Fluid management and vasopressor use during colorectal surgery: the search for the optimal balance.

BACKGROUND: Although it is known that excessive intraoperative fluid and vasopressor agents are detrimental for anastomotic healing, optimal anesthesiology protocols for colorectal surgery are currently lacking. OBJECTIVE: To scrutinize the current hemodynamic practice and vasopressor use and their relation to colorectal anastomotic leakage. DESIGN: A secondary analysis of a previously published prospective observational study: the LekCheck study. STUDY SETTING: Adult patients undergoing a colorectal resection with the creation of a primary anastomosis. OUTCOME MEASURES: Colorectal anastomotic leakage (CAL) within 30 days postoperatively, hospital length of stay and 30-day mortality. RESULTS: Of the 1548 patients, 579 (37%) received vasopressor agents during surgery. Of these, 201 were treated with solely noradrenaline, 349 were treated with phenylephrine, and 29 received ephedrine. CAL rate significantly differed between the patients receiving vasopressor agents during surgery compared to patients without (11.8% vs 6.3%, p < 0.001). CAL was significantly higher in the group receiving phenylephrine compared to noradrenaline (14.3% vs 6%, p < 0.001). Vasopressor agents were used more often in patients treated with Goal Directed Therapy (47% vs 34.6%, p < 0.001). There was a higher mortality rate in patients with vasopressors compared to the group without (2.8% vs 0.4%, p = 0.01, OR 3.8). Mortality was higher in the noradrenaline group compared to the phenylephrine and those without vasopressors (5% vs. 0.4% and 1.7%, respectively, p < 0.001). In multivariable analysis, patients with intraoperative vasopressor agents had an increased risk to develop CAL (OR 2.1, CI 1.3-3.2, p = 0.001). CONCLUSION: The present study contributes to the evidence that intraoperative use of vasopressor agents is associated with a higher rate of CAL. This study helps to create awareness on the (necessity to) use of vasopressor agents in colorectal surgery patients in striving for successful anastomotic wound healing. Future research will be required to balance vasopressor agent dosage in view of colorectal anastomotic leakage.

LekCheck: A Prospective Study to Identify Perioperative Modifiable Risk Factors for Anastomotic Leakage in Colorectal Surgery.

OBJECTIVE: To assess potentially modifiable perioperative risk factors for anastomotic leakage in adult patients undergoing colorectal surgery. SUMMARY BACKGROUND DATA: Colorectal anastomotic leakage (CAL) is the single most important denominator of postoperative outcome after colorectal surgery. To lower the risk of CAL, the current research focused on the association of potentially modifiable risk factors, both surgical and anesthesiological. METHODS: A consecutive series of adult patients undergoing colorectal surgery with primary anastomosis was enrolled from January 2016 to December 2018. Fourteen hospitals in Europe and Australia prospectively collected perioperative data by carrying out the LekCheck, a short checklist carried out in the operating theater as a time-out procedure just prior to the creation of the anastomosis to check perioperative values on 1) general condition 2) local perfusion and oxygenation, 3) contamination, and 4) surgery related factors. Univariate and multivariate logistic regression analysis were performed to identify perioperative potentially modifiable risk factors for CAL. RESULTS: There were 1562 patients included in this study. CAL was reported in 132 (8.5%) patients. Low preoperative hemoglobin (OR 5.40, P < 0.001), contamination of the operative field (OR 2.98, P < 0.001), hyperglycemia (OR 2.80, P = 0.003), duration of surgery of more than 3 hours (OR 1.86, P = 0.010), administration of vasopressors (OR 1.80, P = 0.010), inadequate timing of preoperative antibiotic prophylaxis (OR 1.62, P = 0.047), and application of epidural analgesia (OR, 1.81, P = 0. 014) were all associated with CAL. CONCLUSIONS: This study identified 7 perioperative potentially modifiable risk factors for CAL. The results enable the development of a multimodal and multidisciplinary strategy to create an optimal perioperative condition to finally lower CAL rates.

Non-invasive measurements of pulse pressure variation and stroke volume variation in anesthetized patients using the Nexfin blood pressure monitor.

Nexfin beat-to-beat arterial blood pressure monitoring enables continuous assessment of hemodynamic indices like cardiac index (CI), pulse pressure variation (PPV) and stroke volume variation (SVV) in the perioperative setting. In this study we investigated whether Nexfin adequately reflects alterations in these hemodynamic parameters during a provoked fluid shift in anesthetized and mechanically ventilated patients. The study included 54 patients undergoing non-thoracic surgery with positive pressure mechanical ventilation. The provoked fluid shift comprised 15° Trendelenburg positioning, and fluid responsiveness was defined as a concomitant increase in stroke volume (SV) >10 %. Nexfin blood pressure measurements were performed during supine steady state, Trendelenburg and supine repositioning. Hemodynamic parameters included arterial blood pressure (MAP), CI, PPV and SVV. Trendelenburg positioning did not affect MAP or CI, but induced a decrease in PPV and SVV by 3.3 ± 2.8 and 3.4 ± 2.7 %, respectively. PPV and SVV returned back to baseline values after repositioning of the patient to baseline. Bland-Altman analysis of SVV and PPV showed a bias of -0.3 ± 3.0 % with limits of agreement ranging from -5.6 to 6.2 %. The SVV was more superior in predicting fluid responsiveness (AUC 0.728) than the PVV (AUC 0.636), respectively. The median bias between PPV and SVV was different for patients younger [-1.5 % (-3 to 0)] or older [+2 % (0-4.75)] than 55 years (P < 0.001), while there were no gender differences in the bias between PPV and SVV. The Nexfin monitor adequately reflects alterations in PPV and SVV during a provoked fluid shift, but the level of agreement between PPV and SVV was low. The SVV tended to be superior over PPV or Eadyn in predicting fluid responsiveness in our population.

Microcirculatory perfusion during different perioperative hemodynamic strategies.

OBJECTIVE: We investigated whether hemodynamic optimization of systemic tissue perfusion based on PPV and CI improves microcirculatory perfusion when compared to a MAP-based strategy in patients undergoing elective abdominal surgery. METHODS: Patients were randomized into a PPV/CI guided group (n = 13, target PPV <12%, CI >2.5 L/min/m(2) , and MAP >70 mmHg) or MAP-guided group (n = 18, target MAP >70 mmHg). PPV, CI, and MAP were measured using noninvasive arterial blood pressure measurements. Sublingual microcirculatory perfusion was measured at one, two, and three hours following anesthesia induction, and quantified as TVD, PVD or the proportion of perfused vessels. Data were analyzed using ANOVA RM. RESULTS: Patients in the PPV/CI group required more fluid administration than control patients (1927 ± 747 mL versus 1283 ± 582 mL, respectively; p = 0.01). Despite this difference, we observed similar values for TVD (RM; F(1.28) = 0.01; p = 0.92), PVD (RM; F(1.28) = 0.09; p = 0.77) and the proportion of perfused vessels (RM; F(1.28) = 0.01; p = 0.76) in both groups. CONCLUSION: Hemodynamic optimization of systemic tissue perfusion is not associated with improvement of microcirculatory perfusion compared to a MAP-guided protocol in patients undergoing abdominal surgery.

Towards optimal intraoperative conditions in esophageal surgery: A review of literature for the prevention of esophageal anastomotic leakage.

BACKGROUND: Esophageal anastomotic leakage (EAL) is a severe complication following gastric and esophageal surgery for cancer. Several non-modifiable, patient or surgery related risk factors for EAL have been identified, however, the contribution of modifiable intraoperative parameters remains undetermined. This review provides an overview of current literature on potentially modifiable intraoperative risk factors for EAL. MATERIALS AND METHODS: The PubMed, EMBASE and Cochrane databases were searched by two researchers independently. Clinical studies published in English between 1970 and January 2017 that evaluated the effect of intraoperative parameters on the development of EAL were included. Levels of evidence as defined by the Centre of Evidence Based Medicine (CEBM) were assigned to the studies. RESULTS: A total of 25 articles were included in the final analysis. These articles show evidence that anemia, increased amount of blood loss, low pH and high pCO2 values, prolonged duration of procedure and lack of surgical experience independently increase the risk of EAL. Supplemental oxygen therapy, epidural analgesia and selective digestive decontamination seem to have a beneficial effect. Potential risk factors include blood pressure, requirement of blood products, vasopressor use and glucocorticoid administration, however the results are ambiguous. CONCLUSION: Apart from fixed surgical and patient related factors, several intraoperative factors that can be modified in clinical practice can influence the risk of developing EAL. More prospective, observational studies are necessary focusing on modifiable intraoperative parameters to assess more evidence and to elucidate optimal values of these factors.