Chris Snowden

Randomized clinical trial assessing the effect of Doppler-optimized fluid management on outcome after elective colorectal resection

Protocolized fluid administration using oesophageal Doppler monitoring may improve the postoperative outcome in patients undergoing surgery.

Submaximal cardiopulmonary exercise testing predicts complications and hospital length of stay in patients undergoing major elective surgery.

Objective:To investigate the null hypothesis that an objective, noninvasive technique of measuring cardiorespiratory reserve, does not improve the preoperative assessment of patient risk of postoperative complications, when compared with a standard questionnaire-based assessment of functional capacity. Summary Background Data:Postoperative complications may be increased in patients with reduced cardiorespiratory function. Activity questionnaires are subjective, whereas cardiopulmonary exercise testing (CPET) provides an objective definition of cardiorespiratory reserve. The use of preoperative CPET to predict postoperative complications is not fully defined. Method:CPET and an algorithm-based activity assessment (Veterans Activity Questionnaire Index [VASI]) were performed on consecutive patients (n = 171) with low subjective functional capacity (metabolic equivalent score [METS] < 7), being assessed for major surgery. A morbidity survey determined postoperative day 7 complications. Logistic regression defined independent predictors of complication group. Receiver-operating curve (ROC) analysis defined the predictive value of CPET to outcome. P < 0.05 value demonstrated significance. Results:Objective cardiorespiratory reserve did not differ between operated (n = 116) and nonoperated patients (n = 55). Median complication rate on postoperative day 7 was 1. Patients with >1 complication had an increase in hospital LOS compared to the group with ≤1 complication (26 vs. 10 days; P < 0.001). Anaerobic threshold (AT) was higher in the group with ≤1 complication (11.9 vs. 9.1 mL/kg/min; P = 0.001) and demonstrated high accuracy (AUC = 0.85), sensitivity (88%), and specificity (79%), at an optimum AT of 10.1 mL/kg/min (defined by the furthest left point on the ROC curve). AT, VASI, and surgical reintervention were independent predictors of complication group. Preoperative AT significantly improved outcome prediction when compared with the use of VASI alone. Conclusion:An objective measure of cardiorespiratory reserve was an independent predictor of a major surgical group with increased postoperative complications and hospital LOS. AT measurement significantly improved outcome prediction compared with an algorithm-based activity assessment.

The trouble with kidneys derived from the non heart-beating donor: a single center 10-year experience.

BACKGROUND The demand for renal transplantation has increasingly outstripped the supply of donor organs especially over the past 10 years. Although related and unrelated live donation is being promoted as one option for increasing the donor pool, it is unlikely that this will in itself be able to bridge the gap. Non-heart beating donors (NHBD) can provide an alternative supply of organs, which should substantially increase the donor pool. METHODS In Newcastle, NHBD kidneys have been used for transplantation for a period of 10 years. In the early period (1988-1993) excellent results were obtained (90.5% success); however, these donors were controlled NHBD, Maastricht category III. In the second phase (1994-1998) increasing numbers of donors were obtained from the Accident and Emergency Department unit. These were failed resuscitation for cardiac arrest (category II). The rates of success in this period were poor (45.5% success) and the program was halted. The third phase of the program used machine perfusion of the kidneys and glutathione S transferase enzyme analysis to assess viability. RESULTS Using such approaches renal transplants from largely category II donors produced a success rate of 92.3% which was significantly better than the phase II period of the program (P=0.023, Fisher two-tail test). CONCLUSION Machine perfusion and viability assessment of NHB kidneys in phase III of the program has increased our donor pool as well as improved the graft survival. This is particularly relevant for the use of the category II NHB donor where the incidence of primary nonfunction was high, illustrated by phase II where machine perfusion/viability assessment was not used.

Guidelines for Perioperative Care for Liver Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations

BackgroundEnhanced Recovery After Surgery (ERAS) is a multimodal pathway developed to overcome the deleterious effect of perioperative stress after major surgery. In colorectal surgery, ERAS pathways reduced perioperative morbidity, hospital stay and costs. Similar concept should be applied for liver surgery. This study presents the specific ERAS Society recommendations for liver surgery based on the best available evidence and on expert consensus.MethodsA systematic review was performed on ERAS for liver surgery by searching EMBASE and Medline. Five independent reviewers selected relevant articles. Quality of randomized trials was assessed according to the Jadad score and CONSORT statement. The level of evidence for each item was determined using the GRADE system. The Delphi method was used to validate the final recommendations.ResultsA total of 157 full texts were screened. Thirty-seven articles were included in the systematic review, and 16 of the 23 standard ERAS items were studied specifically for liver surgery. Consensus was reached among experts after 3 rounds. Prophylactic nasogastric intubation and prophylactic abdominal drainage should be omitted. The use of postoperative oral laxatives and minimally invasive surgery results in a quicker bowel recovery and shorter hospital stay. Goal-directed fluid therapy with maintenance of a low intraoperative central venous pressure induces faster recovery. Early oral intake and mobilization are recommended. There is no evidence to prefer epidural to other types of analgesia.ConclusionsThe current ERAS recommendations were elaborated based on the best available evidence and endorsed by the Delphi method. Nevertheless, prospective studies need to confirm the clinical use of the suggested protocol.

A Double-Blind Randomized Controlled Clinical Trial to Assess the Effect of Doppler Optimized Intraoperative Fluid Management on Outcome Following Radical Cystectomy

PURPOSE Cardiovascular optimization via esophageal Doppler can minimize gastrointestinal hypoperfusion, reducing the risk of multiple organ dysfunction and postoperative complications during major surgery. We assessed the effect of esophageal Doppler guided cardiovascular optimization in patients undergoing radical cystectomy. MATERIALS AND METHODS We conducted a prospective, randomized, double-blind controlled trial at a United Kingdom teaching hospital between 2006 and 2009. A total of 66 patients were randomized to a control arm (34) and an intervention arm (32). The control group received standard intraoperative fluids. The intervention group received (additional) Doppler guided fluid. Primary outcomes were markers of gastrointestinal morbidity such as ileus, flatus and bowel opening. Secondary outcomes were postoperative nausea and vomiting, wound infection and operative intravenous fluid volumes (total and hourly). RESULTS There were significant reductions in the control and intervention arms in the incidence of ileus (18 vs 7, p <0.001), flatus (5.36 vs 3.55 days, p <0.01) and bowel opening (9.79 vs 6.53 days, p = 0.02), respectively. Nausea and vomiting were significantly reduced in the study group at 24 and 48 hours postoperatively (11 vs 3, p <0.01 and 13 vs 1, p <0.0001). Wound infection rates were significantly reduced (8 vs 1 superficial, p <0.01 and 10 vs 2 combined, p <0.01). Study patients received significantly higher volumes (ml/kg per minute) of intravenous fluid (0.19 vs 0.23, p <0.01) related to a significantly higher volume (ml/kg) in the first hour of surgery (14.1 vs 21.0, p = 0.0001). CONCLUSIONS Cardiovascular optimization using esophageal Doppler significantly improved postoperative markers of gastrointestinal function.

Acute lung injury after ruptured abdominal aortic aneurysm repair : The effect of excluding donations from females from the production of fresh frozen plasma

Objectives:Transfusion-related acute lung injury may contribute to the development of acute lung injury in the critically ill, due to plasma from female donors containing antileukocyte antibodies. In July 2003, the U.K. National Blood Service stopped using female donor plasma for the production of fresh frozen plasma. Patients undergoing repair of a ruptured abdominal aortic aneurysm receive large amounts of fresh frozen plasma and often develop acute lung injury. We investigated whether the change to male fresh frozen plasma was associated with a change in the frequency of acute lung injury in these patients. Design:A retrospective, before and after, observational, single-center study. Setting:Tertiary care center and a regional blood center. Patients:The study included 211 patients undergoing open repair of a ruptured abdominal aortic aneurysm between 1998 and 2006. Interventions:None. Measurements and Main Results:Primary outcome was the development of acute lung injury in the first 6 hrs after surgery. Secondary outcomes were significant hypoxia (Pao2/Fio2 ratio <300), time to extubation, and survival at 30 days. Groups were well matched and received similar volumes of intravenous fluids and blood components. There was significantly less acute lung injury following the change to male fresh frozen plasma (36% before vs. 21% after, p = .04). At 6 hrs after surgery, fewer patients were hypoxic (87% before vs. 62% after, p < .01). In multivariate analysis, the change in donor policy was associated with a decreased risk of developing acute lung injury (odds ratio 0.39; 95% confidence interval, 0.16–0.90). Time to extubation and survival at 30 days were not statistically different between groups. Conclusions:The policy to exclude female donors from the production of fresh frozen plasma was associated with a decrease in the frequency of acute lung injury in patients undergoing repair of a ruptured abdominal aortic aneurysm.

Cardiorespiratory Fitness Predicts Mortality and Hospital Length of Stay After Major Elective Surgery in Older People

Objective:This study aimed to define the relationship between cardiorespiratory fitness and age in the context of postsurgery mortality and morbidity in older people. Background:Postsurgery mortality and morbidity increase with age. Cardiorespiratory fitness also declines with age, and the independent and linked associations between cardiorespiratory fitness and age on postsurgical mortality and morbidity remain to be determined. Methods:An unselected consecutive group of 389 adults with a mean age of 66 years (range 26–86 years) underwent cardiorespiratory exercise testing before major hepatobiliary surgery at a single center. Mortality and critical care unit and hospital lengths of stay were collected from patient records. Primary outcomes were in-hospital all-cause mortality after surgery and hospital and critical care lengths of stay. Results:Anaerobic threshold was the most significant independent predictor for postoperative mortality (P = 0.003; &bgr; = −0.657 and odds ratio = 0.52) in 18 of 389 (4.6%) patients who died during their in-hospital stay. Age was not a significant predictor in this model. Older people with normal cardiorespiratory fitness spent the same number of days in the hospital or critical care unit as younger people with similar cardiorespiratory fitness (13 vs 12; P = 0.08 and 1 vs 1; P = 0.103). Patients older than 75 years with low cardiorespiratory fitness spent a median of 11 days longer in hospital (23 vs 12; P < 0.0001) and 2 days longer in critical care (2.9 vs 0.9; P < 0.0001) when compared with patients with adequate cardiorespiratory fitness. Conclusions:Cardiorespiratory fitness is an independent predictor of mortality and length of hospital stay and provides significantly more accurate prognostic information than age alone. Clinicians should consider both the prognostic value of cardiorespiratory testing and techniques to preserve cardiorespiratory function before elective surgery in older people.

Submaximal cardiopulmonary exercise testing predicts 90‐day survival after liver transplantation

Liver transplantation has a significant early postoperative mortality rate. An accurate preoperative assessment is essential for minimizing mortality and optimizing limited donor organ resources. This study assessed the feasibility of preoperative submaximal cardiopulmonary exercise testing (CPET) for determining the cardiopulmonary reserve in patients being assessed for liver transplantation and its potential for predicting 90‐day posttransplant survival. One hundred eighty‐two patients underwent CPET as part of their preoperative assessment for elective liver transplantation. The 90‐day mortality rate, critical care length of stay, and hospital length of stay were determined during the prospective posttransplant follow‐up. One hundred sixty‐five of the 182 patients (91%) successfully completed CPET; this was defined as the ability to determine a submaximal exercise parameter: the anaerobic threshold (AT). Sixty of the 182 patients (33%) underwent liver transplantation, and the mortality rate was 10.0% (6/60). The mean AT value was significantly higher for survivors versus nonsurvivors (12.0 ± 2.4 versus 8.4 ± 1.3 mL/minute/kg, P < 0.001). Logistic regression revealed that AT, donor age, blood transfusions, and fresh frozen plasma transfusions were significant univariate predictors of outcomes. In a multivariate analysis, only AT was retained as a significant predictor of mortality. A receiver operating characteristic curve analysis demonstrated sensitivity and specificity of 90.7% and 83.3%, respectively, with good model accuracy (area under the receiver operating characteristic curve = 0.92, 95% confidence interval = 0.82‐0.97, P = 0.001). The optimal AT level for survival was defined to be >9.0 mL/minute/kg. The predictive value was improved when the ideal weight was substituted for the actual body weight of a patient with refractory ascites, even after a correction for the donors age. In conclusion, the preoperative cardiorespiratory reserve (as defined by CPET) is a sensitive and specific predictor of early survival after liver transplantation. The predictive value of CPET requires further evaluation. Liver Transpl 18:152–159, 2012.

Disparity between apolipoprotein E phenotypes and genotypes (as determined by polymerase chain reaction and oligonucleotide probes) in patients with non-insulin-dependent diabetes mellitus

Apolipoprotein (apo) E phenotype and genotype frequencies, due to allelic variation at amino acids 112 and 158, have been investigated in 95 Caucasian non-insulin dependent diabetic patients (NIDDM). Phenotypes were determined by one-dimensional isoelectric focussing (IEF). In this sample, the frequency of the epsilon 2 allele was higher (0.122) and the frequency of the epsilon 4 allele lower (0.101) than previously reported in Caucasian populations (P less than 0.05). Genotypes were assigned using the technique of polymerase chain reaction and allele specific oligonucleotide probes. By contrast, the frequencies of the alleles determined by genotyping was similar to previously reported in Caucasian populations (apo epsilon 2, 0.095; epsilon 3, 0.758; epsilon 4, 0.147; P greater than 0.1). It is possible that in patients with NIDDM post-translational modification of apo E may lead to disparities, with phenotypes being unrepresentative of allelic variation at this gene locus.

Submaximal exercise testing predicts perioperative hospitalization after aortic aneurysm repair

BACKGROUND Aortic aneurysm repair is a high-risk surgical procedure. Patients are often elderly, with multiple comorbidities that predispose them to perioperative morbidity. Use of endovascular aneurysm repair (EVAR) has increased due to reduced early perioperative risk. This study assessed whether preoperative cardiopulmonary exercise testing (CPET) could be used to predict morbidity and hospital length of stay (LOS) after aortic aneurysm repair. METHODS A total of 185 patients underwent surgical repair (84 open repairs, 101 EVAR) and had adequate determination of a submaximal CPET parameter (anaerobic threshold). RESULTS Patient comorbidities and cardiorespiratory fitness, derived from CPET, were similar between surgical procedures. Patients undergoing EVAR had fewer complications (10% vs 32%; P<.0001) and shorter mean (standard deviation [SD]) hospital LOS of 5.7 (9.3) days vs 14.4 (10.9) days compared with open repair (P<.0001). The hospital LOS was significantly increased in patients with one or more complications in both groups compared with those with no complications. In the open repair group, the level of fitness, as defined by anaerobic threshold, was an independent predictor of postoperative morbidity and hospital LOS. When the optimal anaerobic threshold (10 mL/min/kg) derived from receiver operator curve analysis was used as a cutoff value, unfit patients stayed significantly longer than fit patients in critical care (mean, 6.4 [SD, 6.9] days vs 2.4 [SD, 2.9] days; P=.002) and in the hospital (mean, 23.1 [SD, 14.8] days vs 11.0 [SD, 6.1] days; P<.0001). In contrast, fitness in the EVAR group was not predictive of postoperative morbidity but did have predictive value for hospital LOS. CONCLUSIONS Cardiorespiratory fitness holds significant clinical value before aortic aneurysm repair in predicting postsurgical complications and duration of critical care and hospital LOS. Preoperative measurement of fitness could then direct clinical management with regard to operative choice, postoperative resource allocation, and informed patient decision making.