'Liberal' vs. 'restrictive' perioperative fluid therapy--a critical assessment of the evidence

Fluid management guided by a continuous non-invasive arterial pressure device is associated with decreased postoperative morbidity after total knee and hip replacement

Background

The use of goal directed fluid protocols in intermediate risk patients undergoing hip or knee replacement was studied in few trials using invasive monitoring. For this reason we have implemented two different fluid management protocols, both based on a novel totally non-invasive arterial pressure monitoring device and compared them to the standard (no-protocol) treatment applied before the transition in our academic institution.

Methods

Three treatment groups were compared in this prospective study: the observational (CONTROL, N = 40) group before adoption of fluid protocols and two randomized groups after the transition to protocol fluid management with the use of the continuous non-invasive blood pressure monitoring (CNAP®) device. In the PRESSURE group (N = 40) standard variables were used for restrictive fluid therapy. Goal directed fluid therapy using pulse pressure variation was used in the GDFT arm (N = 40). The influence on the rate of postoperative complications, on the hospital length of stay and other parameters was assessed.

Results

Both protocols were associated with decreased fluid administration and maintained hemodynamic stability. Reduced rate of postoperative infection and organ complications (22 (55 %) vs. 33 (83 %) patients; p = 0.016; relative risk 0.67 (0.49–0.91)) was observed in the GDFT group compared to CONTROL. Lower number of patients receiving transfusion (4 (10 %) in GDFT vs. 17 (43 %) in CONTROL; p = 0.005) might contribute to this observation. No significant differences were observed in other end-points.

Conclusion

In our study, the use of the fluid protocol based on pulse pressure variation assessed using continuous non-invasive arterial pressure measurement seems to be associated with a reduction in postoperative complications and transfusion needs as compared to standard no-protocol treatment.

Trial registration

ACTRN12612001014842

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-015-0131-8) contains supplementary material, which is available to authorized users.

Intraoperative Fluid Restriction in Pancreatic Surgery: A Double Blinded Randomised Controlled Trial

Background

Perioperative fluid restriction in a variety of operations has shown improvement of: complications, recovery of gastrointestinal function and length of stay (LOS). We investigated effects of crystalloid fluid restriction in pancreatic surgery. Our hypothesis: enhanced recovery of gastrointestinal function.

Methods

In this double-blinded randomized trial, patients scheduled to undergo pancreatoduodenectomy (PD) were randomized: standard (S:10ml/kg/hr) or restricted (R:5ml/kg/hr) fluid protocols. Primary endpoint: gastric emptying scintigraphically assessed on postoperative day 7.

Results

In 66 randomized patients, complications and 6-year survival were analyzed. 54 patients were analyzed in intention to treat: 24 S-group and 30 R-group. 32 patients actually underwent a PD and 16 patients had a palliative gastrojejunostomy bypass operation in the full protocol analysis. The median gastric emptying time (T½) was 104 minutes (S-group, 95% confidence interval: 74–369) versus 159 minutes (R-group, 95% confidence interval: 61–204) (P = 0.893, NS). Delayed gastric emptying occurred in 10 patients in the S-group and in 13 patients in the R-group (45% and 50%, P = 0.779, NS). The primary outcome parameter, gastric emptying time, did not show a statistically significant difference between groups.

Conclusion

A fluid regimen of 10ml/kg/hr or 5ml/kg/hr during pancreatic surgery did not lead to statistically significant differences in gastric emptying. A larger study would be needed to draw definite conclusions about fluid restriction in pancreatic surgery.

Trial registration

ISRCTN62621488

Radical Cystectomy Perioperative Care Redesign

OBJECTIVE

To present an evidence-based review of the perioperative management of the radical cystectomy (RC) patient in the context of a care redesign initiative.

METHODS

A comprehensive review of the key factors associated with perioperative management of the RC patient was completed. PubMed, Medline, and the Cochrane databases were queried via a computerized search. Specific topics were reviewed within the scope of the three major phases of perioperative management: preoperative, intraoperative, and postoperative. Preference was given to evidence from prospective randomized trials, meta-analyses, and systematic reviews.

RESULTS

Preoperative considerations to improve care in the RC patient should include multi-disciplinary medical optimization, patient education, and formal coordination of care. Efforts to mitigate the risk of malnutrition and reduce postoperative gastrointestinal complications may include carbohydrate loading, protein nutrition supplementation, and avoiding bowel preparation. Intraoperatively, a fluid and opioid sparing protocol may reduce fluid shifts and avoid complications from paralytic ileus. Finally, enhanced recovery protocols including novel medications, early feeding, and multi-modal analgesia approaches are associated with earlier postoperative convalescence.

CONCLUSION

RC is a complex and morbid procedure that may benefit from care redesign. Evidence based quality improvement is integral to this process. We hope that this review will help guide further improvement initiatives for RC.

Diagnostic accuracy of stroke volume variation measured with uncalibrated arterial waveform analysis for the prediction of fluid responsiveness in patients with impaired left ventricular function: a prospective, observational study

Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasive fashion. Evidence about the validity of the technique in patients with impaired left ventricular function is scarce, while adequate cardiac preload assessment would be of great value in these patients. The aim of this study was to investigate the diagnostic accuracy of stroke volume variation (SVV) measured with the FloTrac/Vigileo™ system in patients with impaired left ventricular function. In this prospective, observational study, 22 patients with a left ventricular ejection fraction of 40 % or less undergoing elective coronary artery bypass grafting were included. Patients were considered fluid responsive if cardiac output increased with 15 % or more after volume loading (7 ml kg⁻¹ ideal body weight). The following variables were calculated: area under the receiver operating characteristics (ROC) curve, ideal cut-off value for SVV, sensitivity, specificity, positive and negative predictive values, and overall accuracy. In addition, SVV cut-off points to obtain 90 % true positive and 90 % true negative predictions were determined. ROC analysis revealed an area under the curve of 0.70 [0.47; 0.92]. The ideal SVV cut-off value was 10 %, with a corresponding sensitivity and specificity of 56 and 69 % respectively. Overall accuracy was 64 %, positive and negative predictive values were 69 and 56 % respectively. SVV values to obtain more than 90 % true positive and negative predictions were 16 and 6 % respectively. The ability of uncalibrated arterial waveform analysis SVV to predict fluid responsiveness in patients with impaired LVF was low.

The effect of aging on the cutaneous microvasculature

Aging is associated with a progressive loss of function in all organs. Under normal conditions the physiologic compensation for age-related deficits is sufficient, but during times of stress the limitations of this reserve become evident. Explanations for this reduction in reserve include the changes in the microcirculation that occur during the normal aging process. The microcirculation is defined as the blood flow through arterioles, capillaries and venules, which are the smallest vessels in the vasculature and are embedded within organs and tissues. Optimal strategies to maintain the microvasculature following surgery and other stressors must use multifactorial approaches. Using skin as the model organ, we will review the anatomical and functional changes in the microcirculation with aging, and some of the available clinical strategies to potentially mitigate the effect of these changes on important clinical outcomes.

Assessment of Fluid Balance and the Approach to Fluid Therapy in the Perioperative Patient

Perioperative patients can be highly dynamic and have various metabolic, physiologic, and organ system derangements that necessitate smart monitoring strategies and careful fluid therapy. The interplay between changing patient status, therapeutic interventions, and patient response makes effective monitoring crucial to successful treatment. Monitoring the perioperative patient and an approach to fluid therapy are discussed in this text.

A randomised feasibility study to assess a novel strategy to rationalise fluid in patients after cardiac surgery

BACKGROUND

After cardiac surgery, patients receive large amounts of fluid in the Intensive Care Unit (ICU). We plan to conduct a multi-centre randomised controlled trial, of a conservative fluid regime, in patients after cardiac surgery, and have reported results of a feasibility study that evaluated efficacy and safety of the proposed regime.

METHODS

After ethical approval, a single-centre, prospectively randomised interventional study was undertaken. Participants were randomised to either usual care, or to a protocolised algorithm, utilising stroke volume variation, to guide fluid administration to patients who were deemed to have inadequate cardiac output and were likely to be volume responsive. The study protocol lasted from ICU admission to de-sedation or 24 h, whichever occurred first.

RESULTS

We randomised 144 subjects over 9 months. Less bolus fluid and less total overall fluid volume was administered in the intervention group (median (IQR) 1620 ml (500-3410) and 2525 ml (1440-5250; P<0.001), compared with the usual care group (2050 ml (910-4280) and 2980 ml (2070-6580; P=0.001), from ICU admission to extubation. There was no significant difference in incidence of acute kidney injury or the average amount of fluid administered to the usual care group at the beginning compared with the end of the study.

CONCLUSION

It is both possible and safe to achieve a significant reduction in the amount of fluid administered to patients, allocated to a conservative fluid protocol. These results suggest that a planned multi-centre study is both justified and feasible.

CLINICAL TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry www.anzctr.org.au (ACTRN12612000754842).

Time to readiness for discharge is a valid and reliable measure of short-term recovery after colorectal surgery

BACKGROUND

Short-term recovery after colorectal surgery has been traditionally investigated through length of stay (LOS). However, this measure is influenced by several confounding factors. This study aimed to investigate the construct validity and reliability of assessing the time to achieve standardized discharge criteria (time to readiness for discharge, or TRD) as a measure of short-term recovery. In a secondary analysis, we compared sample size requirements for randomized controlled trials (RCTs) using TRD or LOS as outcome measures.

METHODS

Seventy patients participated in the construct validity study and 21 patients participated in the reliability study. TRD was defined as the number of days to achieve discharge criteria previously defined by consensus. Construct validity was investigated by testing six hypothesis based on the assumption that TRD measures short-term recovery. Reliability was calculated by comparing measures of TRD by two independent assessors. Variability estimates (standard deviations) of LOS and TRD were used for sample size calculations.

RESULTS

Five of the six hypotheses were supported by the data (p < 0.05). Interobserver reliability was excellent (ICC2.1 = 0.99). Sample size estimations showed that RCTs using TRD as an outcome measure require approximately 23 % less participants compared to RCTs using LOS.

CONCLUSIONS

The results of this research support the construct-validity and reliability of TRD as a measure of short-term recovery. Using TRD as an alternative to LOS may reduce sample size requirements in future RCTs.

Goal-Directed Fluid Therapy Using Stroke Volume Variation for Resuscitation after Low Central Venous Pressure-Assisted Liver Resection: A Randomized Clinical Trial

BACKGROUND

The optimal perioperative fluid resuscitation strategy for liver resections remains undefined. Goal-directed therapy (GDT) embodies a number of physiologic strategies to achieve an ideal fluid balance and avoid the consequences of over- or under-resuscitation.

STUDY DESIGN

In a prospective randomized trial, patients undergoing liver resection were randomized to GDT using stroke volume variation as an end point or to standard perioperative resuscitation. Primary outcomes measure was 30-day morbidity.

RESULTS

Between 2012 and 2014, one hundred and thirty-five patients were randomized (GDT: n = 69; standard perioperative resuscitation: n = 66). Median age was 57 years and 56% were male. Metastatic disease comprised 81% of patients. Overall (35% GDT vs 36% standard perioperative resuscitation; p = 0.86) and grade 3 morbidity (28% GDT vs 18% standard perioperative resuscitation; p = 0.22) were equivalent. Patients in the GDT arm received less intraoperative fluid (mean 2.0 L GDT vs 2.9 L standard perioperative resuscitation; p < 0.001). Perioperative transfusions were required in 4% (6% GDT vs 2% standard perioperative resuscitation; p = 0.37) and boluses in the postanesthesia care unit were administered to 24% (29% GDT vs 20% standard perioperative resuscitation; p = 0.23). Mortality rate was 1% (2 of 135 patients; both in GDT). On multivariable analysis, male sex, age, combined procedures, higher intraoperative fluid volume, and fluid boluses in the postanesthesia care unit were associated with higher 30-day morbidity.

CONCLUSIONS

Stroke volume variation-guided GDT is safe in patients undergoing liver resection and led to less intraoperative fluid. Although the incidence of postoperative complications was similar in both arms, lower intraoperative resuscitation volume was independently associated with decreased postoperative morbidity in the entire cohort. Future studies should target extensive resections and identify patients receiving large resuscitation volumes, as this population is more likely to benefit from this technique.

Monitoring needs and goal-directed fluid therapy within an enhanced recovery program

Patients having major abdominal surgery need perioperative fluid supplementation; however, enhanced recovery principles mitigate against many of the factors that traditionally led to relative hypovolemia in the perioperative period. An estimate of fluid requirements for abdominal surgery can be made but individualization of fluid prescription requires consideration of clinical signs and hemodynamic variables. The literature supports goal-directed fluid therapy. Application of this evidence to justify stroke volume optimization in the setting of major surgery within an enhanced recovery program is controversial. This article places the evidence in context, reviews controversies, and suggests implications for current practice and future research.

Early discharge after pancreatoduodenectomy: what helps and what prevents?

OBJECTIVES

Shorter hospital stay after pancreatoduodenectomy (PD) is a desired goal. Implementation of enhanced recovery after surgery (ERAS) protocols can possibly help in achieving this target. We aimed to determine the factors influencing the successful implementation of ERAS protocols by analyzing their relation to the surrogate marker of enhanced recovery, namely, duration of hospital stay.

METHODS

A retrospective analysis of a prospectively maintained ERAS database of 208 consecutive patients who underwent PD at a tertiary referral care center was done.

RESULTS

Two hundred eight patients underwent a classical PD with a median duration of hospital stay of 8 days (range, 4-52 days) with an overall morbidity rate of 34.5% and a mortality rate of 3.8%. The 30-day readmission rate was 4% (8 patients). An elevated body mass index (relative risk, 1.098; 95% confidence interval, 1.015-1.188; P = 0.02) and respiratory comorbidities (relative risk, 8.024; 95% confidence interval, 2.018-31.904; P = 0.003) were independent factors resulting in a longer (>8 days) hospital stay.

CONCLUSIONS

Being overweight or obese and respiratory comorbidities are independent predictors of prolonged hospital stay despite the implementation of ERAS protocol. Hypoalbuminemia does not have a direct effect on hospital stay but may predispose the patient to the development of complications.

Systematic review of preoperative, intraoperative and postoperative risk factors for colorectal anastomotic leaks

BACKGROUND

Anastomotic leak (AL) represents a dreaded complication following colorectal surgery, with a prevalence of 1-19 per cent. There remains a lack of consensus regarding factors that may predispose to AL and the relative risks associated with them. The objective was to perform a systematic review of the literature, focusing on the role of preoperative, intraoperative and postoperative factors in the development of colorectal ALs.

METHODS

A systematic review was performed to identify adjustable and non-adjustable preoperative, intraoperative and postoperative factors in the pathogenesis of AL. Additionally, a severity grading system was proposed to guide treatment.

RESULTS

Of 1707 papers screened, 451 fulfilled the criteria for inclusion in the review. Significant preoperative risk factors were: male sex, American Society of Anesthesiologists fitness grade above II, renal disease, co-morbidity and history of radiotherapy. Tumour-related factors were: distal site, size larger than 3 cm, advanced stage, emergency surgery and metastatic disease. Adjustable risk factors were: smoking, obesity, poor nutrition, alcohol excess, immunosuppressants and bevacizumab. Intraoperative risk factors were: blood loss/transfusion and duration of surgery more than 4 h. Stomas lessen the consequences but not the prevalence of AL. In the postoperative period, CT is the most commonly used imaging tool, with or without rectal contrast, and a C-reactive protein level exceeding 150 mg/l on day 3-5 is the most sensitive biochemical marker. A five-level classification system for AL severity and appropriate management is presented.

CONCLUSION

Specific risk factors and their potential correction or indications for stoma were identified. An AL severity score is proposed to aid clinical decision-making.

Impact of Perioperative Fluid Administration on Postoperative Morbidity and Length of Hospital Stay Following Maxillomandibular Advancement for Obstructive Sleep Apnea

PURPOSE

The purpose of this study was to evaluate whether the volume of perioperative fluids administered to patients undergoing maxillomandibular advancement (MMA) for treatment of obstructive sleep apnea (OSA) is associated with an increased incidence of postoperative complications and prolonged length of hospital stay.

MATERIALS AND METHODS

A retrospective cohort study design was implemented and patients undergoing MMA for OSA at the Mayo Clinic were identified from 2001 through 2014. The primary predictor variable was the total volume of intravenous fluids administered during MMA. The primary outcome variable was length of hospital stay in hours. Secondary outcome variables included the presence of complications incurred during postoperative hospitalization. Additional covariates abstracted included basic demographic data, preoperative body mass index, preoperative apnea-hypopnea index, preoperative Charlson comorbidity index, preoperative American Society of Anesthesiologists score, type of intravenous fluid administered, surgical complexity score, duration of anesthesia, duration of surgery, and the use of planned intensive care unit admission. Univariate and multivariable models were developed to assess associations between the primary predictor variable and covariates relative to the primary and secondary outcome variables.

RESULTS

Eighty-eight patients undergoing MMA for OSA were identified. Total fluid volume was significantly associated with increased length of stay (odds ratio [OR] = 1.34, 95% confidence interval [CI], 1.05-1.71; P = .020) in univariate analysis. Total fluid volume did not remain significantly associated with increased length of hospital stay in stepwise multivariable modeling. Total fluid volume was significantly associated with the presence of postoperative complications (OR = 1.69; 95% CI, 1.08-2.63; P = .021) in univariate logistic regression.

CONCLUSION

Fluid administration was not found to be significantly associated with increased length of hospital stay after MMA for OSA. Increased fluid administration might be associated with the presence of postoperative complications after MMA; however, future large multicenter studies will be required to more comprehensively assess this association.

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.

Fluid management in the cardiothoracic intensive care unit: diuresis--diuretics and hemofiltration

PURPOSE OF REVIEW

The present review discusses the current concepts of fluid management in cardiothoracic surgery, and its clinical implications with special reference to organ-related complications and their prevention.

RECENT FINDINGS

Current strategies in fluid management for cardiothoracic patients, various fluid formulation, and the preventive strategies for minimizing fluid-related complications are described, with particular reference to new discoveries and controversies that have arisen from recent literature.

SUMMARY

The optimal fluid management in cardiothoracic patients has not been settled. Results of recent clinical published trials highlight the need for minimizing fluid administration and attempting to use diuretics to achieve a negative fluid, although hypovolemia and hypoperfusion should be carefully considered. An individualized optimization of fluid status, using goal-directed therapy, has emerged as a possible preferable approach. The old debate between crystalloid and colloid solutions has been partially solved, as some colloids have demonstrated deleterious effect on renal function and coagulation system. Various preventive strategies have also emerged for minimizing fluid-related complications.

The effect of intraoperative fluid volume administration on pancreatic fistulas after pancreaticoduodenectomy

BACKGROUND

Fluid therapy may be one of the most controversial topics in perioperative management. However, data concerning the influence of perioperative fluid administration on complications after pancreaticoduodenectomy are sparse.

METHODS

A group of 147 patients underwent pancreaticoduodenectomy for benign or malignant pathology of the pancreas or the periampullary region between 2005 and 2009. Clinical data, overall morbidity, and long-term outcomes were recorded.

RESULTS

We categorized the patients into two groups according to intraoperative fluid volume administration: a low fluid volume group (LFVG, <8.2 ml kg(-1) hr(-1), n = 90) group, and a high fluid volume group (HFVG, ≥8.2 ml kg(-1) hr(-1), n = 57). In terms of colloid administration, the high fluid volume group received significantly more colloid both during the intraoperative period and 0-12 hr after surgery (p < .001 and p < .007, respectively). Pancreatic fistula rates were significantly greater in the high fluid volume group (p = .035). However, the long-term survival rate was not different between the two groups.

CONCLUSIONS

High intraoperative fluid volume administration is associated with an increased incidence of pancreatic fistulas after pancreaticoduodenectomy.

The influence of goal-directed fluid therapy on the prognosis of elderly patients with hypertension and gastric cancer surgery

Purpose

We aimed to investigate the influence of perioperative goal-directed fluid therapy (GDFT) on the prognosis of elderly patients with gastric cancer and hypertension.

Methods

Sixty elderly patients (>60 years old) with primary hypertension who received gastric cancer radical surgery and who were American Society of Anesthesiologists (ASA) class II or III were enrolled in the current study. Selected patients were divided randomly into two arms, comprising a conventional intraoperative fluid management arm (arm C, n=30) and a GDFT arm (arm G, n=30). Patients in arm C were infused with crystalloids or colloids according to the methods of Miller’s Anesthesia (6th edition), while those in arm G were infused with 200 mL hydroxyethyl starch over 15 minutes under the FloTrac/Vigileo monitoring system, with stroke volume variation between 8% and 13%. Hemodynamics and tissue perfusion laboratory indicators in patients were recorded continuously from 30 minutes before the operation to 24 hours after the operation.

Results

Compared with arm C, the average intraoperative intravenous infusion quantity in arm G was significantly reduced (2,732±488 mL versus 3,135±346 mL, P<0.05), whereas average colloid fluid volume was significantly increased (1,235±360 mL versus 760±280 mL, P<0.05). In addition, there were more patients exhibiting intraoperatively and postoperatively stable hemodynamics and less patients with low blood pressure in arm G. Postoperative complications were less frequent, and the time of postoperative hospital stay shorter, in arm G. No significant differences were observed in mortality between the two arms.

Conclusion

Our research showed that GDFT stabilized perioperative hemodynamics and reduced the occurrence of postoperative complications in elderly patients who underwent gastric cancer surgery.

Impact of intraoperative fluid administration on length of postoperative hospital stay following orthognathic surgery

PURPOSE

The purpose of this study was to evaluate whether the volume of intraoperative fluids administered to patients during routine orthognathic surgery is associated with increased length of hospital stay for postoperative convalescence.

MATERIALS AND METHODS

A retrospective cohort study design was used to identify 168 patients undergoing routine orthognathic surgery at Mayo Clinic from 2010 through 2014. The primary predictor variable was total volume of intravenous fluids administered during orthognathic surgery. The primary outcome variable was the length of hospital stay in hours as measured from the completion of the procedure to patient dismissal from the hospital. Additional covariates were collected including patient demographic data, preoperative American Society of Anesthesiologists (ASA) score, type of intravenous fluid administered, complexity of surgical procedure, and duration of anesthesia.

RESULTS

On univariate analysis, total fluid was significantly associated with increased length of stay (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.42 to 2.33; P < .001). After adjustment for surgical complexity and duration of anesthesia on multivariable regression analysis, the association of fluid level with length of hospital stay was no longer statistically significant (OR, 0.86; 95% CI, 0.61 to 1.22; P = .39). Duration of anesthesia remained the only covariate that was significantly associated with increased length of hospital stay in the multivariable regression model (OR, 2.21; 95% CI, 1.56 to 3.13; P < .001).

CONCLUSIONS

Among surgical complexity, duration of anesthesia, and total volume of intraoperative intravenous fluids administered for routine orthognathic surgery, the duration of anesthesia has the strongest predictive value for patients requiring prolonged hospital stay for postoperative convalescence.

Impact of intraoperative fluid administration on outcome in patients undergoing robotic-assisted laparoscopic prostatectomy--a retrospective analysis

Background

Robotic-assisted laparoscopic prostatectomy (RALP) gained much popularity during the last decade. Although the influence of intraoperative fluid management on patients’ outcome has been largely discussed in general, its impact on perioperative complications and length of hospitalization in patients undergoing RALP has not been examined so far. We hypothesized that a more restrictive fluid management might lead to a shortened length of hospitalization and a decreased rate of complications in our patients.

Methods

Retrospective analysis of data of 182 patients undergoing RALP at an University Hospital (first series of RALP performed at the center).

Results

The amount of fluid administered was initially normalized for body mass index of the patient and the duration of the operation and additionally corrected for age and the interaction of these variables. The application of crystalloids (multiple linear regression model, estimate = -0.044, p = 0.734) had no effect on the length of hospitalization, whereas a negative effect was found for colloids (estimate = -8.317, p = 0.021). Additionally, a significant interaction term between age and the amount of colloid applied (estimate = 0.129, p = 0.028) was calculated. Evaluation of the influence of intraoperative fluid administration using multiple logistic regression models corrected for body mass index, duration of the surgery and additionally for age revealed a negative effect of crystalloids on the incidence of an anastomotic leak between bladder and urethra (estimate = -23.860, p = 0.017), with a significant interaction term between age and the amount of crystalloids (estimate = 0.396, p = 0.0134). Colloids had no significant effect on this particular complication (estimate = 1.887, p = 0.524). Intraoperative blood loss did not alter the incidence of an anastomotic leak (estimate = 0.001, p = 0.086), nor did it affect the length of hospitalization (estimate = 0.0001, p = 0.351).

Conclusions

In accordance to the findings of our study, we suggest that a standardized, more restrictive fluid management might be beneficial in patients undergoing RALP. In older patients this measure would be able to shorten the length of hospitalization and to decrease the incidence of anastomosis leakage as a major complication.

Guiding principles of fluid and volume therapy

Fluid therapy is a core concept in the management of perioperative and critically ill patients for maintenance of intravascular volume and organ perfusion. Recent evidence regarding the vascular barrier and its role in terms of vascular leakage has led to a new concept for fluid administration. The choice of fluid used should be based on the fluid composition and the underlying pathophysiology of the patient. Avoidance of both hypo- and hypervolaemia is essential when treating circulatory failure. In daily practice, the assessment of individual thresholds in order to optimize cardiac preload and avoid hypovolaemia or deleterious fluid overload remains a challenge. Liberal versus restrictive fluid management has been challenged by recent evidence, and the ideal approach appears to be goal-directed fluid therapy.

Perioperative fluid restriction

Perioperative fluid management of the colorectal surgical patient has evolved significantly over the last five decades. Older notions espousing aggressive hydration have been shown to be associated with increased complications. Newer data regarding fluid restriction has shown an association with improved outcomes. Management of perioperative fluid administration can be considered in three primary phases: In the preoperative phase, data suggests that avoidance of preoperative bowel preparation and avoidance of undue preoperative dehydration can improve outcomes. Although the type of intraoperative fluid given does not have a significant effect on outcome, data do suggest that a restrictive fluid regimen results in improved outcomes. Finally, in the postoperative phase of fluid management, a fluid-restrictive regimen, coupled with early enteral feeding also seems to result in improved outcomes.

A prospective observational study of stroke volume responsiveness to a passive leg raise manoeuvre in healthy non-starved volunteers as assessed by transthoracic echocardiography

Current guidelines for intra-operative fluid management recommend the use of increments in stroke volume following intravenous fluid bolus administration as a guide to subsequent fluid therapy. To study the physiological premise of this paradigm, we tested the hypothesis that healthy, non-starved volunteers would develop an increment in their stroke volume following a passive leg raise manoeuvre. Subjects were positioned supine and stroke volume was measured by transthoracic echocardiography at baseline, 30 s, 1 min, 3 min and 5 min after passive leg raise manoeuvre to 45°. Stroke volume was measured at end-expiration during quiet breathing, as the mean of three sequential measurements. Seventeen healthy volunteers were recruited; one volunteer in whom it was not possible to obtain Doppler measurements and a further five for reasons of poor Doppler image quality were not included in the study. Mean (SD) percentage difference from baseline to the largest change in stroke volume was 5.7 (9.6)% (p = 0.16). Of the 11 volunteers evaluated, five (45%) had stroke volume increases of greater than 10%. Mean (SD) maximum percentage change in cardiac index was 14.8 (9.7)% (p = 0.004). A wide variation in baseline stroke volume and response to the passive leg raise manoeuvre was seen, suggesting greater heterogeneity in the normal population than current clinical guidelines recognise.

Anesthesia, microcirculation, and wound repair in aging

Age-related changes in skin contribute to impaired wound healing after surgical procedures. Changes in skin with age include decline in thickness and composition, a decrease in the number of most cell types, and diminished microcirculation. The microcirculation provides tissue perfusion, fluid homeostasis, and delivery of oxygen and other nutrients. It also controls temperature and the inflammatory response. Surgical incisions cause further disruption of the microvasculature of aged skin. Perioperative management can be modified to minimize insults to aged tissues. Judicious use of fluids, maintenance of normal body temperature, pain control, and increased tissue oxygen tension are examples of adjustable variables that support the microcirculation. Anesthetic agents influence the microcirculation of a combination of effects on cardiac output, arterial pressure, and local microvascular changes. The authors examined the role of anesthetic management in optimizing the microcirculation and potentially improving postoperative wound repair in older persons.

Enhanced recovery for esophagectomy: a systematic review and evidence-based guidelines

OBJECTIVE

This article aims to provide the first systematic review of enhanced recovery after surgery (ERAS) programs for esophagectomy and generate guidelines.

BACKGROUND

ERAS programs use multimodal approaches to reduce complications and accelerate recovery. Although ERAS is well established in colorectal surgery, experience after esophagectomy has been minimal. However, esophagectomy remains an extremely high-risk operation, commonly performed in patients with significant comorbidities. Consequently, ERAS may have a significant role to play in improving outcomes. No guidelines or reviews have been published in esophagectomy.

METHODS

We undertook a systematic review of the PubMed, EMBASE, and the Cochrane databases in July 2012. The literature was searched for descriptions of ERAS in esophagectomy. Components of successful ERAS programs were determined, and when not directly available for esophagectomy, extrapolation from related evidence was made. Graded recommendations for each component were then generated.

RESULTS

Six retrospective studies have assessed ERAS for esophagectomy, demonstrating favorable morbidity, mortality, and length of stay. Methodological quality is, however, low. Overall, there is little direct evidence for components of ERAS, with much derived from nonesophageal thoracoabdominal surgery.

CONCLUSIONS

ERAS in principle seems logical and safe for esophagectomy. However, the underlying evidence is poor and lacking. Despite this, a number of recommendations for practice and research can be made.

Hydroxyethyl starch reduces coagulation competence and increases blood loss during major surgery: results from a randomized controlled trial

OBJECTIVE

This study evaluated whether administration of hydroxyethyl starch (HES) 130/0.4 affects coagulation competence and influences the perioperative blood loss.

BACKGROUND

Artificial colloids substitute blood volume during surgery; with the administration of HES 130/0.4 (Voluven, Fresenius Kabi, Uppsala, Sweden) only a minor effect on coagulation competence is expected.

METHODS

Eighty patients were scanned for enrollment in the study, and 40 patients fulfilled the inclusion criteria. Two patients withdrew their consent to participate in the study, and 5 patients were excluded. Thus, 16 patients were randomized to receive lactated Ringer's solution and 17 to receive HES 130/0.4.

RESULTS

Among the patients receiving HES 130/0.4, thrombelastography indicated reduced clot strength (P < 0.001) and blinded evaluation of the perioperative blood loss was 2.2 (range 0.5 to 5.0) versus 1.4 (range 0.5 to 2.4) L in the patients who received HES 130/0.4 or lactated Ringer, respectively (P < 0.038). The patients in the lactated Ringer's group, however, received more fluid (P < 0.0001) than those in the HES 130/0.4 group. There was no significant difference between the 2 groups with regard to frequency of reoperations or the length of hospital stay, but use of HES 130/0.4 was both more expensive and less efficacious than the use of lactated Ringer.

CONCLUSIONS

Administration of HES 130/0.4 reduced clot strength and perioperative hemorrhage increased by more than 50%, while administration of lactated Ringer's solution provoked an approximately 2.5 times greater positive volume balance at the end of surgery.

Perioperative anemia management in colorectal cancer patients: A pragmatic approach

Anemia, usually due to iron deficiency, is highly prevalent among patients with colorectal cancer. Inflammatory cytokines lead to iron restricted erythropoiesis further decreasing iron availability and impairing iron utilization. Preoperative anemia predicts for decreased survival. Allogeneic blood transfusion is widely used to correct anemia and is associated with poorer surgical outcomes, increased post-operative nosocomial infections, longer hospital stays, increased rates of cancer recurrence and perioperative venous thromboembolism. Infections are more likely to occur in those with low preoperative serum ferritin level compared to those with normal levels. A multidisciplinary, multimodal, individualized strategy, collectively termed Patient Blood Management, minimizes or eliminates allogeneic blood transfusion. This includes restrictive transfusion policy, thromboprophylaxis and anemia management to improve outcomes. Normalization of preoperative hemoglobin levels is a World Health Organization recommendation. Iron repletion should be routinely ordered when indicated. Oral iron is poorly tolerated with low adherence based on published evidence. Intravenous iron is safe and effective but is frequently avoided due to misinformation and misinterpretation concerning the incidence and clinical nature of minor infusion reactions. Serious adverse events with intravenous iron are extremely rare. Newer formulations allow complete replacement dosing in 15-60 min markedly facilitating care. Erythropoiesis stimulating agents may improve response rates. A multidisciplinary, multimodal, individualized strategy, collectively termed Patient Blood Management used to minimize or eliminate allogeneic blood transfusion is indicated to improve outcomes.

Fluids are drugs: type, dose and toxicity

PURPOSE OF REVIEW

We discuss the formulation of a prescription for intravenous (i.v.) fluid therapy (a 'volume prescription') for critically ill patients: pros/cons of different fluid types; accurate dosing; and qualitative and quantitative toxicities. Updated physiologic concepts are invoked and results of recent major clinical trials on i.v. fluid therapy in the acutely ill are interpreted.

RECENT FINDINGS

Context is vital and any fluid can be harmful if dosed incorrectly. When contrasting 'crystalloid versus colloid', differences in efficacy are modest, but differences in safety are significant. Differences in chloride load and strong ion difference appear to be clinically important. Quantitative toxicity is mitigated when dosing is based on dynamic parameters that predict volume responsiveness. Qualitative toxicity for colloids (even with newer hydroxyethyl starch 130/0.4 solutions) and isotonic saline remain a concern.

SUMMARY

Similar to any drug used in acutely ill patients, clinicians ordering a volume prescription must recognize that context is crucial. Physiologically balanced crystalloids may be the 'default' fluid for acutely ill patients, and the role for colloids is unclear. Optimal dosing involves assessment of volume responsiveness.

Randomized clinical trial of fluid and salt restriction compared with a controlled liberal regimen in elective gastrointestinal surgery

Background

Excessive intravenous fluid prescription may play a causal role in postoperative complications following major gastrointestinal resectional surgery. The aim of this study was to investigate whether fluid and salt restriction would decrease postoperative complications compared with a more modern controlled liberal regimen.

Methods

In this observer-blinded single-site randomized clinical trial consecutive patients undergoing major gastrointestinal resectional surgery were randomized to receive either a liberal control fluid regimen or a restricted fluid and salt regimen. The primary outcome was postoperative complications of grade II and above (moderate to severe).

Results

Some 240 patients (194 colorectal resections and 46 oesophagogastric resections) were enrolled in the study; 121 patients were randomized to the restricted regimen and 119 to the control (liberal) regimen. During surgery the control group received a median (interquartile range) fluid volume of 2033 (1576–2500) ml and sodium input of 282 (213–339) mmol, compared with 1000 (690–1500) ml and 142 (93–218) mmol respectively in the restricted group. There was no significant difference in major complication rate between groups (38·0 and 39·0 per cent respectively). Median (range) hospital stay was 8 (3–101) days in the controls and 8 (range 3–76) days among those who received restricted fluids. There were four in-hospital deaths in the control group and two in the restricted group. Substantial differences in weight change, serum sodium, osmolality and urine : serum osmolality ratio were observed between the groups.

Conclusion

There were no significant differences in major complication rates, length of stay and in-hospital deaths when fluid restriction was used compared with a more liberal regimen. Registration number: ISRCTN39295230 (http://www.controlled-trials.com).

Goal-directed fluid therapy based on stroke volume variations improves fluid management and gastrointestinal perfusion in patients undergoing major orthopedic surgery

OBJECTIVE

To evaluate the influence of stroke volume variation (SVV)-based goal-directed therapy (GDT) on splanchnic organ functions and postoperative complications in orthopedic patients.

SUBJECTS AND METHODS

Eighty patients scheduled for major orthopedic surgery under general anesthesia were randomly allocated to one of two equal groups to receive either intraoperative volume therapy guided by SVV (GDT) or standard fluid management (control). In the SVV group, patients received colloid boluses of 4 ml/kg to maintain an SVV <10% when in the supine position or an SVV <14% if prone. In the control group, fluids were given to maintain a mean arterial pressure >65 mm Hg, a heart rate <100 bpm, a central venous pressure of 8-14 mm Hg, and a urine output >0.5 ml/kg/h. Intraoperative organ perfusion, hemodynamic data, hospitalization, postoperative complications, and mortality were recorded.

RESULTS

The heart rate at the end of surgery was significantly lower (p < 0.05), there were fewer hypotensive episodes (p < 0.05), the arterial and gastric intramucosal pH were higher (p < 0.05 for both), the gastric intramucosal PCO2 was lower (p < 0.05), the intraoperative infused colloids and the total infused volume were lower (p < 0.05 for both), and the postoperative time to flatus was shorter (p < 0.05) in the GDT group than in the control group. No differences in the length of hospital stay, complications, or mortality were found between the groups.

CONCLUSION

SVV-based GDT during major orthopedic surgery reduced the volume of the required intraoperative infused fluids, maintained intraoperative hemodynamic stability, and improved the perioperative gastrointestinal function.

The effect of positive balance on the outcomes of critically ill noncardiac postsurgical patients: a retrospective cohort study

PURPOSE

Fluid balance remains a highly controversial topic in the critical care field, and no consensus has been reached about the fluid levels required by critically ill surgical patients. In this study, we investigated the relationship between fluid balance and in-hospital mortality in critically ill surgical patients.

METHODS

The medical records of adult patients managed in a surgical intensive care unit (ICU) for more than 48 hours after surgery from January 2010 to February 2011 were reviewed retrospectively. Abstracted data included body weights, Acute Physiology and Chronic Health Evaluation (APACHE) II scores, Sequential Organ Failure Assessment (SOFA) scores, fluid therapy values (intake, output, and balance) during the ICU stay, type of operation, length of stay in the ICU and hospital, and in-hospital mortality.

RESULTS

A total of 148 patients were enrolled. The in-hospital mortality rate was 20.8%, and the median length of stay in the ICU and hospital were 5.0 and 24 days, respectively. The median daily fluid balance over the first 3 postoperative days was positive 11.2 mL/kg. Fluid balances in the ICU were 19.2, 15.0, and -0.6 mL kg(-1) d(-1), respectively, during the first 3 days vs SOFA scores (6.8, 6.3, and 6.5). Comparing the nonsurvival group with the survival group, the univariate analysis showed that age (P = .05), APACHE II score (P < .001), and use of a vasopressor (norepinephrine) (P = .05) affect in-hospital mortality. In the overall patients, any of the fluid balances were not significantly associated with mortality. However, in critically ill patients whose APACHE II scores were greater than 20, the nonsurvivor group showed a significant tendency toward a positive balance compared with the survivor group on the second and third days of ICU stay. Nevertheless, the SOFA scores showed no difference between nonsurvivor and survivors during the initial 2 postoperative days.

CONCLUSION

In critically ill noncardiac postsurgical patients whose APAHCE II scores were greater than 20, a positive balance in the ICU can be associated with mortality risk. To determine the direct effect of positive fluid balance, a larger scaled, prospective randomized study will be required.

Does the central venous pressure predict fluid responsiveness? An updated meta-analysis and a plea for some common sense

BACKGROUND

Despite a previous meta-analysis that concluded that central venous pressure should not be used to make clinical decisions regarding fluid management, central venous pressure continues to be recommended for this purpose.

AIM

To perform an updated meta-analysis incorporating recent studies that investigated indices predictive of fluid responsiveness. A priori subgroup analysis was planned according to the location where the study was performed (ICU or operating room).

DATA SOURCES

MEDLINE, EMBASE, Cochrane Register of Controlled Trials, and citation review of relevant primary and review articles.

STUDY SELECTION

Clinical trials that reported the correlation coefficient or area under the receiver operating characteristic curve (AUC) between the central venous pressure and change in cardiac performance following an intervention that altered cardiac preload. From 191 articles screened, 43 studies met our inclusion criteria and were included for data extraction. The studies included human adult subjects, and included healthy controls (n = 1) and ICU (n = 22) and operating room (n = 20) patients.

DATA EXTRACTION

Data were abstracted on study characteristics, patient population, baseline central venous pressure, the correlation coefficient, and/or the AUC between central venous pressure and change in stroke volume index/cardiac index and the percentage of fluid responders. Meta-analytic techniques were used to summarize the data.

DATA SYNTHESIS

Overall 57% ± 13% of patients were fluid responders. The summary AUC was 0.56 (95% CI, 0.54-0.58) with no heterogenicity between studies. The summary AUC was 0.56 (95% CI, 0.52-0.60) for those studies done in the ICU and 0.56 (95% CI, 0.54-0.58) for those done in the operating room. The summary correlation coefficient between the baseline central venous pressure and change in stroke volume index/cardiac index was 0.18 (95% CI, 0.1-0.25), being 0.28 (95% CI, 0.16-0.40) in the ICU patients, and 0.11 (95% CI, 0.02-0.21) in the operating room patients.

CONCLUSIONS

There are no data to support the widespread practice of using central venous pressure to guide fluid therapy. This approach to fluid resuscitation should be abandoned.

Dose and type of crystalloid fluid therapy in adult hospitalized patients

OBJECTIVE

In this narrative review, an overview is given of the pros and cons of various crystalloid fluids used for infusion during initial resuscitation or maintenance phases in adult hospitalized patients. Special emphasis is given on dose, composition of fluids, presence of buffers (in balanced solutions) and electrolytes, according to recent literature. We also review the use of hypertonic solutions.

METHODS

We extracted relevant clinical literature in English specifically examining patient-oriented outcomes related to fluid volume and type.

RESULTS

A restrictive fluid therapy prevents complications seen with liberal, large-volume therapy, even though restrictive fluid loading with crystalloids may not demonstrate large hemodynamic effects in surgical or septic patients. Hypertonic solutions may serve the purpose of small volume resuscitation but carry the disadvantage of hypernatremia. Hypotonic solutions are contraindicated in (impending) cerebral edema, whereas hypertonic solutions are probably more helpful in ameliorating than in preventing this condition and improving outcome. Balanced solutions offer a better approach for plasma composition than unbalanced ones, and the evidence for benefits in patient morbidity and mortality is increasing, particularly by helping to prevent acute kidney injury.

CONCLUSIONS

Isotonic and hypertonic crystalloid fluids are the fluids of choice for resuscitation from hypovolemia and shock. The evidence that balanced solutions are superior to unbalanced ones is increasing. Hypertonic saline is effective in mannitol-refractory intracranial hypertension, whereas hypotonic solutions are contraindicated in this condition.

Sevoflurane has no adverse effects on renal function in cirrhotic patients: a comparison with propofol

BACKGROUND

Cirrhotic patients are prone to developing renal dysfunction after anaesthesia and surgery. However, no consensus has been reached whether sevoflurane could have adverse effects on renal function in cirrhotic patients. We hypothesised that the use of sevoflurane for general anaesthesia would lead to post-operative renal dysfunction in cirrhotic patients undergoing liver resection.

METHODS

A total of 200 patients undergoing liver resection were randomly assigned to a propofol or sevoflurane group. The influence of sevoflurane or propofol on renal function was evaluated by the maximal change, the difference between the pre-operative baseline and the highest values of serum creatinine and blood urea nitrogen measured at day 1, 3 and 6 post-operatively.

RESULTS

The maximal change in serum creatinine after liver resection was -4.52 (5.78) μmol/l and -3.37 (7.34) μmol/l with P = 0.398, and that in blood urea nitrogen was 0.41 (1.49) mmol/l and 0.93 (1.54) mmol/l with P = 0.098 between the sevoflurane group (n = 52) and the propofol group (n = 50), respectively.

CONCLUSIONS

Sevoflurane does not seem to impair post-operative renal function in cirrhotic patients undergoing liver resection.