Fractional spinal anesthesia and systemic hemodynamics in frail elderly hip fracture patients

Background: Aging and frailty make the elderly patients susceptible to hypotension following spinal anesthesia. The systemic hemodynamic effects of spinal anesthesia are not well known. In this study, we examine the systemic hemodynamic effects of fractional spinal anesthesia following intermittent microdosing of a local anesthetic and an opioid.Methods: We included 15 patients aged over 65 with considerable comorbidities, planned for emergency hip fracture repair. Patients received a spinal catheter and cardiac output monitoring using the LiDCOplus system. Invasive mean arterial pressure (MAP), cardiac index, systemic vascular resistance index, heart rate and stroke volume index were registered. Two doses of bupivacaine 2.25 mg and fentanyl 15µg were administered with 25 minutes in between. Hypotension was defined as a fall in MAP by >30% or a MAP <65 mmHgResults: The incidence of hypotension was 30%. Hypotensive patients (n=5) were treated with low doses of norepinephrine (0.003-0.12 µg/kg/min). MAP showed a maximum reduction of 17% at 10 minutes after the first dose. Cardiac index, systemic vascular resistance index and stroke volume index decreased by 10%, 6%, and 7%, respectively, while heart rate was unchanged over time. After the first dose, none of the systemic haemodynamic variables were affected.Conclusion: Fractional spinal anesthesia causes a low incidence of hypotension, induced mainly by a systemic venodilation, causing a decrease in venous return and fall in cardiac output. Our results show that fractional spinal anesthesia is a safe technique from a hemodynamic point of view and is probably underutilized in high-risk, elderly hip fracture patients

Maintaining oxygen delivery is crucial to prevent intestinal ischemia in critical ill patients

Background Intestinal ischemia is a common complication with obscure pathophysiology in critically ill patients. Since insufficient delivery of oxygen is discussed, we investigated the influence of oxygen delivery, hemoglobin, arterial oxygen saturation, cardiac index and the systemic vascular resistance index on the development of intestinal ischemia. Furthermore, we evaluated the predictive power of elevated lactate levels for the diagnosis of intestinal ischemia. Methods In a retrospective case-control study data (mean oxygen delivery, minimum oxygen delivery, systemic vascular resistance index) of critical ill patients from 02/2009–07/2017 were analyzed using a proportional hazard model. General model fit and linearity were tested by likelihood ratio tests. The components of oxygen delivery (hemoglobin, arterial oxygen saturation and cardiac index) were individually tested in models. Results 59 out of 874 patients developed intestinal ischemia. A mean oxygen delivery less than 250ml/min/m2 (LRT vs. null model: p = 0.018; LRT for non-linearity: p = 0.012) as well as a minimum oxygen delivery less than 400ml/min/m2 (LRT vs null model: p = 0.016; LRT for linearity: p = 0.019) were associated with increased risk of the development of intestinal ischemia. We found no significant influence of hemoglobin, arterial oxygen saturation, cardiac index or systemic vascular resistance index. Receiver operating characteristics analysis for elevated lactate levels, pH, CO2 and central venous saturation was poor with an area under the receiver operating characteristic of 0.5324, 0.52, 0.6017 and 0.6786. Conclusion There was a significant correlation for mean and minimum oxygen delivery with the incidence of intestinal ischemia for values below 250ml/min/m2 respectively 400ml/min/m2. Neither hemoglobin, arterial oxygen saturation, cardiac index, systemic vascular resistance index nor elevated lactate levels could be identified as individual risk factors.

Hemodynamic Differences Between Women and Men with Elevated Blood Pressure in China

Background: Whether there are sex differences in hemodynamic profiles among people with elevated blood pressure is not well understood and could guide personalization of treatment. Methods and results: We described the clinical and hemodynamic characteristics of adults with elevated blood pressure in China using impedance cardiography. We included 45,082 individuals with elevated blood pressure (defined as systolic blood pressure of ≥130 mmHg or a diastolic blood pressure of ≥80 mmHg), of which 35.2% were women. Overall, women had a higher mean systolic blood pressure than men (139.0 [±15.7] mmHg vs 136.8 [±13.8] mmHg, P<0.001), but a lower mean diastolic blood pressure (82.6 [±9.0] mmHg vs 85.6 [±8.9] mmHg, P<0.001). After adjusting for age, region, and body mass index, women <50 years old had lower systemic vascular resistance index (beta-coefficient [β] -31.68; 95% CI: -51.18, -12.19) and higher cardiac index (β 0.07; 95% CI: 0.04, 0.09) than men of their same age group, whereas among those ≥50 years old women had higher systemic vascular resistance index (β 120.43; 95% CI: 102.36, 138.51) but lower cardiac index (β -0.15; 95% CI: -0.16, -0.13). Results were consistent with a propensity score matching sensitivity analysis, although the magnitude of the SVRI difference was lower and non-significant. However, there was substantial overlap between women and men in the distribution plots of these variables, with overlapping areas ranging from 78% to 88%. Conclusions: Our findings indicate that there are sex differences in hypertension phenotype, but that sex alone is insufficient to infer an individual's profile.

Mechanisms contributing to hypotension after anesthetic induction with sufentanil, propofol, and rocuronium: a prospective observational study

It remains unclear whether reduced myocardial contractility, venous dilation with decreased venous return, or arterial dilation with reduced systemic vascular resistance contribute most to hypotension after induction of general anesthesia. We sought to assess the relative contribution of various hemodynamic mechanisms to hypotension after induction of general anesthesia with sufentanil, propofol, and rocuronium. In this prospective observational study, we continuously recorded hemodynamic variables during anesthetic induction using a finger-cuff method in 92 non-cardiac surgery patients. After sufentanil administration, there was no clinically important change in arterial pressure, but heart rate increased from baseline by 11 (99.89% confidence interval: 7 to 16) bpm (P < 0.001). After administration of propofol, mean arterial pressure decreased by 23 (17 to 28) mmHg and systemic vascular resistance index decreased by 565 (419 to 712) dyn*s*cm−5*m2 (P values < 0.001). Mean arterial pressure was < 65 mmHg in 27 patients (29%). After propofol administration, heart rate returned to baseline, and stroke volume index and cardiac index remained stable. After tracheal intubation, there were no clinically important differences compared to baseline in heart rate, stroke volume index, and cardiac index, but arterial pressure and systemic vascular resistance index remained markedly decreased. Anesthetic induction with sufentanil, propofol, and rocuronium reduced arterial pressure and systemic vascular resistance index. Heart rate, stroke volume index, and cardiac index remained stable. Post-induction hypotension therefore appears to result from arterial dilation with reduced systemic vascular resistance rather than venous dilation or reduced myocardial contractility.

The utility of impedance cardiography in hemodynamic monitoring of patients with sepsis

BackgroundCommonly used biochemical indicators and hemodynamic and physiologic parameters of sepsis vary with regard to their sensitivity and specificity to the diagnosis. The aim of this preliminary study was to evaluate non-invasive impedance cardiography as a monitoring tool of the hemodynamic status of patients with sepsis throughout their initial volume resuscitation to explore the possibility of identifying additional measurements to be used in the future treatment of sepsis.MethodsNine patients who presented to the emergency room and received a surgical consultation during a 3-month period in 2016, meeting the clinical criteria of sepsis defined by systemic inflammatory response syndrome in the 2012 Surviving Sepsis Campaign Guidelines, were included in this study. We applied cardiac impedance monitors to each patient’s anterior chest and neck and obtained baseline recordings. Measurements were taken at activation of the sepsis alert and 1 hour after fluid resuscitation with 2 L of intravenous crystalloid solution.ResultsNine patients met the inclusion criteria. The mean age was 60±17 years and two were female; eight were febrile, five were hypotensive, four were tachycardic, seven were treated for infection, and six had positive blood cultures. Hemodynamic parameters at presentation and 1 hour after fluid resuscitation were heart rate (beats per minute) (97±13 and 93±18; p=0.23), mean arterial pressure (mm Hg) (81±13 and 85±14; p=0.55), systemic vascular resistance (dyne-s/cm−5) (861±162 and 1087±272; p=0.04), afterload measured as systemic vascular resistance index (dyne-s/cm−5/m2) (1813±278 and 2283±497; p=0.04), and left cardiac work index (kg*m/m2) (3.6±1.4 and 3.3±1.3; p=0.69).DiscussionThrough measuring a patient’s systemic vascular resistance and systemic vascular resistance index (afterload), statistical significance is achieved after intervention with a 2 L crystalloid bolus. This suggests that, along with clinical presentation and biochemical markers, impedance cardiography may show utility in providing supporting hemodynamic data to trend resuscitative efforts in patients with sepsis.Level of evidenceLevel IV.

P2638Preeclampsia is preceded by changes in the cardiovascular function

The changes in the cardiovascular function (CVF) during preeclampsia are known. Whether they begin prior clinical manifestation or persist after delivery remains unclear. Objective We hypothesized that preeclampsia is preceded by early CVF changes. We evaluated the eventual difference between patients who develop preeclampsia and those who stayed normotensives. Secondly we searched for a link between CVF changes and development of preeclampsia. Methods This prospective study, included 260 normotensive primiparous women, referred for routinely control to the Cardiology section. At week 22 of gestation and 1 year after delivery were performed: Office blood pressure (OBP), blood and urine lab test. Cardiac index (CI) and systemic vascular resistance index (SVRI) through impedance cardiography. Wave pulse velocity (PWV) through pressure signals. According to the evolution during pregnancy patients were assigned to one of 3 groups: G1 preeclampsia:. G2 Gestational hypertension G3 Normotensive. Statistic tests: one-way analysis of variance and the Bonferroni post-hoc test. Results 12 patients evolved to preeclamsia, 18 to gestational hypertension and 230 remained normotensive. G1 had significantly lower value of CI in both measurements and higher values of OBP, SVRPI and WPV comparing to G3. G2 always showed intermediate values between G1 and G2. The median age of the population was 25 ≠ 4 years old. By logistic regression analysis WPV and SVRI at 22 week of gestation were predictors of preeclampsia. (p<0.05) Patient Characteristics Characteristics G1 G2 G3 p<0.05 Systolic, mmHg OBP* 128±10 120±9 107±10 0.001 Diastolic, mmHg OBP* 84±6 75±7 66±6 0.001 Systolic mmHg OBP** 128±11 117±10 114±8 0.01 Diastolic, mmHg OBP** 77±7 71±6 70±6 0.09 WPV, m/sec* 10±4 7±0.8 5.6±1 0.02 WPV, m/sec** 9±1.3 6.4±1 4.7±1.5 0.01 CI, l/m2* 2.7±0.4 3.1±0.4 3.4±0.6 0.01 IC, l/m2** 2.4±0.6 2.6±0.3 3.2±0.6 0.01 SVRPI, dyn sec·cm* 1894±151 1783±454 1431±252 0.01 SVRPI, dyn sec·sec** 1900±436 1657±436 1385±248 0.01 Data are given as median and SD. *Measurements at week 22 of gestation. **Measurements at 1 year after delivery. Conclusion Preeclampsia showed different CVF compare with normotensive, before diagnosis and after delivery. The early endothelial dysfunction could be responsible of these changes.

Prediction of heparin induced hypotension during cardiothoracic surgery: A retrospective observational study

Background: High-dose heparin occasionally causes severe hypotension during cardiothoracic surgery. Being able to predict the severity of the decrease in blood pressure prior to administration of heparin would improve hemodynamic and anesthetic management. The aim of this study was to investigate the predictors of heparininduced hypotension and the effects of high-dose heparin on various hemodynamic and physiologic parameters.Methodology: The records of adult patients who underwent elective cardiothoracic surgery at University of Yamanashi Hospital between January 2016 and December 2017 were retrospectively reviewed. Single and multiple linear regression analyses were conducted to identify the predictors of heparin-induced hypotension. Results: High baseline systemic vascular resistance index (SVRI) and non-use of preoperative antihypertensive medication were significant predictors of heparininduced hypotension with a following regression equation: Percent change in mean arterial pressure = 17.273 + 0.00457 × (baseline SVRI) - 14.043 × (antihypertensive medication), where antihypertensive medication is coded as 0 = no antihypertensive drug and 1 = one or more antihypertensive drug(s), F = 7.80, the multiple correlation coefficient is 0.68645, and R adjusted for degrees of freedom is 0.41078.Conclusion: The baseline SVRI and non-use of preoperative antihypertensive medication are significant predictors of the severity of heparin-induced hypotension.Abbreviations: MAP - Mean arterial blood pressure; CVP - central venous pressure; PAP - pulmonary arterial pressure; SVRI - systemic vascular resistance index; BMI: body mass index; ASA-PS: American Society of Anesthesiologists physical status classification; DM: diabetes mellitus; eGFR: estimated glomerular filtration rate; LVEF: left ventricular ejection fraction; EDVI: end-diastolic volume index; CI: cardiac index; SvO2: mixed venous oxygen saturation; LVEF: left ventricular ejection fraction; HR: heart rate. Preregistration: The study was approved by the institutional review board of University of Yamanashi (study H30036, registered May 28, 2018).Citation: Kotoda M, Ishiyama T, Nakajima H, Matsukawa T. Prediction of heparin induced hypotension during cardiothoracic surgery: A retrospective observational study. Anaesth pain & intensiv care 2019;23(2):145-150

Doppler echocardiography for assessment of systemic vascular resistances in cardiogenic shock patients

Objective: Impaired vascular tone plays an important role in cardiogenic shock. Doppler echocardiography provides a non-invasive estimation of systemic vascular resistance. The aim of the present study was to compare Doppler echocardiography with the transpulmonary thermodilution method for the assessment of systemic vascular resistance in patients with cardiogenic shock. Methods: This prospective monocentric comparison study was conducted in a single cardiology intensive care unit (Hopital Nord, Marseille, France). We assessed the systemic vascular resistance index by both echocardiography and transpulmonary thermodilution in 28 patients admitted for cardiogenic shock, on admission and after the introduction of an inotrope or vasopressor treatment. Results: A total of 35 paired echocardiographic and transpulmonary thermodilution estimations of the systemic vascular resistance index were compared. Echocardiography values ranged from 1309 to 3526 dynes.s.m2/cm5 and transpulmonary thermodilution values ranged from 1320 to 3901 dynes.s.m2/cm5. A statistically significant correlation was found between echocardiography and transpulmonary thermodilution ( r=0.86, 95% confidence interval (CI) 0.74, 0.93; P<0.0001). The intraclass correlation coefficient was 0.84 (95% CI 0.72, 0.92). The mean bias was −111.95 dynes.s.m2/cm5 (95% CI −230.06, 6.16). Limits of agreement were −785.86, 561.96. Conclusions: Doppler echocardiography constitutes an accurate non-invasive alternative to transpulmonary thermodilution to provide an estimation of systemic vascular resistance in patients with cardiogenic shock.

The effects of malnutrition on cardiac function in African children

ObjectiveCardiac dysfunction may contribute to high mortality in severely malnourished children. Our objective was to assess the effect of malnutrition on cardiac function in hospitalised African children.DesignProspective cross-sectional study.SettingPublic referral hospital in Blantyre, Malawi.PatientsWe enrolled 272 stable, hospitalised children ages 6–59 months, with and without WHO-defined severe acute malnutrition.Main outcome measuresCardiac index, heart rate, mean arterial pressure, stroke volume index and systemic vascular resistance index were measured by the ultrasound cardiac output monitor (USCOM, New South Wales, Australia). We used linear regression with generalised estimating equations controlling for age, sex and anaemia.ResultsOur primary outcome, cardiac index, was similar between those with and without severe malnutrition: difference=0.22 L/min/m2 (95% CI −0.08 to 0.51). No difference was found in heart rate or stroke volume index. However, mean arterial pressure and systemic vascular resistance index were lower in children with severe malnutrition: difference=−8.6 mm Hg (95% CI −12.7 to −4.6) and difference=−200 dyne s/cm5/m2 (95% CI −320 to −80), respectively.ConclusionsIn this largest study to date, we found no significant difference in cardiac function between hospitalised children with and without severe acute malnutrition. Further study is needed to determine if cardiac function is diminished in unstable malnourished children.