Perioperative fluid therapy: a statement from the international Fluid Optimization Group. Perioper Med (Lond). 2015;4:3. [PMID: 25897397 PMCID: PMC4403901 DOI: 10.1186/s13741-015-0014-z]

The Ability of Military Critical Care Air Transport Members to Visually Estimate Percent Systolic Pressure Variation

INTRODUCTION

Inappropriate fluid management during patient transport may lead to casualty morbidity. Percent systolic pressure variation (%SPV) is one of several technologies that perform a dynamic assessment of fluid responsiveness (FT-DYN). Trained anesthesia providers can visually estimate and use %SPV to limit the incidence of erroneous volume management decisions to 1-4%. However, the accuracy of visually estimated %SPV by other specialties is unknown. The aim of this article is to determine the accuracy of estimated %SPV and the incidence of erroneous volume management decisions for Critical Care Air Transport (CCAT) team members before and after training to visually estimate and utilize %SPV.

MATERIAL AND METHODS

In one sitting, CCAT team providers received didactics defining %SPV and indicators of fluid responsiveness and treatment with %SPV ≤7 and ≥14.5 defining a fluid nonresponsive and responsive patient, respectively; they were then shown ten 45-second training arterial waveforms on a simulated Propaq M portable monitor's screen. Study subjects were asked to visually estimate %SPV for each arterial waveform and queried whether they would treat with a fluid bolus. After each training simulation, they were told the true %SPV. Seven days post-training, the subjects were shown a different set of ten 45-second testing simulations and asked to estimate %SPV and choose to treat, or not. Nonparametric limits of agreement for differences between true and estimated %SPV were analyzed using Bland-Altman graphs. In addition, three errors were defined: (1) %SPV visual estimate errors that would label a volume responsive patient as nonresponsive, or vice versa; (2) incorrect treatment decisions based on estimated %SPV (algorithm application errors); and (3) incorrect treatment decisions based on true %SPV (clinically significant treatment errors). For the training and testing simulations, these error rates were compared between, and within, provider groups.

RESULTS

Sixty-one physicians (MDs), 64 registered nurses (RNs), and 53 respiratory technicians (RTs) participated in the study. For testing simulations, the incidence and 95% CI for %SPV estimate errors with sufficient magnitude to result in a treatment error were 1.4% (0.5%, 3.2%), 1.6% (0.6%, 3.4%), and 4.1% (2.2%, 6.9%) for MDs, RNs, and RTs, respectively. However, clinically significant treatment errors were statistically more common for all provider types, occurring at a rate of 7%, 10%, and 23% (all P < .05). Finally, students did not show clinically relevant reductions in their errors between training and testing simulations.

CONCLUSIONS

Although most practitioners correctly visually estimated %SPV and all students completed the training in interpreting and applying %SPV, all groups persisted in making clinically significant treatment errors with moderate to high frequency. This suggests that the treatment errors were more often driven by misapplying FT-DYN algorithms rather than by inaccurate visual estimation of %SPV. Furthermore, these errors were not responsive to training, suggesting that a decision-making cognitive aid may improve CCAT teams' ability to apply FT-DYN technologies.

Influence of different intraoperative fluid management on postoperative outcome after abdominal tumours resection

BACKGROUND

Intraoperative fluid management is a crucial aspect of cancer surgery, including colorectal surgery and pancreatoduodenectomy. The study tests if intraoperative multimodal monitoring reduces postoperative morbidity and duration of hospitalisation in patients undergoing major abdominal surgery treated by the same anaesthetic protocols with epidural analgesia.

PATIENTS AND METHODS

A prospective study was conducted in 2 parallel groups. High-risk surgical patients undergoing major abdominal surgery were randomly selected in the control group (CG), where standard monitoring was applied (44 patients), and the protocol group (PG), where cerebral oxygenation and extended hemodynamic monitoring were used with the protocol for intraoperative interventions (44 patients).

RESULTS

There were no differences in the median length of hospital stay, CG 9 days (interquartile range [IQR] 8 days), PG 9 (5.5), p = 0.851. There was no difference in postoperative renal of cardiac impairment. Procalcitonin was significantly higher (highest postoperative value in the first 3 days) in CG, 0.75 mcg/L (IQR 3.19 mcg/L), than in PG, 0.3 mcg/L (0.88 mcg/L), p = 0.001. PG patients received a larger volume of intraoperative fluid; median intraoperative fluid balance +1300 ml (IQR 1063 ml) than CG; +375 ml (IQR 438 ml), p < 0.001.

CONCLUSIONS

There were significant differences in intraoperative fluid management and vasopressor use. The median postoperative value of procalcitonin was significantly higher in CG, suggesting differences in immune response to tissue trauma in different intraoperative fluid status, but there was no difference in postoperative morbidity or hospital stay.

Epidemiology of perioperative RV dysfunction: risk factors, incidence, and clinical implications

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation. There has however been little systematic attempt to quantify the incidence of perioperative RVD. What limited data exists has assessed perioperative RVD using echocardiography, cardiovascular magnetic resonance, and pulmonary artery catheterisation but is beset by challenges resulting from the inconsistencies in RVD definitions. Alongside differences in patient and surgical risk profile, this leads to wide variation in the incidence estimate. Data concerning the clinical implications of perioperative RVD is even more scarce, though there is evidence to suggest RVD is associated with atrial arrhythmias and prolonged length of critical care stay following thoracic surgery, increased need for inotropic support in revision orthopaedic surgery, and increased critical care requirement and mortality following cardiac surgery. Acute manifestations of RVD result from low cardiac output or systemic venous congestion, which are non-specific to the diagnosis of RVD. As such, RVD is easily overlooked, and the relative contribution of RV dysfunction to postoperative morbidity is likely to be underestimated.We applaud the POQI group for highlighting this important condition. There is undoubtedly a need for further study of the RV in the perioperative period in addition to solutions for perioperative risk prediction and management strategies. There is much to understand, study, and trial in this area, but importantly for our patients, we are increasingly recognising the importance of these uncertainties.

Assessment of changes in blood volume during lower body negative pressure-induced hypovolemia using bioelectrical impedance analysis

BACKGROUND

Lower body negative Pressure (LBNP)-induced hypovolemia is simulating acute hemorrhage by sequestrating blood into lower extremities. Bioelectrical Impedance Analysis (BIA) is based on the electrical properties of biological tissues, as electrical current flows along highly conductive body tissues (such as blood). Changes in blood volume will lead to changes in bioimpedance. This study aims to study changes in upper (UL) and lower (LL) extremities bioimpedance during LBNP-induced hypovolemia.

METHODS

This was a prospective observational study of healthy volunteers who underwent gradual LBNP protocol which consisted of 3-minute intervals: at baseline, -15, -30, -45, -60 mmHg, then recovery phases at -30 mmHg and baseline. The UL&LL extremities bioimpedance were measured and recorded at each phase of LBNP and the percentage changes of bioimpedance from baseline were calculated and compared using student's t-test. A P-value of < 0.05 was considered significant. Correlation between relative changes in UL&LL bioimpedance and estimated blood loss (EBL) from LBNP was calculated using Pearson correlation.

RESULTS

26 healthy volunteers were enrolled. As LBNP-induced hypovolemia progressed, there were a significant increase in UL bioimpedance and a significant decrease in LL bioimpedance. During recovery phases (where blood was shifted from the legs to the body), there were a significant increase in LL bioimpedance and a reduction in UL bioimpedance. There were significant correlations between estimated blood loss from LBNP model with UL (R = 0.97) and LL bioimpedance (R = - 0.97).

CONCLUSION

During LBNP-induced hypovolemia, there were reciprocal changes in UL&LL bioimpedance. These changes reflected hemodynamic compensatory mechanisms to hypovolemia.

Prediction of preload dependency using phenylephrine-induced peripheral perfusion index during general anaesthesia: a prospective observational study

BACKGROUND

Tracking preload dependency non-invasively to maintain adequate tissue perfusion in the perioperative period can be challenging.The effect of phenylephrine on stroke volume is dependent upon preload. Changes in stroke volume induced by phenylephrine administration can be used to predict preload dependency. The change in the peripheral perfusion index derived from photoplethysmography signals reportedly corresponds with changes in stroke volume in situations such as body position changes in the operating room. Thus, the peripheral perfusion index can be used as a non-invasive potential alternative to stroke volume to predict preload dependency. Herein, we aimed to determine whether changes in perfusion index induced by the administration of phenylephrine could be used to predict preload dependency.

METHODS

We conducted a prospective single-centre observational study. The haemodynamic parameters and perfusion index were recorded before and 1 and 2 min after administering 0.1 mg of phenylephrine during post-induction hypotension in patients scheduled to undergo surgery. Preload dependency was defined as a stroke volume variation of ≥ 12% before phenylephrine administration at a mean arterial pressure of < 65 mmHg. Patients were divided into four groups according to total peripheral resistance and preload dependency.

RESULTS

Forty-two patients were included in this study. The stroke volume in patients with preload dependency (n = 23) increased after phenylephrine administration. However, phenylephrine administration did not impact the stroke volume in patients without preload dependency (n = 19). The perfusion index decreased regardless of preload dependency. The changes in the perfusion index after phenylephrine administration exhibited low accuracy for predicting preload dependency. Based on subgroup analysis, patients with high total peripheral resistance tended to exhibit increased stroke volume following phenylephrine administration, which was particularly prominent in patients with high total peripheral resistance and preload dependency.

CONCLUSION

The findings of the current study revealed that changes in the perfusion index induced by administering 0.1 mg of phenylephrine could not predict preload dependency. This may be attributed to the different phenylephrine-induced stroke volume patterns observed in patients according to the degree of total peripheral resistance and preload dependency.

TRIAL REGISTRATION

University Hospital Medical Information Network (UMIN000049994 on 9/01/2023).

Postoperative fluid therapy in enhanced recovery after surgery for pancreaticoduodenectomy

Backgrounds/Aims

Optimal intravenous fluid management during the perioperative period for patients undergoing pancreaticoduodenectomy (PD) within the framework of enhanced recovery after surgery (ERAS) is unclear. Studies have indicated that excessive total body salt and water can contribute to the development of oedema, leading to increased morbidity and extended hospital stays. This study aimed to assess the effects of an intravenous therapy regimen during postoperative day (POD) 0 to 2 in PD patients within ERAS.

Methods

A retrospective interventional cohort study was conducted, and it involved all PD patients before and after implementation of ERAS (2009-2017). In the ERAS group, a targeted maintenance fluid regimen of 20 mL/kg/day with a sodium requirement of 0.5 mmoL/kg/day was administered. Outcome measures included the mmol of sodium and chloride administered, length of stay, and morbidity (postoperative pancreatic fistula, POPF; acute kidney injury, AKI; ileus).

Results

The study included 169 patients, with a mean age of 64 ± 11.3 years. Following implementation of the intravenous fluid therapy protocol, there was a significant reduction in chloride and sodium loading. However, in the multivariable analysis, chloride administered (mmoL/kg) did not independently influence the length of stay; or rates of POPF, ileus, or AKI (p > 0.05).

Conclusions

The findings suggested that a postoperative intravenous fluid therapy regimen did not significantly impact morbidity. Notably, there was a trend towards reduced length of stay within an increasingly comorbid patient cohort. This targeted fluid regimen appears to be safe for PD patients within the ERAS program. Further prospective research is needed to explore this area.

Goal-directed fluid therapy using stroke volume variation on length of stay and postoperative gastrointestinal function after major abdominal surgery-a randomized controlled trial

BACKGROUND AND OBJECTIVE

The effectiveness of goal-directed fluid therapy (GDFT) in promoting postoperative recovery remains unclear, the aim of this study was to evaluate the effect of GDFT on length of hospital stay and postoperative recovery of GI function in patients undergoing major abdominal oncologic surgery.

METHODS

In this randomized, double- blinded, controlled trial, adult patients scheduled for elective major abdominal surgery with general anesthesia, were randomly divided into the GDFT protocol (group G) or conventional fluid therapy group (group C). Patients in group C underwent conventional fluid therapy based on mean arterial pressure (MAP) and central venous pressure (CVP) whereas those in group G received GDFT protocol associated with the SVV less than 12% and the cardiac index (CI) was controlled at a minimum of 2.5 L/min/m2. The primary outcomes were the length of hospital stay and postoperative GI function.

RESULTS

One hundred patients completed the study protocol. The length of hospital stay was significantly shorter in group G compared with group C [9.0 ± 5.8 days versus 12.0 ± 4.6 days, P = 0.001]. Postoperative gastrointestinal dysfunction (POGD) occurred in two of 50 patients (4%) in group G and 16 of 50 patients (32%) in the control group (P < 0.001). GDFT significantly also shorten time to first flatus by 11 h (P = 0.009) and time to first tolerate oral diet by 2 days (P < 0.001).

CONCLUSIONS

Guided by SVV and CI, the application of GDFT has the potential to expedite postoperative recovery of GI function and reduce hospitalization duration after major abdominal surgery.

TRIAL REGISTRATION

This study was registered on www.

CLINICALTRIALS

gov on 07/05/2019 with registration number: NCT03940144.

Reliability of pulse pressure and stroke volume variation in assessing fluid responsiveness in the operating room: a metanalysis and a metaregression

BACKGROUND

Pulse pressure and stroke volume variation (PPV and SVV) have been widely used in surgical patients as predictors of fluid challenge (FC) response. Several factors may affect the reliability of these indices in predicting fluid responsiveness, such as the position of the patient, the use of laparoscopy and the opening of the abdomen or the chest, combined FC characteristics, the tidal volume (Vt) and the type of anesthesia.

METHODS

Systematic review and metanalysis of PPV and SVV use in surgical adult patients. The QUADAS-2 scale was used to assess the risk of bias of included studies. We adopted a metanalysis pooling of aggregate data from 5 subgroups of studies with random effects models using the common-effect inverse variance model. The area under the curve (AUC) of pooled receiving operating characteristics (ROC) curves was reported. A metaregression was performed using FC type, volume, and rate as independent variables.

RESULTS

We selected 59 studies enrolling 2,947 patients, with a median of fluid responders of 55% (46-63). The pooled AUC for the PPV was 0.77 (0.73-0.80), with a mean threshold of 10.8 (10.6-11.0). The pooled AUC for the SVV was 0.76 (0.72-0.80), with a mean threshold of 12.1 (11.6-12.7); 19 studies (32.2%) reported the grey zone of PPV or SVV, with a median of 56% (40-62) and 57% (46-83) of patients included, respectively. In the different subgroups, the AUC and the best thresholds ranged from 0.69 and 0.81 and from 6.9 to 11.5% for the PPV, and from 0.73 to 0.79 and 9.9 to 10.8% for the SVV. A high Vt and the choice of colloids positively impacted on PPV performance, especially among patients with closed chest and abdomen, or in prone position.

CONCLUSION

The overall performance of PPV and SVV in operating room in predicting fluid responsiveness is moderate, ranging close to an AUC of 0.80 only some subgroups of surgical patients. The grey zone of these dynamic indices is wide and should be carefully considered during the assessment of fluid responsiveness. A high Vt and the choice of colloids for the FC are factors potentially influencing PPV reliability.

TRIAL REGISTRATION

PROSPERO (CRD42022379120), December 2022. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=379120.

Analysis of Intraoperative Variables Responsible for the Increase in Lactic Acid in Patients Undergoing Debulking Surgery

Background: Cytoreductive surgery (CRS) is a complex procedure with a high incidence of perioperative complications. Elevated lactacidaemia levels have been associated with complications and perioperative morbidity and mortality. This study aims to analyse the intraoperative variables of patients undergoing CRS and their relationship with lactacidaemia levels. Methods: This retrospective, observational study included 51 patients with peritoneal carcinomatosis who underwent CRS between 2014 and 2016 at the Abdomino-Pelvic Oncological Surgery Reference Unit (URCOAP) of the General University Hospital of Castellón (HGUCS). The main variable of interest was the level of lactic acid at the end of surgery. Intraoperative variables, including preoperative haemoglobin, duration of surgery, intraoperative bleeding, fluid therapy administered, administration of blood products, and intraoperative peritoneal cancer index (PCI), were analysed. Results: Positive correlations were found between lactic acid levels and PCI, duration of intervention, fluid therapy, intraoperative bleeding, and transfusion of blood products. Additionally, a negative correlation was observed between haemoglobin levels and lactic acid levels. Notably, the strongest correlations were found with operative PCI (ρ = 0.532; p-value < 0.001) and duration of surgery (ρ = 0.518; p-value < 0.001). Conclusions: PCI and duration of surgery are decisive variables in determining the prognosis of patients undergoing debulking surgery. This study suggests that, for each minute of surgery, lactic acid levels increase by 0.005 mmol/L, and for each unit increase in PCI, lactic acid levels increase by 0.060 mmol/L.

Role of Crystalloids in the Perioperative Setting: From Basics to Clinical Applications and Enhanced Recovery Protocols

Perioperative fluid management, a critical aspect of major surgeries, is characterized by pronounced stress responses, altered capillary permeability, and significant fluid shifts. Recognized as a cornerstone of enhanced recovery protocols, effective perioperative fluid management is crucial for optimizing patient recovery and preventing postoperative complications, especially in high-risk patients. The scientific literature has extensively investigated various fluid infusion regimens, but recent publications indicate that not only the volume but also the type of fluid infused significantly influences surgical outcomes. Adequate fluid therapy prescription requires a thorough understanding of the physiological and biochemical principles that govern the body's internal environment and the potential perioperative alterations that may arise. Recently published clinical trials have questioned the safety of synthetic colloids, widely used in the surgical field. A new clinical scenario has arisen in which crystalloids could play a pivotal role in perioperative fluid therapy. This review aims to offer evidence-based clinical principles for prescribing fluid therapy tailored to the patient's physiology during the perioperative period. The approach combines these principles with current recommendations for enhanced recovery programs for surgical patients, grounded in physiological and biochemical principles.

Grip strength is an important predictor for nutritional risk and early postoperative ambulation in gastrointestinal tumors undergoing laparoscopic surgery: a prospective multicenter clinical study

BACKGROUND

Using grip strength as a predictor of nutritional risk and early ambulation for gastrointestinal tumor surgery and determining its critical value have not been reported. This study was designed to explore the influencing factors of early postoperative ambulation ability for patients with gastrointestinal tumors who underwent laparoscopic surgery.

METHODS

Four-hundred twenty-seven patients with gastrointestinal tumors who underwent laparoscopic surgery at three tertiary A hospitals in Beijing were prospectively enrolled. Subsequently, logistic regression analysis was conducted to determine the independent predictors of early postoperative ambulation. Logistic regression analyses for the different gender were also performed. In addition, the effectiveness of preoperative grip strength measurement in nutritional risk assessment was analyzed by using nutritional risk score 2002 (NRS 2002) as a control.

RESULTS

The included cases were comprised of 283 male and 144 female patients, with an age of 59.35 ± 11.70 years. Gender, preoperative grip strength, operative time, and number of indwelling tubes were independent predictors of early postoperative ambulation. In the male group, lower preoperative grip strength and more indwelling tubes were independent risk factors for early postoperative ambulation. In the female group, lower preoperative grip strength and extended operating time were independent risk factors. Moreover, preoperative grip strength (male < 32 kg, female < 21 kg) can be used as a risk predictor for both preoperative nutritional risk and early postoperative ambulation.

CONCLUSIONS

As a simple and objective measure of muscle strength, grip strength measurement is expected to be an effective predictor for both early postoperative ambulation ability and nutritional status of patients.

Novel parameters for predicting fluid responsiveness during the mini fluid challenge and ability of the cardiac power index: an observational cohort study

Background/aim

The percentage change in the stroke volume index (SVI) due to the mini fluid challenge (MFC) (MFC-ΔSVI%) is used commonly in daily practice. However, up to 20% of patients remain in the gray zone of this variable. Thus, it was aimed to compare the MFC-ΔSVI% and the percentage change in the cardiac power index (CPI) due to the MFC (MFC-ΔCPI%) with the baseline values of the pulse pressure variation (PPV) and stroke volume variation (SVV) in terms of their abilities to predict fluid responsiveness.

Materials and methods

The SVI, CPI, SVV, and PPV were recorded before 100 mL of isotonic saline was infused (MFC), after MFC was completed, and after an additional 400 mL of isotonic saline was infused to complete 500 mL of fluid loading (FL). Patients whose SVI increased more than 15% after the FL were defined as fluid responders.

Results

Sixty-seven patients completed the study and 35 (52%) of them were responders.The areas under the receiver operating characteristics curves for the MFC-ΔSVI% and MFC-ΔCPI% (0.94; 95% CI: 0.86-0.99 and 0.89; 95% CI: 0.79-0.95, respectively) were significantly higher than those for the SVV and PPV (0.63; 95% CI: 0.50-0.75 and 0.55; 95% CI: 0.42-0.67, respectively) (p < 0.001 for all of the comparisons). The gray zone analysis revealed that the MFC-ΔSVI% values of 12 patients were in the gray zone. Of the 12, the MFC-ΔCPI% values of 7 patients were outside of the gray zone.

Conclusion

Fluid responsiveness can be predicted more accurately using the MFC-ΔSVI% and MFC-ΔCPI% than using the SVV and PPV. Additionally, concomitant use of the MFC-ΔSVI% and MFC-ΔCPI% is recommended, as this approach diminishes the number of patients in the gray zone.

Guidelines on perioperative optimization protocol for the adult patient 2023

OBJECTIVE

The French Society of Anesthesiology and Intensive Care Medicine [Société Française d'Anesthésie et de Réanimation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs.

DESIGN

A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. The recommendations were formulated according to the GRADE® methodology and then voted on by all the experts according to the GRADE grid method. As the GRADE® methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a "formalized expert recommendations" format.

RESULTS

The experts' work on synthesis and application of the GRADE® method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations.

CONCLUSIONS

Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields.

Diagnostic accuracy of the peripheral venous pressure variation induced by an alveolar recruitment maneuver to predict fluid responsiveness during high-risk abdominal surgery

BACKGROUND

In patients undergoing high-risk surgery, it is recommended to titrate fluid administration using stroke volume or a dynamic variable of fluid responsiveness (FR). However, this strategy usually requires the use of a hemodynamic monitor and/or an arterial catheter. Recently, it has been shown that variations of central venous pressure (ΔCVP) during an alveolar recruitment maneuver (ARM) can predict FR and that there is a correlation between CVP and peripheral venous pressure (PVP). This prospective study tested the hypothesis that variations of PVP (ΔPVP) induced by an ARM could predict FR.

METHODS

We studied 60 consecutive patients scheduled for high-risk abdominal surgery, excluding those with preoperative cardiac arrhythmias or right ventricular dysfunction. All patients had a peripheral venous catheter, a central venous catheter and a radial arterial catheter linked to a pulse contour monitoring device. PVP was always measured via an 18-gauge catheter inserted at the antecubital fossa. Then an ARM consisting of a standardized gas insufflation to reach a plateau of 30 cmH₂O for 30 s was performed before skin incision. Invasive mean arterial pressure (MAP), pulse pressure, heart rate, CVP, PVP, pulse pressure variation (PPV), and stroke volume index (SVI) were recorded before ARM (T1), at the end of ARM (T2), before volume expansion (T3), and one minute after volume expansion (T4). Receiver-operating curves (ROC) analysis with the corresponding grey zone approach were performed to assess the ability of ∆PVP (index test) to predict FR, defined as an ≥ 10% increase in SVI following the administration of a 4 ml/kg balanced crystalloid solution over 5 min.

RESULTS

∆PVP during ARM predicted FR with an area under the ROC curve of 0.76 (95%CI, 0.63 to 0.86). The optimal threshold determined by the Youden Index was a ∆PVP value of 5 mmHg (95%CI, 4 to 6) with a sensitivity of 66% (95%CI, 47 to 81) and a specificity of 82% (95%CI, 63 to 94). The AUC's for predicting FR were not different between ΔPVP, ΔCVP, and PPV.

CONCLUSION

During high-risk abdominal surgery, ∆PVP induced by an ARM can moderately predict FR. Nevertheless, other hemodynamic variables did not perform better.

Perioperative individualized hemodynamic optimization according to baseline mean arterial pressure in cardiac surgery patients: Rationale and design of the OPTIPAM randomized trial

BACKGROUND

Postoperative morbidity and mortality after cardiac surgery with cardiopulmonary bypass (CPB) remain high despite recent advances in both anesthesia and perioperative management. Among modifiable risk factors for postoperative complications, optimal arterial pressure during and after surgery has been under debate for years. Recent data suggest that optimizing arterial pressure to the baseline of the patient may improve outcomes. We hypothesize that optimizing the mean arterial pressure (MAP) to the baseline MAP of the patient during cardiac surgery with CPB and during the first 24 hours postoperatively may improve outcomes.

STUDY DESIGN

The OPTIPAM trial (NCT05403697) will be a multicenter, randomized, open-label controlled trial testing the superiority of optimized MAP management as compared with a MAP of 65 mm Hg or more during both the intraoperative and postoperative periods in 1,100 patients scheduled for cardiac surgery with CPB. The primary composite end point is the occurrence of acute kidney injury, neurological complications including stroke or postoperative delirium, and death. The secondary end points are hospital and intensive care unit lengths of stay, Day 7 and Day 90 mortality, postoperative cognitive dysfunction on Day 7 and Day 90, and quality of life at Day 7 and Day 90. Two interim analyses will assess the safety of the intervention.

CONCLUSION

The OPTIPAM trial will assess the effectiveness of an individualized target of mean arterial pressure in cardiac surgery with CPB in reducing postoperative morbidity.

CLINICAL TRIAL REGISTRATION

NCT05403697.

State of the art: Proceedings of the American Association for Thoracic Surgery Enhanced Recovery After Cardiac Surgery Summit

Despite the benefits established for multiple surgical specialties, enhanced recovery after surgery has been underused in cardiac surgery. A cardiac enhanced recovery after surgery summit was convened at the 102nd American Association for Thoracic Surgery annual meeting in May 2022 for experts to convey key enhanced recovery after surgery concepts, best practices, and applicable results for cardiac surgery. Topics included implementation of enhanced recovery after surgery, prehabilitation and nutrition, rigid sternal fixation, goal-directed therapy, and multimodal pain management.

Adult Cardiac Surgery-Associated Acute Kidney Injury: Joint Consensus Report

OBJECTIVES

Acute kidney injury (AKI) is increasingly recognized as a source of poor patient outcomes after cardiac surgery. The purpose of the present report is to provide perioperative teams with expert recommendations specific to cardiac surgery-associated AKI (CSA-AKI).

METHODS

This report and consensus recommendations were developed during a joint, in-person, multidisciplinary conference with the Perioperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society. Multinational practitioners with diverse expertise in all aspects of cardiac surgical perioperative care, including clinical backgrounds in anesthesiology, surgery and nursing, met from October 20 to 22, 2021, in Sacramento, California, and used a modified Delphi process and a comprehensive review of evidence to formulate recommendations. The quality of evidence and strength of each recommendation were established using the Grading of Recommendations Assessment, Development, and Evaluation methodology. A majority vote endorsed recommendations.

RESULTS

Based on available evidence and group consensus, a total of 13 recommendations were formulated (4 for the preoperative phase, 4 for the intraoperative phase, and 5 for the postoperative phase), and are reported here.

CONCLUSIONS

Because there are no reliable or effective treatment options for CSA-AKI, evidence-based practices that highlight prevention and early detection are paramount. Cardiac surgery-associated AKI incidence may be mitigated and postsurgical outcomes improved by focusing additional attention on presurgical kidney health status; implementing a specific cardiopulmonary bypass bundle; using strategies to maintain intravascular euvolemia; leveraging advanced tools such as the electronic medical record, point-of-care ultrasound, and biomarker testing; and using patient-specific, goal-directed therapy to prioritize oxygen delivery and end-organ perfusion over static physiologic metrics.

Standardized blood volume changes monitored by capnodynamic hemodynamic variables: An experimental comparative study in pigs

BACKGROUND

The capnodynamic method, based on Volumetric capnography and differential Fick mathematics, assess cardiac output in mechanically ventilated subjects. Capnodynamic and established hemodynamic monitoring parameters' capability to depict alterations in blood volume were investigated in a model of standardized hemorrhage, followed by crystalloid and blood transfusion.

METHODS

Ten anesthetized piglets were subjected to controlled hemorrhage (450 mL), followed by isovolemic crystalloid bolus and blood re-transfusion. Intravascular blood volume, and all hemodynamic variables, were determined twice after each intervention. The investigated hemodynamic variables were: cardiac output and stroke volume for capnodynamics and pulse contour analysis, respectively, pulse pressure and stroke volume variability and mean arterial pressure. One-way ANOVA and Tukey's test for multiple comparisons were used to identify significant changes. Trending was assessed by correlation and concordance.

RESULT

Concordance against intravascular volume changes for capnodynamic cardiac output and stroke volume were 96 and 94%, with correlations r = .78 and .68, (p < .0001) with significant changes for 6 and 5 of the 6 measuring points, respectively. Mean arterial pressure and pulse pressure variation had a concordance of 85% and 87%, r = .67 (p < .0001) and r = -.45 (p < .0001), respectively, and both changed significantly for 3 of 6 measuring points. Pulse contour stroke volume variation, stroke volume and cardiac output, showed concordance and correlation of 76%, r = -.18 (p = .11), 63%, r = .28 (p = .01) and 50%, r = .31 (p = .007), respectively and significant change for 1, 1 and 0 of the measuring points, respectively.

CONCLUSION

Capnodynamic cardiac output and stroke volume did best depict the changes in intravascular blood volume. Pulse contour parameters did not follow volume changes in a reliable way.

Blood volume in patients likely to be preload responsive: a post hoc analysis of a randomized controlled trial

BACKGROUND

Preload responsive postoperative patients with signs of inadequate organ perfusion are commonly assumed to be hypovolemic and therefore treated with fluids to increase preload. However, preload is influenced not only by blood volume, but also by venous vascular tone and the contribution of these factors to preload responsiveness in this setting is unknown. Based on this, the objective of this study was to investigate blood volume status in preload-responsive postoperative patients.

METHODS

Data from a clinical trial including postoperative patients after major abdominal surgery were analyzed. Patients with signs of inadequate organ perfusion and with data from a passive leg raising test (PLR) were included. An increase in pulse pressure by ≥ 9% was used to identify patients likely to be preload responsive. Blood volume was calculated from plasma volume measured using radiolabelled albumin and hematocrit. Patients with a blood volume of at least 10% above or below estimated normal volume were considered hyper- and hypovolemic, respectively.

RESULTS

A total of 63 patients were included in the study. Median (IQR) blood volume in the total was 57 (50-65) ml/kg, and change in pulse pressure after PLR was 14 (7-24)%. A total of 43 patients were preload responsive. Of these patients, 44% were hypovolemic, 28% euvolemic and 28% hypervolemic.

CONCLUSIONS

A large fraction of postoperative patients with signs of hypoperfusion that are likely to be preload responsive, are hypervolemic. In these patients, treatments other than fluid administration may be a more rational approach to increase cardiac output. Trial registration EudraCT 2013-004446-42.

Fluid management in septic patients with pulmonary hypertension, review of the literature

The management of sepsis in patients with pulmonary hypertension (PH) is challenging due to significant conflicting goals of management and complex hemodynamics. As PH progresses, the ability of right heart to perfuse lungs at a normal central venous pressure (CVP) is impaired. Elevated pulmonary vascular pressure, due to pulmonary vasoconstriction and vascular remodeling, opposes blood flow through lungs thus limiting the ability of right ventricle (RV) to increase cardiac output (CO) and maintain adequate oxygen delivery to tissue. In sepsis without PH, avoidance of volume depletion with intravascular volume replacement, followed by vasopressor therapy if hypoperfusion persists, remains the cornerstone of therapy. Intravenous fluid (IVF) resuscitation based on individualized hemodynamic assessment can help improve the prognosis of critically ill patients. This is accomplished by optimizing CO by maintaining adequate preload, afterload and contractility. Particular challenges in patients with PH include RV failure as a result of pressure and volume overload, gas exchange abnormalities, and managing IVF and diuretic use. Suggested approaches to remedy these difficulties include early recognition of symptoms associated with pressure and volume overload, intravascular volume management strategies and serial lab monitoring to assess electrolytes and renal function.

Surgical Pharmacy for Optimizing Medication Therapy Management Services within Enhanced Recovery after Surgery (ERAS®) Programs

Drug-related problems (DRPs) are common among surgical patients, especially older patients with polypharmacy and underlying diseases. DRPs can potentially lead to morbidity, mortality, and increased treatment costs. The enhanced recovery after surgery (ERAS) system has shown great advantages in managing surgical patients. Medication therapy management for surgical patients (established as "surgical pharmacy" by Guangdong Province Pharmaceutical Association (GDPA)) is an important part of the ERAS system. Improper medication therapy management can lead to serious consequences and even death. In order to reduce DRPs further, and promote the rapid recovery of surgical patients, the need for pharmacists in the ERAS program is even more pressing. However, the medication therapy management services of surgical pharmacy and how surgical pharmacists should participate in ERAS programs are still unclear worldwide. Therefore, this article reviews the main perioperative medical management strategies and precautions from several aspects, including antimicrobial agents, antithrombotic agents, pain medication, nutritional therapy, blood glucose monitoring, blood pressure treatment, fluid management, treatment of nausea and vomiting, and management of postoperative delirium. Additionally, the way surgical pharmacists participate in perioperative medication management, and the relevant medication pathways are explored for optimizing medication therapy management services within the ERAS programs. This study will greatly assist surgical pharmacists' work, contributing to surgeons accepting that pharmacists have an important role in the multidisciplinary team, benefitting medical workers in treating, counseling, and advocating for their patients, and further improving the effectiveness, safety and economy of medication therapy for patients and promoting patient recovery.

A low peripheral perfusion index can accurately detect prolonged capillary refill time during general anesthesia: A prospective observational study

Background

Capillary refill time (CRT) is the gold standard for evaluating peripheral organ perfusion; however, intraoperative CRT measurement is rarely used because it cannot be conducted continuously, and it is difficult to perform during general anesthesia. The peripheral perfusion index (PI) is another noninvasive method for evaluating peripheral perfusion. The PI can easily and continuously evaluate peripheral perfusion and could be an alternative to CRT for use during general anesthesia. This study aimed to determine the cutoff PI value for low peripheral perfusion status (prolonged CRT) by exploring the relationship between CRT and the PI during general anesthesia.

Methods

We enrolled 127 surgical patients. CRT and the PI were measured in a hemodynamically stable state during general anesthesia. A CRT >3 s indicated a low perfusion status.

Results

Prolonged CRT was observed in 27 patients. The median PI values in the non-prolonged and prolonged CRT groups were 5.0 (3.3-7.9) and 1.5 (1.2-1.9), respectively. There was a strong negative correlation between the PI and CRT (r = -0.706). The area under the receiver operating characteristic curve generated for the PI was 0.989 (95% confidence interval, 0.976-1.0). The cutoff PI value for detecting a prolonged CRT was 1.8.

Conclusion

A PI <1.8 could accurately predict a low perfusion status during general anesthesia in the operating room. A PI <1.8 could be used to alert the possibility of a low perfusion status in the operating room.

Trial Registration

University Hospital Medical Information Network (UMIN000043707; retrospectively registered on March 22, 2021, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno = R000049905).

Factors associated with prolonged postoperative length of hospital stay after laparoscopic colorectal cancer resection: a secondary analysis of a randomized controlled trial

BACKGROUND

The postoperative length of hospital stay (PLOS) is an important indicator of surgical quality. We identified perioperative factors that affect prolonged PLOS (PPLOS) after laparoscopic colorectal cancer resection, which is the preferred surgical approach for colorectal cancer, the third most common cancer.

METHODS

This study was a secondary analysis of a randomized trial (clinicaltrials.gov ID: NCT03160144) that included 280 patients who underwent laparoscopic colorectal cancer resection. The primary outcome was a PPLOS, defined as a PLOS that was longer than the median PLOS. Baseline, anesthetic, surgical, and postoperative management factors were included in the univariate and multivariate analyses to identify factors influencing PPLOS.

RESULTS

The median PLOS was 10 days, and 117 patients had a PPLOS. We identified six influencing factors for PPLOS: preoperative pulse oxygen saturation < 96% (odds ratio [OR], 3.09 [95% confidence interval (CI) 1.38-6.92]; P = 0.006), distant tumor metastasis (OR, 0.34 [95% CI 0.13-0.91]; P = 0.031), the Miles procedure or left hemicolectomy (OR, 4.51 [95% CI 1.67-12.18]; P = 0.003), perioperative surgical events (OR, 2.44 [95% CI 1.25-4.76]; P = 0.009), postoperative albumin infusion (OR, 2.19 [95% CI 1.14-4.19]; P = 0.018), and postoperative early ambulation (OR, 0.35 [95% CI 0.18-0.68]; P = 0.002). Further stratified analysis showed that postoperative albumin infusion might be a risk factor for PPLOS, even in patients with a preoperative albumin level < 40 g/L (OR, 2.29 [95% CI 0.98-5.34]; P = 0.056) or duration of surgery ≥ 3 h (OR, 2.52 [95% CI 1.08-5.87]; P = 0.032).

CONCLUSIONS

A low preoperative pulse oximetry reading, complex surgical procedures, perioperative surgical events, and postoperative albumin infusion may be risk factors for PPLOS after laparoscopic colorectal cancer resection, whereas distant tumor metastasis and postoperative early ambulation might be protective factors. The association between postoperative albumin infusion, a modifiable factor, and PLOS or clinical outcomes warrants further investigation.

Impact of fluid balance and blood transfusion during extracorporeal circulation on outcome for acute type A aortic dissection surgery

BACKGROUND

In thoracic aortic surgery, fluid replacement and blood transfusion during extracorporeal circulation (ECC) are associated with increased coagulopathy, elevated inflammatory response, and end-organ dysfunction. The optimal strategy has not been established in this regard. The aim of this study was to evaluate the effect of the fluid balance during ECC in thoracic aortic dissection surgery on outcome.

METHODS

Between 2009 and 2020, 358 patients suffering from acute type A aortic dissection (ATAAD) underwent aortic surgery at our heart center. In-hospital mortality, major complications (postoperative stroke, respiratory failure, heart failure, acute renal failure), and follow-up mortality were assessed. Logistic regression analysis was used to identify whether fluid balance and blood transfusion during ECC were risk factors for occurring adverse events.

RESULTS

The in-hospital mortality amounted to 20.4%. Major complications included temporary neurologic deficit in 13.4%, permanent neurologic deficit in 6.1%, acute renal failure in 32.7%, prolonged ventilation for respiratory failure in 17.9%, and acute heart failure in 10.9% of cases. At a mean of 42 months after discharge of 285 survivors, follow-up mortality was 13.3%. Multivariate analysis revealed major complications as well as the risk of in-hospital and follow-up mortality to increase with fluid balance and blood transfusion during ECC.

CONCLUSIONS

Fluid balance and blood transfusion during ECC present with predictive potential concerning the risk of postoperative adverse events.

Preoperative clinical diagnostic accuracy of heart failure among patients undergoing major noncardiac surgery: a single-centre prospective observational analysis

Background

Reliable diagnosis of heart failure during preoperative evaluation is important for perioperative management and long-term care. We aimed to quantify preoperative heart failure diagnostic accuracy and explore characteristics of patients with heart failure misdiagnoses.

Methods

We performed an observational cohort study of adults undergoing major noncardiac surgery at an academic hospital between 2015 and 2019. A preoperative clinical diagnosis of heart failure was defined using keywords from the history and clinical examination or administrative documentation. Across stratified subsamples of cases with and without clinically diagnosed heart failure, health records were intensively reviewed by an expert panel to develop an adjudicated heart failure reference standard using diagnostic criteria congruent with consensus guidelines. We calculated agreement among experts, and analysed performance of clinically diagnosed heart failure compared with the adjudicated reference standard.

Results

Across 40 555 major noncardiac procedures, a stratified subsample of 511 patients was reviewed by the expert panel. The prevalence of heart failure was 9.1% based on clinically diagnosed compared with 13.3% (95% confidence interval [CI], 10.3-16.2%) estimated by the expert panel. Overall agreement and inter-rater reliability (kappa) among heart failure experts were 95% and 0.79, respectively. Based upon expert adjudication, heart failure was clinically diagnosed with an accuracy of 92.8% (90.6-95.1%), sensitivity 57.4% (53.1-61.7%), specificity 98.3% (97.1-99.4%), positive predictive value 83.5% (80.3-86.8%), and negative predictive value 93.8% (91.7-95.9%).

Conclusions

Limitations exist to the preoperative clinical diagnosis of heart failure, with nearly half of cases undiagnosed preoperatively. Considering the risks of undiagnosed heart failure, efforts to improve preoperative heart failure diagnoses are warranted.

Development and comparison of an esophageal Doppler monitoring-based treatment algorithm with a heart rate and blood pressure-based treatment algorithm for goal-directed fluid therapy in anesthetized dogs: A pilot study

The objective of this pilot study was to determine the feasibility of a study comparing the efficacy of an esophageal Doppler monitor (EDM)-based fluid therapy algorithm with a heart rate (HR)- and mean arterial blood pressure (MAP)-based algorithm in reducing hypotension and fluid load in anesthetized dogs. Client-owned dogs undergoing general anesthesia for surgical procedures were randomized to two groups. An EDM probe for monitoring blood flow in the descending aorta was placed in each dog before receiving a crystalloid bolus (5 mL/kg) over 5 min. Fluids were repeated in case of fluid responsiveness defined by increasing Velocity Time Integral (VTI) ≥ 10% in group EDM and by decreasing HR ≥ 5 beats/min and/or increasing MAP ≥ 3 mmHg in group standard. The feasibility outcomes included the proportion of dogs completing the study and the clinical applicability of the algorithms. The clinical outcomes were the total administered fluid volume and the duration of hypotension defined as MAP < 60 mmHg. Data was compared between groups with Mann-Whitney U-test. p < 0.05 were deemed significant. Of 25 dogs screened, 14 completed the study (56%). There were no differences in the proportion of recorded time spent in hypotension in group standard [2 (0–39)% (median (range))] and EDM [0 (0–63) %, p = 1], or the total volume of fluids [standard 8 (5–14) mL/kg/h, EDM 11 (4–20) mL/kg/h, p = 0.3]. This study declined the feasibility of a study comparing the impact of two newly developed fluid therapy algorithms on hypotension and fluid load in their current form. Clinical outcome analyses were underpowered and no differences in treatment efficacy between the groups could be determined. The conclusions drawn from this pilot study provide important information for future study designs.

The Impact of Goal-Directed Fluid Therapy on Postoperative Nausea and Vomiting in High-Risk Patients Undergoing Laparoscopic Sleeve Gastrectomy

PURPOSE

Patients with laparoscopic sleeve gastrectomy (LSG) are at high risk of postoperative nausea and vomiting (PONV). Goal-directed fluid therapy (GDFT) has been proven effective in improving postoperative gastrointestinal function in patients with obesity, but its effect on prevention of PONV remains controversial. This study aimed to investigate the impact of GDFT on PONV in high-risk patients with LSG.

METHODS

In a randomized, single-blinded, two-arm trial, patients with an Apfel score ≥ 3 and scheduled for LSG were included. Patients in the GDFT group received stroke volume-guided fluid therapy. Patients in the control group received conventional fluid therapy. The primary outcome was the incidence of PONV within 48 h after LSG. The second outcome included intensity of PONV, use of rescue therapy, recovery of gastrointestinal function, and postoperative length of stay (LOS).

RESULTS

A total of 137 patients were analyzed. The incidence of PONV in the GDFT group was lower than that in the control group (47.1% vs. 71.6%; odds ratio [95%CI], 0.35 [0.17-0.72]; P = 0.004). Fewer patients in the GDFT group received rescue therapy (30% vs. 58.2%; P = 0.001). Patients following GDFT protocol had a faster return of flatus (27.5 (19, 31) vs. 31 (20, 48) hours, P = 0.037) and shorter postoperative LOS (6.1 ± 1.0 vs. 6.6 ± 1.1 days; P = 0.007).

CONCLUSION

GDFT is conducive to deceasing PONV occurrence, restoring intestinal function, and shortening postoperative LOS in high-risk patients undergoing LSG.

Effect of the respiratory rate on the pulse pressure variation induced by hemorrhage in anesthetized dogs

BACKGROUND

Studies on anesthetized dogs regarding pulse pressure variation (PPV) are increasing. The influence of respiratory rate (RR) on PPV, in mechanically ventilated dogs, has not been clearly identified.

OBJECTIVES

This study evaluated the influence of RR on PPV in mechanically ventilated healthy dogs after hemorrhage.

METHODS

Five healthy adult Beagle dogs were premedicated with intravenous (IV) acepromazine (0.01 mg/kg). Anesthesia was induced with alfaxalone (3 mg/kg IV) and maintained with isoflurane in 100% oxygen. The right dorsal pedal artery was cannulated with a 22-gauge catheter for blood removal, and the left dorsal pedal artery was cannulated and connected to a transducer system for arterial blood pressure monitoring. The PPV was automatically calculated using a multi-parameter monitor and recorded. Hemorrhage was induced by withdrawing 30% of blood (24 mL/kg) over 30 min. Mechanical ventilation was provided with a tidal volume of 10 mL/kg and a 1:2 inspiration-to-expiration ratio at an initial RR of 15 breaths/min (baseline). Thereafter, RR was changed to 20, 30, and 40 breaths/min according to the casting lots, and the PPV was recorded at each RR. After data collection, the blood was transfused at a rate of 10 mL/kg/h, and the PPV was recorded at the baseline ventilator setting.

RESULTS

The data of PPV were analyzed using the Friedman test followed by the Wilcoxon signed-rank test (p < 0.05). Hemorrhage significantly increased PPV from 11% to 25% at 15 breaths/min. An increase in RR significantly decreased PPV from 25 (baseline) to 17%, 10%, and 10% at 20, 30, and 40 breaths/min, respectively (all p < 0.05).

CONCLUSIONS

The PPV is a dynamic parameter that can predict a dog's hemorrhagic condition, but PPV can be decreased in dogs under high RR. Therefore, careful interpretation may be required when using the PPV parameter particularly in the dogs with hyperventilation.

Intraoperative Circulatory Support in Lung Transplantation: Current Trend and Its Evidence

Lung transplantation has a high risk of haemodynamic complications in a highly vulnerable patient population. The effects on the cardiovascular system of the various underlying end-stage lung diseases also contribute to this risk. Following a literature review and based on our own experience, this review article summarises the current trends and their evidence for intraoperative circulatory support in lung transplantation. Identifiable and partly modifiable risk factors are mentioned and corresponding strategies for treatment are discussed. The approach of first identifying risk factors and then developing an adjusted strategy is presented as the ERSAS (early risk stratification and strategy) concept. Typical haemodynamic complications discussed here include right ventricular failure, diastolic dysfunction caused by left ventricular deconditioning, and reperfusion injury to the transplanted lung. Pre- and intra-operatively detectable risk factors for the occurrence of haemodynamic complications are rare, and the therapeutic strategies applied differ considerably between centres. However, all the mentioned risk factors and treatment strategies can be integrated into clinical treatment algorithms and can influence patient outcome in terms of both mortality and morbidity.

A randomised controlled feasibility trial of a clinical protocol to manage hypotension during major non-cardiac surgery

Intra-operative hypotension is a risk factor for postoperative morbidity and mortality. Minimally invasive monitors that derive other haemodynamic parameters, such as stroke volume, may better inform the management of hypotension. As a prelude to a multicentre randomised controlled trial, we conducted a single-centre feasibility trial of a protocol to treat hypotension as informed by minimally invasive haemodynamic monitoring during non-cardiac surgery. We recruited adults aged ≥40 years with cardiovascular risk factors who underwent non-cardiac surgery requiring invasive arterial pressure monitoring. Participants were randomly allocated to usual care, or a clinical protocol informed by an arterial waveform contour analysis monitor. Participants, outcome assessors, clinicians outside operating theatres and analysts were blinded to treatment allocation. Feasibility was evaluated based on: consent rate; recruitment rate; structured feedback from anaesthesia providers; and between-group differences in blood pressure, processes-of-care and outcomes. The consent rate among eligible patients was 33%, with 30 participants randomly allocated to the protocol and 30 to usual care. Anaesthesia providers rated the protocol to be feasible and acceptable. The protocol was associated with reduced fluid balance and hypotension exposure in the peri-operative setting. Postoperative complications included: acute myocardial injury in 18 (30%); acute kidney injury in 17 (28%); and surgical site infection in 7 (12%). The severity of complications was rated as moderate or severe in 25 (42%) participants. In summary, this single-centre study confirmed the feasibility of a multicentre trial to assess the efficacy and safety of a physiologically guided treatment protocol for intra-operative hypotension based on minimally invasive haemodynamic monitors.

Preoperative Evaluation and Management of Patients With Select Chronic Gastrointestinal, Liver, and Renal Diseases

Patients with chronic gastrointestinal, hepatic, and renal disease are frequently encountered in clinical practice. This is due in part to the rising prevalence of risk factors associated with these conditions. These patients are increasingly being considered for surgical intervention and are at higher risk for multiple perioperative complications. Many are able to safely undergo surgery but require unique considerations to ensure optimal perioperative care. In this review, we highlight relevant perioperative physiology and outline our approach to the evaluation and management of patients with select chronic gastrointestinal, hepatic, and renal diseases. A comprehensive preoperative evaluation with a multidisciplinary approach is often beneficial, and specialist involvement should be considered. Intraoperative and postoperative plans should be individualized based on the unique medical and surgical characteristics of each patient.

Stroke volume variation for predicting responsiveness to fluid therapy in patients undergoing cardiac and thoracic surgery: a systematic review and meta-analysis

OBJECTIVE

To evaluate the reliability of stroke volume variation (SVV) for predicting responsiveness to fluid therapy in patients undergoing cardiac and thoracic surgery.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, Web of Science up to 9 August 2020.

METHODS

Quality of included studies were assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We conducted subgroup analysis according to different anaesthesia and surgical methods with Stata V.14.0, Review Manager V.5.3 and R V.3.6.3. We used random-effects model to pool sensitivity, specificity and diagnostic odds ratio with 95% CI. The area under the curve (AUC) of receiver operating characteristic was calculated.

RESULTS

Among the 20 relevant studies, 7 were conducted during thoracic surgery, 8 were conducted during cardiac surgery and the remaining 5 were conducted in intensive critical unit (ICU) after cardiac surgery. Data from 854 patients accepting mechanical ventilation were included in our systematic review. The pooled sensitivity and specificity were 0.73 (95％ CI: 0.59 to 0.83) and 0.62 (95％ CI: 0.46 to 0.76) in the thoracic surgery group, 0.71 (95％ CI: 0.65 to 0.77) and 0.76 (95％ CI: 0.69 to 0.82) in the cardiac surgery group, 0.85 (95％ CI: 0.60 to 0.96) and 0.85 (95％ CI: 0.74 to 0.92) in cardiac ICU group. The AUC was 0.73 (95% CI: 0.69 to 0.77), 0.80 (95% CI: 0.77 to 0.83) and 0.88 (95% CI: 0.86 to 0.92), respectively. Results of subgroup of FloTrac/Vigileo system (AUC=0.80, Youden index=0.38) and large tidal volume (AUC=0.81, Youden index=0.48) in thoracic surgery, colloid (AUC=0.85, Youden index=0.55) and postoperation (AUC=0.85, Youden index=0.63) in cardiac surgery, passive leg raising (AUC=0.90, Youden index=0.72) in cardiac ICU were reliable.

CONCLUSION

SVV had good predictive performance in cardiac surgery or ICU after cardiac surgery and had moderate predictive performance in thoracic surgery. Nevertheless, technical and clinical variables may affect the predictive value potentially.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Impact of conventional vs. goal-directed fluid therapy on urethral tissue perfusion in patients undergoing liver surgery: A pilot randomised controlled trial

BACKGROUND

Although fluid administration is a key strategy to optimise haemodynamic status and tissue perfusion, optimal fluid administration during liver surgery remains controversial.

OBJECTIVE

To test the hypothesis that a goal-directed fluid therapy (GDFT) strategy, when compared with a conventional fluid strategy, would better optimise systemic blood flow and lead to improved urethral tissue perfusion (a new variable to assess peripheral blood flow), without increasing blood loss.

DESIGN

Single-centre prospective randomised controlled superiority study.

SETTING

Erasme Hospital.

PATIENTS

Patients undergoing liver surgery.

INTERVENTION

Forty patients were randomised into two groups: all received a basal crystalloid infusion (maximum 2 ml kg-1 h-1). In the conventional fluid group, the goal was to maintain central venous pressure (CVP) as low as possible during the dissection phase by giving minimal additional fluid, while in the posttransection phase, anaesthetists were free to compensate for any presumed fluid deficit. In the GDFT group, patients received in addition to the basal infusion, multiple minifluid challenges of crystalloid to maintain stroke volume (SV) variation less than 13%. Noradrenaline infusion was titrated to keep mean arterial pressure more than 65 mmHg in all patients.

MAIN OUTCOME MEASURE

The mean intra-operative urethral perfusion index.

RESULTS

The mean urethral perfusion index was significantly higher in the GDFT group than in the conventional fluid group (8.70 [5.72 to 13.10] vs. 6.05 [4.95 to 8.75], P = 0.046). SV index (ml m-2) and cardiac index (l min-1 m-2) were higher in the GDFT group (48 ± 9 vs. 33 ± 7 and 3.5 ± 0.7 vs. 2.4 ± 0.4, respectively; P < 0.001). Although CVP was higher in the GDFT group (9.3 ± 2.5 vs. 6.5 ± 2.9 mmHg; P = 0.003), intra-operative blood loss was not significantly different in the two groups.

CONCLUSION

In patients undergoing liver surgery, a GDFT strategy resulted in a higher mean urethral perfusion index than did a conventional fluid strategy and did not increase blood loss despite higher CVP.

TRIAL REGISTRATION

NCT04092608.

The effect of vasoconstriction on intestinal perfusion is determined by preload dependency: A prospective observational study

BACKGROUND

The effects of vasoconstriction on cardiac stroke volume (SV) and indices of peripheral and intestinal perfusion are insufficiently described.

METHODS

In a non-randomized clinical study, 30 patients undergoing elective rectal surgery were exposed to modulation of preload. The primary endpoint was intestinal perfusion (flux), measured by single-point laser Doppler flowmetry. Secondary endpoints were central cardiovascular variables obtained by the LiDCO rapid monitor, the peripheral perfusion index (PPI) derived from the pulse oximetry signal and muscle (StO₂ ) and cerebral oxygenation (ScO₂ ) determined by near-infrared spectroscopy.

RESULTS

For the whole cohort (n = 30), administration of Phenylephrine during HUT induced a median [IQR] increase in SV by 22% [14-41], p = .003 and in mean arterial pressure (MAP) by 54% [31-62], p < .001, with no change in PPI, StO₂ and ScO₂ or flux. In patients who were preload dependent during HUT (stroke volume variation; SSV >10%; n = 23), administration of phenylephrine increased SV by 29% [12-43], p = .01 and MAP by 54% [33-63], p < .001, followed by an increase in intestinal perfusion flux by 60% [15-289], p = .05, while PPI, StO₂ and ScO₂  remained unchanged. For non-preload dependent patients (SSV <10%; n = 7), no changes in hemodynamic indices were seen besides an increase in MAP by 54% [33-58], p = .002.

CONCLUSION

The reflection of vasoconstrictive modulation of preload in systemic cardiovascular variables and indices of perfusion was dependent on preload responsiveness. Administration of phenylephrine to increase preload did not appear to compromise organ perfusion.

Safety and Feasibility of Video-Assisted Thoracoscopic Day Surgery and Inpatient Surgery in Patients With Non-small Cell Lung Cancer: A Single-Center Retrospective Cohort Study

Background and Objective: This study was undertaken to evaluate how safe and viable the use of video-assisted thoracoscopic day surgery (VATDS) is for individuals diagnosed with early-stage non-small cell lung cancer (NSCLC).

Methods: Data obtained from the selected patients with NSCLC who underwent video-assisted thoracoscopic surgery (VATS) in the same medical group were analyzed and a single-center, propensity-matched cohort study was performed. In total, 353 individuals were included after propensity score matching (PSM) with 136 individuals in the day surgery group (DSG) and 217 individuals in the inpatient surgery group (ISG).

Results: The 24-h discharge rate in the DSG was 93.38% (127/136). With respect to the postoperative complications (PPCs), no difference between the two groups was found (DSG vs. ISG: 11.76 vs. 11.52%, p = 0.933). In the DSG, a shorter length of stay (LOS) after surgery (1.47 ± 1.09 vs. 2.72 ± 1.28 days, p < 0.001) and reduced drainage time (8.45 ± 3.35 vs. 24.11 ± 5.23 h, p < 0.001) were found, while the drainage volume per hour (mL/h) was not notably divergent between the relevant groups (p = 0.312). No difference was observed in the cost of equipment and materials between the two groups (p = 0.333). However, the average hospital cost and drug cost of the DSG were significantly lower than those of the ISG (p < 0.001).

Conclusion: The study indicated that the implementation of VATDS showed no difference in PPCs, but resulted in shorter in-hospital stays, shorter drainage times, and lower hospital costs than inpatient surgery. These results indicate the safety and feasibility of VATDS for a group of highly selected patients with early-stage NSCLC.

Changes in stroke volume induced by lung recruitment maneuver can predict fluid responsiveness during intraoperative lung-protective ventilation in prone position

Background

The present study aimed to evaluate the reliability of hemodynamic changes induced by lung recruitment maneuver (LRM) in predicting stroke volume (SV) increase after fluid loading (FL) in prone position.

Methods

Thirty patients undergoing spine surgery in prone position were enrolled. Lung-protective ventilation (tidal volume, 6–7 mL/kg; positive end-expiratory pressure, 5 cmH₂O) was provided to all patients. LRM (30 cmH₂O for 30 s) was performed. Hemodynamic variables including mean arterial pressure (MAP), heart rate, SV, SV variation (SVV), and pulse pressure variation (PPV) were simultaneously recorded before, during, and at 5 min after LRM and after FL (250 mL in 10 min). Receiver operating characteristic curves were generated to evaluate the predictability of SVV, PPV, and SV decrease by LRM (ΔSV_LRM) for SV responders (SV increase after FL > 10%). The gray zone approach was applied for ΔSV_LRM.

Results

Areas under the curve (AUCs) for ΔSV_LRM, SVV, and PPV to predict SV responders were 0.778 (95% confidence interval: 0.590–0.909), 0.563 (0.371–0.743), and 0.502 (0.315–0.689), respectively. The optimal threshold for ΔSV_LRM was 30% (sensitivity, 92.3%; specificity, 70.6%). With the gray zone approach, the inconclusive values ranged 25 to 75% for ΔSV_LRM (including 50% of enrolled patients).

Conclusion

In prone position, LRM-induced SV decrease predicted SV increase after FL with higher reliability than traditional dynamic indices. On the other hand, considering the relatively large gray zone in this study, future research is needed to further improve the clinical significance.

Trial registration

UMIN Clinical Trial Registry UMIN000027966. Registered 28th June 2017.

Impact of colloids or crystalloids in renal function assessed by NGAL and KIM-1 after hysterectomy: randomized controlled trial

Background

Hydroxyethyl starches are colloids used in fluid therapy that may reduce volume infusion compared with crystalloids, but they can affect renal function in critical care patients. This study aims to assess renal effects of starches using renal biomarkers in the perioperative setting.

Methods

This prospective, controlled, randomized study compared Hydroxyethyl starch 6% (HES) with Ringer's lactate (RL) in hysterectomy. Each episode of mean arterial pressure (MAP) below 60 mmHg guided the fluid replacement protocol. The RL group received 300 mL bolus of RL solution while the HES group received 150 mL of HES solution. All patients received RL (2 mL.kg⁻¹.h⁻¹) intraoperatively to replace insensible losses. Blood and urine samples were collected at three time points (preoperatively, 24 hours, and 40 days postoperatively) to assess urinary NGAL and KIM-1, as primary outcome, and other markers of renal function.

Results

Seventy patients were randomized and 60 completed the study. The RL group received a higher crystalloid volume (1,277 ± 812.7 mL vs. 630.4 ± 310.2 mL; p = 0.0002) with a higher fluid balance (780 ± 720 mL vs. 430 ± 440 mL; p = 0.03) and fluid overload (11.7% ± 10.4% vs. 7.0% ± 6.3%; p = 0.04) compared to the HES group. NGAL and KIM-1 did not differ between groups at each time point, however both biomarkers increased 24 hours postoperatively and returned to preoperative levels after 40 days in both groups.

Conclusion

HES did not increase renal biomarkers following open hysterectomy compared to RL. Moreover, HES provided better hemodynamic parameters using less volume, and reduced postoperative fluid balance and fluid overload.

Credibility Assessment of a Subject-Specific Mathematical Model of Blood Volume Kinetics for Prediction of Physiological Response to Hemorrhagic Shock and Fluid Resuscitation

Subject-specific mathematical models for prediction of physiological parameters such as blood volume, cardiac output, and blood pressure in response to hemorrhage have been developed. In silico studies using these models may provide an effective tool to generate pre-clinical safety evidence for medical devices and help reduce the size and scope of animal studies that are performed prior to initiation of human trials. To achieve such a goal, the credibility of the mathematical model must be established for the purpose of pre-clinical in silico testing. In this work, the credibility of a subject-specific mathematical model of blood volume kinetics intended to predict blood volume response to hemorrhage and fluid resuscitation during fluid therapy was evaluated. A workflow was used in which: (i) the foundational properties of the mathematical model such as structural identifiability were evaluated; (ii) practical identifiability was evaluated both pre- and post-calibration, with the pre-calibration results used to determine an optimal splitting of experimental data into calibration and validation datasets; (iii) uncertainty in model parameters and the experimental uncertainty were quantified for each subject; and (iv) the uncertainty was propagated through the blood volume kinetics model and its predictive capability was evaluated via validation tests. The mathematical model was found to be structurally identifiable. Pre-calibration identifiability analysis led to splitting the 180 min of time series data per subject into 50 and 130 min calibration and validation windows, respectively. The average root mean squared error of the mathematical model was 12.6% using the calibration window of (0 min, 50 min). Practical identifiability was established post-calibration after fixing one of the parameters to a nominal value. In the validation tests, 82 and 75% of the subject-specific mathematical models were able to correctly predict blood volume response when predictive capability was evaluated at 180 min and at the time when amount of infused fluid equals fluid loss.

Video-Assisted Thoracoscopic Day Surgery for Patients with Pulmonary Nodules: A Single-Center Clinical Experience of 200 Cases

Background

We reviewed our experience with 200 patients who underwent video-assisted thoracoscopic day surgery (VATDS) at the Day Surgery Center at West China Hospital to identify the safety and feasibility of VATDS and assess the value of novel management in patients with pulmonary nodules.

Methods

Between June 2019 and December 2020, 200 patients with pulmonary nodules underwent VATDS at the Day Surgery Center at West China Hospital. The medical records of these 200 patients were reviewed for age, sex, preoperative history, operative and pathological findings, amount of daily chest tube drainage, procedure method and duration, length of stay (LOS), visual analog scale (VAS), and postoperative pulmonary complications (PPCs).

Results

There were 45 male and 155 female patients with a median age of 43 years (range 18 to 58 years). A total of 158 (79.00%) patients were diagnosed with lung adenocarcinoma, 35 (17.50%) were diagnosed with chronic inflammation with fibrous hyperplasia, and seven (3.50%) were diagnosed with granulomatous inflammation with necrosis. The mean LOS of the 200 patients was 1.25±0.95 days, and 187 (93.50%) patients were discharged within 24 hours as planned. Thirteen patients were transferred to the thoracic surgery ward for further treatment because of PPCs. The median VAS was 3 points (range 1 to 7 points), and the rate of PPCs was 11.50%.

Conclusion

Two hundred patients underwent VATDS with an acceptable 24-hour discharge rate. However, selection of patients for VATDS is required, and the implementation of VATDS on a larger scale requires further discussion.

Perianesthesia Care of the Oncologic Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy: A Retrospective Study

PURPOSE

This study was to understand the perianesthesia care for patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS  + HIPEC).

METHOD

This is a retrospective study.

DESIGN

The perioperative electronic medical records of 189 CRS  + HIPEC surgical cases at a hospital of Western Pennsylvania from 2012 to 2018 were analyzed to study the characteristics of perianesthesia care for CRS  + HIPEC surgery.

FINDINGS

The patients' median age was 57 (range 21-83) years, and 60% were men. The mean anesthesia time was 10.47 ± 2.54 hours. Most tumors were appendix or colorectal in origin, and the mean peritoneal cancer index score was 16.19 ± 8.76. The mean estimated blood loss was 623 ± 582 mL. The mean total intravenous crystalloid administered was 8,377 ± 4,100 mL. Fifty-two patients received packed red blood cells during surgery. Postoperatively, 100% of the patients were transferred to the intensive care unit. A majority (52%) of patients were extubated in the operating room. Median lengths of hospital and intensive care unit stays were 13 and 2 days, respectively. A majority (73%) of patients had 1 or more postoperative complications and 29% of patients experienced major postoperative complications (Clavien-Dindo grade III or higher) during the hospital stay. Prolonged hospitalization was owing to gastrointestinal dysfunctions and respiratory failure related to atelectasis and pleural effusion.

CONCLUSIONS

CRS  + HIPEC is a major surgery with numerous challenges to the perianesthesia care team regarding hemodynamic adjustment, pain control, and postoperative complications, which demand training and future studies from the perianesthesia care team.

Perioperative fluid management in esophagectomy for cancer and its relation to postoperative respiratory complications

The optimal perioperative fluid management during esophagectomy is still not clear. Liberal regimens have been associated with higher morbidity and respiratory complications. Restrictive regimens might raise concerns for kidney function and increase the need to associate vasopressors. The aim of this study was to investigate retrospectively the perioperative fluid administration during esophagectomy and to correlate this with postoperative respiratory outcome. All patients who underwent esophagectomy between January and December 2016 were retrospectively analyzed. Patient characteristics, type of surgery and postoperative course were reviewed. Fluid administration and vasopressor use were calculated intraoperatively and during the postoperative stay at the recovery unit. Fluid overload was defined as a positive fluid balance of more than 125 mL/m2/h during the first 24 hours. Patients were divided in 3 groups: GRP0 (no fluid overload/no vasopressors); GRP1 (no fluid overload/need for vasopressors); GRP2 (fluid overload with/without vasopressors). Postoperative complications were prospectively recorded according to Esophagectomy Complications Consensus Group criteria. A total of 103 patients were analyzed: 35 (34%) GRP0, 50 (49%) GRP1 and 18 (17%) GRP2. No significant differences were found for age, treatment (neoadjuvant vs. primary), type of surgery (open/minimally invasive), histology nor comorbidities. There were significant (P ≤ 0.001) differences in fluid balance/m2/h (75 ± 21 mL; 86 ± 22 mL and 144 ± 20 mL) across GRP0, GRP1 and GRP2, respectively. We found differences in respiratory complications (GRP0 (20%) versus GRP1 (42%; P = 0.034) and GRP0 (20%) versus GRP2 (61%; P = 0.002)) and "Comprehensive Complications Index" (GRP0 (20.5) versus GRP1 (34.6; P = 0.015) and GRP0 (20.5) versus GRP2 (35.1; P = 0.009)). Multivariable analysis (binary logistic regression) for "any respiratory complication" was performed. Patients who received fluid overload (GRP2) had a 10.24 times higher risk to develop postoperative respiratory complications. When patients received vasopressors alone (GRP1), the chances of developing these complications were 3.57 times higher compared to GRP0. Among patients undergoing esophagectomy, there is a wide variety in the administration of fluid during the first 24 hours. There was a higher incidence of respiratory complications when patients received higher amounts of fluid or when vasopressors were used. We believe that a personalized and protocolized fluid administration algorithm should be implemented and that individual risk factors should be identified.

Association of the intraoperative peripheral perfusion index with postoperative morbidity and mortality in acute surgical patients: a retrospective observational multicentre cohort study

Background

We hypothesised that in acute high-risk surgical patients, a lower intraoperative peripheral perfusion index (PPI) would indicate a higher risk of postoperative complications and mortality.

Methods

This retrospective observational study included 1338 acute high-risk surgical patients from November 2017 until October 2018 at two University Hospitals in Denmark. Intraoperative PPI was the primary exposure variable and the primary outcome was severe postoperative complications defined as a Clavien–Dindo Class ≥III or death, within 30 days.

Results

intraoperative PPI was associated with severe postoperative complications or death: odds ratio (OR) 1.12 (95% confidence interval [CI] 1.05–1.19; P<0.001), with an association of intraoperative mean PPI ≤0.5 and PPI ≤1.5 with the primary outcome: OR 1.79 (95% CI 1.09–2.91; P=0.02) and OR 1.65 (95% CI 1.20–2.27; P=0.002), respectively. Each 15-min increase in intraoperative time spend with low PPI was associated with the primary outcome (per 15 min with PPI ≤0.5: OR 1.11 (95% CI 1.05–1.17; P<0.001) and with PPI ≤1.5: OR 1.06 (95% CI 1.02–1.09; P=0.002)). Thirty-day mortality in patients with PPI ≤0.5 was 19% vs 10% for PPI >0.5, P=0.003. If PPI was ≤1.5, 30-day mortality was 16% vs 8% in patients with a PPI >1.5 (P<0.001). In contrast, intraoperative mean MAP ≤65 mm Hg was not significantly associated with severe postoperative complications or death (OR 1.21 [95% CI 0.92–1.58; P=0.2]).

Conclusions

Low intraoperative PPI was associated with severe postoperative complications or death in acute high-risk surgical patients. To guide intraoperative haemodynamic management, the PPI should be further investigated.

Changes in arterial blood pressure characteristics following an extrasystolic beat or a fast 50 ml fluid challenge do not predict fluid responsiveness during cardiac surgery

Prediction of fluid responsiveness is essential in perioperative goal directed therapy, but dynamic tests of fluid responsiveness are not applicable during open-chest surgery. We hypothesised that two methods could predict fluid responsiveness during cardiac surgery based on their ability to alter preload and thereby induce changes in arterial blood pressure characteristics: (1) the change caused by extrasystolic beats and (2) the change caused by a fast infusion of 50 ml crystalloid (micro-fluid challenge). Arterial blood pressure and electrocardiogram waveforms were collected during surgical preparation of the left internal mammary artery in patients undergoing coronary artery bypass surgery. Patients received a fluid challenge (5 ml/kg ideal body weight). The first 50 ml were infused in 10 s and comprised the micro-fluid challenge. Predictor variables were defined as post-ectopic beat changes (compared with sinus beats preceding ectopy) in arterial blood pressure characteristics, such as pulse pressure and systolic pressure, or micro-fluid challenge induced changes in the same blood pressure characteristics. Patients were considered fluid responsive if stroke volume index increased by 15% or more after the full fluid challenge. Diagnostic accuracy was calculated by the area under the receiver operating characteristics curve (AUC). Fifty-six patients were included for statistical analysis. Thirty-one had extrasystoles. The maximal AUC was found for the extrasystolic change in pulse pressure and was 0.70 (CI [0.35 to 1.00]). The micro-fluid challenge method generally produced lower AUC point estimates. Extrasystoles did not predict fluid responsiveness with convincing accuracy in patients undergoing cardiac surgery and changes in arterial waveform indices following a micro-fluid challenge could not predict fluid responsiveness. Given a low number of fluid responders and inherently reduced statistical power, our data does not support firm conclusions about the utility of the extrasystolic method. CLINICAL TRIAL REGISTRATION: Unique identifier: NCT02903316. https://clinicaltrials.gov/ct2/show/NCT02903316?cond=NCT02903316&rank=1 .

Mini fluid chAllenge aNd End-expiratory occlusion test to assess flUid responsiVEness in the opeRating room (MANEUVER study): A multicentre cohort study

BACKGROUND

The fluid challenge response in surgical patients can be predicted by functional haemodynamic tests. Two tests, the mini-fluid challenge (mini-FC) and end-expiratory occlusion test (EEOT), have been assessed in a few small single-centre studies with conflicting results. In general, functional haemodynamic tests have not performed reliably in predicting fluid responsiveness in patients undergoing laparotomy.

OBJECTIVE

This trial is designed to address and compare the reliability of the EEOT and the mini-FC in predicting fluid responsiveness during laparotomy.

DESIGN

Prospective, multicentre study.

SETTING

Three university hospitals in Italy.

PATIENTS

A total of 103 adults patients scheduled for elective laparotomy with invasive arterial monitoring.

INTERVENTIONS

The study protocol evaluated the changes in the stroke volume index (SVI) 20 s (EEOT20) and 30 s (EEOT30) after an expiratory hold and after a mini-FC of 100 ml over 1 min. Fluid responsiveness required an increase in SVI at least 10% following 4 ml kg-1 of Ringer's solution fluid challenge infused over 10 min.

MAIN OUTCOME MEASUREMENTS

Haemodynamic data, including SVI, were obtained from pulse contour analysis. The area under the receiver operating characteristic curves of the tests were compared with assess fluid responsiveness.

RESULTS

Fluid challenge administration induced an increase in SVI at least 10% in 51.5% of patients. The rate of fluid responsiveness was comparable among the three participant centres (P = 0.10). The area under the receiver operating characteristic curves (95% CI) of the changes in SVI after mini-FC was 0.95 (0.88 to 0.98), sensitivity 98.0% (89.5 to 99.6) and specificity 86.8% (75.1 to 93.4) for a cut-off value of 4% of increase in SVI. This was higher than the SVI changes after EEOT20, 0.67 (0.57 to 0.76) and after EEOT30, 0.73 (0.63 to 0.81).

CONCLUSION

In patients undergoing laparotomy the mini-FC reliably predicted fluid responsiveness with high-sensitivity and specificity. The EEOT showed poor discriminative value and cannot be recommended for assessment of fluid responsiveness in this surgical setting.

TRIAL REGISTRATION

NCT03808753.

Guidelines for enhanced recovery after cardiac surgery. Consensus document of Spanish Societies of Anesthesia (SEDAR), Cardiovascular Surgery (SECCE) and Perfusionists (AEP)

The ERAS guidelines are intended to identify, disseminate and promote the implementation of the best, scientific evidence-based actions to decrease variability in clinical practice. The implementation of these practices in the global clinical process will promote better outcomes and the shortening of hospital and critical care unit stays, thereby resulting in a reduction in costs and in greater efficiency. After completing a systematic review at each of the points of the perioperative process in cardiac surgery, recommendations have been developed based on the best scientific evidence currently available with the consensus of the scientific societies involved.