Pathophysiology and clinical implications of perioperative fluid excess

Fluid and Hemodynamics

Several components of an Enhanced Recovery After Surgery (ERAS) pathway act to improve and simplify perioperative fluid and hemodynamic therapy. Modern perioperative fluid management has shifted away from the liberal fluid therapy and toward more individualized approaches. Clinical evidence has also emphasized the importance of maintaining adequate mean arterial pressure and avoiding intraoperative hypotension. Goal-directed hemodynamic therapy (GDHT), or the use of cardiac output monitoring to guide fluid and vasopressor use, has been shown to reduce complications, but its role within ERAS pathways is likely best-suited to high-risk patients or those undergoing high-risk procedures. This article reviews the mechanisms by which ERAS pathways aid the provider in hemodynamic management, reviews trends, and evidence regarding fluid and hemodynamic therapy approaches, and provides guidance on the practical implementation of these concepts within ERAS pathways.

Impact of introduction of an enhanced recovery protocol on the outcomes of laparoscopic liver resections: A propensity-score matched study

BACKGROUND

Presently, data on the impact of enhanced recovery protocols on the outcomes of laparoscopic liver resection remain limited. We performed propensity matched analysis comparing the outcomes between patients undergoing laparoscopic liver resection before and after the introduction of an enhanced recovery protocol.

METHODS

Between 2013 and 2019, 462 consecutive patients underwent laparoscopic liver resection by 3 surgeons of which 360 met the study inclusion criteria. There were 89 patients who underwent surgery under an enhanced recovery protocol and 271 without an enhanced recovery protocol. One-to-one propensity matched analysis was performed for 84 enhanced recovery protocol patients and 84 nonenhanced recovery protocol patients.

RESULTS

Comparisons between propensity matched cohorts revealed that patients who received laparoscopic liver resection with enhanced recovery protocol had reduced median blood loss (200 vs 300 mL, P = .013), postoperative stay (3 vs 4 days, P = .003), and lower open conversion rates (0% vs 8.3%, P = .008). There was no difference in other key perioperative outcomes such as operation time, postoperative morbidity, postoperative major morbidity, and 30-day readmission rates.

CONCLUSION

A combined approach of enhanced recovery protocol and laparoscopic liver resection was associated with improved perioperative outcomes as opposed to laparoscopic liver resection alone.

Effect of Intra- and Post-Operative Fluid and Blood Volume on Postoperative Pulmonary Edema in Patients with Intraoperative Massive Bleeding

In patients with intraoperative massive bleeding, the effects of fluid and blood volume on postoperative pulmonary edema are uncertain. Patients with intraoperative massive bleeding who had undergone a non-cardiac surgery in five hospitals were enrolled in this study. We evaluated the association of postoperative pulmonary edema risk and intra- and post-operatively administered fluid and blood volumes in patients with intraoperative massive bleeding. In total, 2090 patients were included in the postoperative pulmonary edema analysis, and 300 patients developed pulmonary edema within 72 h of the surgery. The postoperative pulmonary edema with hypoxemia analysis included 1660 patients, and the condition occurred in 161 patients. An increase in the amount of red blood cells transfused per hour after surgery increased the risk of pulmonary edema (hazard ratio: 1.03; 95% confidence interval: 1.01–1.05; p = 0.013) and the risk of pulmonary edema with hypoxemia (hazard ratio: 1.04; 95% confidence interval: 1.01–1.07; p = 0.024). An increase in the red blood cells transfused per hour after surgery increased the risk of developing pulmonary edema. This increase can be considered as a risk factor for pulmonary edema.

Postoperative Ileus: Comparative Pathophysiology and Future Therapies

Postoperative ileus (POI), a decrease in gastrointestinal motility after surgery, is an important problem facing human and veterinary patients. 37.5% of horses that develop POI following small intestinal (SI) resection will not survive to discharge. The two major components of POI pathophysiology are a neurogenic phase which is then propagated by an inflammatory phase. Perioperative care has been implicated, namely the use of opioid therapy, inappropriate fluid therapy and electrolyte imbalances. Current therapy for POI variably includes an early return to feeding to induce physiological motility, reducing the inflammatory response with agents such as non-steroidal anti-inflammatory drugs (NSAIDs), and use of prokinetic therapy such as lidocaine. However, optimal management of POI remains controversial. Further understanding of the roles of the gastrointestinal microbiota, intestinal barrier function, the post-surgical inflammatory response, as well as enteric glial cells, a component of the enteric nervous system, in modulating postoperative gastrointestinal motility and the pathogenesis of POI may provide future targets for prevention and/or therapy of POI.

Anesthetic Management of Adults With Epidermolysis Bullosa

Epidermolysis bullosa (EB) is a group of rare, inherited diseases characterized by skin fragility and multiorgan system involvement that presents many anesthetic challenges. Although the literature regarding anesthetic management focuses primarily on the pediatric population, as life expectancy improves, adult patients with EB are more frequently undergoing anesthesia in nonpediatric hospital settings. Safe anesthetic management of adult patients with EB requires familiarity with the complex and heterogeneous nature of this disease, especially with regard to complications that may worsen during adulthood. General, neuraxial, and regional anesthetics have all been used safely in patients with EB. A thorough preoperative evaluation is essential. Preoperative testing should be guided by EB subtype, clinical manifestations, and extracutaneous complications. Advanced planning and multidisciplinary coordination are necessary with regard to timing and operative plan. Meticulous preparation of the operating room and education of all perioperative staff members is critical. Intraoperatively, utmost care must be taken to avoid all adhesives, shear forces, and friction to the skin and mucosa. Special precautions must be taken with patient positioning, and standard anesthesia monitors must be modified. Airway management is often difficult, and progressive airway deterioration can occur in adults with EB over time. A smooth induction, emergence, and postoperative course are necessary to minimize blister formation from excess patient movement. With careful planning, preparation, and precautions, adult patients with EB can safely undergo anesthesia.

Goal-directed fluid therapy in emergency abdominal surgery: a randomised multicentre trial

BACKGROUND

More than 50% of patients have a major complication after emergency gastrointestinal surgery. Intravenous (i.v.) fluid therapy is a life-saving part of treatment, but evidence to guide what i.v. fluid strategy results in the best outcome is lacking. We hypothesised that goal-directed fluid therapy during surgery (GDT group) reduces the risk of major complications or death in patients undergoing major emergency gastrointestinal surgery compared with standard i.v. fluid therapy (STD group).

METHODS

In a randomised, assessor-blinded, two-arm, multicentre trial, we included 312 adult patients with gastrointestinal obstruction or perforation. Patients in the GDT group received i.v. fluid to near-maximal stroke volume. Patients in the STD group received i.v. fluid following best clinical practice. Postoperative target was 0-2 L fluid balance. The primary outcome was a composite of major complications or death within 90 days. Secondary outcomes were time in intensive care, time on ventilator, time in dialysis, hospital stay, and minor complications.

RESULTS

In a modified intention-to-treat analysis, we found no difference in the primary outcome between groups: 45 (30%) (GDT group) vs 39 (25%) (STD group) (odds ratio=1.24; 95% confidence interval, 0.75-2.05; P=0.40). Hospital stay was longer in the GDT group: median (inter-quartile range), 7 (4-12) vs 6 days (4-8.5) (P=0.04); no other differences were found.

CONCLUSION

Compared with pressure-guided i.v. fluid therapy (STD group), flow-guided fluid therapy to near-maximal stroke volume (GDT group) did not improve the outcome after surgery for bowel obstruction or gastrointestinal perforation but may have prolonged hospital stay.

CLINICAL TRIAL REGISTRATION

EudraCT number 2015-000563-14; the Danish Scientific Ethics Committee and the Danish Data Protection Agency (REG-18-2015).

Intraoperative crystalloid utilization variability and association with postoperative outcomes: A post hoc analysis of two multicenter prospective cohort studies

BACKGROUND

The optimal regimen for intravenous administration of intraoperative fluids remains unclear. Our goal was to analyze intraoperative crystalloid volume administration practices and their association with postoperative outcomes.

METHODS

We extracted clinical data from two multicenter observational studies including adult patients undergoing colorectal surgery and total hip (THA) and knee arthroplasty (TKA). We analyzed the distribution of intraoperative fluid administration. Regression was performed using a general linear model to determine factors predictive of fluid administration. Patient outcomes and intraoperative crystalloid utilization were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low intraoperative crystalloid with the likelihood of increased postoperative complications, mainly acute kidney injury (AKI) and hospital length of stay (LOS).

RESULTS

7580 patients were included. The average adjusted intraoperative crystalloid infusion rate across all surgeries was to 7.9 (SD 4) mL/kg/h. The regression model strongly favored the type of surgery over other patient predictors. We found that high fluid volume was associated with 40% greater odds ratio (OR 1.40; 95% confidence interval 1.01-1.95, p = 0.044) of postoperative complications in patients undergoing THA, while we found no associations for the other types of surgeries, AKI and LOS CONCLUSIONS: A wide variability was observed in intraoperative crystalloid volume administration; however, this did not affect postoperative outcomes.

The Perioperative Surgical Home, Enhanced Recovery After Surgery and how integration of these models may improve care for medically complex patients

Perioperative medicine is changing rapidly, and with this change comes the opportunity to improve upon current models of care delivery and integration within the health care system. Perioperative models of care are structured or conceptual arrangements for surgical patients before, during and after their surgery. Models of care such as the Perioperative Surgical Home and Enhanced Recovery After Surgery pathways are increasingly used to guide the structure of perioperative care delivery with an aim to improve patient outcomes and experience in Canadian settings. In this narrative review, we summarize the origins of these perioperative models of care. They are fundamentally different in scope and level of evidence. Both models have potential benefits and limitations to their broad implementation in our health care system. As currently developed, both models are limited in their application to patients with chronic disease. We discuss how these models of care can be used to develop integrated horizontal and vertical perioperative pathways in a Canadian setting. Such integration is a potential solution that will improve their applicability to patients with medically complex conditions and in times when health care systems are under pressure. We describe this approach using the example of patients with kidney failure receiving dialysis.

Calculated plasma volume status predicts outcomes after transcatheter aortic valve implantation

Objectives

Congestion can worsen outcomes after transcatheter aortic valve implantation (TAVI), but can be difficult to quantify non-invasively. We hypothesised that preprocedural plasma volume status (PVS), estimated using a validated formula that enumerates percentage change from ideal PV, would provide prognostic utility post-TAVI.

Methods

This retrospective cohort study identified patients who underwent TAVI (2007–2017) from a prospectively collected database. Actual ([1-haematocrit] × [a + (b × weight (Kg))] and ideal (c × weight (Kg)) PV were quantified from equations where a, b and c are sex-dependent constants. Calculated PVS was then derived (100% x [(actual – ideal PV)/ideal PV]).

Results

In 564 patients (mean age 82±7 years, 49% male), mean PVS was −2.7±10.2%, with PV expansion (PVS >0%) evident in 39%. Only logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) independently predicted a PVS >0% (OR 1.85, p=0.002). On Cox analyses, a PVS >0% was associated with greater mortality at 3 (HR 2.29, 95% CI 1.11 to 4.74, p=0.03) and 12 months (HR 2.00, 95% CI 1.23 to 3.26, p=0.006) after TAVI, independently of, and incremental to, the EuroSCORE and New York Heart Association class. A PVS >0% was also independently associated with more days in intensive care (coefficient: 0.41, 95% CI 0.04 to 0.78, p=0.03) and in hospital (coefficient: 1.95, 95% CI 0.48 to 3.41, p=0.009).

Conclusion

Higher PVS values, calculated simply from weight and haematocrit, are associated with greater mortality and longer hospitalisation post-TAVI. PVS could help refine risk stratification and further investigations into the utility of PVS-guided management in TAVI patients is warranted.

Association between intraoperative fluid balance, vasopressors and graft complications in liver transplantation: A cohort study

Introduction

Biliary complications following liver transplantation are common. The effect of intraoperative fluid balance and vasopressors on these complications is unknown.

Materials and methods

We conducted a cohort study between July 2008 and December 2017. Our exposure variables were the total intraoperative fluid balance and the use of vasopressors on ICU admission. Our primary outcome was any biliary complication (anastomotic and non-anastomotic strictures) up to one year after transplantation. Our secondary outcomes were vascular complications, primary graft non-function and survival.

Results

We included 562 consecutive liver transplantations. 192 (34%) transplants had a biliary complication, 167 (30%) had an anastomotic stricture and 56 had a non-anastomotic stricture (10%). We did not observe any effect of intraoperative fluid balance or vasopressor on biliary complications (HR = 0.97; 95% CI, 0.93 to 1.02). A higher intraoperative fluid balance was associated with an increased risk of primary graft non-function (non-linear) and a lower survival (HR = 1.40, 95% CI, 1.14 to 1.71) in multivariable analyses.

Conclusion

Intraoperative fluid balance and vasopressors upon ICU admission were not associated with biliary complications after liver transplantation but may be associated with other adverse events. Intraoperative hemodynamic management must be prospectively studied to further assess their impact on liver recipients’ outcomes.

Preoperative carbohydrate loading and intraoperative goal-directed fluid therapy for elderly patients undergoing open gastrointestinal surgery: a prospective randomized controlled trial

Background

The effect of a combination of a goal-directed fluid protocol and preoperative carbohydrate loading on postoperative complications in elderly patients still remains unknown. Therefore, we designed this trial to evaluate the relative impact of preoperative carbohydrate loading and intraoperative goal-directed fluid therapy versus conventional fluid therapy (CFT) on clinical outcomes in elderly patients following gastrointestinal surgery.

Methods

This prospective randomized controlled trial with 120 patients over 65years undergoing gastrointestinal surgery were randomized into a CFT group (n=60) with traditional methods of fasting and water-deprivation, and a GDFT group (n=60) with carbohydrate (200ml) loading 2h before surgery. The CFT group underwent routine monitoring during surgery, however, the GDFT group was conducted by a Vigileo/FloTrac monitor with cardiac index (CI), stroke volume variation (SVV), and mean arterial pressure (MAP). For all patients, demographic data, intraoperative parameters and postoperative outcomes were recorded.

Results

Patients in the GDFT group received significantly less crystalloids fluid (1111442.9ml vs 1411412.6ml; p<0.001) and produced significantly less urine output (200ml [150300] vs 400ml [290500]; p<0.001) as compared to the CFT group. Moreover, GDFT was associated with a shorter average time to first flatus (5614.1h vs 6422.3h; p=0.002) and oral intake (7216.9h vs 8526.8h; p=0.011), as well as a reduction in the rate of postoperative complications (15 (25.0%) vs 29 (48.3%) patients; p=0.013). However, postoperative hospitalization or hospitalization expenses were similar between groups (p>0.05).

Conclusions

Focused on elderly patients undergoing open gastrointestinal surgery, we found perioperative fluid optimisation may be associated with improvement of bowel function and a lower incidence of postoperative complications.

Trial registration

ChiCTR, ChiCTR1800018227. Registered 6 September 2018 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01377-8.

Goal-Directed Fluid Therapy Based on Pulse-Pressure Variation Compared with Standard Fluid Therapy in Patients Undergoing Complex Spine Surgery: A Randomized Controlled Trial

Study Design

Prospective, randomized, controlled study.

Purpose

To determine whether the use of goal-directed fluid therapy (GDT) guided by pulse-pressure variation (PPV) and fluid management protocol can reduce intraoperative hypotension, blood transfusion requirements, and postoperative complications in adults undergoing complex spine surgery.

Overview of Literature

Complex spine surgeries involve a significant risk of blood loss and intraoperative hypotension. Previous studies showed that GDT reduces intraoperative hypotension and postoperative complications in these surgery types; however, limited information exists about GDT guided by PPV.

Methods

Sixty adults (18–70 years) patients undergoing complex spine surgeries at Siriraj Hospital, Mahidol University, Thailand were enrolled. Patients were allocated to two groups (30 patients in each) using computer-generated randomization. Intraoperative fluid and vasopressor were administrated via either GDT or standard care. The GDT algorithm used PPV and fluid protocol as the primary tool to guide hemodynamic management. The incidences and episodes of perioperative hypotension were measured as the outcomes.

Results

Fifty-seven patients were analyzed (three patients in the GDT group were excluded). The baseline characteristics and surgical procedures of the two groups did not differ significantly. The prevalence of intraoperative hypotension was 80.0% for the control group and 66.7% for the GDT group (p=0.25). Two episodes (1–3) of intraoperative hypotension occurred in the control group, and one episode (0–3) occurred in the GDT group; the difference was not significantly different (p=0.57). The intraoperative blood transfusion requirements and postoperative complications were similar in both the groups. In the subgroup analysis, patients with intraoperative hypotension exhibited a higher incidence of postoperative bowel dysfunction.

Conclusions

PPV-guided GDT and fluid protocol, as compared with standard practice, did not show significant advantages with respect to intraoperative hypotension, blood transfusion, or postoperative complications in patients undergoing complex spine surgery in the prone position.

Intraoperative crystalloid utilization variability and association with postoperative outcomes: A post hoc analysis of two multicenter prospective cohort studies

BACKGROUND

The optimal regimen for intravenous administration of intraoperative fluids remains unclear. Our goal was to analyze intraoperative crystalloid volume administration practices and their association with postoperative outcomes.

METHODS

We extracted clinical data from two multicenter observational studies including adult patients undergoing colorectal surgery and total hip (THA) and knee arthroplasty (TKA). We analyzed the distribution of intraoperative fluid administration. Regression was performed using a general linear model to determine factors predictive of fluid administration. Patient outcomes and intraoperative crystalloid utilization were summarized for each surgical cohort. Regression models were developed to evaluate associations of high or low intraoperative crystalloid with the likelihood of increased postoperative complications, mainly acute kidney injury (AKI) and hospital length of stay (LOS).

RESULTS

7,580 patients were included. The average adjusted intraoperative crystalloid infusion rate across all surgeries was to 7.9 (SD 4) mL/kg/h. The regression model strongly favored the type of surgery over other patient predictors. We found that high fluid volume was associated with 40% greater odds ratio (OR 1.40; 95% confidence interval1.01-1.95, p = 0.044) of postoperative complications in patients undergoing THA, while we found no associations for the other types of surgeries, AKI and LOS CONCLUSIONS: A wide variability was observed in intraoperative crystalloid volume administration; however, this did not affect postoperative outcomes.

Non-traumatic emergency abdominal surgery in nonagenarian patients: a retrospective study

PURPOSE

The primary aim of this study was to evaluate the 30-day survival of nonagenarian patients who underwent non-traumatic emergency abdominal surgery. Other aims were: 90-day and 12-month survival rates, the postoperative complications rate, the impact of the emergency operation on postoperative functional status, the accuracy of the P-POSSUM in predicting 30-day postoperative mortality and changes in care services after surgery.

METHODS

This was a retrospective cohort study of nonagenarian patients who underwent non-traumatic emergency abdominal surgery between January 2010 and June 2017. Patients were divided in two groups according to the 30-day survival status to compare the distribution of patients' characteristics and postoperative outcomes. Overall survival was estimated using the Kaplan-Meier method. To assess the accuracy of P-POSSUM to predict 30-day mortality, a receiver operating characteristic curve and the Hosmer-Lemeshow goodness of fit test were used.

RESULTS

85 nonagenarian patients were enrolled in this study; of these, 27 (31.8%) died within 30 days. The Kaplan-Meier curve showed a rapid decline in survival over the first 30 postoperative days, followed by a more gradual reduction during the rest of the first year. The majority of patients (92.6%) who died within 30 days experienced a medical complication, with a preponderance of respiratory failure (48.2%) and multiple organ failure (33.3%). In the surviving patients, the postoperative functional status had worsened, and 64.2% of patients did not return to their original housing situation or were institutionalized. The accuracy of P-POSSUM in predicting 30-day mortality in nonagenarian patients was poor.

CONCLUSIONS

This study may help doctors convey the postoperative risks of morbidity and mortality, and also to adequately inform relatives about the possible adverse discharge destination of surviving nonagenarian patients with a consequent increase in care needs.

Perioperative fluid balance and major postoperative complications in surgery for advanced epithelial ovarian cancer

OBJECTIVE

Appropriate fluid balance in the perioperative period is important as both hypo- and hypervolemia are associated with increased risk of complications. Women undergoing cytoreductive surgery (CRS) for advanced epithelial ovarian cancer (EOC) may have major fluid shifts. The optimal perioperative fluid balance in these women is yet to be determined. Our objective was to investigate the association between perioperative fluid balance and major postoperative complications.

METHODS

Women with advanced stage EOC who underwent surgery at Karolinska University Hospital, Stockholm, Sweden were identified from the institutional database. Women subjected to surgery with curative intent were included in the analysis. Additional data were retrieved from medical records. The association between perioperative fluid balance and major postoperative complications was investigated by multivariable regression and adjusted for predefined confounders.

RESULTS

Of the 270 women identified in the institutional database during 2014-2017, 184 women were included in the analyses. Of these women, 22% (n = 40) experienced a major postoperative complication. The fully adjusted odds of major postoperative complications increased when perioperative fluid balance exceeded >3000 mL, (Odds Ratio (OR) 4.85, 95% Confidence Interval (CI) 1.23-19.2, p = 0.02) and > 5000 mL (OR 33.7, 95% CI 4.13-275, p < 0.01). There was no association between negative fluid balance and major postoperative complications (OR 3.33, 95% CI 0.25-44.1, p = 0.36).

CONCLUSIONS

Fluid balance >3000 mL perioperatively during surgery for advanced EOC increased the odds of major postoperative complications. Management of perioperative fluid balance in advanced EOC surgery remains a challenge.

Impact of goal-directed hemodynamic management on the incidence of acute kidney injury in patients undergoing partial nephrectomy: a pilot randomized controlled trial

Background

The incidence of acute kidney injury (AKI) remains high after partial nephrectomy. Ischemia-reperfusion injury produced by renal hilum clamping during surgery might have contributed to the development of AKI. In this study we tested the hypothesis that goal-directed fluid and blood pressure management may reduce AKI in patients following partial nephrectomy.

Methods

This was a pilot randomized controlled trial. Adult patients who were scheduled to undergo partial nephrectomy were randomized into two groups. In the intervention group, goal-directed hemodynamic management was performed from renal hilum clamping until end of surgery; the target was to maintain stroke volume variation < 6%, cardiac index 3.0–4.0 L/min/m² and mean arterial pressure > 95 mmHg with crystalloid fluids and infusion of dobutamine and/or norepinephrine. In the control group, hemodynamic management was performed according to routine practice. The primary outcome was the incidence of AKI within the first 3 postoperative days.

Results

From June 2016 to January 2017, 144 patients were enrolled and randomized (intervention group, n = 72; control group, n = 72). AKI developed in 12.5% of patients in the intervention group and in 20.8% of patients in the control group; the relative reduction of AKI was 39.9% in the intervention group but the difference was not statistically significant (relative risk 0.60, 95% confidence interval [CI] 0.28–1.28; P = 0.180). No significant differences were found regarding AKI classification, change of estimated glomerular filtration rate over time, incidence of postoperative 30-day complications, postoperative length of hospital stay, as well as 30-day and 6-month mortality between the two groups.

Conclusion

For patients undergoing partial nephrectomy, goal-directed circulatory management during surgery reduced postoperative AKI by about 40%, although not significantly so. The trial was underpowered. Large sample size randomized trials are needed to confirm our results.

Trial registration

Clinicaltrials.gov identifier: NCT02803372. Date of registration: June 6, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01288-8.

Effect of Feed Intake on Water Consumption in Horses: Relevance to Maintenance Fluid Therapy

Maintenance fluid therapy is challenging in horses that cannot drink or are denied feed and water because of concerns about gastrointestinal tract function and patency. Intravenous fluid delivery to meet water needs based on current recommendations for maintenance requirements were obtained in fed horses and therefore might not apply to horses that are not being fed. This is a critical flaw because of the interdependence between intestinal tract water and extracellular water to support digestion while preserving water balance, a concept explained by the enterosystemic cycle. Because horses drink less when they are not eating and hence have lower water needs than fed horses, maintenance water requirements need to be adjusted accordingly. This article reviews this topic and identifies benefits of adjusting maintenance fluid therapy to meet lower demands from gastrointestinal function, such as reduced volumes, lower cost, avoidance of overhydration.

Prehospital Damage Control: The Management of Volume, Temperature… and Bleeding!

Damage control resuscitation should be initiated as soon as possible after a trauma event to avoid metabolic decompensation and high mortality rates. The aim of this article is to assess the position of the Trauma and Emergency Surgery Group (CTE) from Cali, Colombia regarding prehospital care, and to present our experience in the implementation of the “Stop the Bleed” initiative within Latin America. Prehospital care is phase 0 of damage control resuscitation. Prehospital damage control must follow the guidelines proposed by the “Stop the Bleed” initiative. We identified that prehospital personnel have a better perception of hemostatic techniques such as tourniquet use than the hospital providers. The use of tourniquets is recommended as a measure to control bleeding. Fluid management should be initiated using low volume crystalloids, ideally 250 cc boluses, maintaining the principle of permissive hypotension with a systolic blood pressure range between 80- and 90-mm Hg. Hypothermia must be management using warmed blankets or the administration of intravenous fluids warmed prior to infusion. However, these prehospital measures should not delay the transfer time of a patient from the scene to the hospital. To conclude, prehospital damage control measures are the first steps in the control of bleeding and the initiation of hemostatic resuscitation in the traumatically injured patient. Early interventions without increasing the transfer time to a hospital are the keys to increase survival rate of severe trauma patients.

Postoperative Ileus and Postoperative Gastrointestinal Tract Dysfunction: Pathogenic Mechanisms and Novel Treatment Strategies Beyond Colorectal Enhanced Recovery After Surgery Protocols

Postoperative ileus (POI) and postoperative gastrointestinal tract dysfunction (POGD) are well-known complications affecting patients undergoing intestinal surgery. GI symptoms include nausea, vomiting, pain, abdominal distention, bloating, and constipation. These iatrogenic disorders are associated with extended hospitalizations, increased morbidity, and health care costs into the billions and current therapeutic strategies are limited. This is a narrative review focused on recent concepts in the pathogenesis of POI and POGD, pipeline drugs or approaches to treatment. Mechanisms, cellular targets and pathways implicated in the pathogenesis include gut surgical manipulation and surgical trauma, neuroinflammation, reactive enteric glia, macrophages, mast cells, monocytes, neutrophils and ICC's. The precise interactions between immune, inflammatory, neural and glial cells are not well understood. Reactive enteric glial cells are an emerging therapeutic target that is under intense investigation for enteric neuropathies, GI dysmotility and POI. Our review emphasizes current therapeutic strategies, starting with the implementation of colorectal enhanced recovery after surgery protocols to protect against POI and POGD. However, despite colorectal enhanced recovery after surgery, it remains a significant medical problem and burden on the healthcare system. Over 100 pipeline drugs or treatments are listed in Clin.Trials.gov. These include 5HT4R agonists (Prucalopride and TAK 954), vagus nerve stimulation of the ENS-macrophage nAChR cholinergic pathway, acupuncture, herbal medications, peripheral acting opioid antagonists (Alvimopen, Methlnaltexone, Naldemedine), anti-bloating/flatulence drugs (Simethiocone), a ghreline prokinetic agonist (Ulimovelin), drinking coffee, and nicotine chewing gum. A better understanding of the pathogenic mechanisms for short and long-term outcomes is necessary before we can develop better prophylactic and treatment strategies.

Effect of azygos arch preservation during thoracoscopic esophagectomy on facilitation of postoperative refilling

PURPOSE

In esophageal cancer surgery, the significance of preserving the azygos arch during thoracoscopic esophagectomy remains unknown. To determine the significance, we examined the difference in postoperative courses between patients who underwent an azygos arch-preserving technique and patients whose azygos arch had been dissected.

METHODS

We retrospectively analyzed 119 patients with esophageal cancer who underwent thoracoscopic esophagectomy from January 2017 to December 2019. Statistical tests, including univariate or multivariate analyses and propensity score-matched analysis, were performed focusing on changes in fluid balance caused by the preservation of the azygos arch.

RESULTS

The azygos arch was preserved in 65 patients and dissected in 54 patients. Urine output on postoperative day 2 was higher, and the IN-OUT balance on postoperative day 2 or accumulated IN-OUT balance up to postoperative day 2 tended to be lower in the azygos arch-preserving group than in the dissected group. The azygos arch-preserving technique did not affect the number of dissected mediastinal lymph nodes.

CONCLUSION

The azygos arch-preserving technique during thoracoscopic esophagectomy facilitated postoperative refilling and avoided postoperative fluid excess. This technique might be a novel minimally invasive option for an otherwise highly invasive esophageal cancer surgery.

Hydroxyethyl starch for perioperative goal-directed fluid therapy in 2020: a narrative review

BACKGROUND

Perioperative fluid management - including the type, dose, and timing of administration -directly affects patient outcome after major surgery. The objective of fluid administration is to optimize intravascular fluid status to maintain adequate tissue perfusion. There is continuing controversy around the perioperative use of crystalloid versus colloid fluids. Unfortunately, the importance of fluid volume, which significantly influences the benefit-to-risk ratio of each chosen solution, has often been overlooked in this debate.

MAIN TEXT

The volume of fluid administered during the perioperative period can influence the incidence and severity of postoperative complications. Regrettably, there is still huge variability in fluid administration practices, both intra-and inter-individual, among clinicians. Goal-directed fluid therapy (GDFT), aimed at optimizing flow-related variables, has been demonstrated to have some clinical benefit and has been recommended by multiple professional societies. However, this approach has failed to achieve widespread adoption. A closed-loop fluid administration system designed to assist anesthesia providers in consistently applying GDFT strategies has recently been developed and tested. Such an approach may change the crystalloid versus colloid debate. Because colloid solutions have a more profound effect on intravascular volume and longer plasma persistence, their use in this more "controlled" context could be associated with a lower fluid balance, and potentially improved patient outcome. Additionally, most studies that have assessed the impact of a GDFT strategy on the outcome of high-risk surgical patients have used hydroxyethyl starch (HES) solutions in their protocols. Some of these studies have demonstrated beneficial effects, while none of them has reported severe complications.

CONCLUSIONS

The type and volume of fluid used for perioperative management need to be individualized according to the patient's hemodynamic status and clinical condition. The amount of fluid given should be guided by well-defined physiologic targets. Compliance with a predefined hemodynamic protocol may be optimized by using a computerized system. The type of fluid should also be individualized, as should any drug therapy, with careful consideration of timing and dose. It is our perspective that HES solutions remain a valid option for fluid therapy in the perioperative context because of their effects on blood volume and their reasonable benefit/risk profile.

A comparison of intraoperative goal-directed intravenous administration of crystalloid versus colloid solutions on the postoperative maximum N-terminal pro brain natriuretic peptide in patients undergoing moderate- to high-risk noncardiac surgery

BACKGROUND

N-terminal pro brain natriuretic peptide (NT-proBNP) and troponin T are released during myocardial wall stress and/or ischemia and are strong predictors for postoperative cardiovascular complications. However, the relative effects of goal-directed, intravenous administration of crystalloid compared to colloid solutions on NT-proBNP and troponin T, especially in relatively healthy patients undergoing moderate- to high-risk noncardiac surgery, remains unclear. Thus, we evaluated in this sub-study the effect of a goal-directed crystalloid versus a goal-directed colloid fluid regimen on postoperative maximum NT-proBNP concentration. We further evaluated the incidence of myocardial injury after noncardiac surgery (MINS) between both study groups.

METHODS

Thirty patients were randomly assigned to receive additional intravenous fluid boluses of 6% hydroxyethyl starch 130/0.4 and 30 patients to receive lactated Ringer's solution. Intraoperative fluid management was guided by oesophageal Doppler-according to a previously published algorithm. The primary outcome were differences in postoperative maximum NT-proBNP (maxNT-proBNP) between both groups. As our secondary outcome we evaluated the incidence of MINS between both study groups. We defined maxNT-proBNP as the maximum value measured within 2 h after surgery and on the first and second postoperative day.

RESULTS

In total 56 patients were analysed. There was no significant difference in postoperative maximum NT-proBNP between the colloid group (258.7 ng/L (IQR 199.4 to 782.1)) and the crystalloid group (440.3 ng/L (IQR 177.9 to 691.2)) during the first 2 postoperative days (P = 0.29). Five patients in the colloid group and 7 patients in the crystalloid group developed MINS (P = 0.75).

CONCLUSIONS

Based on this relatively small study goal-directed colloid administration did not decrease postoperative maxNT-proBNP concentration as compared to goal-directed crystalloid administration.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT01195883 ) Registered on 6th September 2010.

Perioperative fluid management for major elective surgery

BACKGROUND

Adequate fluid balance before, during and after surgery may reduce morbidity. This review examines current concepts surrounding fluid management in major elective surgery.

METHOD

A narrative review was undertaken following a PubMed search for English language reports published before July 2019 using the terms 'surgery', 'fluids', 'fluid therapy', 'colloids', 'crystalloids', 'albumin', 'starch', 'saline', 'gelatin' and 'goal directed therapy'. Additional reports were identified by examining the reference lists of selected articles.

RESULTS

Fluid therapy is a cornerstone of the haemodynamic management of patients undergoing major elective surgery. Both fluid overload and hypovolaemia are deleterious during the perioperative phase. Zero-balance fluid therapy should be aimed for. In high-risk patients, individualized haemodynamic management should be titrated through the use of goal-directed therapy. The optimal type of fluid to be administered during major surgery remains to be determined.

CONCLUSION

Perioperative fluid management is a key challenge during major surgery. Individualized volume optimization by means of goal-directed therapy is warranted during high-risk surgery. In most patients, balanced crystalloids are the first choice of fluids to be used in the operating theatre. Additional research on the optimal type of fluid for use during major surgery is needed.

A Preliminary Investigation into the Association of Chloride Concentration on Morbidity and Mortality in Hospitalized Canine Patients

Purpose

To evaluate whole blood chloride concentration and hospital-acquired AKI in hospitalized canine patients. Secondary outcome measures included the volume-adjusted chloride load, in-hospital mortality and length of ICU stay.

Patients and Methods

This is a prospective, observational study. Sixty dogs admitted to the ICU and receiving IV fluid therapy for >24 hours from February 2018 to July 2019. Corrected chloride and creatinine concentrations were obtained twice daily. Total volume of IV fluid and total chloride load were recorded. Volume-adjusted chloride load (VACL) was calculated by dividing the chloride administered by the volume of fluid administered. Hospital-acquired AKI was defined as an increase in creatinine of ≥26.5 μmol/L (0.3 mg/dL) or 150% from baseline to maximum. Survival to hospital discharge or non-survival and ICU length of stay were also recorded.

Results

Fifteen out of 60 patients developed hospital-acquired AKI. Maximum corrected chloride was significantly different in AKI group (median 122.3 mmol/L) vs non-AKI group (median 118.1 mmol/L; p=0.0002). Six out of 60 patients developed hyperchloremia. Hyperchloremic patients were significantly more likely to develop in-hospital AKI (p=0.03). Patients hospitalized ≥2 days had a significantly higher [Cl⁻]_max compared to those with shorter ICU stay (121.8 ± 5.9 mmol/L vs 117.5 ± 4.3 mmol/L; p=0.002). Eight out of 60 patients were non-survivors. Maximum corrected chloride and creatinine concentrations were not significantly different between survivors and non-survivors. VACL was not significantly different between AKI or mortality groups.

Conclusion

Maximum corrected chloride concentration was significantly higher in dogs with hospital-acquired AKI, even amongst dogs without hyperchloremia. Additionally, maximum corrected chloride concentrations were significantly higher in dogs hospitalized in the ICU longer compared to those hospitalized for fewer than two days. There was no significant difference in VACL in any of the outcome groups. Results from this study suggest alterations in chloride may be observed alongside the development of acute kidney injuries. Future studies in critically ill dogs are warranted.

Ileus in the critically ill: causes, treatment and prevention

Bowel dysfunction, especially ileus, has been increasingly recognized in critically ill patients. Ileus is commonly associated to constipation, however abnormal motility can also concern the upper digestive tract, therefore impaired gastrointestinal transit (IGT) seems to be a more appropriate term. IGT, especially constipation, is common among patients under mechanical ventilation, occurring in up to 80% of the patients during the first week, and has been associated with worse outcome in intensive care unit (ICU). It is acknowledged that the most relevant definition for constipation in ICU is the absence of stool for the first six days after admission. Concerning the upper digestive intolerance (UDI), the diagnosis should rely only on vomiting and the systematic gastric residual volume (GRV) monitoring should be avoided. IGT results from a complex pathophysiology in which both the critical illness and its specific treatments may have a deleterious role. Both observational and experimental studies have shown the deleterious effect of sepsis, multiorgan failure, sedation (especially opioids) and mechanical ventilation on gut function. To date few studies have reported effect of treatment on IGT and the level of evidence is low. However, cholinesterase inhibitors seem safe and could probably be used in case of constipation but remains poorly prescribed. Prevention with bowel management protocol using osmotic laxatives appears to be safe but did not demonstrate its effectiveness. For patients treated with high posology of opioids during sedation, enteral opioid antagonists may be a promising strategy.

Role of TFA-1 adhesive forehead sensors in predicting fluid responsiveness in anaesthetised children: A prospective cohort study

BACKGROUND

The TFA-1 adhesive forehead sensor is a newly developed pulse oximeter for the measurement of the plethysmographic variability index (PVI) at the forehead, and for the rapid detection of changes in oxygen saturation during low perfusion.

OBJECTIVES

We evaluated the ability of the TFA-1 sensor to predict fluid responsiveness in children under general anaesthesia.

DESIGN

Prospective cohort study.

SETTING

Single tertiary care children's hospital.

PATIENTS

Thirty-seven children aged 1 to 5 years under general anaesthesia and requiring invasive arterial pressure monitoring.

MAIN OUTCOME MEASURES

The baseline PVI of TFA-1 and finger sensors, respiratory variation of aorta blood flow peak velocity (ΔVpeak) and stroke volume index (SVI) obtained using transthoracic echocardiography were assessed. After fluid loading of 10 ml kg crystalloids over 10 min, SVI was reassessed. Responders were defined as those with an increase in SVI greater than 15% from the baseline. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive ability of the PVI of TFA-1 and finger sensors and ΔVpeak for fluid responsiveness.

RESULTS

Seventeen (56.6%) patients responded to volume expansion. Before fluid loading, the PVI of TFA-1 and finger sensors and ΔVpeak (mean ± SD) of the responders were 11.2 ± 4.4, 11.4 ± 5.1 and 14.8 ± 3.9%, respectively, and those of the nonresponders were 7.4 ± 3.9, 8.1 ± 3.6 and 11.0 ± 3.3%, respectively. ROC curve analysis indicated that the PVI of TFA-1 and finger sensors and ΔVpeak could predict fluid responsiveness. The areas under the curve were 0.8 [P = 0.00; 95% confidence interval (CI) 0.60 to 0.91], 0.7 (P = 0.02; 95% CI 0.53 to 0.87) and 0.8 (P = 0.00; 95% CI 0.59 to 0.91), respectively. The cut-off values for the PVI of TFA-1 and finger sensors and ΔVpeak were 6.0, 9.0 and 10.6%, respectively.

CONCLUSION

The PVI of TFA-1 forehead sensor is a good alternative, but is not superior to the finger sensor and ΔVpeak in evaluating fluid responsiveness in mechanically ventilated children under general anaesthesia.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, NCT03132480.

[Anesthesiological concepts in fast-track arthroplasty]

Whereas only a few years ago the only expectation of skilful anesthesia was an undisturbed execution of surgical procedures, today this has changed to a perioperative responsibility in which all physicians involved in the treatment process try to optimize the existing circumstances and risks of the patient before, during and after surgery. Thus, the tasks for the anesthesiologist have been mainly extended to a rapid recovery strategy with as few side effects as possible, such as nausea and vomiting or postoperative cognitive deficits (POCD). The establishment of evident structures and the introduction of suitable perioperative procedures with the goal of maintaining homeostasis, adequate opioid-sparing pain treatment and rapid postoperative convalescence determine the anesthesiological fast-track concept.

Intraoperative fluid therapy and postoperative complications during minimally invasive esophagectomy for esophageal cancer: a single-center retrospective study

PURPOSE

Compared with open thoracotomy, minimally invasive esophagectomy (MIE) methods, such as transhiatal or thoracoscopic esophagectomy, likely have lower morbidity. However, the relationship between intraoperative fluid management and postoperative complications after MIE remains unclear. Thus, we investigated the association of cumulative intraoperative fluid balance and postoperative complications in patients undergoing MIE.

METHODS

This single-center retrospective cohort study examined patients undergoing thoracoscopic esophagectomy for esophageal cancer in the prone position. Postoperative complications included pneumonia, arrhythmia, thrombotic events and acute kidney injury (AKI). We compared patients with higher and lower intraoperative fluid balance (higher and lower than the median). Multivariable logistic regression analyses were performed to estimate the odds ratio of intraoperative fluid balance status on the incidence of postoperative complications.

RESULTS

In total, 135 patients were included in the study. Postoperative complications occurred in 43 (32%), including cardiac arrhythmia (n = 12, 9%), thrombosis (n = 20, 15%), pneumonia (n = 13, 10%), and AKI required hemodialysis (n = 1, 1%). Patients with a higher fluid balance had higher incidence of complications than those with a lower fluid balance (46% vs. 18%, p < 0.001). After adjusting for age, ASA-PS ≥ III, blood loss, and the use of radical surgery, the higher intraoperative fluid balance group was significantly and independently associated with postoperative complications (adjusted OR 5.31, 95% CI 2.26-13.6, p < 0.0001).

CONCLUSIONS

In patients undergoing thoracoscopic esophagectomy in the prone position, a greater intraoperative positive fluid balance was independently associated with a higher incidence of complications.

Effect of cumulative fluid balance on acute kidney injury and patient outcomes after orthotopic liver transplantation: A retrospective cohort study

AIM

Acute kidney injury (AKI) is a serious complication following orthotopic liver transplantation (OLT) and it affects long-term patient survival. The aims of this study were to identify the effects of cumulative fluid balance (FB) on early post-OLT AKI and adverse outcomes and to construct a model to predict AKI.

METHODS

We retrospectively analysed 146 adult patients who underwent OLT. AKI severity was classified according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Univariate and multivariate logistic regression analyses were used to evaluate the association between cumulative FB and post-OLT AKI. The Kaplan-Meier method was used to estimate the survival rate.

RESULTS

Within the perioperative period of 72 hours, 50% (66/132) of patients developed AKI, with 36 (54%), 16 (24%) and 14 (21%) patients having AKI stages 1, 2 and 3, respectively. The cumulative FB was the risk factors for post-OLT AKI (odds ratio [OR], 1.011; 95% confidence interval [CI], 1.156~6.001; P = .021). Preoperative albumin was a protective factor for post-OLT AKI (OR, 0.309; 95% CI, 0.140~0.731; P = .007). The AKI group requires renal replacement therapy (RRT) more (15.2% vs 0%, P = .001) and associated with postoperative complications (56% vs 28.8%, P = .003). The complication-free survival was lower in the AKI group ([11.90 vs 18.74] months, χ² = 9.60, P = .002).

CONCLUSION

Cumulative FB within 72 hours is associated with post-OLT AKI and requires RRT. Cumulative FB impacts the long-term complication-free survival of the recipients.

Perioperative Glucocorticoid Therapy for Patients with Adrenal Insufficiency: Dosing Based on Pharmacokinetic Data

BACKGROUND

Perioperative glucocorticoid therapy for patients with adrenal insufficiency (AI) is currently based on anecdotal reports, without supporting pharmacokinetic data.

METHODS

We determined the half-life, clearance, and volume of distribution of 2 consecutive intravenously (IV)-administered doses of hydrocortisone (15 or 25 mg every 6 hours) to 22 dexamethasone-suppressed healthy individuals and used the data to develop a novel protocol to treat 68 patients with AI who required surgical procedures. Patients received 20 mg of hydrocortisone orally 2 to 4 hours before intubation and were started on 25 mg of IV hydrocortisone every 6 hours for 24 hours and 15 mg every 6 hours during the second day. Nadir cortisol concentrations were repeatedly measured during that period.

RESULTS

In healthy individuals, cortisol half-life was longer when the higher hydrocortisone dose was administered (2.02 ± 0.15 vs 1.81 ± 0.11 hours; P < 0.01), and in patients with AI, the half-life was longer than in healthy individuals given the same hydrocortisone dose. In both populations, the cortisol half-life increased further with the second hormone injection. Prolongation of cortisol half-life was due to decreased hydrocortisone clearance and an increase in its volume of distribution. Nadir cortisol levels determined throughout the 48 postoperative hours were within the range of values and often exceeded those observed perioperatively in patients without adrenal dysfunction.

CONCLUSIONS

Cortisol pharmacokinetics are altered in the postoperative period and indicate that lower doses of hydrocortisone can be safely administered to patients with AI undergoing major surgery. The findings of this investigation call into question the current practice of administering excessive glucocorticoid supplementation during stress.

Introduction of an enhanced recovery protocol into a laparoscopic living donor nephrectomy programme

INTRODUCTION

Living-donor renal transplantation is the optimal treatment for patients with end-stage renal disease. The rate of living donation in the UK is sub-optimal, and potential donor concerns regarding postoperative recovery may be contributory. Enhanced recovery programmes are well described for a number of surgical procedures, but experience in living-donor surgery is sparse. This study reports the impact of introducing an enhanced recovery protocol into a living-donor renal transplant programme.

MATERIALS AND METHODS

All consecutive patients undergoing laparoscopic living-donor nephrectomy over a 25-month period were included. The principles of enhanced recovery were fluid restriction, morphine sparing and expectation management. Outcome measures were postoperative pain scores and complications for donor and recipients.

RESULTS

Standard care was provided for 24 (30%) patients and 57 (70%) followed an enhanced recovery pathway. The latter group received significantly less preoperative intravenous fluid (0ml vs 841ml p < 000.1) and opiate medication (14.83mg vs 23.85mg p = 0.001). Pain scores, postoperative complications and recipient transplant outcomes were comparable in both groups.

CONCLUSIONS

Enhanced recovery for living-donor nephrectomy is a safe approach for donors and recipients. Application of these techniques and further refinement should be pursued to enhance the experience of living donors.

Intraoperative Anesthetic Management of Patients with Chronic Obstructive Pulmonary Disease to Decrease the Risk of Postoperative Pulmonary Complications after Abdominal Surgery

Patients with chronic obstructive pulmonary disease (COPD) exhibit airflow limitation and suboptimal lung function, and they are at high risk of developing postoperative pulmonary complications (PPCs). We aimed to determine the factors that would decrease PPC risk in patients with COPD. We retrospectively analyzed 419 patients with COPD who were registered in our institutional PPC database and had undergone an abdominal surgery under general anesthesia. PPCs comprised respiratory failure, pleural effusion, atelectasis, respiratory infection, and bronchospasm; the presence or type of PPC was diagnosed by respiratory physicians and recorded in the database before this study. Binary logistic regression was used for statistical analysis. Of the 419 patients, 121 patients (28.8%) experienced 200 PPCs. Multivariable analysis showed three modifiable anesthetic factors that could decrease PPC risk: low tidal volume ventilation, restricted fluid infusion, and sugammadex-induced neuromuscular blockade reversal. We found that the 90-day mortality risk was significantly greater in patients with PPC than in those without PPC (5.8% vs. 1.3%; p = 0.016). Therefore, PPC risk in patients with COPD can be decreased if low tidal volume ventilation, restricted fluid infusion, and sugammadex-induced reversal during abdominal surgery are efficiently managed, as these factors result in decreased postoperative mortality.

Early postoperative weight gain is associated with increased risk of graft failure in living donor liver transplant recipients

Fluid overload (FO) has been shown to adversely affect multiple organs and survival in critically ill patients. Liver transplantation (LT) carries the risk of massive transfusion, which frequently results in FO. We investigated the association of postoperative weight gain with graft failure, early allograft dysfunction (EAD), and overall mortality in LT. 1833 living donor LT (LDLT) recipients were retrospectively analysed. Patients were divided into 2 groups according to postoperative weight gain (<3% group [n = 1391] and ≥3% group [n = 442]) by using maximally selected log-rank statistics for graft failure. Multivariate Cox and logistic regression analyses were performed. The ≥3% group was associated with graft failure (adjusted HR [aHR], 1.763; 95% CI, 1.248–2.490; P = 0.001). When postoperative weight change was used as a continuous variable, the aHR for each 1% increase in postoperative weight was 1.045 (95% CI, 1.009–1.082; P = 0.015). In addition, the ≥3% group was associated with EAD (adjusted OR [aOR], 1.553; 95% CI, 1.024–2.356; P = 0.038) and overall mortality (aHR, 1.731; 95% CI, 1.182–2.535; P = 0.005). In conclusion, postoperative weight gain may be independently associated with increased risk of graft failure, EAD, and mortality in LDLT recipients.

Goal-Directed vs Traditional Approach to Intraoperative Fluid Therapy during Open Major Bowel Surgery: Is There a Difference?

Introduction

Optimum perioperative fluid therapy is important to improve the outcome of the surgical patient. This study prospectively compared goal-directed intraoperative fluid therapy with traditional fluid therapy in general surgical patients undergoing open major bowel surgery.

Methodology

Patients between 20 and 70 years of age, either gender, ASA I and II, and scheduled for elective open major bowel surgery were included in the study. Patients who underwent laparoscopic and other surgeries were excluded. After routine induction of general anaesthesia, the patients were randomised to either the control group (traditional fluid therapy), the FloTrac group (based on stroke volume variation), or the PVI group (based on pleth variability index). Fluid input and output, recovery characteristics, and complications were noted.

Results

306 patients, with 102 in each group, were enrolled. Five patients (control (1), FloTrac (2), and PVI (2)) were inoperable and were excluded. Demographic data, ASA PS, anaesthetic technique, duration of surgery, and surgical procedures were comparable. The control group received significantly more crystalloids (3200 ml) than the FloTrac (2000 ml) and PVI groups (1875 ml), whereas infusion of colloids was higher in the FloTrac (400–700 ml) and PVI (200–500 ml) groups than in the control group (0–500 ml). The control group had significantly positive net fluid balance intraoperatively (2500 ml, 9 ml/kg/h) compared to the FloTrac (1515 ml, 5.4 ml/kg/h) and PVI (1420 ml, 6 ml/kg/h) groups. Days to ICU stay, HDU stay, return of bowel movement, oral intake, morbidity, duration of hospital stay, and survival rate were comparable. The total number of complications was not different between the three groups. Anastomotic leaks occurred more often in the Control group than in the others, but the numbers were small.

Conclusions

Use of goal-directed fluid management, either with FloTrac or pleth variability index results in a lower volume infusion and lower net fluid balance. However, the complication rate is similar to that of traditional fluid therapy. This trial is registered with CTRI/2018/04/013016.

Early postoperative fluid retention is a strong predictor for complications after pancreatoduodenectomy

BACKGROUND

Perioperative fluid overload has been reported to increase complications after a variety of operative procedures. This study was conducted to investigate the incidence of fluid retention after pancreatic resection and its association with postoperative complications.

METHODS

Data from 1174 patients undergoing pancreatoduodenectomy between 2010 and 2016 were collected from the Swedish National Pancreatic and Periampullary Cancer Registry. Early postoperative fluid retention was defined as a weight gain ≥2 kg on postoperative day 1. Outcome measures were overall complications, as well as procedure-specific complications.

RESULTS

The weight change on postoperative day 1 ranged from -1 kg to +9 kg. A total of 782 patients (66.6%) were considered to have early fluid retention. Patients with fluid retention had significantly higher rates of total complications (p = 0.002), surgical complications (p = 0.001), pancreatic anastomotic leakage (p = 0.018) and wound infection (p = 0.023). Multivariable logistic regression confirmed early fluid retention as an independent risk factor for total complications (OR 1.46; p = 0.003), surgical complications (OR 1.49; p = 0.002), pancreatic anastomotic leakage (OR 1.48; p = 0.027) and wound infection (OR 1.84; p = 0.023).

CONCLUSIONS

Fluid retention is common after elective pancreatic resection, and its associated with an increased rate of postoperative complications.

[Anesthesia for renal transplantation in patients with dilated cardiomyopathy: a retrospective study of 31 cases]

BACKGROUND AND OBJECTIVES

Dilated cardiomyopathy is a state of progressive enlargement of cardiac chambers mainly left ventricle which leads to decreased cardiac output and ultimately cardiac failure. Although it has multifactorial etiology, it is quite common in patients with end stage renal disease who require renal transplant surgery for their cure. Both conditions go side by side and anesthetic management of such cases poses real challenge to anesthesiologist. Strict monitoring and control of cardiac physiology is of utmost importance besides meticulous fluid management, thus preserving renal blood flow on one hand and preventing cardiac failure on other hand. This is the basis of achieving good outcome of the renal transplant surgery.

METHODS

This is a retrospective observational study done by analysing electronic database of 31 patients with dilated cardiomyopathy who underwent renal transplant surgery. Data was studied in terms of demographics, duration of renal disease, comorbidities mainly hypertension, cardiac echo graphic findings including ejection fraction, medications and post-operative outcome.

RESULTS

Most common perioperative complication in this patient population was hypotension (51.61%) followed by pulmonary complications postoperative mechanical ventilation (12.9%) and pulmonary edema (6.45%). High incidence of hypotension may be a causative factor to increased rate of delayed graft functioning (12.9%) and acute tubular necrosis (2.23%) in these patients.

CONCLUSION

Strict monitoring and control of hemodynamic parameters as well as meticulous fluid therapy is the cornerstone in improving outcome in patients with dilated cardiomyopathy undergoing renal transplant surgery.

Liver mitochondrial membrane permeability modulation in insulin-resistant, uninephrectomised male rats by Clerodendrum volubile P. Beauv and Manihot esculenta Crantz

Background

Non-alcoholic fatty liver disease, which occurs in people who are not alcohol drinkers, describes some of the pathogenic conditions that may be in the least characterized by simple steatosis or can be as serious as non-alcoholic steatohepatitis and cirrhosis. Its mechanistic pathogenesis has been said to arise from insulin resistance and oxidative stress, which may be compounded by obesity. An experimental model showing, systemic insulin resistance, obesity and accumulated hepatic fatty acids was created in adult male rats using high-fat diet manipulation and surgical removal of the left kidney (uninephrectomy). This study sought to identify the impact of these multiple burdens on the liver mitochondrial membrane permeability transition pore opening, and the possible in vitro effects of the extracts ofClerodendrum volubileandManihot esculentaleaves on the membrane permeabilization.

Results

The results indicated that the methanolic extract ofClerodendrum volubileleaf inhibited mitochondrial membrane pore opening in the insulin resistance condition or when it is followed by uni-nephrectomy, while the ethanolic extract ofManihot esculentaleaf does the same in the insulin resistance condition both prior to and following uni-nephrectomy.

Conclusion

Since the vegetable extracts were able to abrogate mitochondrial pore opening at low concentrations, the structural integrity of the mitochondria can possibly be restored over time if treated by the vegetable extracts. Research efforts should, therefore, be made to harness the drugability of the bioactives of these vegetables for use in the treatment of non-alcoholic fatty liver disease arising from insulin resistance and renal failure.

Pulse Pressure Variation-Guided Fluid Therapy during Supratentorial Brain Tumour Excision: A Randomized Controlled Trial

BACKGROUND:

Goal-directed fluid therapy (GDFT) improved patient outcomes in various surgical procedures; however, its role during mass brain resection was not well investigated.

AIM:

In this study, we evaluated a simple protocol based on intermittent evaluation of pulse pressure variation for guiding fluid therapy during brain tumour resection.

METHODS:

Sixty-one adult patients scheduled for supratentorial brain mass excision were randomized into either GDFT group (received intraoperative fluids guided by pulse pressure variation) and control group (received standard care). Both groups were compared according to the following: brain relaxation scale (BRS), mean arterial pressure, heart rate, urine output, intraoperative fluid intake, postoperative serum lactate, and length of hospital stay.

RESULTS:

Demographic data, cardiovascular data (mean arterial pressure and heart rate), and BRS were comparable between both groups. GDFT group received more intraoperative fluids {3155 (452) mL vs 2790 (443) mL, P = 0.002}, had higher urine output {2019 (449) mL vs 1410 (382) mL, P < 0.001}, and had lower serum lactate {0.9 (1) mmol versus 2.5 (1.1) mmol, P = 0.03} compared to control group.

CONCLUSION:

In conclusion, PPV-guided fluid therapy during supratentorial mass excision, increased intraoperative fluids, and improved peripheral perfusion without increasing brain swelling.

Should Transfusion Trigger Thresholds Differ for Critical Care Versus Perioperative Patients? A Meta-Analysis of Randomized Trials

Supplemental Digital Content is available in the text.

Objective:

To address the significant uncertainty as to whether transfusion thresholds for critical care versus surgical patients should differ.

Design:

Meta-analysis of randomized controlled trials.

Setting:

Medline, EMBASE, and Cochrane Library searches were performed up to 15 June 2016.

Patients:

Trials had to enroll adult surgical or critically ill patients for inclusion.

Interventions:

Studies had to compare a liberal versus restrictive threshold for the transfusion of allogeneic packed RBCs.

Measurements and Main Results:

The primary outcome was 30-day all-cause mortality, sub-grouped by surgical and critical care patients. Secondary outcomes included myocardial infarction, stroke, renal failure, allogeneic blood exposure, and length of stay. Odds ratios and weighted mean differences were calculated using random effects meta-analysis. To assess whether subgroups were significantly different, tests for subgroup interaction were used. Subgroup analysis by trials enrolling critically ill versus surgical patients was performed. Twenty-seven randomized controlled trials (10,797 patients) were included. In critical care patients, restrictive transfusion resulted in significantly reduced 30-day mortality compared with liberal transfusion (odds ratio, 0.82; 95% CI, 0.70–0.97). In surgical patients, a restrictive transfusion strategy led to the opposite direction of effect for mortality (odds ratio, 1.31; 95% CI, 0.94–1.82). The subgroup interaction test was significant (p = 0.04), suggesting that the effect of restrictive transfusion on mortality is statistically different for critical care (decreased risk) versus surgical patients (potentially increased risk or no difference). Regarding secondary outcomes, for critically ill patients, a restrictive strategy resulted in reduced risk of stroke/transient ischemic attack, packed RBC exposure, transfusion reactions, and hospital length of stay. In surgical patients, restrictive transfusion resulted in reduced packed RBC exposure.

Conclusions:

The safety of restrictive transfusion strategies likely differs for critically ill patients versus perioperative patients. Further trials investigating transfusion strategies in the perioperative setting are necessary.

Evidence Review Conducted for the Agency for Healthcare Research and Quality Safety Program for Improving Surgical Care and Recovery: Focus on Anesthesiology for Hip Fracture Surgery

Enhanced recovery after surgery (ERAS) protocols represent patient-centered, evidence-based, multidisciplinary care of the surgical patient. Although these patterns have been validated in numerous surgical specialities, ERAS has not been widely described for patients undergoing hip fracture (HFx) repair. As part of the Agency for Healthcare Research and Quality Safety Program for Improving Surgical Care and Recovery, we have conducted a full evidence review of interventions that form the basis of the anesthesia components of the ERAS HFx pathway. A literature search was performed for each protocol component, and the highest levels of evidence available were selected for review. Anesthesiology components of care were identified and evaluated across the perioperative continuum. For the preoperative phase, the use of regional analgesia and nonopioid multimodal analgesic agents is suggested. For the intraoperative phase, a standardized anesthetic with postoperative nausea and vomiting prophylaxis is suggested. For the postoperative phase, a multimodal (primarily nonopioid) analgesic regimen is suggested. A summary of the best available evidence and recommendations for inclusion in ERAS protocols for HFx repair are provided.

Restrictive Versus Liberal Fluid Regimens in Patients Undergoing Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis

BACKGROUND

Pancreaticoduodenectomy is associated with significant morbidity and mortality which may be influenced by perioperative fluid management. It remains unclear whether liberal and restrictive fluid regimens impact mortality and morbidity in patients undergoing pancreaticoduodenectomy.

METHODS

Medline, EMBASE, Cochrane Library and clinicaltrials.gov were searched for studies comparing restrictive and liberal perioperative fluids in patients undergoing pancreaticoduodenectomy. Both prospective and retrospective studies in those undergoing pancreaticoduodenectomy were eligible for inclusion where the patient outcomes were stratified to restrictive and liberal perioperative fluid management regimens, with mortality as the primary outcome. Following study identification, a systematic review and meta-analysis with trial sequential analysis was completed.

RESULTS

Thirteen studies including five prospective trials and eight retrospective analyses totalling 3062 patients were included. Restrictive fluid regimens were associated with a significant reduction in mortality compared to liberal fluid regimens for the overall cohort (odds ratio 0.54; 95% CI 0.31-0.94, p = 0.03). There were no significant differences in complication profile. Subgroup analysis revealed this result was contributed to significantly by retrospective studies. The results of the trial sequential analysis suggest this mortality benefit may be due to a type I statistical error and that further patient numbers are required for definitive conclusions.

CONCLUSIONS

Restrictive fluid regimens are associated with a reduction in mortality following pancreaticoduodenectomy. The clinical relevance of this finding needs to be interpreted pragmatically given the lack of association with significant causes of morbidity and in considering the results of the recently published RELIEF study.

A mathematical model to investigate the effects of intravenous fluid administration and fluid loss

The optimal fluid administration protocol for critically ill perioperative patients is hard to estimate due to the lack of tools to directly measure the patient fluid status. This results in the suboptimal clinical outcome of interventions. Previously developed predictive mathematical models focus on describing the fluid exchange over time but they lack clinical applicability, since they do not allow prediction of clinically measurable indices. The aim of this study is to make a first step towards a model predictive clinical decision support system for fluid administration, by extending the current fluid exchange models with a regulated cardiovascular circulation, to allow prediction of these indices. The parameters of the model were tuned to correctly reproduce experimentally measured changes in arterial pressure and heart rate, observed during infusion of normal saline in healthy volunteers. With the resulting tuned model, a different experiment including blood loss and infusion could be reproduced as well. These results show the potential of using this model as a basis for a decision support tool in a clinical setting.

Improving Orthopedic-Related Postoperative Edema Management in a Rehabilitative Nursing Setting

PURPOSE

The aim of the study was to reduce postoperative edema in total knee and hip arthroplasty rehabilitation patients.

DESIGN

A pre- and posttest design was used for this quality improvement project at a rehabilitation facility.

METHODS

Staff and patient edema education was standardized. Staff pre- and posttests were administered. Patients were interviewed to assess for knowledge of edema management. Chart audits were assessed for edema management and length of stay.

FINDINGS

Average staff knowledge scores (n = 50) increased pre- to posteducational video (64% vs. 70%). Of patients interviewed posteducation (n = 24), 38% were able to list two characteristics of edema. Two chart audits completed pre- and posteducation demonstrated that the majority of patients (n = 30 per group) had edema upon admission (96% vs. 97%). However, length of stay decreased by 3 days (19.2 vs. 16.3).

CONCLUSION

Standardized postoperative edema education can improve staff and patient edema knowledge and management.

CLINICAL RELEVANCE

Edema education is recommended for orthopedic patients in rehabilitation facilities.

Body Mass Index does not affect intraoperative goal-directed fluid requirements

BACKGROUND

Perioperative normovolemia is a major determinant of tissue oxygen availability and postoperative outcome. Thus, adequate volume replacement therapy remains an essential part of perioperative management. Nevertheless, volume optimization in overweight and obese surgical patients with alterations in cardiovascular function, peripheral perfusion, and body composition remains challenging. We, therefore, tested the hypothesis that Body Mass Index (BMI) correlates with fluid requirements during goal-directed management. Furthermore, we evaluated subcutaneous tissue oxygen tension (PsqO2) as an indicator of intravascular volume status and peripheral perfusion.

METHODS

Ninety women, undergoing open gynecologic surgery, were assigned to three groups according to their BMI, (lean: BMI 18.5 to 24.9 kg/m2, overweight: BMI 25 to 29.9 kg/m2, obese: BMI>30 kg/m2). Esophageal Doppler monitoring guided intraoperative crystalloid administration. Tissue oxygen tension was measured with a polarographic electrode in the subcutaneous tissue of the upper arm and served as a secondary outcome parameter.

RESULTS

BMI and fluid requirements did not correlate (r=0.093, P=0.384). Total amounts of administered crystalloids were comparable. Lean patients received 2223±1811 mL in total, while overweight patients received 1866±1261 mL. Obese patients required 2416±1143 mL of total crystalloids (P=0.327). Intra- and postoperative PsqO2 did not differ significantly (97.3 vs. 86.8 vs. 79.6 mmHg, P=0.06 and 74.5 vs. 83 vs. 81.5 mmHg, P=0.63, respectively).

CONCLUSIONS

BMI did not affect intraoperative fluid requirements. Doppler-guided intravascular volume optimization was associated with well-maintained subcutaneous tissue oxygen availability in all BMI groups.