Effects of perioperative fasting on haemodynamics and intravascular volumes

Different preoperative fluids do not affect the hemodynamic status but gastric volume: results of a randomized crossover pilot study

Background and objective

Inferior vena cava (IVC) examination has been reported as a noninvasive method for evaluating the hemodynamic state. We conducted this crossover pilot study to investigate the effects of the administration of water and high-carbohydrate-containing fluids on the hemodynamic status of volunteers through collapsibility index of IVC (IVCCI) measurement.

Methods

Twenty volunteers were randomly assigned to a water or high-carbohydrate group according to computer-generated random numbers in a 1:1 ratio. In the water group, volunteers received water (5 mL/kg), and in the high-carbohydrate group, patients received carbohydrate drinks (5 mL/kg). Respiratory variations in the IVC diameter, gastric volume, and blood pressure and heart rates in erect and supine positions were measured at admission (T1), 1 h (T2), 2 h (T3), 3 h (T4), and 4 h (T5).

Results

When considering participants with an IVCCI of more than 42%, there were no significant differences between the water and carbohydrate drink groups at each time point (all p > 0.05). At T2, more participants had an empty stomach in water group than in carbohydrate drink group (p < 0.001). At T3, 30% of the participants could not empty their stomachs in carbohydrate drink group. However, with regard to the number of volunteers with empty stomach at T3, there was no significant difference between water and carbohydrate drink group. Repeated measures data analysis demonstrated that IVCCI showed no significant differences over time (p = 0.063 for T1-T5). There were no differences between water and carbohydrate drinks (p = 0.867).

Conclusion

Our results suggested that neither water nor carbohydrate drinking affected the hemodynamic status through IVCCI measurement over time, up to 4 h after drinking. Furthermore, carbohydrate drinking might delay gastric emptying at 1 h, but not 2 h after drinking, in comparison with water.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01697-3.

Atrial Fibrillation and Chronic Kidney Disease-A Risky Combination for Post-Contrast Acute Kidney Injury

Atrial fibrillation (AF) symptoms may mimic coronary artery disease (CAD) which reflects the difficulties in qualifying AF patients for invasive diagnostics. A substantial number of coronary angiographies may be unnecessary or even put patients at risk of post-contrast acute kidney injury (PC-AKI), especially patients with chronic kidney disease (CKD). We aimed to investigate the hypothesis indicating higher prevalence of PC-AKI in patients with AF scheduled for coronary angiography. The study population comprised of 8026 patients referred for elective coronarography including 1621 with AF. In the comparison of prevalence of PC-AKI in distinguished groups we can see that kidney impairment was twice more frequent in patients with AF in both groups with CKD (CKD (+)/AF (+) 6.24% vs. CKD (+)/AF (−) 3.04%) and without CKD (CKD (−)/AF (+) 2.32% vs. CKD (−)/AF (−) 1.22%). In our study, post-contrast acute kidney disease is twice more frequent in patients with AF, especially in subgroup with chronic kidney disease scheduled for coronary angiography. Additionally, having in mind results of previous studies stating that AF is associated with non-obstructive coronary lesions on angiography, patients with AF and CKD may be unnecessarily exposed to contrast agent and possible complications.

Renal Dysfunction following Direct Current Cardioversion of Atrial Fibrillation: Incidence and Risk Factors

INTRODUCTION

Emerging data suggest that cardioversion for atrial fibrillation (AF) may be associated with acute kidney injury (AKI). However, limited data are available regarding the incidence and risk factors for AKI after direct current cardioversion (DCCV) of AF.

METHODS

All patients undergoing DCCV at Mayo Clinic between 2001 and 2012 for AF were prospectively enrolled in a database. All patients with serum creatinine (SCR) values pre- and post-cardioversion were reviewed for AKI, defined as a ≥25% decline in eGFR (estimated glomerular filtration rate) from baseline value within 7 days of the DCCV.

RESULTS

Of the 6,427 eligible patients, 1,256 (19.5%) patients had pre- and post-DCCV SCR available and formed the cohort under study. The mean age was 70.4 (SD 11.7) years, and 67.3% were male. During the study period, 131 (10.4%) patients suffered from AKI following DCCV. AKI was independently associated with inpatient status (OR 26.79; 95% CI 3.69-194.52), CHA2DS2-VASc score (OR 1.25; 95% CI 1.11-1.41), prior use of diuretics (OR 1.59; 95% CI 1.03-2.46), and absence of CKD (OR 1.61; 95% CI 1.04-2.49), and was independent of the success of the DCCV. None of the patients required acute dialysis during the study outcome period.

CONCLUSION

AKI following DCCV of AF is common, self-limited, and without the need for replacement therapies.

Pre-operative fluid bolus for improved haemodynamic stability during minor surgery: A prospectively randomized clinical trial

BACKGROUND

Haemodynamic instability during the induction of anaesthesia and surgery is common and may be related to hypovolaemia caused by pre-operative fasting or chronic diuretic therapy. The aim of our prospective, controlled, randomized study was to test the hypothesis that a predefined fluid bolus given prior to general anaesthesia for minor surgery would increase haemodynamic stability during anaesthetic induction.

METHODS

Two hundred and nineteen fairly healthy adult patients requiring minor surgery were enrolled. All received standard treatment, including a pulse contour analysing device for non-invasive measurement of cardiac index. Infusion therapy was started in all patients at induction. The intervention group (106 patients) was randomized to receive an additional fluid bolus of 8 mL/kg Ringer's acetate solution before the induction of anaesthesia. The primary endpoint was the incidence of haemodynamic instability, defined as a significant reduction of blood pressure or cardiac index during induction of anaesthesia.

RESULTS

The interventional group had a lesser incidence of haemodynamic instability during induction (41.5% vs 56.6%, P = .025). This group also had higher cardiac index, stroke volume index, systolic and mean blood pressure and a greater left ventricular end-diastolic area.

CONCLUSIONS

A fluid bolus prior to anaesthesia reduced the incidence of haemodynamic instability during induction of general anaesthesia. The total fluid volume was slightly greater in the intervention group compared to the control group (1370 ± 439 mL vs 1219 ± 483 mL, P = .007). We conclude that a defined fluid bolus can help stabilizing haemodynamics in patients undergoing general anaesthesia.

Influence of Fasting Duration on Body Fluid and Hemodynamics

Fasting before general anesthesia aims to reduce the volume and acidity of stomach contents, which reduces the risk of regurgitation and aspiration. Prolonged fasting for many hours prior to surgery could lead to unstable hemodynamics, however. Therefore, preoperative oral intake of clear fluids 2 hours prior to surgery is recommended to decrease dehydration without an increase in aspiration risk. In this study, we investigated the body fluid composition and hemodynamics of patients undergoing general anesthesia as the first case of the day versus the second subsequent case. We retrospectively reviewed the general anesthesia records of patients over 20 years old who underwent oral maxillofacial surgery. We investigated patient demographics, preoperative fasting time, anesthetic time, urine output, infusion volume, and opioid and vasopressor use. With respect to body fluid and hemodynamics, we extracted the data from the induction of anesthesia through 2 hours of anesthesia time. Thirty patients were suitable for this study. Patients were divided into 2 groups: patients who underwent surgery as the first case of the day (am group: n = 15) and patients who underwent surgery as the second case (pm group: n = 15). There were no significant differences between the 2 groups in patient demographics. In the pm group, fasting time for a light meal (832 minutes) was significantly longer than for the am group (685 minutes), p = .005. In the pm group, fasting time for clear fluids (216 minutes) was also significantly longer than for the am group (194 minutes), p = .005. Body fluid composition was not significantly different between the 2 groups. In addition, cardiac parameters intraoperatively were stable. In the pm group, vasopressors were used in 4 patients at the induction of anesthesia (p = .01). There were not statistically significant changes in cardiac function or body fluid composition between patients treated as the first case of the day vs patients who underwent surgery with general anesthesia as the second case of the day.

Frequency of Left Ventricular End-Diastolic Volume-Mediated Declines in Ejection Fraction in Patients Receiving Potentially Cardiotoxic Cancer Treatment

We sought to determine the frequency by which decreases in left ventricular (LV) end-diastolic volume (LVEDV) with and without increases in end-systolic volume (LVESV) influenced early cancer treatment-associated declines in LV ejection fraction (LVEF) or LV mass. One hundred twelve consecutively recruited subjects (aged 52 ± 14 years) with cancer underwent blinded cardiovascular magnetic resonance measurements of LV volumes, mass, and LVEF before and 3 months after initiating potentially cardiotoxic chemotherapy (72% of participants received anthracyclines). Twenty-six participants developed important declines in LVEF of >10% or to values <50% at 3 months, in whom 19% versus 60%, respectively, experienced their decline in LVEF due to isolated declines in LVEDV versus an increase in LVESV; participants who dropped their LVEF due to decreases in LVEDV lost more LV mass than those who dropped their LVEF due to an increase in LVESV (p = 0.03). Nearly one fifth of subjects experience marked LVEF declines due to an isolated decline in LVEDV after initiating potentially cardiotoxic chemotherapy. Because reductions in intravascular volume (which could be treated by volume repletion) may account for LVEDV-related declines in LVEF, these data indicate that LV volumes should be reviewed along with LVEF when acquiring imaging studies for cardiotoxicity during the treatment for cancer.

Clinical practice guide for the choice of perioperative volume-restoring fluid in adult patients undergoing non-cardiac surgery

The present Clinical practice guide responds to the clinical questions about security in the choice of fluid (crystalloid, colloid or hydroxyethyl starch 130) in patients who require volume replacement during perioperative period of non-cardiac surgeries. From the evidence summary, recommendations were made following the GRADE methodology. In this population fluid therapy based on crystalloids is suggested (weak recommendation, low quality evidence). In the events where volume replacement is not reached with crystalloids, the use of synthetic colloids (hydroxyethyl starch 130 or modified fluid gelatin) is suggested instead of 5% albumin (weak recommendation, low quality evidence). The choice and dosage of the colloid should be based in the product characteristics, patient comorbidity and anesthesiologist's experience.

Optimizing perioperative hemodynamics: what is new?

PURPOSE OF REVIEW

Using perioperative goal-directed therapy (GDT) or peroperative hemodynamic optimization significantly reduces postoperative complications and risk of death in patients undergoing noncardiac major surgeries. In this review, we discuss the main changes in the field of perioperative optimization over the last few years.

RECENT FINDINGS

One of the key aspects that has changed in the last decade is the shift from invasive monitoring with pulmonary artery catheters (PACs) to less or minimally invasive monitoring systems. The evaluation of intravascular fluid volume deficits has also changed dramatically from the use of static indices to the assessment of fluid responsiveness using either dynamic indices or functional hemodynamic. Finally, attention has been directed toward more restrictive strategies of crystalloids as maintenance fluids.

SUMMARY

GDT is safe and more likely to tailor the amount of fluids given to the amount of fluids actually needed. This approach includes assessment of fluid responsiveness and, if necessary, the use of inotropes; moreover, this approach can be coupled with a restrictive strategy for maintenance fluids. These strategies have been increasingly incorporated into protocols for perioperative hemodynamic optimization in high-risk patients undergoing major surgery, resulting in more appropriate use of fluids, vasopressors, and inotropes.