Acetaldehyde removal using an atmospheric non-thermal plasma combined with a packed bed: role of the adsorption process.

This work is an attempt in order to help towards understanding the influence of the adsorption process on the removal of a VOC (acetaldehyde, CH3CHO) using cyclic non thermal plasma (NTP) combined with a packed-bed of a catalyst support, α-Al2O3. In the first part, the results obtained by placing the saturated alumina pellets inside the plasma discharge zone are discussed, in terms of acetaldehyde removal, CO and CO2 production. In the second part, adsorption of CH3CHO, CO, CO2 and O3 was carried out, from single and multicomponent mixtures of the different compounds. The results showed that (i) the adsorption capacities followed the order CH3CHO≫ CO2>CO; (ii) O3 was decomposed on the alumina surface; (iii) CO oxidation occurred on the surface when O3 was present. In the third part, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to follow the alumina surface during acetaldehyde adsorption. DRIFTS measurements demonstrated that besides the bands of molecularly adsorbed acetaldehyde, several absorptions appeared on the spectra showing the intermediate surface transformation of acetaldehyde already at 300K. Finally, the relationship between the adsorption results and the NTP combined with a packed-bed process is discussed.

Heterogeneity of colon cancer patients reported as emergencies.

BACKGROUND: Up to one-fourth of all colon cancer patients are reported as emergencies, and the aim of the present study was to scrutinize mode of presentation in this group. MATERIALS AND METHODS: All reported cases of emergency (n = 263) and randomly selected elective controls (1:2) of colon cancer in four Swedish counties 2006-2008 were eligible (n = 854). Symptoms and aspects of management were retrieved from surgery and primary care records. Outcomes were compared using Kaplan-Meier estimates and Cox regression. RESULTS: Among patients reported as emergencies, 158/263 (60 %) underwent operation within three days (acute), and 105 (40 %) after more than 3 days (subacute). In the latter group, 20/94 (21 %) had reported two symptoms, and 31/94 (33 %) had reported three or more symptoms associated with colon cancer to primary care during the last 12 months prior to surgery. In total, 46/105 (44 %) had already had an examination of the large bowel, and 52/105 (50 %) were stage IV, as opposed to 36/158 (23 %) in the acute group and 83/577 (15 %) in the elective group (p < 0.001). Mortality at 30 and 90 days was 15.2 and 35.6 % in the subacute group, 8.2 and 14.9 % in the acute group (p = 0.001), and 1.9 and 4.3 % in the elective group (p < 0.001); 5-year survival was 28.3, 40.1, and 57.8 %, respectively, in the three groups (p < 0.001). The hazard ratio, adjusted for age, sex, and stage, was 1.88 95 % confidence interval (CI) 1.5-2.4) for the acute group and 2.29 (95 % CI 1.7-3.1) for the subacute group. CONCLUSIONS: Colon cancer patients reported as emergencies but operated upon more than three days after admission had the worst outcome. Efforts to decrease the interval between admission and surgery is one important aspect of care, but wider attention must also be paid to this group of patients.

Degree of specialisation of the surgeon influences lymph node yield after right-sided hemicolectomy.

AIM: To investigate the degree to which specialisation or case-load of the surgeon is associated with the number of lymph nodes isolated from pathology specimens after right-sided hemicolectomy. METHOD: Data from 6 hospitals with well-defined catchment areas included in the Uppsala/Örebro Regional Oncology Centre Colon Cancer Register 1997-2006 were used to assess 821 patients undergoing right-sided hemicolectomy for stages I-III colon cancer. Factors influencing the lymph node yield were evaluated. RESULTS: A surgeon with colorectal accreditation and a university pathology department were both associated with a significantly higher proportion of patients having 12 or more lymph nodes isolated from surgical specimens after right-sided hemicolectomy in both unadjusted and multivariate analyses. Emergency surgery did not affect the lymph node yield. CONCLUSION: The degree of specialisation of the surgeon influences the number of lymph nodes isolated from specimens obtained during routine right-sided colon cancer surgery.

Population-based data from the Swedish Colon Cancer Registry.

BACKGROUND: Evaluating the external validity of clinical trials requires knowledge not only of the study population but also of a relevant reference population. The main aim of this study was to present data from a large, contemporary, population-based cohort of patients with colonic cancer. METHODS: Data on patients diagnosed between 2007 and 2011 were extracted from the Swedish Colon Cancer Registry. The data, registered prospectively in a national population of almost 10 million, included over 99 per cent of all diagnosed adenocarcinomas of the colon. RESULTS: This analysis included 18,889 patients with 19,526 tumours (3·0 per cent had synchronous tumours). The sex distribution was fairly equal, and the median age was 74·1 (interquartile range 65-81) years. The overall and relative (cancer-specific) survival rates after 3 years were 62·7 and 71·4 per cent respectively. Some 88·0 per cent of the patients were operated on, and 83·8 per cent had tumours resected. Median blood loss during bowel resection was 200 (mean 311) ml, and the median operating time was 160 min; 5·6 per cent of the procedures were laparoscopic. Preoperative chemotherapy was administered to 2·1 per cent of patients; postoperative chemotherapy was planned in 90·1 per cent of fit patients aged less than 75 years with stage III disease. In patients operated on in an emergency setting (21·5 per cent), the preoperative evaluation was less extensive, the proportion of R0 resections was lower, and the outcomes were poorer, in both the short and long term. CONCLUSION: These population-based data represent good-quality reference points.

Surgeon and hospital-related risk factors in colorectal cancer surgery.

AIM: The aim of this study was to identify surgeon and hospital-related factors in a well-defined population-based cohort; the results of this study could possibly be used to improve outcome in colorectal cancer. METHOD: Data from the colonic (1997-2006) and rectal (1995-2006) cancer registers of the Uppsala/Örebro Regional Oncology Centre were used to assess 1697 patients with rectal and 2692 with colonic cancer. Putative risk factors and their impact on long-term survival were evaluated using the Cox proportional hazard model. RESULTS: The degree of specialization of the operating surgeon had no significant effect on long-term survival. When comparing the surgeons with the highest degree of specialization, noncolorectal surgeons demonstrated a slightly lower long-term survival for rectal cancer stage I and II (HR, 2.03; 95% CI, 1.05-3.92). Surgeons with a high case-load were not associated with better survival in any analysis model. Regional hospitals had a lower survival rate for rectal cancer stage III surgery (HR, 1.47; 95% CI, 1.08-2.00). CONCLUSION: Degree of specialization, surgeon case-load and hospital category could not be identified as important factors when determining outcome in colorectal cancer surgery in this study.

Risk factors for anastomotic leakage after rectal cancer surgery: a case-control study.

BACKGROUND: With introduction of the total mesorectal excision technique and preoperative radiotherapy in rectal cancer surgery, the local recurrence rate has decreased and the overall survival has improved. One drawback, however, is the high anastomotic leakage rate of approximately 10-18%. Male gender and low anastomoses are known risk factors for such leakage. The aim of this study was to identify potentially modifiable risk factors. METHOD: In a case-control study, data from the Swedish Rectal Cancer Registry (1995-2000) were analysed. Cases were all patients with anastomotic leakage after an anterior resection (n = 134). Two controls were randomly selected for each case. The medical records (n = 402) were checked against a study protocol. Due to incorrect recording two cases and 28 controls were excluded from further analyses. RESULTS: In the multivariate analysis significant risk factors were American Society of Anesthesiologists score > 2 [OR = 1.40 (95% CI 1.05-1.83)], preoperative radiotherapy [OR = 1.34 (95% CI 1.06-1.69)], intraoperative adverse events [OR = 1.85 (95% CI 1.32-2.58)], level of anastomosis

Cancer staging and survival in colon cancer is dependent on the quality of the pathologists' specimen examination.

Correct staging of colon cancer is decisive regarding further oncological treatment, surveillance and prediction of long-term survival. This study investigated the variability in accuracy of pathology reports with focus on differences between pathology departments and their compliance to regional guidelines. Data from the colon cancer register (1997-2002) of the Uppsala/Orebro, Sweden, health care region were analysed and the seven pathology departments in this region were compared. Included were 3735 patients who had undergone resection of a colon cancer. Cumulative 5-year survival was the main end-point. For 64% (n = 2390) of the cases, the number of lymph nodes examined was given (median 8). Survival in stage II was lower when fewer than 12 nodes were examined or when the number of nodes sampled was not given (P = 0.001, log-rank test). In stage III, those with at the most 3 nodes positive (N1) had a better survival than those with 4 or more nodes positive (N2) (P < 0.001, log-rank test). An index of metastases (IM), derived from the number of nodes with metastases divided by the number of nodes examined, was calculated for stage III tumours. Examination of 12 nodes is necessary to assure stage III cases with the median IM (0.32), whereas 20 nodes are necessary to assure 90% of cases with the lower quartile of IM (0.16). Irrespective of the number of nodes investigated, overall survival was better among patients with IM < 0.33 vs. IM > or = 33 (P < 0.001, log-rank test). The prognostic information of the IM was higher than that of the N-stage. Quality of a pathology department, measured by the median number of lymph nodes investigated and by the proportion of reports where the number is given, was determined to indicate correct staging and management of the patient. An index of metastases (IM) is a possible basis for guidance in the choice of adjuvant treatments that appears superior to that of N-stage.

Emergency surgery for colonic cancer in a defined population.

BACKGROUND: The aim of this study was to identify risk factors in emergency surgery for colonic cancer in a large population and to investigate the economic impact of such surgery. METHODS: Data from the colonic cancer registry (1997-2001) of the Uppsala/Orebro Regional Oncological Centre were analysed and classified by hospital category. Some 3259 patients were included; 806 had an emergency and 2453 an elective procedure. Data for calculating effects on health economy were derived from a national case-costing register. RESULTS: Patients who had emergency surgery had more advanced tumours and a lower survival rate than those who had an elective procedure (5-year survival rate 29.8 versus 52.4 per cent; P < 0.001). There was a stage-specific difference in survival, with poorer survival both for patients with stage I and II tumours and for those with stage III tumours after emergency compared with elective surgery (P < 0.001). Emergency surgery was associated with a longer hospital stay (mean 18.0 versus 10.0 days; P < 0.001) and higher costs (relative cost 1.5 (95 per cent confidence interval 1.4 to 1.6)) compared with elective surgery. The duration of hospital stay was the strongest determinant of cost (r(2) = 0.52, P < 0.001). CONCLUSION: Emergency surgery for colonic cancer is associated with a stage-specific increase in mortality rate.

Elective surgery for colorectal cancer in a defined Swedish population.

AIMS: The aim of this study was to describe variability in compliance to clinical guidelines in colorectal cancer surgery related to hospital structure. METHODS: All patients registered in the databases of the Regional Oncologic Centre, operated upon electively for colon cancer between the start of the register in 1997 until 2000 (n=1771) and for rectal cancer between the start of the register in 1995 until 2000 (n=1841) were selected for analysis. RESULTS: There was no difference in 5-year survival rate between colon and rectal cancer (mean follow-up 2.6 and 3.0 years, respectively; p=0.22). There was a significant difference in frequency of preoperative liver scan depending on hospital category with an increase in colon cancer from 39 to 46% (p=0.02) and in rectal cancer from 42 to 64% (p<0.001). For colon cancer there was no difference, according to hospital category, in quotient sigmoid and high anterior resection to left-sided resection. Furthermore, high anterior resection was more common at university and general district hospitals (8%) compared with district hospitals (4%) (p=0.01). Sphincter-saving surgery was more common at university hospitals and district general hospitals than at district hospitals (low anterior/abdomino-perineal resection quotients 2.3, 2.4 and 1.6, respectively; p<0.001). CONCLUSIONS: Population-based audit forms an appropriate and valuable basis for quality assurance projects. In addition to describing compliance to guidelines and pointing to process steps that can be improved, such investigations may also indicate changes due to scientific development. Linked to case-costing data, such results may form an important basis for decisions about modifications in health care.

Registration and validity of surgical complications in colorectal cancer surgery.

BACKGROUND: Population-based quality registers have become an important tool in quality assessment during the past decade. For registers to be reliable, however, data must be checked carefully for validity. METHODS: The present study describes the validity of surgical complications registered in a national register run by the National Board of Health and Welfare (NBH), a register run by Regional Oncological Centres (ROC) and, for comparison, a local quality assurance system at Uppsala University Hospital (UUH). A specialized, independent surgeon checked 10 per cent of patient records against datasheets from the registers. RESULTS: The local quality assurance system at UUH showed the best validity for surgical complications. Data for complications of colonic cancer surgery were more valid than those for rectal cancer surgery. Registration of serious complications was more valid than that of wound infections. The calculated proportion of missed surgical complications was 0.69, 0.64, 0.40, 0.22 and 0.07 for rectal and colonic cancer in the NBH register, rectal and colonic cancer in the ROC register, and the UUH register respectively. Corresponding figures for reoperation were 0.45, 0.48, 0.04, 0.09 and 0.21. CONCLUSION: Local interest and routine use of data for quality assurance are crucial factors for valid registers. Careful monitoring of validity is necessary for use of registry data in structured systems for improvement of surgical results.