Perioperative fluid management: current consensus and controversies

Day-surgery adult patients with obesity and obstructive sleep apnea: Current controversies and concerns

Obesity and obstructive sleep apnea are considered independent risk factors that can adversely affect perioperative outcomes. A combination of these two conditions in the ambulatory surgery patient can pose significant challenges for the anesthesiologist. Nevertheless, these patients should not routinely be denied access to ambulatory surgery. Instead, patients should be appropriately optimized. Anesthesiologists and surgeons must work together to implement fast-track anesthetic and surgical techniques that will ensure successful ambulatory outcomes.

The effect of passive leg-raising maneuver on hemodynamic stability during anesthesia induction for adult cardiac surgery

Introduction

Some cardiac patients do not tolerate the intravenous fluid load commonly administered before anesthesia induction. This study investigated preinduction passive leg-raising maneuver (PLRM) as an alternative method to fluid loading before cardiac anesthesia.

Methods and materials

During a 6-month period, 120 adult elective heart surgery patients were enrolled in this study and allocated into 2 groups: PLRM group vs control group (n=60). Anesthesia was induced using midazolam, fentanyl, and cisatracurium. Initially, 250 mL of fluid was administrated intravenously in all of patients before anesthesia induction. Then in the PLRM group, PLRM was performed starting 2 minutes before anesthesia induction and continued for 20 minutes after tracheal intubation. In the control group, anesthesia was induced in a simple supine position. Heart rate, invasive mean arterial blood pressure (MAP), and central venous pressure (CVP) were recorded before PLRM, before anesthetic induction, before laryngoscopy, and at 5, 10, and 20 minutes after tracheal intubation. The hypotension episode rate (MAP <70 mmHg) and CVP changes were compared between the 2 groups. The predictive value of the ≥3 mmHg increase in CVP value in response to PLRM for hypotension prevention was defined.

Results

Hypotension rates were lower in the PLRM group (63.3% vs 81.6%; P-value 0.04), and MAP was higher among PLRM patients immediately before anesthetic injection, before laryngoscopy, and 20 minutes after intubation, compared to the control group. PLRM increased CVP by 3.57±4.9 mmHg (from 7.50±2.94 to 11.05±3.55 mmHg), which required several minutes to reach peak value, returning to baseline after 15 minutes. This change did not correlate to subsequent MAP changes; an increase in the CVP value ≥3 mmHg decreased the postinduction hypotension rate by 62.50%.

Conclusion

Preinduction PLRM can provide a more stable hemodynamic status in adult cardiac surgery patients and decreases anesthesia-induced hypotension rates by 62.50%. Rate of the changes in the CVP value caused by PLRM is not predictive of subsequent MAP changes.

Anesthesia-Associated Relative Hypovolemia: Mechanisms, Monitoring, and Treatment Considerations

Although the utility and benefits of anesthesia and analgesia are irrefutable, their practice is not void of risks. Almost all drugs that produce anesthesia endanger cardiovascular stability by producing dose-dependent impairment of cardiac function, vascular reactivity, and compensatory autoregulatory responses. Whereas anesthesia-related depression of cardiac performance and arterial vasodilation are well recognized adverse effects contributing to anesthetic risk, far less emphasis has been placed on effects impacting venous physiology and venous return. The venous circulation, containing about 65–70% of the total blood volume, is a pivotal contributor to stroke volume and cardiac output. Vasodilation, particularly venodilation, is the primary cause of relative hypovolemia produced by anesthetic drugs and is often associated with increased venous compliance, decreased venous return, and reduced response to vasoactive substances. Depending on factors such as patient status and monitoring, a state of relative hypovolemia may remain clinically undetected, with impending consequences owing to impaired oxygen delivery and tissue perfusion. Concurrent processes related to comorbidities, hypothermia, inflammation, trauma, sepsis, or other causes of hemodynamic or metabolic compromise, may further exacerbate the condition. Despite scientific and technological advances, clinical monitoring and treatment of relative hypovolemia still pose relevant challenges to the anesthesiologist. This short perspective seeks to define relative hypovolemia, describe the venous system’s role in supporting normal cardiovascular function, characterize effects of anesthetic drugs on venous physiology, and address current considerations and challenges for monitoring and treatment of relative hypovolemia, with focus on insights for future therapies.

The Effect of a Surgery-Specific Cardiac Output–Guided Haemodynamic Algorithm on Outcomes in Patients Undergoing Pancreaticoduodenectomy in a High-Volume Centre: A Retrospective Comparative Study

In this retrospective observational study performed in a high-volume hepatobiliary–pancreatic unit, we evaluated the effect of a surgery-specific goal-directed therapy (GDT) physiologic algorithm on complications and length of hospital stay. We compared patients who underwent pancreaticoduodenectomy with either a standardised Enhanced Recovery After Surgery program (usual care group), or a standardised Enhanced Recovery After Surgery program in combination with a surgery-specific cardiac output–guided algorithm (GDT group). We included 145 consecutive patients: 47 in the GDT group and 98 in the usual care group. Multivariable associations between GDT and lengths of stay and complications were investigated using negative binomial regression. Postoperative complications were common and occurred at similar frequencies amongst the GDT and usual care groups: 64% versus 68% respectively, P=0.71; odds ratio 0.82; (95% confidence interval 0.39–1.70). There were fewer cardiorespiratory complications in the GDT group. Median (interquartile range) length of hospital stay was ten days (8.0–14.0) in the GDT group compared to 13 days (8.8–21.3) in the usual care group, P=0.01. Median (interquartile range) total intraoperative fluid was 3,000 ml (2,050–4,175) in the GDT group compared to 4,500 ml (3,275–5,325) in the usual care group, P <0.0001; but by day one, the median (interquartile range) fluid balance was similar (1,198 ml [700–1,729] in the GDT group versus 977 ml [419–2,044] in the usual care group, P=0.96). Use of vasoactive medications was higher in the GDT group. In our patients undergoing pancreaticoduodenectomy, GDT was associated with restrictive intraoperative fluid intervention, fewer cardiorespiratory complications and a shorter hospital length of stay compared to usual care. However, we could not exclude an influence of surgical caseload, which we have previously found to be an important variable. We also could not relate the increased hospital length of stay to cardiorespiratory complications in individual patients. Therefore, these observational retrospective findings would require confirmation in a prospective randomised study.

Systemic inflammatory response during cardiac surgery: a pilot study

OBJECTIVE

There is a growing body of evidence indicating that perioperative fluid management during cardiac surgery influences patient care and outcome. The choice of fluid therapy and the degree of systemic inflammatory response triggered during surgery control the effects of tissue edema formation and end-organ function. As such, "goal-directed" fluid resuscitation protocols that measure colloid osmotic pressure (COP) may promote improvements in patient morbidity and mortality.

METHODS

Thirty patients scheduled for primary coronary artery bypass grafting were prospectively randomized for perioperative fluid treatment under COP guidance [albumin (ALB), n = 17] or conventional fluid protocols without COP support (control, n = 13). Whole-blood samples were drawn at four different time intervals including (A) anesthesia induction, (B) 10 minutes after the initiation of cardiopulmonary bypass, (C) at the completion of sternal skin approximation, and (D) 3 hours after admission to the cardiac intensive care unit. Interleukin 6 (IL-6) and IL-8 were measured by immunometric, enzyme-linked immunosorbent assays as well as C-reactive protein. Colloid osmotic pressure values were measured using a colloid osmometer.

RESULTS

As compared with conventional fluid protocols, the patients treated in the intervention (ALB) group received significantly less total perioperative fluid [7893.6 (1874.5) vs 10,754.8 (2403.9), P = 0.001], and this relationship remained after controlling for age, sex, and The Society of Thoracic Surgeons risk score (β = -0.5, t = -3.1, P = 0.005). Colloid osmotic pressure values were significantly higher in the ALB group at time point D after surgery (P = 0.03). There were no significant differences in IL-6, IL-8, and C-reactive protein values between the groups at any of the time blood draw intervals. Perioperative outcomes were evaluated by treatment group. For both groups, the incidence of perioperative morbidity was low and did not differ by treatment group.

CONCLUSIONS

The use of COP-guided fluid resuscitation was associated with a significant reduction in perioperative fluid demand. However, patients prescribed to COP-guided fluid therapy did not experience a reduction in whole-body inflammation or improved surgical outcome as compared with conventional fluid management techniques.

Perioperative fluid therapy: a statement from the international Fluid Optimization Group

BACKGROUND

Perioperative fluid therapy remains a highly debated topic. Its purpose is to maintain or restore effective circulating blood volume during the immediate perioperative period. Maintaining effective circulating blood volume and pressure are key components of assuring adequate organ perfusion while avoiding the risks associated with either organ hypo- or hyperperfusion. Relative to perioperative fluid therapy, three inescapable conclusions exist: overhydration is bad, underhydration is bad, and what we assume about the fluid status of our patients may be incorrect. There is wide variability of practice, both between individuals and institutions. The aims of this paper are to clearly define the risks and benefits of fluid choices within the perioperative space, to describe current evidence-based methodologies for their administration, and ultimately to reduce the variability with which perioperative fluids are administered.

METHODS

Based on the abovementioned acknowledgements, a group of 72 researchers, well known within the field of fluid resuscitation, were invited, via email, to attend a meeting that was held in Chicago in 2011 to discuss perioperative fluid therapy. From the 72 invitees, 14 researchers representing 7 countries attended, and thus, the international Fluid Optimization Group (FOG) came into existence. These researches, working collaboratively, have reviewed the data from 162 different fluid resuscitation papers including both operative and intensive care unit populations. This manuscript is the result of 3 years of evidence-based, discussions, analysis, and synthesis of the currently known risks and benefits of individual fluids and the best methods for administering them.

RESULTS

The results of this review paper provide an overview of the components of an effective perioperative fluid administration plan and address both the physiologic principles and outcomes of fluid administration.

CONCLUSIONS

We recommend that both perioperative fluid choice and therapy be individualized. Patients should receive fluid therapy guided by predefined physiologic targets. Specifically, fluids should be administered when patients require augmentation of their perfusion and are also volume responsive. This paper provides a general approach to fluid therapy and practical recommendations.

Role of intraoperative fluids on hospital length of stay in laparoscopic bariatric surgery: a retrospective study in 224 consecutive patients

BACKGROUND

Studies are unclear regarding optimal intraoperative fluid management during laparoscopic bariatric surgery. The purpose of this 1-year study was to investigate the role of intraoperative fluid administration on hospital length of stay (hLOS) and postoperative complications in laparoscopic bariatric surgery.

METHODS

Patient data analyzed included previously reported demographics, comorbidities, and intraoperative fluid administration on the duration of hLOS and incidence of postoperative complications.

RESULTS

Logistic regression analysis of demographic and comorbidity variables revealed that BMI (P = 0.0099) and history of anemia (P = 0.0084) were significantly associated with hLOS (C index statistic, 0.7). Lower rates of intraoperative fluid administration were significantly associated with longer hLOS (P = 0.0005). Recursive partitioning observed that patients who received <1,750 ml of intraoperative fluids resulted in longer hLOS when compared to patients who received ≥ 1,750 ml (LogWorth = 0.5). When intraoperative fluid administration rates were defined by current hydration guidelines for major abdominal surgery, restricted rates (<5 ml/kg/h) were associated with the highest incidence of extended hLOS (>1 postoperative day) at 54.1 % when compared to 22.9 % with standard rates (5-7 ml/kg/h) and were lowest at 14.5 % in patients receiving liberal rates (>7 ml/kg/h) (P < 0.0001). Finally, lower rates of intraoperative fluid administration were significantly associated with delayed wound healing (P = 0.03).

CONCLUSIONS

The amount of intravenous fluids administered during laparoscopic bariatric surgery plays a significant role on hLOS and on the incidence of delayed wound healing.

Choices in fluid type and volume during resuscitation: impact on patient outcomes

We summarize the emerging new literature regarding the pathophysiological principles underlying the beneficial and deleterious effects of fluid administration during resuscitation, as well as current recommendations and recent clinical evidence regarding specific colloids and crystalloids. This systematic review allows us to conclude that there is no clear benefit associated with the use of colloids compared to crystalloids and no evidence to support the unique benefit of albumin as a resuscitation fluid. Hydroxyethyl starch use has been associated with increased acute kidney injury (AKI) and use of renal replacement therapy. Other synthetic colloids (dextran and gelatins) though not well studied do not appear superior to crystalloids. Normal saline (NS) use is associated with hyperchloremic metabolic acidosis and increased risk of AKI. This risk is decreased when balanced salt solutions are used. Balanced crystalloid solutions have shown no harmful effects, and there is evidence for benefit over NS. Finally, fluid resuscitation should be applied in a goal-directed manner and targeted to physiologic needs of individual patients. The evidence supports use of fluids in volume-responsive patients whose end-organ perfusion parameters have not been met.

Surgery for lung adenocarcinoma with smokers' polycythemia: a case report

Background

Smoking is a cause of cancer and polycythemia. Therefore, surgeons who treat patients with cancer may also encounter patients with polycythemia. However, few cases of surgical patients with polycythemia have been reported; in particular, a surgical case involving smokers’ polycythemia has never been reported. We herein report a patient with lung cancer and smokers’ polycythemia who successfully underwent lobectomy with control of hematocrit based on a modified formula in the perioperative period.

Case presentation

A 67-year-old man underwent abdominoperineal resection for rectal carcinoma in June 2008. A ground glass opacity had been identified in the upper lobe of the right lung and was gradually enlarging. In March 2012, bronchoscopic cytology for investigation of the mass revealed non-small cell lung cancer, suggesting primary lung non-small cell carcinoma (T1bN0M0, Stage IA). When he was referred to our hospital for surgery, his complete blood count showed a red blood cell level of 6.50×10⁶/μL, hemoglobin of 21.0 g/dL, and hematocrit of 60.1%. The hematologists’ diagnosis was secondary polycythemia due to heavy smoking (smokers’ polycythemia) because the white blood cell and platelet counts were within normal limits and the erythropoietin was not increased. We calculated the appropriate phlebotomy and infusion volumes based on a formula that we modified. After 550 g of blood was phlebotomized to reduce the hematocrit to approximately 55%, video-assisted right lung upper lobectomy with lymph node dissection was performed in April 2012. The hematocrit was maintained at <50% postoperatively, and the patient was uneventfully discharged on postoperative day 7. The predictive hematocrit and measured hematocrit were very closely approximated in this case.

Conclusion

We experienced a patient with smokers’ polycythemia who underwent right upper lobectomy for adenocarcinoma. The findings in this case report are meaningful for surgeons treating cancer patients because there are few reports discussing the perioperative care of surgical patients with polycythemia.

Fluid overload deteriorate chylothorax: evaluation in a canine model

No conservative treatments for chylothorax have yet been established, and surgical ligation of the thoracic duct is required in many cases. In the present study, we investigated the management of body fluid in a canine chylothorax model. Twelve beagle dogs were divided evenly into three groups: A, B, and C. Under general anesthesia, the thoracic duct was cut and opened, and the amount of lymph fluid leakage was measured. Intravenous extracellular fluid infusion was started at 5mL/kg/h for the first 2h, and then between 2 and 4h, the infusion rate was increased to 10 mL/kg/h in group A and to 20mL/kg/h in group B. During the first 2h after cutting the thoracic duct, the mean lymph fluid leakage rates in groups A, B, and C were 0.466, 0.635, and 0.575 mL/kg/h, respectively. The rates of leakage did not differ significantly among the groups. Between 2 and 4h, the mean rates of leakage were 0.750, 1.43, and 0.544mL/kg/h, respectively, being significantly higher in groups A and B than in group C. The amount of lymph fluid ascending the thoracic duct correlates with the amount of intravenous fluid infusion. For the management of chylothorax, it is important to avoid fluid overload.