Effect of Sevoflurane Anesthesia on Diastolic Function: A Prospective Observational Study

BACKGROUND

The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function.

METHODS

This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e' < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e' on 2 TTEs (Δe'). Secondary end points were ΔE/e', Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups.

RESULTS

e' (Δe': 30 [6, 64] vs 0 [-18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:-15 [-31, -3] vs -4 [-20, 10]%, P = .091). ΔE/e' was not different between the 2 groups (11 [-16, 26] vs 12 [-9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups.

CONCLUSIONS

In this study, echocardiographic parameters of diastolic function, including septal e', E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.

Remifentanil improves left ventricular diastolic parameters in patients with impaired diastolic function: a prospective clinical study

BACKGROUND

Left ventricular diastolic dysfunction has a significant impact on perioperative morbidity and mortality, and its incidence is high in elderly individuals. Anesthetic agents may impair diastolic function, which may increase the incidence of perioperative complications. The aim of this prospective, clinical, phase 4 study was to investigate the effects of remifentanil on left ventricle (LV) diastolic function in patients with diastolic dysfunction. The study was performed on 30 spontaneously breathing subjects (aged 60-80 years) with diastolic dysfunction.

METHODS

Thirty patients (aged 60-80 years) with diastolic dysfunction scheduled for surgery were recruited between November 2019 and March 2023. Left ventricle function was evaluated once the intravenous remifentanil infusion reached a target-controlled concentration of 2 ng/ml with transthoracic echocardiography. Analysis of systolic function focused on left ventricular ejection fraction and mean mitral annular S velocity (Sm), whereas diastolic function focused on changes in transmitral peak flow (E), E/A, mitral septal and lateral e' waves, E/e' ratios and left atrial volume index following remifentanil infusion.

RESULTS

Diastolic function measures of LV (mitral E/e', septal and lateral e' waves) statistically significantly improved (E/e' from 10.6 ± 2.9 cm.sn- 1 to 9.5 ± 2.2 cm.sn- 1; p = 0.006) following remifentanil infusion. Left atrial volume index decreased following remifentanil infusion without statistical significance (from 55 ± 14.4 ml.cm- 2 to 51.6 ± 13.3 ml.cm- 2; p = 0.1). Systolic function (ejection fraction and Sm) did not change following remifentanil infusion.

CONCLUSIONS

Remifentanil improves left ventricular diastolic parameters in patients with preexisting diastolic dysfunction. Our study suggests that remifentanil at a plasma concentration of 2 ng.ml- 1 might be used safely in patients with left ventricular diastolic dysfunction.

Role of Echocardiography for the Perioperative Assessment of the Right Ventricle

Purpose of Review

This review aims to highlight the perioperative echocardiographic evaluation of right ventricular (RV) function with strengths and limitations of commonly used and evolving techniques. It explains the value of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) and describes the perioperative changes of RV function echocardiographers should be aware of.

Recent Findings

RV dysfunction is an entity with strong influence on outcome. However, its definition and assessment in the perioperative interval are not well-defined. Moreover, values assessed by TTE and TEE are not interchangeable; while some parameters seem to correlate well, others do not. Myocardial strain analysis and three-dimensional echocardiography may overcome the limitations of conventional echocardiographic measures and provide further insight into perioperative cardiac mechanics.

Summary

Echocardiography has become an essential part of modern anesthesiology in patients with RV dysfunction. It offers the opportunity to evaluate not only global but also regional RV function and distinguish alterations of RV contraction.

Do Elderly Patients With Diastolic Dysfunction Require Higher Doses of Norepinephrine During General Anesthesia for Noncardiac Surgeries? A Prospective Observational Study

BACKGROUND

Diastolic dysfunction is a risk factor for postoperative major cardiovascular events. During anesthesia, patients with diastolic dysfunction might experience impaired hemodynamic function and worsening of diastolic function, which in turn, might be associated with a higher incidence of postoperative complications.We aimed to investigate whether patients with diastolic dysfunction require higher doses of norepinephrine during general anesthesia. Furthermore, we aimed to examine the association between the grade of diastolic dysfunction and the E/e' ratio during anesthesia. A high E/e' ratio corresponds to elevated filling pressures and is an important measure of impaired diastolic function.

METHODS

We conducted a prospective observational cohort study at a German university hospital from February 2017 to September 2018. Patients aged ≥60 years and undergoing general anesthesia (ie, propofol and sevoflurane) for elective noncardiac surgery were enrolled. Exclusion: mitral valve disease, atrial fibrillation, and implanted mechanical device.The primary outcome parameter was the administered dose of norepinephrine within 30 minutes after anesthesia induction (μg·kg-1 30 min-1). The secondary outcome parameter was the change of Doppler echocardiographic E/e' from ECHO1 (baseline) to ECHO2 (anesthesia). Linear models and linear mixed models were used for statistical evaluation.

RESULTS

A total of 247 patients were enrolled, and 200 patients (75 female) were included in the final analysis. Diastolic dysfunction at baseline was not associated with a higher dose of norepinephrine during anesthesia (P = .6953). The grade of diastolic dysfunction at baseline was associated with a decrease of the E/e' ratio during anesthesia (P < .001).

CONCLUSIONS

We did not find evidence for an association between diastolic dysfunction and impaired hemodynamic function, as expressed by high vasopressor support during anesthesia. Additionally, our findings suggest that diastolic function, as expressed by the E/e' ratio, does not worsen during anesthesia.

Intraoperative Secondary Insults During Orthopedic Surgery in Traumatic Brain Injury

BACKGROUND

Secondary insults worsen outcomes after traumatic brain injury (TBI). However, data on intraoperative secondary insults are sparse. The primary aim of this study was to examine the prevalence of intraoperative secondary insults during orthopedic surgery after moderate-severe TBI. We also examined the impact of intraoperative secondary insults on postoperative head computed tomographic scan, intracranial pressure (ICP), and escalation of care within 24 hours of surgery.

MATERIALS AND METHODS

We reviewed medical records of TBI patients 18 years and above with Glasgow Coma Scale score <13 who underwent single orthopedic surgery within 2 weeks of TBI. Secondary insults examined were: systemic hypotension (systolic blood pressure<90 mm Hg), intracranial hypertension (ICP>20 mm Hg), cerebral hypotension (cerebral perfusion pressure<50 mm Hg), hypercarbia (end-tidal CO2>40 mm Hg), hypocarbia (end-tidal CO2<30 mm Hg in absence of intracranial hypertension), hyperglycemia (glucose>200 mg/dL), hypoglycemia (glucose<60 mg/dL), and hyperthermia (temperature >38°C).

RESULTS

A total of 78 patients (41 [18 to 81] y, 68% male) met the inclusion criteria. The most common intraoperative secondary insults were systemic hypotension (60%), intracranial hypertension and cerebral hypotension (50% and 45%, respectively, in patients with ICP monitoring), hypercarbia (32%), and hypocarbia (29%). Intraoperative secondary insults were associated with worsening of head computed tomography, postoperative decrease of Glasgow Coma Scale score by ≥2, and escalation of care. After Bonferroni correction, association between cerebral hypotension and postoperative escalation of care remained significant (P<0.001).

CONCLUSIONS

Intraoperative secondary insults were common during orthopedic surgery in patients with TBI and were associated with postoperative escalation of care. Strategies to minimize intraoperative secondary insults are needed.

Early Systolic Dysfunction Following Traumatic Brain Injury: A Cohort Study

OBJECTIVE

Prior studies have suggested that traumatic brain injury may affect cardiac function. Our study aims were to determine the frequency, longitudinal course, and admission risk factors for systolic dysfunction in patients with moderate-severe traumatic brain injury.

DESIGN

Prospective cohort study.

SETTING

Level 1 trauma center.

MEASUREMENTS

Transthoracic echocardiogram within 1 day and over the first week after moderate-severe traumatic brain injury; transthoracic echocardiogram within 1 day after mild traumatic brain injury (comparison group).

MEASUREMENTS AND MAIN RESULTS

Systolic function was assessed by transthoracic echocardiogram, and systolic dysfunction was defined as fractional shortening less than 25%. Multivariable Poisson regression models examined admission risk factors for systolic dysfunction. Systolic function in 32 patients with isolated moderate-severe traumatic brain injury and 32 patients with isolated mild traumatic brain injury (comparison group) was assessed with transthoracic echocardiogram. Seven (22%) moderate-severe traumatic brain injury and 0 (0%) mild traumatic brain injury patients had systolic dysfunction within the first day after injury (p < 0.01). All patients with early systolic dysfunction recovered in 1 week. Younger age (relative risk, 0.87; 95% CI, 0.79-0.94; for 1 yr increase in age) and lower admission Glasgow Coma Scale score (relative risk, 0.34; 95% CI, 0.20-0.58; for one unit increase in Glasgow Coma Scale) were independently associated with the development of systolic dysfunction among moderate-severe traumatic brain injury patients.

CONCLUSIONS

Early systolic dysfunction can occur in previously healthy patients with moderate-severe traumatic brain injury, and it is reversible over the first week of hospitalization. Younger age and lower admission Glasgow Coma Scale score are independently associated with the development of systolic dysfunction after moderate-severe traumatic brain injury.

[Perioperative care of patients with diastolic heart failure. Interface to anesthesia]

Diastolic heart failure leads to an increase in perioperative morbidity and mortality. The prevalence of this disease is rising and multiple risk factors have already been identified. Besides higher age and female gender, arterial hypertension, diabetes mellitus and coronary artery disease in particular have to be considered. Clinical examination and laboratory analyses are important for preoperative evaluation; however, echocardiography plays the most important role in the diagnostics of diastolic heart failure. The transmitral flow profile can be used to differentiate the grades of diastolic dysfunction using the ratio between early passive ventricular filling (E) and late active filling due to atrial contraction (A). Data concerning the ideal anesthesia technique are for the most part lacking; however, the application of thoracic epidural anesthesia seems to be beneficial. A great deal of attention has to be paid to the intraoperative volume status of patients with diastolic dysfunction as hypovolemia and hypervolemia can both have detrimental effects. Arrhythmias and major changes in blood pressure put this special group of patients at additional risks.

Analysis of transthoracic echocardiographic data in major vascular surgery from a prospective randomised trial comparing sevoflurane and fentanyl with propofol and remifentanil anaesthesia

The aim of this study was to define pre-operative echocardiographic data and explore if postoperative indices of cardiac function after open abdominal aortic surgery were affected by the anaesthetic regimen. We hypothesised that volatile anaesthesia would improve indices of cardiac function compared with total intravenous anaesthesia. Transthoracic echocardiography was performed pre-operatively in 78 patients randomly assigned to volatile anaesthesia and 76 to total intravenous anaesthesia, and compared with postoperative data. Pre-operatively, 16 patients (10%) had left ventricular ejection fraction < 46%. In 138 patients with normal left ventricular ejection fraction, 5/8 (62%) with left ventricular dilatation and 41/130 (33%) without left ventricular dilatation had evidence of left ventricular diastolic dysfunction (p < 0.001). Compared with pre-operative findings, significant increases in left ventricular end-diastolic volume, left atrial maximal volume, cardiac output, velocity of early mitral flow and early myocardial relaxation occurred postoperatively (all p < 0.001). The ratio of the velocity of early mitral flow to early myocardial relaxation remained unchanged. There were no significant differences in postoperative echocardiographic findings between patients anaesthetised with volatile anaesthesia or total intravenous anaesthesia. Patients had an iatrogenic surplus of approximately 4.1 l of fluid volume by the first postoperative day. N-terminal prohormone of brain natriuretic peptide increased on the first postoperative day (p < 0.001) and remained elevated after 30 days (p < 0.001) in both groups. Although postoperative echocardiographic alterations were most likely to be related to increased preload due to a substantial iatrogenic surplus of fluid, a component of peri-operative myocardial ischaemia cannot be excluded. Our hypothesis that volatile anaesthesia improved indices of cardiac function compared with total intravenous anaesthesia could not be verified.

Myocardial dysfunction in acute traumatic brain injury relieved by surgical decompression

Traumatic brain injury (TBI) is a major public health issue and is a leading cause of death in North America. After a primary TBI, secondary brain insults can predispose patients to a worse outcome. One of the earliest secondary insults encountered during the perioperative period is hypotension, which has been directly linked to both mortality and poor disposition after TBI. Despite this, it has been shown that hypotension commonly occurs during surgery for TBI. We present a case of intraoperative hypotension during surgery for TBI, where the use of transthoracic echocardiography had significant diagnostic and therapeutic implications for the management of our patient. We then discuss the issue of cardiac dysfunction after brain injury and the implications that echocardiography may have in the management of this vulnerable patient population.

Impact of propofol anesthesia induction on cardiac function in low-risk patients as measured by intraoperative Doppler tissue imaging

BACKGROUND

Despite a few experimental studies showing a dose-dependent myocardial depressive effect of propofol anesthesia induction, few clinical data are available to determine its precise impact on myocardial function, probably because of its brevity and a lack of appropriate evaluation tools. The purpose of this study was to examine the impact of propofol-based anesthesia induction on left ventricular (LV) function using Doppler tissue and speckle-tracking imaging.

METHODS

In 19 low-risk patients with normal LV systolic and diastolic function undergoing noncardiac surgery (all women; mean age, 42 years), propofol bolus (2.0 mg/kg) was administered intravenously for anesthesia induction. LV ejection fraction, global peak systolic longitudinal strain, and tissue Doppler-derived indices of mitral annular velocity during systole (S'), early diastole (e'), and atrial contraction (a') were determined by intraoperative transthoracic echocardiography before and 1, 3, and 5 min after propofol bolus (T0, T1, T2, and T3, respectively).

RESULTS

The following at T1, T2, and T3 were significantly less in magnitude than at T0: septal S' (5.61, 5.61, and 5.51 vs 7.60 cm/sec, P < .001), lateral S' (5.75, 5.89, and 5.94 vs 8.12 cm/sec, P < .001), septal e' (10.10, 10.26, and 10.07 vs 11.4 cm/sec, P < .01), septal a' (6.70, 6.21, and 6.13 vs 8.58 cm/sec, P < .01), lateral a' (7.29, 6.81, and 6.85 vs 9.01 cm/sec, P < .01), and longitudinal strain (-19.36%, -19.71%, and -19.61% vs -22.28%, P < .001). LV ejection fraction was not significantly changed (P = .361).

CONCLUSIONS

Propofol anesthesia induction diminished LV and atrial contraction in low-risk patients with prior normal LV function. Further studies are needed to understand the clinical implications, particularly for higher risk populations.

Prevalence and risk factors for intraoperative hypotension during craniotomy for traumatic brain injury

BACKGROUND

Hypotension after traumatic brain injury (TBI) is associated with poor outcomes. However, data on intraoperative hypotension (IH) are scarce and the effect of anesthetic agents on IH is unknown. We examined the prevalence and risk factors for IH, including the effect of anesthetic agents during emergent craniotomy for isolated TBI.

METHODS

This is a retrospective cohort study of patients 18 years and above, who underwent emergent craniotomy for TBI at Harborview Medical Center (level 1 trauma center) between October 2007 and January 2010. Demographic, clinical, and radiographic characteristics and hemodynamic and anesthetic data were abstracted from medical and electronic anesthesia records. Hypotension was defined as systolic blood pressure <90 mm Hg. Univariate analyses were performed to compare the clinical characteristics of patients with and without IH, and multiple logistic regression analysis was used to determine independent risk factors for IH.

RESULTS

Data abstracted from 113 eligible patients aged 48±19 years were analyzed. IH was common (n=73, 65%) but not affected by the choice of anesthetic agent. Independent risk factors for IH were multiple computed tomographic (CT) lesions [adjusted odds ratios (AOR) 19.1; 95% confidence interval (CI), 2.08-175.99; P=0.009], subdural hematoma (AOR 17.9; 95% CI, 2.97-108.10; P=0.002), maximum CT lesion thickness (AOR 1.1; 95% CI, 1.01-1.13; P=0.016), and anesthesia duration (AOR 1.1; 95% CI, 1.01-1.30; P=0.009).

CONCLUSIONS

IH was common in adult patients with isolated TBI undergoing emergent craniotomy. The presence of multiple CT lesions, subdural hematoma, maximum thickness of CT lesion, and longer duration of anesthesia increase the risk for IH.

Elevated factor VIII enhances thrombin generation in the presence of factor VIII-deficiency, factor XI-deficiency or fondaparinux

BACKGROUND

Increased levels of factor VIII occur as a response to vascular injury and/or inflammation, and may increase thrombotic risks. In contrast, factor VIII deficiency poses a major hemostatic challenge. The role of factor VIII in modulating hemostasis/thrombosis was investigated in plasma models of hypocoagulable and hypercoagulable state using thrombin generation (TG) assay.

METHODS

TG was performed in undiluted/diluted control, FVIII-deficient, FVIII-deficient with low antithrombin (AT activity, ~59%), and factor XI-deficient plasma samples using relipidated tissue factor (TF, 2 pM) or dilute Actin as activators. The impact of elevated FVIII on TG was simulated by adding Humate-P (0 to 3 U/ml) to the above plasma samples. In fondaparinux (1 μg/ml) treated plasma with normal or lower AT activity effects of Humate-P vs. 60 nM of recombinant activated factor VII (rFVIIa) were also evaluated.

RESULTS

Humate-P increased TG concentration dependently in undiluted and diluted control plasma with TF activation. With Actin activation, only the concentration dependent shortening of lag time, but no change in peak thrombin was observed. In FVIII-deficient, FVIII-deficient with low AT, and FXI-deficient samples, 3 U/ml of Humate-P increased TG, and decreased its onset with either activator. The reduced peak thrombin due to fondaparinux was reversed with Humate-P (3 U/ml) more than with rFVIIa. Elevated FVIII levels seem to favor intrinsic tenase formation and antagonize fondaparinux because anti-FIXa aptamer added to fondaparinux effectively attenuated TG.

CONCLUSION

Elevated FVIII supports the propagation of TG via intrinsic tenase formation under low TF condition, factor XI deficiency or in the presence of fondaparinux.