Low-volume Group Research Articles

Evaluation of Low Tidal Volume During General Anesthesia in Prone Position on Respiratory Functions

<i>Background:</i> Surgery is accompanied by postoperative pulmonary functions impairment especially in the prone position. There is evidence suggested that using low tidal volume during general anesthesia may decrease post-operative lung injury. This study aimed to evaluate the effect of low tidal volume on lung functions during mechanical ventilation for general anesthesia while patients lying in the prone position. A prospective clinical trial was performed on 88 patients ASA I&II scheduled for elective surgery while patients lying prone and were randomly assigned to either protective ventilation group A with tidal volume; 5-7 ml/kg, 10 cm H₂O positive end expiratory pressure (PEEP) with recruitment maneuver (RM) or conventional group B with Tidal Volume; 10-12 ml/kg, without both PEEP and RM. The primary efficacy variables were assessed by pulmonary function tests, performed before surgery, and 6, 12 and 24 hours postoperatively. Improvement of lung functions were found in the first post-operative 6 and 12 hours in the low tidal volume group and significant difference was found in all parameters P value 0.001 except PaO₂/FIO₂ ratio P value 0.4. After 24 hours there were significant difference in the FVC, predicted FEV1 and FVC and FEV1/FVC ratio being higher in the low tidal volume group with P value 0.001. Patients in both groups showed similar rates of postoperative chest complications without significant difference. Lung protective ventilation improved lung functions in the first post-operative 24 hours. There was no significant postoperative chest complications difference between the two groups.

Low versus high volume of culture medium during embryo transfer: a randomized clinical trial.

The aim of this prospective randomized control trial was to evaluate if the use of two different volumes (20-25 vs 40-45μl) of media used for embryo transfer affects the clinical outcomes in fresh in vitro fertilization (IVF) cycles. In total, 236 patients were randomized in two groups, i.e., "low volume" group (n = 118) transferring the embryos with 20-25μl of medium and "high volume" group (n = 118) transferring the embryos with 40-45μl of medium. The clinical pregnancy, implantation, and ongoing pregnancy rates were compared between the two groups. No statistically significant differences were observed in clinical pregnancy (46.8 vs 54.3%, p = 0.27), implantation (23.7 vs 27.8%, p = 0.30), and ongoing pregnancy (33.3 vs 40.0%, p = 0.31) rates between low and high volume group, respectively. Higher volume of culture medium to load the embryo into the catheter during embryo transfer does not influence the clinical outcome in fresh IVF cycles. NCT03350646.

The influence of different semen volumes on pregnancy rates in unexplained infertility

Purpose: The purpose of this study was to determine the efficacy of low- and large-volume techniques of intrauterine insemination (IUI) on pregnancy rates in unexplained infertility couples. Materials and Methods: This retrospective study was performed in a single center over a 33-month period which included a total of 272 couples that underwent 272 IUI cycles that were divided into two groups. Low-volume group underwent 0.5 ml of inseminated semen; large-volume group underwent four ml of inseminated semen. The clinical pregnancy rates per cycle in each age group were evaluated. Results: In the large-volume group, clinical pregnancy rates were higher. In ≤ 34 age groups, clinical pregnancy rates were higher in large-volume group while in > 35 age group, clinical pregnancy rates were higher in low-volume group. Conclusion: This study clearly demonstrated the effectiveness of large-volume technique on IUI success in < 35 age women with unexplained infertility.

Is There a Role for Enterohormones in the Gastroparesis of Critically Ill Patients?

Delayed gastric emptying occurs in critically ill patients and impairs the delivery, digestion, and absorption of enteral feeding. A pathophysiologic role of the enterohormones peptide YY and ghrelin is supported by preclinical data. To compare the circulating plasma levels of peptide YY and ghrelin in control subjects and in critically ill patients, during feeding and fasting, and to search for a correlation with gastric emptying. A prospective observational trial. Mixed ICU of an academic hospital. Healthy volunteers and patients expected to stay in ICU for at least 3 days in whom enteral nutrition was indicated. None. Plasma peptide YY and ghrelin (enzyme-linked immunosorbent assay) were measured once in 10 fasting volunteers (controls) and daily from admission until day 5 of the ICU stay in 30 critically ill patients (median [interquartile range] age 63 [57-67] yr, median [interquartile range] Acute Physiology and Chronic Health Evaluation II score 21 [14-24]). Eight patients could not be fed (fasting group). In fed patients, 13 never had a gastric residual volume higher than 250 mL (low gastric residual volume group), in contrast to the high gastric residual volume group (n = 9). The plasma levels of peptide YY did not differ between patients (6.4 [0-18.1] pg/mL) and controls (4.8 [0.3-17.7] pg/mL). Ghrelin levels were lower in patients than in control (213 [54.4-522.7] vs 1,435 [1,321.9-1,869.3] pg/mL; p < 0.05). Plasma peptide YY or ghrelin did not differ between fasting and fed patients or between the high and low gastric residual volume groups. In critically ill patients, plasma concentration of ghrelin significantly differs from that of controls, irrespective of the feeding status. No correlation was found between the temporal profile of ghrelin or peptide YY plasma concentration with bedside functional assessment of gastric emptying.

Evaluation of I-125 Seed Migration After Prostate Brachytherapy

One of the risks of transperineal interstitial prostate brachytherapy is seed migration after treatment. Sometimes, seed migration cause serious side effects such as seed embolization which may cause organ ischemia. The purpose of this study is to evaluate the seed migration after brachytherapy at our facility and report on finding new predictors of seed migration. From May 2006 to April 2016, 320 patients were treated with permanent I-125 seed implantation, 202 patients were treated with brachytherapy alone and 118 patients were treated with brachytherapy combined with external beam radiotherapy. We used free seeds in all cases. We planned the prescription dose of brachytherapy alone was 145 Gy and that of brachytherapy combined with external beam radiotherapy was 104 Gy and 40 Gy (20 fraction / 4 weeks). The average age of patients was 66.2 years old (median 66 y, range 50 – 78 y). The average volume of prostate was 25.4 cc (median 24.5 cc, range 11.3 – 54.5 cc). The chest, abdominal, and pelvic radiographs were performed at 1st and 30th days after implantation (Day 1 and Day 30), and also pelvic CT was performed at Day 1 and Day 30 in each case. We investigated not only the location, the number, and the frequency of the migration, but as a new indicator of seed migration, we calculated “seed density” that was defined by the following formula: seed density = the number of Implanted seeds / prostate volume (cc). Seed migration was observed in 92 cases (28.8%) in 320 cases. The number of migration seeds was 144 out of 21876 (0.66%). In 16 cases (5.0%), seed migration was observed on day 1, and further seed dislocation was observed at Day 30. The numbers of migrated seeds located at lung region, abdominal/pelvic region, and other regions were 47 (32.6%), 89 (61.8%), and 8 (5.6%). Other sites included thigh, obturator muscle, spinal canal, kidney, and atrium. The average seed density was 2.8 (median 2.7, range 1.5 – 4.8). There was no significant difference in migration ratio by comparison for every 50 cases ( #1 – 50: 26% (13 of 50 cases), #51 – 100: 38% (19 of 50 cases), #101 – 150: 22% (11 of 50 cases), #151 – 200: 28% (14 of 50 cases), #201 – 251: 30% (15 of 50 cases), #251 – 300: 34% (17 of 50 cases), #301 – 320: 15% (3 of 20 cases)). And, there was no significant difference in migration ratio between high prostate volume group (≥ 25 cc, 34.0% (52 of 153 cases)) and low prostate volume group (< 25 cc, 24% (40 of 167 cases)). The migration ratio of high seed density group (≥ 3, 41.6% (37 of 89 cases)) was significantly higher than that of low seed density group (< 3, 23.8% (55 of 231 cases)) (p= 0.0073). The seed migration ratio after prostate brachytherapy at our institution was 28.8% (92 of 320 cases), which was comparable to previous reports. The migration ratio of high seed density group (density ≥ 3) was significantly higher than that of low seed density group (density < 3). This study showed that the seed density could be a new indicator of seed migration after prostate brachytherapy.

Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases

BackgroundHigh procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu nicompartmental knee arthroplasty in the Nordic countries.Methods14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI).ResultsThe implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups.ConclusionLow volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.

The Intensity of Postlaparoscopic Shoulder Pain Is Positively Correlated with the Amount of Residual Pneumoperitoneum

Study ObjectiveResidual carbon dioxide, which is inevitably retained in the abdominal cavity after laparoscopy, plays an important role in inducing postlaparoscopic shoulder pain (PLSP). The aim of this study was to determine the relationship between the volume of a residual pneumoperitoneum and the intensity of PLSP. DesignA prospective cohort study (Canadian Task Force classification II-2). SettingA university hospital. PatientsA total of 203 patients undergoing laparoscopy for nonmalignant gynecologic diseases. InterventionsGynecologic laparoscopy. Main Outcome MeasuresThe volume of the residual pneumoperitoneum was measured by performing chest radiography 24 hours after surgery. The pneumoperitoneum was graded as high volume (defined as ≥the median volume of the pneumoperitoneum) and low volume (defined as <the median volume). Perioperative data including PLSP intensity scores were collected. ResultsThe median volume of the residual pneumoperitoneum was 17.0 mL (0.5–133.8 mL). The intensity of PLSP was significantly higher in the high-volume group compared with the low-volume group (p < .001). A lower volume of the pneumoperitoneum was associated with less analgesic requirement (p = .032), a shorter hospitalization period (p = .007), and higher satisfaction from the surgery (p = .005). The residual gas volume and PLSP score exhibited a positive correlation that was statistically significant (r = 0.735, p < .001). ConclusionThe volume of the residual pneumoperitoneum was positively correlated with the intensity of shoulder pain after laparoscopy. Therefore, surgeons should release as much gas as possible from the peritoneal cavity at the end of laparoscopy.

Relationship between hospital volume and outcomes in patients with traumatic brain injury: A retrospective observational study using a national inpatient database in Japan

BackgroundThe relationship between hospital volume and outcome after traumatic brain injury (TBI) is not completely understood in a real clinical setting. We investigated whether patients admitted with TBI achieved better outcomes in high-volume hospitals than in low-volume hospitals using a national inpatient database in Japan. MethodsThis retrospective cohort study used the Diagnosis Combination Procedure database in Japan. We included patients with TBI admitted to hospitals with a Japan Coma Scale (JCS) score ≥2 between April 1, 2013 and March 31, 2014. Hospital volume was defined as the annual number of all admissions with TBI in individual hospitals. The hospital volume was categorized into four volume groups: low (≤60 admissions per hospital), medium-low (61–120 admissions per hospital), medium-high (121–180 admissions per hospital) and high (≥181 admissions per hospital). The outcomes of interest included 28-day mortality and survival discharge with complete dependency defined as a Barthel Index score of 0 at discharge. We used multivariate logistic regression models fitted with generalized estimating equations to evaluate relationships between the hospital volume and the outcomes. The hospital volume was evaluated both as categorical variables defined above and as continuous variables. ResultsThe analysis dataset consisted of 20,146 eligible patients. Of these, 2,784 died within 28days (13.8%) and 3,409 were completely dependent among 16,996 patients discharged alive (20.1%). Multivariate analyses found that there was no significant difference between the high-volume and low-volume groups for 28-day mortality (adjusted odds ratio [OR] 0.79, 95% confidence interval [CI] 0.58–1.06 for the high-volume group) or complete dependency at discharge (adjusted OR 0.94, 95% CI 0.71–1.23 for the high-volume group). The results were the same when the hospital volume was evaluated as a continuous variable. ConclusionsHospital volume did not appear to influence outcomes in patients with TBI. High-volume hospitals may not be necessarily beneficial for patients with TBI exhibiting impaired consciousness as a whole.

Effect of caudal block using different volumes of local anaesthetic on optic nerve sheath diameter in children: a prospective, randomized trial

Background:Caudal block is commonly administered for postoperative analgesia in children. Although caudal block with 1.5 ml kg−1 local anaesthetic has been reported to reduce cerebral oxygenation in infants, the effect of caudal block on intracranial pressure (ICP) in children has not been well investigated. Optic nerve sheath diameter (ONSD) correlates with degree of ICP. This study aimed to estimate the effects of caudal block on ICP according to volume of local anaesthetic using ultrasonographic measurement of ONSD in children. Methods:Eighty patients, 6- to 48-months-old, were randomly allocated to the high-volume (HV) or low-volume (LV) groups for caudal block with ropivacaine 0.15%, 1.5 ml kg−1 or 1.0 ml kg−1, respectively. Measurement of ONSD was performed before (T0), immediately after (T1), and 10 min (T2) and 30 min (T3) after caudal block. Results:The two groups exhibited significant differences in ONSD according to time (PGroup x Time=0.003). The HV group exhibited significantly greater changes in ONSD from T0 to T2 and T3 than the LV group. However, in both groups, ONSDs at T1, T2 and T3 were significantly greater compared with those at T0, with the highest values at T2. Conclusions:Caudal block with a high volume of local anaesthetic can cause a greater increase in ICP than caudal block with a low volume of local anaesthetic. However, caudal block with 1.0 ml kg−1 of local anaesthetic can also result in a significant increase in ICP. Clinical trial registrationNCT02768493.

Attenuation of the volume-outcome relationship for gastrointestinal cancer surgery over time: Is a push towards continued regionalization justified?

131 Background: Research demonstrating a volume-outcome relationship has resulted in regionalization of complex cancer surgery to high volume hospitals. A simultaneous national trend towards improved surgical outcomes brings into question whether the potential benefits of regionalization are still relevant. We hypothesize that the difference in adjusted post-operative mortality between low and high volume hospitals has decreased over time. Methods: The National Cancer Database (NCDB) was used to identify patients with colon, esophageal, and pancreatic cancer undergoing curative intent surgery from 2003-2011. Hospitals were divided into low ( &lt; 25th percentile), medium (25th-75th) and high ( &gt; 75thpercentile) volume groups depending on annual volume of cancer-specific surgery. Year-specific hospital averaged observed/expected (O/E) ratios were calculated for 90-day mortality. Poisson regression was used to model hospital averaged O/E ratios over time. Results: Our study population included 343,929 patients with colon (88%), esophageal (5%) and pancreatic (7%) cancer. There were significant (p &lt; 0.05) improvements in adjusted 90-day mortality from 2003 and 2011 for all volume categories and cancer types, except in high volume hospitals for esophageal cancer. In 2003, high volume hospitals had significantly better outcomes compared to low volume hospitals for all cancer types, as suggested by lower O/E ratios for 90 day mortality (p &lt; 0.05). However, by 2011 the difference in O/E ratios for 90 day mortality was no longer significantly lower for high compared to low volume hospitals (p &gt; 0.05); this was true for all three cancer types (Figure1). Conclusions: During the period of our study, 90-day mortality following gastrointestinal cancer surgery improved in low, medium and high volume hospitals. However, by 2011 the difference in adjusted post-operative mortality between low and high volume hospitals was not significantly different, likely due to global improvements in operative and peri-operative care. This attenuation of the volume-outcome curve has important implications for policy pertaining to regionalization of cancer care in the US.

Hospital characteristics and favourable neurological outcome among patients with out-of-hospital cardiac arrest in Osaka, Japan

ObjectiveTo assess the association between favourable neurological outcome and hospital characteristics such as hospital volume and number of critical care centres (CCMCs) after out-of-hospital cardiac arrest (OHCA). MethodsThis retrospective, population-based observational study conducted in Osaka Prefecture, Japan included adult patients with OHCA, aged ≥18 years who were transported to acute care hospitals between January 2005 and December 2012. We divided acute care hospitals into CCMCs or non-CCMCs, the latter of which were divided into the following three groups according to the annual average number of transported OHCA cases: low-volume (≤10 cases), middle-volume (11–39 cases), and high-volume (≥40 cases) groups. Random effects logistic regression models, with hospital treated as a random effect, were used to assess factors potentially associated with a favourable neurological outcome. ResultsA total of 44,474 patients were eligible. The proportions of favourable neurological outcome from OHCA were 0.9% (31/3559) in the low-volume group, 1.2% (106/9171) in the middle-volume group, 1.6% (222/14,007) in the high-volume group, and 4.3% (766/17,737) in the CCMC group (P<0.001). In the multivariable analysis, transport to CCMCs was significantly associated with favourable neurological outcome, compared with transport to non-CCMCs (adjusted odds ratio 1.63; 95% confidence interval, 1.60–1.66). Among the non-CCMC group, there was no significant relationship between hospital volume and favourable neurological outcome. ConclusionsIn this population, transport of OHCA patients to CCMCs led to significantly higher one-month survival rates with favourable neurological outcome from OHCA, whereas no significant association was noted among the hospitals with different volumes.

Low Tidal Volume Reduces Lung Inflammation Induced by Liquid Ventilation in Piglets With Severe Lung Injury.

Total liquid ventilation (TLV) is an alternative treatment for severe lung injury. High tidal volume is usually required for TLV to maintain adequate CO2 clearance. However, high tidal volume may cause alveolar barotrauma. We aim to investigate the effect of low tidal volume on pulmonary inflammation in piglets with lung injury and under TLV. After the establishment of acute lung injury model by infusing lipopolysaccharide, 12 piglets were randomly divided into two groups, TLV with high tidal volume (25 mL/kg) or with low tidal volume (6 mL/kg) for 240 min, respectively. Extracorporeal CO2 removal was applied in low tidal volume group to improve CO2 clearance and in high tidal volume group as sham control. Gas exchange and hemodynamic status were monitored every 30 min during TLV. At the end of the study, pulmonary mRNA expression and plasmatic concentration of interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured by collecting lung tissue and blood samples from piglets. Arterial blood pressure, PaO2 , and PaCO2 showed no remarkable difference between groups during the observation period. Compared with high tidal volume strategy, low tidal volume resulted in 76% reduction of minute volume and over 80% reduction in peak inspiratory pressure during TLV. In addition, low tidal volume significantly diminished pulmonary mRNA expression and plasmatic level of IL-6 and IL-8. We conclude that during TLV, low tidal volume reduces lung inflammation in piglets with acute lung injury without compromising gas exchange.

Hospital Volume and Mortality in Mechanically Ventilated Children: Analysis of a National Inpatient Database in Japan.

To evaluate the relationship between annual hospital volume of mechanical ventilation in children and mortality. A retrospective analysis. Japanese hospitals (n = 641) in the Japanese Diagnosis Procedure Combination database from July 2010 to March 2013. Patients 15 years old or younger receiving mechanical ventilation during hospitalization. None. A total of 26,981 mechanically ventilated pediatric patients were identified. They were categorized into four subgroups based on the quartiles of mean annual hospital volume of mechanical ventilation in children. Multivariable logistic regression analyses were performed to examine the effects of hospital volume on 30-day mortality, with adjustment for patient and hospital characteristics. Compared with the low volume group (≤ 34 per year), the odds ratios (95% CI) for 30-day mortality of low-medium (35-80), medium-high (81-165), and high (≥ 166) volume groups were 0.63 (0.50-0.79), 0.56 (0.42-0.74), and 0.57 (0.50-0.79), respectively. Subgroup analyses of surgical and nonsurgical patients showed similar trends. In mechanically ventilated pediatric patients divided by hospital volume quartiles, all three higher volume groups had lower mortality than the lowest volume group.

Prostate Cancer in Patients With High Prostate-Specific Antigen Levels but Otherwise Very-Low-Risk Disease Behaves Like Prostate Cancer in High-Risk Patients.

Rarely, patients with prostate cancer present with prostate-specific antigen (PSA) scores > 20 ng/mL but with otherwise very-low-risk disease. Oncologists have debated whether the malignancies in these patients behave more comparably to low-risk or high-risk disease. Our objective was to elucidate the behavior of these malignancies. A retrospective review was conducted of prostate cancer patients treated with radiation from 2000 to 2013. The inclusion criteria for very-low-risk disease included stage T1a-T1c, Gleason score≤6,≤ 3 positive cores,≤ 50% involvement of any core, and PSA level< 10 ng/mL. The divergent-risk group metall the same criteria but had a PSA score of 20 to 80 ng/mL. The high-grade, low-volume group consisted of patients with stage T1c-T2a, PSA level< 20 ng/mL, Gleason score of 4+4, and< 4 positive cores. Treatment failure was defined as a PSA nadir plus 2 ng/mL. A total of 18, 60, and 19 patients were in the divergent, low-risk, and high-grade groups, respectively. Biochemical progression-free survival at 5 years was 71.3% for the divergent group, 68.8% for the high-grade group, and 98.3% for the low-risk group. The biochemical failure rate for the divergent group differed significantly from the low-risk group (P= .021), and that for the low-risk group was significantly different from that of the high-grade group (P= .025). However, the divergent group did not appear different from the high-grade group (P= .53). The results of our study have shown that the disease prognosis for the divergent-risk group is worse than that for the very-low-risk disease group and does not appear to be different from that for the low-volume, high-grade disease group. Oncologists should be aware that the outcomes for divergent patients are similarly poor to their low-volume, classically high-risk counterparts.

Annual colonoscopy volume and maintenance of competency for surgeons.

To determine whether the annual case volume of general surgeons (greater or less than 200 colonoscopies) is associated with quality outcomes. This retrospective cohort study involved all adults who underwent colonoscopy by a surgeon in the city of St. John's, NL, during the first 6months of 2012. Subjects were identified through records from the health authority, and data were recorded on a standardized data sheet. Univariate analysis followed by stepwise multivariable logistic regression was performed to determine whether there was an association between quality outcomes (colonoscopy completion rate, adenoma detection rate) and predictors of these outcomes including annual colonoscopy volume, patient age, gender, indication for colonoscopy, and ASA score. A Chi-squared test was used to determine whether other outcomes were associated with annual colonoscopy volume. Data were collected on 1060 patients. Mean age was 59.5 (sd 12.2) years with 550 females. A total of 13 surgeons were studied, of which 7 performed less than 200 annual colonoscopies over the previous 2years (low-volume group) and 6 performed more than 200 annual colonoscopies over the previous 2years (high-volume group). While there was a significant difference in the colonoscopy completion rate favoring the high-volume group (82.2 vs. 91.1%, p<0.001), no difference was noted in the adenoma detection rate between groups (16.7 vs. 17.7%, p=0.762). The regression model revealed that colonoscopy completion was also associated with an indication of screening or surveillance and an ASA score of 1 or 2. The adenoma detection rate was associated with older age and male gender. There was no statistically significant association between annual colonoscopy volume and other safety outcome measures. Performing over 200 colonoscopies annually is associated with higher colonoscopy completion rates, but does not appear to be associated with other quality measures.

A meta-analysis of low tidal volume on the outcome of adult patients without acute respiratory distress syndrome

Objective: To evaluate the effects of tidal volume on the survival in adult patients without acute respiratory distress syndrome (non-ARDS). Methods: We searched relevant clinical randomized controlled trials (RCT) from January 2000 to December 2015. Meta analyses related to the effects of tidal volume on mortality in non-ARDS adults were conducted using the methods recommended by the Cochrane Collaboration. Results: A total of nineteen RCTs (n=1 679) were finally included. There were 838 patients ventilated with low tidal volume, and the other 841 patients ventilated with normal tidal volume. The mortality rates were not significantly different between low tidal volume group and control group (5.87% vs 6.52%; RR=0.9, P=0.58). But respiratory complications were significantly lower in low tidal volume group, such as development of acute respiratory distress syndrome(RR=0.32, 95% CI 0.16-0.63, P=0.001), pneumonia (RR=0.48, 95%CI 0.29-0.78, P=0.003), while the incidence of atelectasis was quite comparable between two groups (RR=0.78, 95%CI 0.391-1.356, P=0.48). Conclusion: Non-ARDS patients ventilated with low tidal volume is associated with a lower risk of pulmonary complications, yet clinical outcome, mainly mortality is similar to that of patients with regular tidal volume.

Effect of high-frequency oscillatory ventilation on inflammatory responses in lung tissues of dogs with severe acute respiratory distress syndrome

Objective To investigate the effect of high-frequency oscillatory ventilation(HFOV)on inflammatory responses in lung tissues of dogs with severe acute respiratory distress syndrome(ARDS). Methods Healthy mongrel dogs of both sexes, weighing 13.7-16.2 kg, in which severe ARDS was induced by intravenous infusion of the mixture of oleic acid 0.2 ml/kg and autologous blood(equal to the volume of oleic acid). Twenty-four dogs with severe ARDS were randomly divided into 4 groups(n=6 each)using a random number table: conventional mechanical ventilation with low tidal volume group(group CMV), HFOV-9 Hz group, HFOV-12 Hz group and HFOV-15 Hz group.In HFOV-9 Hz, HFOV-12 Hz and HFOV-15 Hz groups, the frequency was 9, 12, and 15 Hz, respectively, mean airway pressure 20 cmH2O, oscillation pressure 70 cmH2O, and inspired oxygen fraction ratio 1.0.In group CMV, the animals were mechanically ventilated in volume-controlled mode, with positive end-expiratory pressure 5 cmH2O, tidal volume 6 ml/kg, respiratory rate 30 breaths/min, inspiratory/expiratory ratio 1∶2, and inspired oxygen fraction ratio 1.0.At 4 h of ventilation, the animals were sacrificed, and lungs were removed for determination of wet/dry weight(W/D)ratio, contents of tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6)and IL-10(by enzyme-linked immunosorbent assay), and expression of vascular endothelial(VE)-Cadherin(by Western blot)and for microscopic examination.Lung injury scores were assessed. Results Compared with group CMV, the lung injury scores, W/D ratio, and contents of TNF-α and IL-6 were significantly decreased, the content of IL-10 was significantly increased, and the expression of VE-Cadherin was significantly up-regulated in the other three groups(P<0.05). Compared with group HFOV-9Hz, the lung injury scores, W/D ratio and contents of TNF-α and IL-6 were significantly decreased, the content of IL-10 was significantly increased, and the expression of VE-Cadherin was significantly up-regulated in group HFOV-15 Hz, and the content of IL-6 was significantly decreased in group HFOV-12 Hz(P<0.05). Conclusion HFOV can significantly inhibit inflammatory responses in lung tissues of dogs with severe ARDS as compared with mechanical ventilation with low tidal volume, which may be involved in the mechanism of lung-protective ventilation effect. Key words: Respiratory distress syndrome, adult; High-frequency ventilation; Inflammation

The Impact of Lung Ventilation on Some Cytokines after Coronary Artery Bypass Grafting.

Cardiopulmonary bypass induces a systematic inflammatory response, which is partly understood by investigation of peripheral blood cytokine levels alone; the lungs may interfere with the net cytokine concentration. We investigated whether lung ventilation influences lung passage of some cytokines after coronary artery bypass grafting. In total, 47 patients undergoing coronary artery bypass grafting were enrolled, and 37 were randomized according to the ventilation technique: (1) No-ventilation group, with intubation tube detached from the ventilator; (2) low tidal volume group, with continuous low tidal volume ventilation; and (3) continuous 10 cm H2O positive airway pressure. Ten selected patients undergoing surgery without cardiopulmonary bypass served as a referral group. Representative pulmonary and radial artery blood samples were collected for the evaluation of calculated lung passage (pulmonary/radial artery) of the pro-inflammatory cytokines (interleukin 6 and interleukin 8) and the anti-inflammatory interleukin 10 immediately after induction of anesthesia (T1), 1 h after restoring ventilation/return of flow in all grafts (T2), and 20 h after restoring ventilation/return of flow in all grafts (T3). Pulmonary/radial artery interleukin 6 and pulmonary/radial artery interleukin 8 ratios ( p = 0.001 and p = 0.05, respectively) decreased, while pulmonary/radial artery interleukin 10 ratio ( p = 0.001) increased in patients without cardiopulmonary bypass as compared with patients with cardiopulmonary bypass. The pulmonary/radial artery equation is an innovative means for the evaluation of cytokine lung passage after coronary artery bypass grafting. The mode of lung ventilation has no impact on some cytokines after coronary artery bypass grafting in patients treated with cardiopulmonary bypass.

Clinical Experience amongst Surgeons in the Asymptomatic Carotid Surgery Trial-1

Introduction: Hospital volume may influence the outcomes of carotid revascularization, but in trials the effect of the clinical experience of individual surgeons on procedural outcome is less certain. We assessed perioperative event rates amongst centers with different trial entry volumes and also the effects of individual operator experience in the first Asymptomatic Carotid Surgery Trial-1 (ACST-1). Methods: In 126 centers participating in ACST-1, surgeons were classified according to their in-trial experience (group A: 50 cases; group B: 51-100 cases; group C: >100 cases), center enrolment volume (group I: <30 patients; group II: 30-75 patients; group III: >75 patients) and center annual hospital volume (group 1: <40 carotid endarterectomies (CEAs); group 2: 40-75 CEAs; group 3: >75 cases). Differences in perioperative event rates were compared using logistic regression analysis. Results: In centers with the most clinical experience compared with those with least experience (groups C vs. A), the number of strokes or deaths was 8 of 275 (2.9%) versus 24 of 810 (3.0%) with OR 0.99 (95% CI 0.44-2.25, p = 0.986). Numbers of strokes or death in high enrolment centers compared with those in low enrolment centers (groups III vs. I) was 20 of 680 (2.9%) versus 21 of 580 (3.6%) with OR 0.81 (95% CI 0.43-1.51, p = 0.921). In centers with a high annual volume compared with those of low annual volume (groups 3 vs. 1), numbers of strokes and death were non-significantly lower, 26 of 823 (3.2%) versus 19 of 422 (4.5%) with OR 0.68 (95% CI 0.37-1.26, p = 0.386). Cumulative stroke risk at 5 and 10 years were similar among different levels of reported clinical experience, enrolment volume and annual hospital volume. Conclusion: Although our data did not demonstrate an association between perioperative complications and operators' experience, enrolment volume or annual hospital volume, rates of stroke or death were numerically lower in both high enrolment and high annual volume centers. This lack of association could be explained by an overall low procedural risk in ACST-1.

Clinical and histopathological results of the adult patients with unilateral cryptorchidism.

To evaluate the clinical and histopathological results of adult unilateral cryptorchidism patients. Data from adult unilateral cryptorchidism patients that underwent orchiectomy in our clinic between between January 2004 and March 2013 were retrospectively evaluated. Patients were divided into three groups as intra-abdominal, inguinal canal and superficial inguinal region according to the location of the undescended testes. Patients were also grouped according to their testicular volume (<4 cc, 4.1-12 cc, and >12 cc). Histopathology results of orchiectomy specimens were classified as follows: 1. Sertoli cells only, testicular atrophy and vanished testis (anorchia) 2. Hypospermatogenesis, and 3. Maturation arrest. Patients were grouped as normospermia, azoospermia and oligo/astheno/teratospermia groups according to semen analysis results. Correlations between testicular localization, testicular size, semen analysis and pathology results were evaluated. Incidental tumor detection rates were also calculated. Two hundred and forty-four adult unilateral cryptorchidism patients underwent orchiectomy in our clinic. There was no a significant relationship between location of the testis and testicular pathology results (p=0.707). Most common semen analysis results was normospermia in patients with high testicular volume group however azoospermia and oligoasthenospermia observed commonly in patients with low testicular volume group. There was a significant relationship between testicular volume and semen analysis results (p=0.023). No significant relationship was observed between semen analysis and pathological results (p=0.929). After an evaluation of all factors with possible effects on the semen analysis results, only testicular volume (p=0.036) was found to have a significant impact. Only one case (0.4%) was incidentally diagnosed seminoma after a review of 233 patients with available histopathological results on record. Adult unilateral cryptorchidism has a minimal effect on male fertility or even this effect can be overlooked. Low detection rates of incidental germ cell tumors also make an orchiectomy decision questionable in such cases.