It is unclear how positive end-expiratory pressure (PEEP) and recruitment maneuvers impact patients during one-lung ventilation (OLV). We conducted a systematic review and meta-analysis of the effect ...of lung recruitment and PEEP on ventilation and oxygenation during OLV.
A systematic review and random-effects meta-analysis were performed. Mean difference with standard deviation was calculated. Included studies were evaluated for quality and risk of bias using the Cochrane Risk of Bias tool and the modified Newcastle-Ottawa Score where appropriate.
In total, 926 articles were identified, of which 16 were included in meta-analysis. Recruitment maneuvers increased arterial oxygen tension (PaO2) by 82 mm Hg 20, 144 mm Hg and reduced dead-space by 5.9% 3.8, 8.0%. PEEP increased PaO2 by 30.3 mm Hg 11.9, 48.6 mm Hg. Subgroup analysis showed a significant increase in PaO2 (P = .0003; +35.4 mm Hg 16.2, 54.5 mm Hg) with PEEP compared with no PEEP but no such difference in comparisons with PEEP-treated controls. No significant difference in PaO2 was observed between “high” and “low” PEEP-treated subgroups (P = .29). No significant improvement in PaO2 was observed for subgroups coadministered PEEP, lung recruitment, and low tidal volumes. PEEP was associated with a modest but statistically significant increase in compliance (P = .03; 4.33 mL/cmH2O 0.33, 8.32). High risk of bias was identified in the majority of studies. Considerable heterogeneity was observed.
Recruitment maneuvers and PEEP have physiologic advantages during OLV. The optimal use of PEEP is yet to be determined. The evidence is limited by heavy use of surrogate outcomes. Future studies with clinical outcomes are necessary to determine the impact of recruitment maneuvers and PEEP during OLV.
A systematic literature search of lung-protective ventilation strategies for one-lung ventilation identified 926 articles, of which 16 were selected for meta-analysis. Lung recruitment was evaluated in 5 studies, with significant improvements in PaO2 by 82 mm Hg and significant reductions in Vd/Vt by 5.9%. PEEP was evaluated in 12 studies, finding a significant improvement in PaO2 by 30 mm Hg. The evidence is unclear regarding the optimal selection of PEEP. Despite evidence of improvement in physiologic outcomes with recruitment and PEEP, clinical outcomes were notably absent in all included studies. This article should cautiously inform one-lung ventilation practices and encourage further research with patient-important outcomes. PaO2, Arterial oxygen tension; PEEP, positive end-expiratory pressure; Vd/Vt, dead-space fraction. Display omitted
The hysteroscopic approach to the correction of congenital anomalies in utero may be helped by the temporary introduction of clear, electrically neutral fluids (liquids or gases) into the amniotic ...cavity. Accordingly, the authors determined the effects of three candidate fluids (helium, carbon dioxide, and water) on the oxygenation, acid-base balance, electrolyte concentrations, and hemodynamic function of nine sheep fetuses at 120 days' gestation (full term 145 days). Each fetus was exposed, in random order, to each of the three fluids, at an intraamniotic pressure of 15 mm Hg. The authors found that helium produced no changes in any of the measurements and was well tolerated by the fetus and the mother. Carbon dioxide decreased fetal arterial pH, and increased both arterial P
co
2 and P
o
2. Although the decrease in pH was explained entirely by the increase in P
co
2, the increase in arterial P
o
2 may have resulted from vasodilatation of the placental circulation or vasoconstriction of the fetal circulation with a redistribution of blood flow to the placenta. Water caused mild fetal hyponatremia and hypochloremia, without significant changes in acid-base balance or oxygenation. The results suggest that both helium and water may represent viable alternatives for amniotic fluid replacement during hysteroscopic surgery.
The objective of this study was to describe recent trends in the management of mild-to-moderate gallstone pancreatitis and assess patient outcomes. Acute gallstone pancreatitis has traditionally been ...managed with open cholecystectomy and intraoperative cholangiography during the initial hospitalization. The popularization of endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic cholecystectomy has made a reassessment necessary. Two consecutive time periods were retrospectively analyzed: prior to laparoscopic cholecystectomy (prelaparoscopic era PLE) and after the diffusion of laparoscopic cholecystectomy (laparoscopic cholectomy era LCE). There were 35 patients in the PLE group and 58 in the LCE group. LCE patients waited 37.1 +63 days from admission until cholecystectomy, compared to 9.8 +14.8 days in the PLE group (P = 0.04). Biliary-pancreatic complications occurred in 24% of LCE patients and only 6% of PLE patients (P = 0.05), nearly always while they were awaiting cholecystectomy (P = 0.009). Patients in either time period who underwent cholecystectomy with intraoperative cholangiography developed less pancreatic-biliary complications than those who underwent ERCP prior to cholecystectomy, with or without sphincterotomy. Delaying the interval from pancreatitis to laparoscopic cholecystectomy beyond historical values is associated with a greater risk of recurrent biliary-pancreatic complications, which are not prevented by the use of ERCE Early cholecystectomy with intraoperative ductal evaluation is still the approach of choice.PUBLICATION ABSTRACT
Submucosal Collagen in Experimental Gastroschisis Srinathan, Sadeesh K.; Langer, Jacob C.; Botney, Mitchell D. ...
The Journal of surgical research,
09/1996, Letnik:
65, Številka:
1
Journal Article
Recenzirano
Gastroschisis is a congenital anomaly in which the intestines are exposed to amniotic fluid throughout fetal life. Previous studies in animal models have demonstrated smooth muscle thickening and ...decreased contractility, epithelial dysfunction, and submucosal thickening. The present studies were done to further define the mechanism of submucosal changes by investigating collagen deposition and gene expression in a rabbit model. Gastroschisis was surgically created in fetal rabbits at 24 days gestation (term is 31 days). Sham-operated and unoperated fetuses served as controls. Fetuses were sacrificed and bowels were harvested at 26, 28, and 31 days gestation. Animal weight and gross and histologic appearance were assessed. Submucosal collagen content was measured using the van Geison stain.In situhybridization of the expression of alpha (1) procollagen RNA was done to determine the distribution and source of submucosal collagen. At term, submucosal thickening was present in animals with gastroschisis, associated with a significantly increased collagen content. Collagen distribution was also more diffuse in the gastroschisis animals than in controls.In situhybridization revealed procollagen expression in round cells located in the submucosa and not in smooth muscle. These cells did not resemble fibroblasts, and their identity is uncertain. Experimental gastroschisis is characterized by submucosal thickening which is associated with changes in collagen, including increased deposition and more diffuse distribution in the submucosa. The cells responsible for production of procollagen are round, nonfibroblast cells which are located in the submucosa and not in the smooth muscle layer. These findings may have some importance in understanding the mechanisms responsible for intestinal malfunction in infants with gastroschisis.
The selection of tidal volumes for 1-lung ventilation remains unclear, because there exists a trade-off between oxygenation and risk of lung injury. We conducted a systematic review and meta-analysis ...to determine how oxygenation, compliance, and clinical outcomes are affected by tidal volume during 1-lung ventilation.
A systematic search of MEDLINE and EMBASE was performed. A systematic review and random-effects meta-analysis was conducted. Pooled mean difference estimated arterial oxygen tension, compliance, and length of stay; pooled odds ratio was calculated for composite postoperative pulmonary complications. Risk of bias was determined using the Cochrane risk of bias and Newcastle-Ottawa tools.
Eighteen studies were identified, comprising 3693 total patients. Low tidal volumes (5.6 ±0.9 mL/kg) were not associated with significant differences in partial pressure of oxygen (−15.64 −88.53-57.26 mm Hg; P = .67), arterial oxygen tension to fractional intake of oxygen ratio (14.71 −7.83-37.24; P = .20), or compliance (2.03 −5.22-9.27 mL/cmH2O; P = .58) versus conventional tidal volume ventilation (8.1 ±3.1 mL/kg). Low versus conventional tidal volume ventilation had no significant impact on hospital length of stay (−0.42 −1.60-0.77 days; P = .49). Low tidal volumes are associated with significantly decreased odds of pulmonary complications (pooled odds ratio, 0.40 0.29-0.57; P < .0001).
Low tidal volumes during 1-lung ventilation do not worsen oxygenation or compliance. A low tidal volume ventilation strategy during 1-lung ventilation was associated with a significant reduction in postoperative pulmonary complications.
This systematic review and meta-analysis of 18 studies, comprising 3693 total patients, was performed to determine how oxygenation, compliance, and clinical outcomes are affected by tidal volume during 1-lung ventilation. Low tidal volumes during 1-lung ventilation do not worsen oxygenation or compliance. A low tidal volume ventilation strategy during 1-lung ventilation was associated with a significant reduction in postoperative pulmonary complications. Display omitted
Preliminary data suggest that preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) may improve risk prediction in patients undergoing noncardiac surgery.
To determine whether ...preoperative NT-proBNP has additional predictive value beyond a clinical risk score for the composite of vascular death and myocardial injury after noncardiac surgery (MINS) within 30 days after surgery.
Prospective cohort study.
16 hospitals in 9 countries.
10 402 patients aged 45 years or older having inpatient noncardiac surgery.
All patients had NT-proBNP levels measured before surgery and troponin T levels measured daily for up to 3 days after surgery.
In multivariable analyses, compared with preoperative NT-proBNP values less than 100 pg/mL (the reference group), those of 100 to less than 200 pg/mL, 200 to less than 1500 pg/mL, and 1500 pg/mL or greater were associated with adjusted hazard ratios of 2.27 (95% CI, 1.90 to 2.70), 3.63 (CI, 3.13 to 4.21), and 5.82 (CI, 4.81 to 7.05) and corresponding incidences of the primary outcome of 12.3% (226 of 1843), 20.8% (542 of 2608), and 37.5% (223 of 595), respectively. Adding NT-proBNP thresholds to clinical stratification (that is, the Revised Cardiac Risk Index RCRI) resulted in a net absolute reclassification improvement of 258 per 1000 patients. Preoperative NT-proBNP values were also statistically significantly associated with 30-day all-cause mortality (less than 100 pg/mL incidence, 0.3%, 100 to less than 200 pg/mL incidence, 0.7%, 200 to less than 1500 pg/mL incidence, 1.4%, and 1500 pg/mL or greater incidence, 4.0%).
External validation of the identified NT-proBNP thresholds in other cohorts would reinforce our findings.
Preoperative NT-proBNP is strongly associated with vascular death and MINS within 30 days after noncardiac surgery and improves cardiac risk prediction in addition to the RCRI.
Canadian Institutes of Health Research.
Of the 200 million adults worldwide who undergo noncardiac surgery each year, more than 1 million will die within 30 days.
To determine the relationship between the peak fourth-generation troponin T ...(TnT) measurement in the first 3 days after noncardiac surgery and 30-day mortality.
A prospective, international cohort study that enrolled patients from August 6, 2007, to January 11, 2011. Eligible patients were aged 45 years and older and required at least an overnight hospital admission after having noncardiac surgery.
Patients' TnT levels were measured 6 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We undertook Cox regression analysis in which the dependent variable was mortality until 30 days after surgery, and the independent variables included 24 preoperative variables. We repeated this analysis, adding the peak TnT measurement during the first 3 postoperative days as an independent variable and used a minimum P value approach to determine if there were TnT thresholds that independently altered patients' risk of death.
A total of 15,133 patients were included in this study. The 30-day mortality rate was 1.9% (95% CI, 1.7%-2.1%). Multivariable analysis demonstrated that peak TnT values of at least 0.02 ng/mL, occurring in 11.6% of patients, were associated with higher 30-day mortality compared with the reference group (peak TnT ≤ 0.01 ng/mL): peak TnT of 0.02 ng/mL (adjusted hazard ratio aHR, 2.41; 95% CI, 1.33-3.77); 0.03 to 0.29 ng/mL (aHR, 5.00; 95% CI, 3.72-6.76); and 0.30 ng/mL or greater (aHR, 10.48; 95% CI, 6.25-16.62). Patients with a peak TnT value of 0.01 ng/mL or less, 0.02, 0.03-0.29, and 0.30 or greater had 30-day mortality rates of 1.0%, 4.0%, 9.3%, and 16.9%, respectively. Peak TnT measurement added incremental prognostic value to discriminate those likely to die within 30 days for the model with peak TnT measurement vs without (C index = 0.85 vs 0.81; difference, 0.4; 95% CI, 0.2-0.5; P < .001 for difference between C index values). The net reclassification improvement with TnT was 25.0% (P < .001).
Among patients undergoing noncardiac surgery, the peak postoperative TnT measurement during the first 3 days after surgery was significantly associated with 30-day mortality.
Troponin elevation after noncardiac surgery is associated with an elevated risk of 30-day mortality. Little is known about relative merit of using a high-sensitivity Troponin T (hsTnT), the ...fifth-generation assay, vs the nonhigh sensitivity Troponin T (non-hsTnT), the fourth-generation assay, in the noncardiac surgery setting. We aimed to identify whether hsTnT can identify additional patients at risk that would have gone undetected with non-hsTnT measurement.
The VISION Study included 40,004 noncardiac surgery patients with postoperative troponin measurements. Among them, 1,806 patients had both fourth-generation non-hsTnT and fifth-generation hsTnT concomitant measurements (4,451 paired results). We compared the absolute concentrations, the timing, and the impact of different thresholds on predicting 30-day major cardiovascular complications (composite of death, nonfatal cardiac arrest, coronary revascularization, and congestive heart failure).
Based on the manufacturers’ threshold of 14 ng/L, 580 (32.1%) patients had postoperative hsTnT concentrations greater than the threshold, while their non-hsTnT concentrations were below the manufacturer's threshold. These 580 patients had higher risk of major cardiovascular events (OR 2.33; CI 95% 1.04-5.23; P = .049) than patients with hsTnT concentrations below the manufacturer threshold. Among patients with myocardial injury after noncardiac surgery, only 50% would be detected by the fourth-generation non-hsTnT assay at 6 to 12 hours postoperative as compared to 85% with the fifth-generation hsTnT assay (P-value < .001).
Within the first 3 postoperative days, fifth-generation hsTnT identified at least 1 in 3 patients with troponin elevation that would have gone undetected by fourth-generation non-hsTnT using published thresholds in this setting. Furthermore, fifth-generation hsTnT identified patients with an elevation earlier than fourth-generation non-hsTnT, indicating potential to improve postoperative risk stratification.
Several investigators have reported good results after a one-stage Soave procedure without a stoma for infants with Hirschsprung's disease. The authors reviewed their concurrent experience with the ...one- and two-stage approaches, comparing the two groups with respect to rate of complications and clinical outcome. Over a 3-year period, 36 infants with colonic Hirschsprung's disease presenting in the first year of life were treated with a Soave pull-through. Thirteen had a one-stage pull-through, and 23 had a two-stage procedure using an initial stoma. There was no difference with respect to median age at time of diagnosis, median follow-up period, length of aganglionosis, or male:female ratio between the groups. The incidences of major complications such as small bowel obstruction, segmental or acquired aganglionosis, anastomotic leak, and malabsorption were equal between the two groups. However, 13% of the two-stage patients required revision of the stoma. All major complications in the one-stage group were in those who weighed less than 4 kg at the time of surgery. Minor complications such as wound infection, perianal excoriation, and need for repeated dilatation were similar between the groups, but minor stoma-related complications (prolapse or retraction) occurred in 26% of the two-stage infants. When complications were stratified using a more sophisticated scale of severity, no significcant difference was found between the groups. The overall complication rate was 1.5 events per patient in the one-stage group and 2.0 events per patient in the two-stage group. This small difference was related to the presence of a stoma in the two-stage group. Overall, 10 of 12 survivors in the one-stage group and 22 of 23 in the two-stage group were doing well, with normal bowel function noted on long-term follow-up (mean period, of 14 and 19 months, respectively). Both one- and two-stage approaches were associated with a significant complication rate, although long-term outcome was excellent in both groups. The higher complication rate in the two-stage group was attributable to the presence of a stoma. For small infants, it may be beneficial to delay the one-stage pull-through until weight exceeds 4 kg.
The association between growth differentiation factor-15 concentrations and cardiovascular disease has been well described. The study hypothesis was that growth differentiation factor-15 may help ...cardiac risk stratification in noncardiac surgical patients, in addition to clinical evaluation.
The objective of the study was to determine whether preoperative serum growth differentiation factor-15 is associated with the composite primary outcome of myocardial injury after noncardiac surgery and vascular death at 30 days and can improve cardiac risk prediction in noncardiac surgery. This is a prospective cohort study of patients 45 yr or older having major noncardiac surgery. The association between preoperative growth differentiation factor-15 and the primary outcome was determined after adjusting for the Revised Cardiac Risk Index. Preoperative N-terminal-pro hormone brain natriuretic peptide was also added to compare predictive performance with growth differentiation factor-15.
Between October 27, 2008, and October 30, 2013, a total of 5,238 patients were included who had preoperative growth differentiation factor-15 measured (median, 1,325; interquartile range, 880 to 2,132 pg/ml). The risk of myocardial injury after noncardiac surgery and vascular death was 99 of 1,705 (5.8%) for growth differentiation factor-15 less than 1,000 pg/ml, 161 of 1,332 (12.1%) for growth differentiation factor-15 1,000 to less than 1,500 pg/ml, 302 of 1476 (20.5%) for growth differentiation factor-15 1,500 to less than 3,000 pg/ml, and 247 of 725 (34.1%) for growth differentiation factor-15 concentrations 3,000 pg/ml or greater. Compared to patients who had growth differentiation factor-15 concentrations less than 1,000 pg/ml, the corresponding adjusted hazard ratio for each growth differentiation factor-15 category was 1.93 (95% CI, 1.50 to 2.48), 3.04 (95% CI, 2.41 to 3.84), and 4.8 (95% CI, 3.76 to 6.14), respectively. The addition of growth differentiation factor-15 improved cardiac risk classification by 30.1% (301 per 1,000 patients) compared to Revised Cardiac Risk Index alone. It also provided additional risk classification beyond the combination of preoperative N-terminal-pro hormone brain natriuretic peptide and Revised Cardiac Risk Index (16.1%; 161 per 1,000 patients).
Growth differentiation factor-15 is strongly associated with 30-day risk of major cardiovascular events and significantly improved cardiac risk prediction in patients undergoing noncardiac surgery.
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