Peri-operative endothelial dysfunction in patients undergoing minor abdominal surgery: An observational study

Ultrasonographic assessment of brachial artery reactivity as a predictor of adverse outcome in patients undergoing emergency laparotomy for perforated peritonitis - Prospective observational study

Background and Aims

This study aimed to assess if pre- and postoperative parameters of brachial artery reactivity (BAR), like flow-mediated dilation (FMD) and hyperaemic velocity (HV), could predict in-hospital mortality in perforation peritonitis patients undergoing emergency laparotomy.

Methods

In this prospective observational study, adult patients with perforation peritonitis undergoing emergency laparotomy were recruited. FMD and HV were measured preoperatively, postoperatively and at 24 and 48 h post-surgery. Adult patients undergoing elective laparotomy served as the control group. The primary outcome was in-hospital mortality. Baseline and BAR parameters were compared between survivors and non-survivors. Risk factors for mortality were identified by univariate analysis. Prognostic performances of BAR parameters were assessed by different models using logistic regression. All statistical analyses were performed on STATA version 13 for Mac OS.

Results

Seventy-six emergency laparotomy patients were recruited, and 26 died during the hospital stay. FMD and HV were comparable at all time points between survivors and non-survivors, except that HV was higher in survivors at 48 h post-surgery (median [interquartile range] 1.28 [1.16-1.49] vs. 1.16 [0.86-1.35], P = 0.010]. HV at 48 h predicted mortality (adjusted odds ratio [OR] [95% confidence interval] 21.05 [1.04-422.43], P = 0.046), and a model consisting of age, Acute Physiology and Chronic Health Evaluation (APACHE) score and HV at 48 h was the best predictor of mortality (area under the receiver operating characteristic (AUROC) curve 0.82).

Conclusion

HV, as measured by ultrasonography of the brachial artery at 48 h postoperatively, is a good predictor of mortality in patients undergoing emergency laparotomy for perforation peritonitis.

Myocardial injury and long-term oncological outcomes in patients undergoing surgery for colorectal cancer

PURPOSE

Myocardial injury after noncardiac surgery (MINS) is associated with increased mortality and postoperative complications. In patients with colorectal cancer (CRC), postoperative complications are a risk factor for cancer recurrence and disease-free survival. This study investigates the association between MINS and long-term oncological outcomes in patients with CRC in an ERAS setting.

METHODS

This retrospective cohort study was conducted at Zealand University Hospital, Denmark, between June 2015 and July 2017. Patients undergoing CRC surgery were included if troponin was measured twice after surgery. Outcomes were all-cause mortality, recurrence, and disease-free survival within five years of surgery.

RESULTS

Among 586 patients, 42 suffered MINS. After five years, 36% of patients with MINS and 26% without MINS had died, p = 0.15. When adjusted for sex, age and UICC, the hazard ratio (aHR) for 1-year all-cause mortality, recurrence, and disease-free survival were 2.40 [0.93-6.22], 1.47 [0.19-11.29], and 2.25 [0.95-5.32] for patients with MINS compared with those without, respectively. Further adjusting for ASA status, performance status, smoking, and laparotomies, the aHR for 3- and 5-year all-cause mortality were 1.05 [0.51-2.15] and 1.11 [0.62-1.99], respectively. Similarly, the aHR for 3- and 5-year recurrence were 1.38 [0.46-4.51], and 1.49 [0.56-3.98] and for 3- and 5-year disease-free survival the aHR were 1.19 [0.63-2.23], and 1.19 [0.70-2.03].

CONCLUSION

In absolute numbers, we found no difference in all-cause mortality and recurrence in patients with and without MINS. In adjusted Cox regression analyses, the hazard was increased for all-cause mortality, recurrence, and disease-free survival in patients with MINS without reaching statistical significance.

Effect of Remote Ischaemic Preconditioning on Perioperative Endothelial Dysfunction in Non-Cardiac Surgery: A Randomised Clinical Trial

Endothelial dysfunction result from inflammation and excessive production of reactive oxygen species as part of the surgical stress response. Remote ischemic preconditioning (RIPC) potentially exerts anti-oxidative and anti-inflammatory properties, which might stabilise the endothelial function after non-cardiac surgery. This was a single centre randomised clinical trial including 60 patients undergoing sub-acute laparoscopic cholecystectomy due to acute cholecystitis. Patients were randomised to RIPC or control. The RIPC procedure consisted of four cycles of five minutes of ischaemia and reperfusion of one upper extremity. Endothelial function was assessed as the reactive hyperaemia index (RHI) and circulating biomarkers of nitric oxide (NO) bioavailability (L-arginine, asymmetric dimethylarginine (ADMA), L-arginine/ADMA ratio, tetra- and dihydrobiopterin (BH4 and BH2), and total plasma biopterin) preoperative, 2–4 h after surgery and 24 h after surgery. RHI did not differ between the groups (p = 0.07). Neither did levels of circulating biomarkers of NO bioavailability change in response to RIPC. L-arginine and L-arginine/ADMA ratio was suppressed preoperatively and increased 24 h after surgery (p < 0.001). The BH4/BH2-ratio had a high preoperative level, decreased 2–4 h after surgery and remained low 24 h after surgery (p = 0.01). RIPC did not influence endothelial function or markers of NO bioavailability until 24 h after sub-acute laparoscopic cholecystectomy. In response to surgery, markers of NO bioavailability increased, and oxidative stress decreased. These findings support that a minimally invasive removal of the inflamed gallbladder countereffects reduced markers of NO bioavailability and increased oxidative stress caused by acute cholecystitis.

Impaired vascular endothelial function as a perioperative risk predictor - a prospective observational trial

Background

In the recent years, an increasing number of patients with multiple comorbidities (e.g. coronary artery disease, diabetes, hypertension) presents to the operating room. The clinical risk factors are accompanied by underlying vascular-endothelial dysfunction, which impairs microcirculation and may predispose to end-organ dysfunction and impaired postoperative outcome. Whether preoperative endothelial dysfunction identifies patients at risk of postoperative complications remains unclear. In this prospective observational study, we tested the hypothesis that impaired flow-mediated dilation (FMD), a non-invasive surrogate marker of endothelial function, correlates with Days at Home within 30 days after surgery (DAH30). DAH30 is a patient-centric metric that captures postoperative complications and importantly also hospital re-admissions.

Methods

Seventy-one patients scheduled for major abdominal surgery were enrolled. FMD was performed pre-operatively prior to major abdominal surgery and patients were dichotomised at a threshold value of 10%. FMD was then correlated with DAH30 (primary endpoint) and postoperative complications (secondary endpoints).

Results

DAH30 did not differ between patients with reduced FMD and normal FMD (14 (4) (median (IQR)) vs. 15 (8), P = 0.8). Similary, no differences between both groups were found for CCI (normal FMD: 21 (30) (median (IQR)), reduced FMD: 26 (38), P = 0.4) or frequency of major complications (normal FMD: 7 (19%) (n (%)), reduced FMD: 12 (35%), P = 0.12). The regression analyses revealed that FMD in combination with ASA status and surgery duration had no additional significant predictive effect for DAH30, CCI or Clavien-Dindo score.

Conclusion

FMD does not add predictive value with regards to DAH30, CCI or Clavien-Dindo score within our study cohort of patients undergoing abdominal surgery.

Trial registration

The study was registered in the German Clinical Trials Register (DRKS00005472), prospectively registered on 25/11/2013.

Altered microvascular reactivity assessed by near-infrared spectroscopy after hepato-pancreato-biliary surgery

Little is known about microcirculatory dysfunction following abdominal surgeries. This study aimed to evaluate changes in microvascular reactivity (MVR) before and after major abdominal surgery, assessed by near-infrared spectroscopy in conjunction with a vascular occlusion test. This prospective observational study included 50 adult patients who underwent hepato-pancreato-biliary surgery lasting ≥ 8 h. MVR was assessed by tissue oxygen saturation (StO₂) changes in the plantar region of the foot during 3 min of vascular occlusion and subsequent release under general anesthesia before and after surgery. The primary outcome was alteration in the recovery slope of StO₂ (RecStO₂) and recovery time (tM) between the preoperative and postoperative values. Postoperative short-term outcome was represented by the Post-operative Morbidity Survey (POMS) score on the morning of postoperative day 2. After surgery, RecStO₂ was reduced (0.74% [0.58-1.06]/s vs. 0.89% [0.62-1.41]/s, P = 0.001), and tM was longer (57.0 [42.9-71.0] s vs. 41.3 [35.5-56.5] s, P < 0.001), compared to the preoperative values. Macrohemodynamic variables such as cardiac index, arterial pressure, and stroke volume during postoperative measurement did not differ with or without relative MVR decline. In addition, the POMS score was not associated with postoperative alterations in microcirculatory responsiveness. MVR in the plantar region of the foot was reduced after major hepato-pancreato-biliary surgery regardless of macrocirculatory adequacy. Impaired MVR was not associated with short-term outcomes as long as macrocirculatory indices were well maintained. The impact of relative microcirculatory changes, especially combined with inadequate macrocirculation, on postoperative complications remains to be elucidated.Clinical Trial Registrations UMIN-CTR trial ID: 000033461.

The effect of remote ischaemic preconditioning on endothelial function after hip fracture surgery

BACKGROUND

Endothelial dysfunction seems to play a role in the pathophysiology of myocardial injury after surgery. The aim of this randomised clinical trial was to examine whether remote ischaemic preconditioning in relation to hip fracture surgery ameliorates post-operative systemic endothelial dysfunction.

METHODS

This was a planned single-centre pilot sub-study of a multicentre, randomised clinical trial. Patients ≥45 years with a cardiovascular risk factor were randomised to remote ischaemic preconditioning (RIPC) or control (standard treatment) performed in relation with their hip fracture operation. RIPC consisted of four cycles of 5 minutes forearm ischaemia and reperfusion. The procedure was performed non-invasively with a tourniquet. The endothelial function was assessed with non-invasive digital pulse amplitude tonometry on post-operative day 1 and expressed as the reactive hyperaemia index (RHI). Endothelial dysfunction was defined as RHI < 1.22.

RESULTS

Between February 2015 and December 2016, 18 patients were allocated to the RIPC group and 20 patients to the control group. The endothelial function was impaired in both groups on post-operative day 1. RHI did not differ between the groups, 1.47 (95% CI 1.20-1.75) in the RIPC group vs. 1.54 (95% CI 1.17-1.91) in the control group, P = .76. Endothelial dysfunction was present in 3/18 patients (16.7%) in the RIPC group and 8/20 patients (40%) in the control group, P = .11.

CONCLUSION

No beneficial effect of remote ischaemic preconditioning on the systemic endothelial dysfunction, assessed at a single time point on post-operative day one, was detected after hip fracture surgery.

Endothelial dysfunction and myocardial injury after major emergency abdominal surgery: a prospective cohort study

Background

Preoperative endothelial dysfunction is a predictor of myocardial injury and major adverse cardiac events. Non-cardiac surgery is known to induce acute endothelial changes. The aim of this explorative cohort study was to assess the extent of systemic endothelial dysfunction after major emergency abdominal surgery and the potential association with postoperative myocardial injury.

Methods

Patients undergoing major emergency abdominal surgery were included in this prospective cohort study. The primary outcome was the change in endothelial function expressed as the reactive hyperemia index from 4-24 h after surgery until postoperative day 3–5. The reactive hyperemia index was assessed by non-invasive digital pulse tonometry. Secondary outcomes included changes in biomarkers of nitric oxide metabolism and bioavailability. All assessments were performed at the two separate time points in the postoperative period. Clinical outcomes included myocardial injury within the third postoperative day and major adverse cardiovascular events within 30 days of surgery.

Results

Between October 2016 and June 2017, 83 patients were included. The first assessment of the endothelial function, 4–24 h, was performed 15.8 (SD 6.9) hours after surgery and the second assessment, postoperative day 3–5, was performed 83.7 (SD 19.8) hours after surgery. The reactive hyperemia index was suppressed early after surgery and did not increase significantly; 1.64 (95% CI 1.52–177) at 4–24 h after surgery vs. 1.75 (95% CI 1.63–1.89) at postoperative day 3–5, p = 0.34. The L-arginine/ADMA ratio, expressing the nitric oxide production, was reduced in the perioperative period and correlated significantly with the reactive hyperemia index. A total of 16 patients (19.3%) had a major adverse cardiovascular event, of which 11 patients (13.3%) had myocardial injury. The L-arginine/ADMA ratio was significantly decreased at 4–24 h after surgery in patients suffering myocardial injury.

Conclusion

This explorative pathophysiological study showed that acute systemic endothelial dysfunction was present early after major emergency abdominal surgery and remained unchanged until day 3–5 after the procedure. Early postoperative disturbances in the nitric oxide bioavailability might add to the pathogenesis of myocardial injury. This pathophysiological link should be confirmed in larger studies.

Trial registration

clinicaltrials.gov no. NCT03010969.

Utility of the cold pressor test to predict future cardiovascular events

INTRODUCTION

The cold pressor test (CPT) is a common and extensively validated test, which induces systemic stress involving immersion of an individual's hand in ice water (normally temperature between 0 and 5 degrees Celsius) for a period of time. CPT has been used in various fields, like examining effects of stress on memory, decision-making, pain and cardiovascular health. Areas covered: In terms of cardiovascular health, current research is mainly interested in predicting the occurrence of cardiovascular (CV) events. The objective of this review is to give an overview of the history and methodology of the CPT, and clinical utility in possibly predicting CV events in CAD and other atherosclerotic diseases. Secondly, we will discuss possible future applications of the CPT in clinical care. Expert opinion: An important issue to address is the fact that the physiology of the CPT is not fully understood at this moment. As pointed out multiple mechanisms might be responsible for contributing to either coronary vasodilatation or coronary vasoconstriction. Regarding the physiological mechanism of the CPT and its effect on the measurements of the carotid artery reactivity even less is known.