULTS: Preoperative pulmonary function was normal in both groups. There were no differences between groups in the preoperative respiratory function test and SpO(2). Following surgery SpO(2), forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow (PEF) decreased in both groups. The FEV1/FVC did not change in either of the groups. In the TT group, compared to patients using the LMA, there was a greater relative decrease of SpO(2) (2.7 +/- 2.7% vs. 1.3 +/- 2.2%, P=0.017), FEV1 (17.6 +/- 12.2% vs. 8 +/- 17.4%, P=0.008), FVC (15.8 +/- 12.4% vs. 9 +/- 13.4%, P=0.023) and PEF (20.6% +/- 15.3% vs. 8.1 +/- 33.3%, P=0.033). CONCLUSIONS: This study demonstrates greater early postoperative respiratory restrictive syndrome and lower arterial oxygen saturation following tracheal intubation compared to LMA use in patients without respiratory disease.     

腹腔镜与开腹脾切除术对肺功能影响的对比研究

目的:对比分析腹腔镜脾切除术与开腹脾切除术对肺功能的影响。方法:选择需行脾切除术的38例患者,随机分为腔镜组(n=19)与开腹组(n=19)。分别记录两组患者术前1天及术后24 h的用力肺活量(forced vital capacity,FVC)及第1秒用力呼气容积(forced expiratory volume in 1 second,FEV1)。结果:两组患者术前FVC、FEV1实测值差异无统计学意义,术后24 h腹腔镜组FVC、FEV1实测值高于开腹组,差异有统计学意义。结论:腹腔镜脾切除术对肺功能的影响小于开腹脾切除术,具有手术创伤小、对呼吸系统影响小的优点。     

Reduced acute phase response after laparoscopic total extraperitoneal bilateral hernia repair compared to open repair with the Stoppa procedure

BACKGROUND: Although laparoscopic hernia repair has been shown to be associated with less postoperative pain and an earlier recovery, there is still controversy about its role in hernia surgery. In general, laparoscopy produces less trauma to tissues than open surgery. This has been reflected by the reduced acute phase inflammatory response observed after laparoscopic surgery compared to open surgery in various settings, such as cholecystectomy or hysterectomy. The aim of this study was to evaluate the acute phase response after bilateral hernia repair by comparing the open Stoppa procedure with the laparoscopic totally extraperitoneal prosthetic repair (TEPP). METHODS: Patients were randomly allocated to either technique after written informed consent was obtained. Measurements were made of complete blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-1b (IL-1b), IL-6, and tumor necrosis factor-a (TNF-a) preoperatively and 4, 24, and 48 h postoperatively. VAS pain scores, consumption of analgesics, and delay before resumption of normal activities were also recorded. All the procedures were performed under general anesthesia by or in the presence of the same surgeon. RESULTS: Thirty-nine patients were included: 19 underwent the Stoppa procedure and 20 had a laparoscopic repair. The two groups were well matched for age, sex, ASA score, and preoperative values. The operation took longer (p <0.001) in the group undergoing TEPP. Patients resumed their normal activities earlier (p <0.05) after laparoscopy. In the open group, there was a larger decrease of the lymphocyte count after 4 (p <0.01) and 24 h (p = 0.04); an increased elevation of ESR after 48 h (p = 0.02); a larger increase of IL-6 after 4 (p = 0.05), 24 (p = 0.003), and 48 h (p <0.001); and a larger increase in CRP after 24 (p = 0.05) and 48 h (p = 0.01). There was no morbidity. There was no difference in postoperative IL-1b, TNF-a, total white blood cell count, polymorphonuclear count, VAS for pain, or need for analgesics between the two groups, except on the operative day. CONCLUSIONS: The acute phase inflammatory response in clearly more active after the open Stoppa procedure than after TEPP, indicating that the former is associated with increased tissue trauma. This may play a role in the earlier recovery seen after the TEPP procedure.     

Assessment of pulmonary function in patients before and after laparoscopic and open esophagogastric surgery

Background Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery.Methods For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF_25–75%).Results A decrease in FEV_1, FVC, and FEF_(25–75%) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV₁ and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF_(25–75%) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV₁ between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF_(25–75%) was observed only on postoperative day 4.Conclusions Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.     

老年患者腹部手术对呼吸功能的影响

目的评价老年患者腹部手术后呼吸功能的变化及其影响因素.方法60岁以上(包括60岁)择期腹部手术患者35例,分别在手术前和手术后第1、3、5、10d,应用脉冲振荡肺功能测定仪(IOS)测定最大肺活量(VCmax);用力肺活量(FVC)、第1s用力呼气容积(FEV10)、FEV1.0/FVC、最大通气量(MVV);呼气流速峰值(PEF)、用力肺活量为25%、50%和75%时的气流量(FEF25、FEF50、和FEF7s);中心气道阻力(Rc)、周边气道阻力(Rp)、共振频率(Fres)、呼吸总阻抗(Zrs)以及不同振荡频率下的通气阻力5赫兹时呼吸阻力(R5)、20赫兹时呼吸阻力(R20)和5赫兹时呼吸电抗(X5).结果与手术前相比,手术后第1、3、5dVCmax、FVC、FEV10、MVV、PEF、FEF25、FEF50均明显降低(P<0.01),并以手术后第1d最为明显,手术后第1dFres、Zrs和R5明显增加(P<0.01或0.05),而R20和R5不变.年龄70～79岁组较60～69岁组患者手术前和手术后第1、3、5dFEF10、MVV、PEF均显著降低(P<0.01或0.05);手术前ASA≥Ⅱ级患者肺通气功能(PEF、MVV)明显低于ASAⅠ级患者(P<0.05或0.01),而麻醉类型、手术部位、伤口疼痛程度、手术时间、术后胃肠减压持续时间及患者体重系数对手术后肺通气功能无明显影响(P>0.05).结论老年患者腹部手术后呼吸功能的改变主要发生于手术后早期,除表现为限制性通气障碍外,还存在阻塞性通气障碍,其改变程度与患者的年龄和术前伴随疾病有关.     

进胸取膈神经移位术后肺功能的变化

目的　研究进胸取膈神经移位术后患者肺功能的变化。方法　对 5例进胸取膈神经移位患者术前及术后 (8～ 14个月 )肺功能的变化进行比较。结果　 5例在术后均未出现供氧不足症状。 3例出现膈肌抬高 ;术后肺活量 (VC)、肺活量预计值百分数 (VC % )分别比术前减少 17.3 %和 3 2 .3 % ,两者差异有显著性意义 (tvc=3 .49、tvc% =4.17,P <0 .0 5 )。其它项目如残气量 (RV)、肺总量 (TLC)、残气量 /肺总量比值 (RV/TLC)、用力肺活量 (FVC)、1s用力呼气量 (FEV1)、1s用力呼气量 /用力肺活量比值(FEV1/FVC)、5 0 %肺活量的最大呼气流量预计值百分数 (FEF 5 0 % )的变化 ,和术前相比均无明显差异。结论　进胸取膈神经移位术后成人的肺容量有部分丧失 ,但其丧失程度在机体可耐受范围内 ,不会导致呼吸功能障碍     

The effects of isothermic and hypothermic carbon dioxide pneumoperitoneum on respiratory function test results

BACKGROUND/PURPOSE: This study investigated the effects of isothermic and hypothermic carbon dioxide, used for pneumoperitoneum during laparoscopic cholecystectomy, on respiratory function test results. METHODS: Thirty patients who underwent elective laparoscopic cholecystectomy were enrolled in this prospective randomized study. The patients were divided into two groups. Carbon dioxide at 37 degrees C (isothermic) was used in the isothermic group, and carbon dioxide at 21 degrees C (hypothermic) was used in the hypothermic group. Respiratory function tests were performed in the preoperative period and at 12 h after the operation. RESULTS: Mean forced vital capacity (FVC), forced expiratory volume (FEV1), maximum peak expiratory flow (PEF), and the FEV1/FVC ratio were significantly higher in the isothermic group than in the hypothermic group (P < 0.05). CONCLUSIONS: Using isothermic carbon dioxide for pneumoperitoneum has fewer negative effects than hypothermic carbon dioxide on respiratory function tests results. Isothermic carbon dioxide may be preferable for patients with respiratory problems.     

Open versus laparoscopic cholecystectomy. A comparison of postoperative pulmonary function.

Upper abdominal surgery is associated with characteristic changes in pulmonary function which increase the risk of lower lobe atelectasis. Sixteen patients undergoing open cholecystectomy and 20 patients undergoing laparoscopic cholecystectomy were prospectively evaluated by pulmonary function tests (forced vital capacity [FVC], forced expiratory volume [FEV-1], and forced expiratory flow [FEF] 25% to 75%) before operation and on the morning after surgery to determine if the laparoscopic technique lessens the pulmonary risk. Fraction of the baseline pulmonary function was calculated by dividing the postoperative pulmonary function by the preoperative pulmonary function and multiplying by 100%. Postoperative FVC measured 52% of preoperative function for open cholecystectomy and 73% for laparoscopic cholecystectomy (p = 0.002). Postoperative FEV-1 measured 53% of baseline function for open cholecystectomy and 72% for laparoscopic cholecystectomy (p = 0.006). Postoperative FEF 25% to 75% measured 53% for open cholecystectomy and 81% for laparoscopic cholecystectomy (p = 0.07). It is concluded that laparoscopic cholecystectomy offers improved pulmonary function compared to the open technique.     

Postoperative spirometry after laparoscopy for lower abdominal or upper abdominal surgical procedures

In this prospective study, we have compared women undergoing laparoscopic cholecystectomy, laparoscopic gynaecological surgery and laparoscopic minor gynaecological procedures (diagnostic, tubal, ligation) (n = 10 in each group) to determine if lower abdominal laparoscopy results in less postoperative pulmonary dysfunction than upper abdominal laparoscopy. Pulmonary testing was performed before operation, and 3 and 6 h after operation, on the first and second days after surgery. After operation, a significant reduction in forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate occurred after laparoscopic cholecystectomy at each time. There were no significant changes after minor gynaecologic laparoscopy, whereas laparoscopic gynaecological surgery resulted in minor pulmonary dysfunction on the day of surgery only. We conclude that postoperative pulmonary function was less impaired after gynaecological laparoscopy than after laparoscopic cholecystectomy. This study suggests that the site of surgery is an important determinant of lung dysfunction after laparoscopy.      

Effect of paraesophageal hernia repair on pulmonary function

BACKGROUND: Paraesophageal hernias classically present in elderly patients with symptoms of postprandial pain, bloating, dysphagia, and anemia. Most surgeons would advocate repairing paraesophageal hernias whenever they are encountered, however, significant levels of dyspnea or pulmonary dysfunction could previously have led to concerns regarding individual patient suitability for repair. We have noted that patients complaining of dyspnea prior to paraesophageal hernia repair often noted significant improvement following surgery. METHODS: Between 1995 and 2001, 45 patients (mean age 71.5 years) presented with paraesophageal hernias. Patients had preoperative investigations including chest roentgenogram and barium swallow, 100%; upper endoscopy, 96%; manometry, 89%; and 24-hour pH studies, 27%. Operative repair was accomplished with an open Hill repair with intraoperative manometrics. All patients had assessment of pre- and postoperative spirometry, diffusion capacity, dyspnea index, and quality of life assessment. RESULTS: Presenting symptoms included dyspnea, 84%; heartburn, 71%; dysphagia, 67%; regurgitation, 64%; and anemia, 47%. Type II hernias were found in 2 patients, type III in 33 patients, and type IV in 10 patients. Complications were minimal; mortality was zero. Mean length of stay was 4.7 days (range 3 to 9). Significant improvement in spirometry levels were noted in mean forced expiratory volume in 1 second (FEV1) (preop, 1.87 liters; postop, 2.17 liters; percent improvement, 16%), p < 0.0001; mean forced vital capacity (FVC) (preop, 2.52 liters; postop, 2.89 liters; percent improvement, 14.7%), p < 0.0001; mean percent predicted FEV1 (preop, 75.8%; postop, 88.6%), p < 0.0001; and mean percent predicted FVC (preop, 78.8%; postop, 91.5%), p < 0.0001. An improvement trend was noted in diffusing capacity, which did not reach statistical significance. The degree of improvement was seen to correlate with the size of the hernia. When hernias involved 100% of the stomach, percent improvement in FEV1 of 19.6% and FVC of 19.7% were noted. Two patients who required home oxygen were able to discontinue therapy following surgery. Significant improvements in quality of life scores and dyspnea index were documented. CONCLUSIONS: Elderly patients with paraesophageal hernias are occasionally considered inappropriate candidates for surgical repair on the basis of coexistent medical problems including pulmonary dysfunction. Paraesophageal hernia repair is routinely associated with significant improvement in spirometry values, dyspnea index, and quality of life scores.     

Laparoscopic transperitoneal sublay mesh repair: a new technique for the cure of ventral and incisional hernias

Background

Incisional hernia is a frequent complication after abdominal surgery. Today open sublay mesh repair and the laparoscopic intraperitoneal onlay mesh repair are the most widely used techniques for its cure. We developed a laparoscopic transperitoneal sublay mesh repair for the treatment of small- and medium-size ventral and incisional hernias. Outcomes of the new technique and the Rives–Stoppa repair were compared.

Methods

This prospective cohort study with a control group involved 93 patients. Between 2008 and 2010, 43 patients underwent the laparoscopic transperitoneal sublay mesh repair. During the same period of time, a control group of 50 patients underwent an open sublay repair after Rives and Stoppa. In 2011, all patients were invited for follow-up. This included pain assessments and physical examinations with use of ultrasound.

Results

The two groups were comparable in terms of patient characteristics and hernia data. The operating time was slightly longer for the laparoscopic technique. The hospital stay was shorter in the laparoscopy group. There was less chronic pain in the laparoscopy group, but this difference was not statistically significant. There was no significant difference in postoperative complications, use of analgetics, foreign body sensation, and paresthesia between the two groups. We found one long-term hematoma in the laparoscopy group and one seroma in the open group. In this series, there were no recurrences and no wound infections.

Conclusions

Our initial results indicate that the new laparoscopic transperitoneal sublay mesh repair is a safe and effective method for the treatment of small- and medium-size ventral and incisional hernias.     

Gastroesophageal reflux as a cause of pulmonary dysfunction after lung transplantation

Gastroesophageal reflux is a potential cause of allograft dysfunction after lung transplantation due to microaspiration, lung inflammation, and development of bronchitis obliterans. A 16-year-old Japanese boy who had been suffering from interstitial lung disease received bilateral lung transplant from a braindead donor in the United States. Three months after lung transplantation, his lung function has not increased as expected. Spirometory revealed forced vital capacity (FVC) of 1.11 l (33% of predicted) and forced expiratory volume in one second (FEV1.0) of 0.81 l (28% of predicted). All possible etiologies, including infection, acute and chronic rejection, and other abnormalities were investigated. The only positive finding was the presence of gastroesophageal reflux. He first underwent pyroloplasty which did not improve lung function. Twenty-four-hour pH monitor performed after surgery revealed frequent gastroesophageal reflux. He eventually underwent laparoscopic fundoplication 9 months after initial lung transplantation. His lung function gradually improving after fundoplication, an FVC was 1.56 l (44% of predicted) and FEV1 was 1.25 l (33% of predicted).     

Long-term follow-up of pediatric open and laparoscopic inguinal hernia repair

BackgroundPediatric laparoscopic inguinal hernia repair is not widely accepted.Study designChildren 0–14 years who underwent inguinal hernia repair during 2010–2016 at Kaiser Permanente Northern California were classified into five groups: (1) open unilateral repair without contralateral exploration; (2) open unilateral repair with contralateral laparoscopic exploration (“open + explore”); (3) open bilateral repair; (4) laparoscopic unilateral repair; and (5) laparoscopic bilateral repair. Outcomes included ipsilateral reoperation, metachronous contralateral repair, incision time, and complications.ResultsThe study included 1697 children. Follow-up averaged 3.6 years after open (N = 1156) and 2.6 years after laparoscopic (N = 541) surgery. Metachronous contralateral repair was performed in 3.8% (26/683) of patients with open unilateral surgery without contralateral exploration, 0.7% (2/275) of open + explore patients, and 0.9% (3/336) of laparoscopic unilateral patients (p < 0.01). Ipsilateral repair was performed in 0.8% (10/1156) of open repairs and 0.3% (2/541) of laparoscopic repairs. Chart review confirmed 5 postoperative infections in 1156 patients with open surgery (0.43%) and 6 infections in 541 patients with laparoscopic surgery (1.11%) (p = 0.11).ConclusionOur study's laparoscopic and open approaches have similar low ipsilateral reoperation rates, incision times, and complications. The use of laparoscopy to visualize the contralateral side resulted in a significantly lower rate of metachronous contralateral repair.Level of evidenceLevel III.     

Thoracic epidural analgesia as an adjunct to general anaesthesia for cardiac surgery. Effects on pulmonary mechanics

BACKGROUND: A lasting impairment of pulmonary function is common after cardiac surgery. Pain from the sternotomy may contribute to the impairment. Thoracic epidural analgesia (TEA) can efficiently relieve pain in the postoperative phase, but may also affect respiratory muscle function if local anaesthetics are used. We examined the effects of TEA on pulmonary function and ventilation at rest, before and after coronary artery bypass graft surgery (CABG). METHODS: Thirty patients scheduled for CABG were randomized to receive either general anaesthesia alone or general anaesthesia with TEA. Before and after the operation the patients were examined by respiratory inductive plethysmography and spirometric tests. RESULTS: Before the operation, TEA caused significant reductions in forced vital capacity (FVC), forced expired volume in 1 s (FEV1), maximal inspiratory (PImax) and expiratory (PEmax) pressure. The rib cage contribution to tidal volume decreased significantly but the co-ordination of the thoracic and abdominal movements remained essentially unaffected. Minute volume and respiratory frequency did not change significantly. On the first postoperative day a decrease in maximal breathing efforts was found in both groups. No differences between the groups in FVC, FEV1 and PImax were found, but PEmax was significantly greater in the TEA group. Despite the impairment, breathing at rest was largely normal in both groups. CONCLUSIONS: A better pain-relief from TEA after CABG may improve the ability to cough by a greater expiratory muscle strength. FVC, FEV1, PImax and breathing at rest are not affected by TEA after cardiac surgery.     

Effect of breathing circuit resistance on the measurement of ventilatory function

BACKGROUND: The American Thoracic Society (ATS) has set the acceptable resistance for spirometers at less than 1.5 cm H2O/l/s over the flow range 0-14 l/s and for monitoring devices at less than 2.5 cm H2O/l/s (0-14 l/s). The aims of this study were to determine the resistance characteristics of commonly used spirometers and monitoring devices and the effect of resistance on ventilatory function. METHODS: The resistance of five spirometers (Vitalograph wedge bellows, Morgan rolling seal, Stead Wells water sealed, Fleisch pneumotachograph, Lilly pneumotachograph) and three monitoring devices (Spiro 1, Ferraris, mini-Wright) was measured from the back pressure developed over a range of known flows (1.6-13.1 l/s). Peak expiratory flow (PEF), forced expiratory flow in one second (FEV1), forced vital capacity (FVC), and mid forced expiratory flow (FEF25-75%) were measured on six subjects with normal lung function and 13 subjects with respiratory disorders using a pneumotachograph. Ventilatory function was then repeated with four different sized resistors (approximately 1-11 cmH2O/l/s) inserted between the mouthpiece and pneumotachograph. RESULTS: All five diagnostic spirometers and two of the three monitoring devices passed the ATS upper limit for resistance. PEF, FEV1 and FVC showed significant (p < 0.05) inverse correlations with added resistance with no significant difference between the normal and patient groups. At a resistance of 1.5 cm H2O/l/s the mean percentage falls (95% confidence interval) were: PEF 6.9% (5.4 to 8.3); FEV1 1.9% (1.0 to 2.8), and FVC 1.5% (0.8 to 2.3). CONCLUSIONS: The ATS resistance specification for diagnostic spirometers appears to be appropriate. However, the specification for monitoring devices may be too conservative. PEF was found to be the most sensitive index to added resistance.     

Forced expiratory indices in normal black southern African children aged 6-19 years.

Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory ratio (FEV1/FVC x 100), forced mid expiratory flow (FMF), and peak expiratory flow (PEF) were measured in 2000 non-smoking black African schoolchildren aged 6-19 years from Umtata in the Republic of Transkei in Southern Africa. FVC, FEV1, FMF, and PEF were highly correlated with each other and all were highly correlated with age and standing height in both sexes. There was a significant negative correlation between FEV1/FVC and both age and standing height. An increase in the slope of the increase in FVC for both age and height occurred at 11 years and 143 cm in girls and at 13 years and 150 cm in boys. This continued for about two years and 10 cm in both groups before it declined. The mean values of FEV1, FEV1/FVC, and PEF in the present study were 14% lower than those obtained in black American schoolchildren. The present study is the largest study of urban black African schoolchildren and provides useful reference values.