Decrease In Systemic Vascular Resistance Research Articles

Overview of acute liver failure in India.

Acute liver failure (ALF) is an infrequent, but serious complication subsequent to severe acute liver injury (sALI) due to various hepatotoxic agents such as hepatotropic virus(es) and drugs such as anti-tubercular medications, paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics and anti-cancer and anti-epileptic therapy and due to metabolic and autoimmune disease flares. ALF after sALI presents with encephalopathy associated with prolonged international normalized ratio (INR). Mortality in ALF is high and ranges between 50% and 80%. Due to severe liver damage, multiple sequels consequent to hepatic dysfunction result in complications such as hyperammonemia that culminates in encephalopathy associated with cerebral edema; innate immune paralysis resulting in increased frequency of infections and endotoxemia causing decrease in systemic vascular resistance (SVR) and tissue hypoperfusion and damage-associated molecular patterns (DAMPs) released from damaged hepatic parenchyma inducing pro-inflammatory cytokine storm, which may cause other organ dysfunctions. Certain etiologies such as hepatitis E virus and hepatitis A virus-related ALF or paracetamol-ALF (hyper-acute presentation) have better survival than remaining causes. In addition, if etiology-specific treatment (antivirals for ALF related to hepatitis B virus (HBV) or Herpes simplex virus (HSV) or N-acetylcysteine for paracetamol) is available, then the outcome with treatment is better. About half of the patients can be salvaged with medical therapy. All patients need intensive care and organ support to provide time for the liver to regenerate. Various prognostic models to predict high probability of mortality have been described, which should be used to select patient early during the disease for liver transplantation, which is associated with high long-term survival in these sick patients. The Indian National Association for Study of the Liver (INASL) recommends the ALF-Early Dynamic (ALFED) model as a preferred prognostic model in the Indian scenario, where hepatitis viruses are a dominant etiology of ALF and occur on a naïve liver with good regenerative capacity.

Causes and prognosis analysis of hyperdynamic left ventricular ejection fraction in intensive care unit patients with sepsis

To analyze the causes of hyperdynamic left ventricular ejection fraction (LVEF) in sepsis patients in the intensive care unit (ICU) and its impact on prognosis. A retrospective cohort study was conducted. The clinical data of 273 sepsis patients admitted to the department of critical care medicine of the Affiliated People's Hospital of Jiangsu University from January 2018 to October 2021 were collected including gender, age, severity score, comorbidities, source of infection, vital signs, transthoracic echocardiographic (TTE) parameters, fluid intake and output, vasoactive drug dose, therapeutic measures and prognostic indicators. The patients were divided into normal LVEF group (LVEF 0.55-0.70), low LVEF group (LVEF < 0.55) and hyperdynamic LVEF group (LVEF > 0.70) according to the TTE examination results within 7 days of ICU admission. The clinical indicators among the three groups were compared and analyzed, and multivariate Logistic regression analysis was used to screen risk factors for the development of hyperdynamic LVEF in patients with sepsis. Spearman correlation analysis was used to determine the correlation between the mortality of different types of LVEF and clinical variables. Among 273 patients, 20 patients with severe valvular or cardiomyopathy at admission and those who did not completed cardiac ultrasound within 7 days of ICU admission were excluded. A total of 253 patients were finally enrolled, including 169 patients in the normal LVEF group, 40 patients in the low LVEF group, and 44 patients in the hyperdynamic LVEF group. There were statistically significant differences in age, sequential organ failure assessment (SOFA) score, central venous pressure (CVP), heart rate (HR), oxygenation index (PaO2/FiO2), blood lactate (Lac), urine output, vasoactive drug dose, ratio of hypertension, ischemic heart disease, chronic liver disease, cancer, invasive mechanical ventilation and renal replacement therapy (RRT), and incidence of septic shock among the different types of LVEF groups. TTE results analysis showed that the hyperdynamic LVEF group had higher stroke volume (SV) and cardiac index (CI) than those in the normal LVEF and low LVEF groups, lower systemic vascular resistance (SVR) than that in the normal LVEF and low LVEF groups, and an increased E/A ratio. The 90-day mortality in the hyperdynamic LVEF group was significantly higher than that in the normal LVEF and low LVEF groups [59.1% (26/44) vs. 24.9% (42/169), 32.5% (13/40), both P < 0.05]. Multivariate Logistic regression analysis showed that chronic liver disease [odds ratio (OR) = 1.712, 95% confidence interval (95%CI) was 0.912-3.234, P < 0.001], cancer (OR = 2.784, 95%CI was 1.296-6.151, P < 0.001), HR (OR = 1.026, 95%CI was 1.014-1.038, P < 0.001), vasoactive drug dose (OR = 1.133, 95%CI was 1.009-1.291, P < 0.001), and invasive mechanical ventilation (OR = 2.141, 95%CI was 1.285-3.651, P < 0.001) were independent factors for hyperdynamic LVEF in ICU sepsis patients. Correlation analysis showed that the mortality of hyperdynamic LVEF, normal LVEF and low LVEF patients was positively correlated with vasoactive drug dose (r value was 0.251, 0.361, 0.289, respectively, all P < 0.001). The mortality of the hyperdynamic LVEF patients was negatively correlated with SVR (r = -0.545, P < 0.001). Chronic liver disease, cancer, HR, vasoactive drugs dose, and invasive mechanical ventilation are independent risk factors for hyperdynamic LVEF in patients with sepsis. Hyperdynamic LVEF is positively associated with mortality in sepsis patients, which may be due to the the decrease of SVR caused by septic vascular paralysis.

Anesthetic management of omphalopagus twins with pentalogy of Fallot undergoing separation surgery

The management of conjoined twins has several special aspects, mostly linked to the parents of the twins, such as communication, ethics and trust issues. A multidisciplinary team approach plus high level of vigilance at each perioperative stage is required. Conjoined omphalopagus twins, aged one year, were planned for separation surgery. They had fused liver, fused portal and hepatic veins, and partially fused intestines. Patient B appeared with complications of pentalogy of Fallot (PoF). The patient also had polycythemia (hemoglobin 14.7 g/dL, hematocrit 50%). Radiological features showed anterior abdominal wall with images of interconnected intestinal system between the two. In thoracoabdominopagus conjoined twins, the possibility of shared circulation becomes important especially associated with injection of intravenous drugs. The goal of anesthesia in PoF is to maintain cardiac output by maintaining heart rate, contractility and preload; and preventing right to left shunting via ventricular septal defect (VSD). Induction can cause vasodilation and the resultant decrease in systemic vascular resistance (SVR) can exacerbate right-to-left shunts. Monitoring end tidal CO2 (EtCO2) is needed. We present a report of anesthesia for such a case.&#x0D; Abbreviations: ASD: Atrial Septal Defect; PoF: Pentalogy of Fallot; VSD: Ventricular Septal Defect; SVR: Systemic Vascular Resistance&#x0D; Key words: Conjoined Twins; Pentalogy of Fallot; Congenital Heart Disease; Cyanosis; Anesthesia&#x0D; Citation: Purwoko, Santosa SB, Novianto B, Ganitafuri H. Anesthetic management of omphalopagus twins with pentalogy of Fallot undergoing separation surgery. Anaesth. pain intensive care 2023;27(3):434−440.&#x0D; DOI: 10.35975/apic.v27i3.2224&#x0D; Received: May 24, 2022; Reviewed: Sep 18, 2022; Accepted: Jan 04, 2023

Hypertension in pregnancy: challenges in the management

Pregnancy is a cardiovascular and metabolic challenge to the human female body.During pregnancy, systemic vascular resistance and blood pressure decrease, whereas cardiac output and blood volume increase to safeguard an adequate circulation in the utero-placental arterial bed.Hypertensive disorders of pregnancy affect approximately from 5 to 10% of all pregnant women, and are the main contributors of maternal and neonatal morbidity and mortality worldwide. Hypertension in pregnancy includes a wide spectrum of conditions, including pre-eclampsia and eclampsia, pre-eclampsia superimposed on chronic hypertension, chronic hypertension, and gestational hypertension. Endothelial dysfunction, oxidative stress and an exaggerated inflammatory response are features related to hypertensive disorders. To reduce the risk of maternal and foetal complications due to haemodynamic maladaptation, the current management includes rest at home or in the hospital, closes monitoring of maternal and foetal signs and symptoms, early start of antihypertensive therapy, and timely delivery regarding maternal and foetal survival chances. Thresholds to initiate blood pressure lowering treatment during pregnancy are 160 mmHg systole or 110 mmHg diastole. Below these thresholds, treatment must be individualized because current evidence does not support aggressive medical interventions. Alpha-methyldopa and dihydropyridine calcium channel blockers are among the recommended antihypertensives. The major goal is to prevent maternal complications without compromising uteroplacental perfusion and fetal circulation. Before an antihypertensive agent is prescribed, the potential risk to the fetus from intrauterine drug exposure should be carefully reviewed. Bangladesh J Medicine 2023; Vol. 34, No. 2(1) Supplement: 186

Chronic kidney disease and pregnancy: an interdisciplinary assessment of gestational risks and complications. A literature review

Chronic kidney disease represents a heterogeneous group of diseases characterized by changes in the kidneys structure and functions. It significantly increases the risks of adverse maternal and perinatal outcomes. These risks increase with worsening renal dysfunction corresponding to an increase in the degree of proteinuria and arterial hypertension. Anatomical and physiological changes in the kidneys during pregnancy are characterized by dilatation of the pelvicalyceal system, a decrease in systemic and renal vascular resistance, and an increase in the glomerular filtration rate. These clinically significant changes can complicate the diagnosis of the renal dysfunction, as well as its progression. Pregnancy can affect the kidney as it can manifest as declining kidney function, especially in the context of concomitant arterial hypertension and proteinuria, while chronic kidney disease, regardless of the stage, contributes to a higher risk of adverse pregnancy outcomes including preeclampsia, premature birth and fetal growth restriction.&#x0D; Optimization strategies of pregnancy outcomes include strict control of blood pressure, treatment of hypertension and proteinuria, and prevention of preeclampsia. The latter is difficult to diagnose in pregnant women with chronic kidney disease. Serum markers such as soluble fms-like tyrosine kinase 1 and placental growth factor may aid in definitive diagnosis. The choice of delivery mode in women with chronic kidney disease should be based on common obstetric indications. A multidisciplinary team, including an obstetrician-gynecologist, a nephrologist, an anaesthesiologist and a neonatologist, must focus on preconception medical care, antenatal care and treatment of pregnant women with chronic kidney disease for a successful pregnancy outcome.

Pregnancy in Patients with Pulmonary Arterial Hypertension in Light of New ESC Guidelines on Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is defined as an elevated mean pulmonary artery pressure (mPAP) of >20 mmHg together with a pulmonary arterial wedge pressure (PAWP) of ≤15 mmHg and pulmonary vascular resistance (PVR) of>2 Wood units (WU). Although the total mortality of pregnant women with PAH has decreased significantly in recent years and is reported to be around 12% in some databases, total mortality is still at an unacceptably high percentage. Moreover, some subgroups, such as patients with Eisenmenger's syndrome, have a particularly high mortality rate of up to 36%. Pregnancy in patients with PAH is contraindicated; its appearance is an indication for a planned termination. Education of patients with PAH, including counseling on effective contraception, is essential. During pregnancy, blood volume, heart rate, and cardiac output increase, while PVR and systemic vascular resistance decrease. The hemostatic balance is shifted towards hypercoagulability. Among PAH-specific drugs, the use of inhaled or intravenous prostacyclins, phosphodiesterase inhibitors, and calcium channel blockers (in patients with preserved vasoreactivity) is acceptable. Endothelin receptor antagonists and riociguat are contraindicated. Childbirth can take place through either vaginal delivery or caesarean section; similarly, neuraxial and general anesthesia have proven indications. In a situation where all pharmacological options have been used in pregnant or postpartum patients in a serious condition, veno-arterial ECMO is a useful therapeutic option. For PAH patients who want to become mothers, an option that does not endanger their lives is adoption.

S-52-3: ROLE OF NOVEL ECHOCARDIOGRAPHIC METHODS TO DETECT EARLY MYOCARDIAL DYSFUNCTION IN WOMEN WITH PREECLAMPSIA

Normal pregnancy is associated with reversible changes in both systolic and diastolic mechanics, consistent with an increase in preload and decrease in afterload and systemic vascular resistance. The aim of the study is to evaluate left ventricular cardiac mechanics via speckle tracking echocardiography in a population of pregnant women with per partum cardiomyopathy and preeclampsia(PE) after invitro fertilization (IVF) during different stages of pregnancy. The study population included 525 pregnant women with PE, after IVF, 100 of them with multiple pregnancy (46.5 ± 3 years) and 30 healthy nonpregnant women (33 ± 4years).Apical and basal short axis and apical view for three, two and four chamber for 2D images were acquired (65 ± 7 frames/s) during the first, second and third trimester of the pregnancy, as well as up to two months post partum. The curves of longitudinal(GLS), circumferential(GCS), radial strain(GRS) and LVT /LVUR were extracted using a commercial software. Results: Peak LVT and LVUR increased significantly in the 3rd trimester in both pregnancy groups (13.48 ± 2.90°,13.12 ± 3.30?,16.83 ± 3.61?,P &lt; 0.001; and -111.52 ± 23.54°/sec,-107.40 ± 26.58?/sec,-144.30 ± 45.14?/sec, P &lt; 0.001; in the 1st, 2nd, and 3rd trimester, respectively.The pregnants with twins have the highest value for LVT and LVUR compare with other pregnants (p &lt; 0.01), but in the last trimester, the time to peak LVUR is prolonged. An independent correlation was found between the change in LVT and LV end-systolic volume in 1st and 3rd trimester (r = 0,56). Peak LVUR at the 3rd trimester correlated significantly with LV end-diastolic volume. Multiple regression analysis indicates that only systolic blood pressure (r = 0.394, P = 0.005) was an independent predictor for increased LV torsion. Arterial hypertension (AH) and prevalence of preeclampsia (PE) are more often in IVF group. Longitudinal strain decreased significantly (p &lt; 0.001) during 3th trimester in women with AH and PE. Global longitudinal strain measures of the LV were non-significantly different between the different groups in first and second trimester (GLS-20.6 ± 3,14 vs.-19,29 ± 2,17).There are not found significant differences for GCS and GRS during pregnancy. Conclusions: During pregnancy LV twist and peak untwisting rate increase in the 3rd trimester and correlate with end-systolic and end-diastolic volume, respectively. Blood pressure and condition of multiple pregnancy are independently associated with increased torsion during pregnancy and may predict the new onset heart failure and perinatal cardiomyopathy. Global longitudinal strain is the main predictor of new onset peripartum cardiomyopathy

Influencing factors and hemodynamic study of initial and sustained orthostatic hypotension in middle-aged and elderly patients.

Orthostatic hypotension (OH) is a common autonomic disorder. This study aimed to investigate the influencing factors and hemodynamic mechanisms of initial and sustained OH in middle-aged and elderly patients. The authors analyzed the clinical characteristics and hemodynamic variables of patients aged ≥ 50years according to the various forms of OH, diagnosed by an active orthostatic test using the CNAP monitor. The study included 473 participants; 119 (25.2%) patients had initial (54, 45.4%) or sustained (65, 54.6%) OH. Age, comorbidities, or medications did not differ significantly between the initial OH and non-OH groups. Sustained OH was associated with age and diabetes (p =.003 and p =.015, respectively). Hemodynamic analysis revealed higher cardiac output (CO) in the sustained OH group within 15 s than in the non-OH and initial OH groups (both p <.001); no difference in CO was observed between the initial OH and non-OH groups. The systemic vascular resistance (SVR) in both initial OH and sustained OH groups within 15 s was lower than that in the non-OH group (both p <.001). No differences in SVR at 3min were observed between the initial OH and non-OH groups. The SVR at 3min in the sustained OH group was significantly lower than in non-OH and initial OH groups (both p <.001). Age and diabetes emerged as the independent risk factors associated with sustained OH. Initial OH is associated with a mismatch of increase in CO and decrease in SVR. Sustained OH is mainly associated with sustained inadequate adjustment in SVR.

First trimester placental extracellular vesicles likely contribute to the vasodilation of maternal resistance arteries in normal pregnancy

During the first trimester of pregnancy, there is a large decrease in systemic vascular resistance (SVR) which coincides temporally with increasing extrusion of extracellular vesicles (EVs) from the placenta. We hypothesized that placental EVs may be one of the mechanisms contributing to maternal vasodilation.Macro-, micro-, nano-EVs from human first trimester placenta, or control injections containing EVs derived from fresh culture media, were injected into pregnant mice at day 12.5. After 30 min or 24 h, second order resistance arteries assessed for their reactivity to various vasomodulators.Placental EVs induced an anti-constrictive, pro-vasodilatory effect in maternal resistance arteries compared to control injections after 24 h suggesting that placental EVs may contribute to the maternal vasodilation during pregnancy.

Efficacy of Variable Doses of Prophylactic Intravenous Ondansetron in Attenuating Spinal Induced Hypotension in Parturients Undergoing Caesarean Delivery: A Randomised Control Trial.

IntroductionSpinal anaesthesia is frequently associated with adverse effects like maternal hypotension and bradycardia. This effect is due to a decrease in systemic vascular resistance, a decrease in central venous pressure or Bezold-Jarisch Reflex (mediated by 5-HT3 receptors). We aimed to measure the effect of three different doses of prophylactic intravenous ondansetron (5-HT3 antagonists) with a placebo on maternal haemodynamics.MethodsA prospective randomised control study was done over 240 parturients, aged 19-35 years. They were randomly allocated into four groups (n=60) Group O4, Group O6, Group O8 and Group S to receive either intravenous ondansetron 4 mg, 6 mg, 8 mg or 0.9% normal saline respectively. Haemodynamic variables (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP], heart rate [HR]) were recorded at 2-minute intervals for the first 20 minutes and at 5-minute intervals for further 30 minutes.ResultsA significant decrease in haemodynamic parameters was observed in group S when compared with ondansetron groups at various time intervals (p<0.05). The difference was most significant in groups O6 and O8. Development of nausea and vomiting was significantly higher in Group S compared to ondansetron groups (p< 0.005). The requirement for ephedrine was more in Group S in comparison to ondansetron groups (p<0.0001).ConclusionAll three groups of ondansetron showed a decrease in the incidence of hypotension and use of vasopressor but Group O6 and O8 were more effective in attenuating spinal-induced hypotension in parturients undergoing caesarean section.

Anesthetic Management in Parturients With Fontan Physiology

Anesthetic Management in Parturients With Fontan Physiology

Effect of norepinephrine on blood volume, cardiac output, and systemic filling pressure in patients undergoing liver transplantation

Patients with liver cirrhosis develop symptoms comparable to those of patients with sepsis, who have increased total vascular compliance, which may cause blood pooling in the venous pool. No previous studies have evaluated the effect of using norepinephrine on the intravascular blood volume. We investigated the norepinephrine infusion's effect on the mean systemic filling pressure, venous return, and cardiac preload in patients undergoing liver transplantation. Overall, 33 patients who underwent living donor liver transplantation were included in this study. Cardiac output (CO) was measured using a PiCCO device (Pulsion Medical Systems, Munich, Germany). The mean systemic filling pressure was calculated using the inspiratory hold maneuver at four time intervals - at baseline, 10 min after the norepinephrine infusion, 5 min after norepinephrine discontinuation, and after infusion of 500 cc of 5% albumin. Other hemodynamic parameters, including the mean arterial pressure (MAP), pulse pressure variation, stroke volume variation, global end-diastolic volume, and mitral inflow velocity (E wave), were also evaluated. The norepinephrine infusion increased MAP and systemic vascular resistance in all patients. Moreover, it increased CO, mean systemic filling pressure, and global end-diastolic volume in 20 patients (60%), whereas there were no changes in these variables in 13 patients (40%). In all patients, norepinephrine infusion discontinuation caused a significant decrease in MAP, CO, resistance to venous return, and mean systemic filling pressure. Infusion of 500 cc colloid increased CO; however, interestingly, it was associated with a significant decrease in systemic vascular resistance; hence, MAP and mean systemic filling pressure showed no changes. The norepinephrine infusion at 0.1 µg-1 kg-1 min-1 was associated with an increase in CO in patients with liver cirrhosis undergoing liver transplantation. Norepinephrine's effect on CO was primarily attributable to an increase in venous return due to an increase in mean systemic filling pressure.

Cholinergic‐mediated Circulatory Responses at the Onset of Isometric Exercise: Does Sex Matter?

IntroductionWe have shown that handgrip exercise evokes an initial decrease in systemic vascular resistance (SVR), which was abolished by cholinergic blockade (glycopyrrolate) and, thereby, augmented the blood pressure (BP) response. These findings suggest that a cholinergic mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans. Noteworthy, this previous study included men only, and was not designed to investigate the potential existence of sex‐related differences in immediate BP and circulatory responses evoked at the exercise onset. Given this, the aim of this study was to test the hypothesis that women present an attenuated fall in SVR and increased pressor response compared to men at the onset of isometric handgrip exercise due to a blunted cholinergic vasodilation.MethodsTen healthy men (aged 21 ± 1 year) and 10 women (aged 24 ± 1 year) were recruited. Women were non‐oral contraceptives users and performed experiments in the early follicular phase of the menstrual cycle. Participants performed 20s bout of isometric handgrip exercise at 40% of maximal voluntary contraction. Beat‐to‐beat heart rate (HR) (ECG) and mean BP (finger photopletysmography) were continuously measured. Beat‐to‐beat stroke volume (SV) was obtained with the Modelflow method and matched with HR to estimate cardiac output (CO) and SVR. The exercise responses were expressed as a change from 10s immediately before the onset of voluntary contraction.ResultsThe BP response pattern appeared to be different between men and women at the onset of isometric exercise. While men presented a typical exercise‐evoked biphasic BP response (3s: Δ2 ± 2 mmHg; 10s: Δ1 ± 1 mmHg; 20s: Δ5 ± 3 mmHg), women showed a progressive increase in mean BP (3s: Δ1 ± 1 mmHg; 10s; Δ3 ± 1 mmHg; 20s: Δ6 ± 1 mmHg; P=0.681). Men demonstrated a decrease in SVR at 3s (Δ‐0.9 ± 0.3 mmHg.L‐1.min), 10s (Δ ‐1.6 ± 0.4 mmHg.L‐1.min) and 20s (Δ‐1.9 ± 0.7 mmHg.L‐1.min) following the exercise onset, and these responses tended to be attenuated in women (3s: Δ‐0.3 ± 0.3 mmHg.L‐1.min; 10s: Δ‐1.2 ± 0.4 mmHg.L‐1.min; 20s: Δ‐0.6 ± 0.5 mmHg.L‐1.min; P=0.131). There were no sex differences in HR, SV and CO responses to exercise.ConclusionThese findings suggest a lack of sex differences in immediate BP and circulatory responses at the onset of isometric handgrip exercise, indicative of similar cholinergic‐mediated vasodilation in skeletal muscle between men and women.

Anesthesia Management in Patient with Uncorrected Double Outlet Right Ventricle Underwent Cesarean Section: Serial Case Report

Background: Double outlet right ventricle (DORV) is a rare cardiac condition in which the heart demonstrates single ventricle physiology. Pregnancy complicates cyanotic heart disease as the decrease in systemic vascular resistance (SVR) worsens the right-to-left shunt. The effect worsens by neuraxial anesthesia for cesarean delivery. Anesthesia for these patients needs understanding for the physiology of DORV in order to maintain stable hemodynamics. Heart defect still become non obstetric main factor causing morbidity and mortality in pregnant woman. Case: We present three case of parturients with DORV scheduled for cesarean section. Elective caesarean section was scheduled using spinal anesthesia hyperbaric bupivacain combined with fentanyl. Hemodynamic during operation was stable. Conclusion: Low dose spinal anesthesia performed in this patient did not cause hypotension and minimal hemodynamic changes because the intensity of the sympathetic block was lower.

High-output heart failure

High output heart failure (HOHF) is a particular type of heart failure with multiple etiologies but a similar underlying mechanism, namely a decrease in systemic vascular resistance, in some instances associated with increased metabolic requirements. This leads to neurohormonal activation, fluid and sodium retention and a chronic hyperdynamic state resulting in a classic congestive state associated with clinical signs of high output. While no clear definition of HOHF exists, such findings and an increase in cardiac output (cardiac index >4 L/min/m2) strongly suggest the diagnosis. This probably under-diagnosed entity should actively be sought, particularly in obese patients and/or patients labelled with heart failure with preserved ejection fraction (HFpEF). Treatment and prognosis depend on the etiology.

Study of the hemodynamic effect of inhaled milrinone versus inhaled nitroglycerin on mechanically ventilated patients with pulmonary hypertension after mitral valve replacement surgeries

IntroductionPulmonary arterial hypertension (PH) is commonly found in patients with mitral valve diseases. Most of the drugs used for PH treatment are nonselective pulmonary vasodilators that may cause a modest decrease in pulmonary arterial pressure, but they may cause a marked decrease in systemic vascular resistance as well, which leads to hypotension and a decrease in perfusion of vital organs. Inhaled drugs such as milrinone and nitroglycerine may be safer as a large dose of the drug can selectively target the pulmonary circulation, which leads to a reduction of their systemic adverse effects.AimThis double-blind, randomized study compared milrinone inhalation versus nitroglycerin inhalation on pulmonary artery pressure and other hemodynamics in postoperative patients immediately after mitral valve replacement surgery.Patients and methodsA total of 40 participants with isolated mitral stenosis or isolated mitral incompetence or their combination plus PH [mean pulmonary artery pressure (mPAP) >40 mmHg] scheduled for mitral valve replacement were interviewed. Immediately postoperatively in the ICU, we randomized the patients into two groups, with 20 patients each. Group A consisted of 20 patients who received milrinone inhalation, whereas group B consisted of 20 patients who received nitroglycerine inhalation. Hemodynamic parameters (heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure, central venous pressure, pulmonary artery systolic pressure, pulmonary diastolic pressure, mPAP, fractional shortening, ejection fraction, and pressure of oxygen/fraction of inspired oxygen ratio) were recorded in both groups at three time points: T1, before drug delivery; T2, just after drug delivery; and T3, just before extubation.ResultsThe study showed that both milrinone and nitroglycerin inhalation caused a marked reduction in systolic, diastolic, and mPAPs without causing any hemodynamic deterioration effects on systolic, diastolic, or mean arterial pressures.ConclusionAlthough both milrinone and nitroglycerin inhalation proved to be effective pulmonary artery vasodilators that avoided systemic adverse effects, nitroglycerin inhalation is a less expensive, easily obtained drug that can serve as an inhaled pulmonary vasodilator in patients with mitral valve diseases and PH following mitral valve replacement surgeries.

Safety during interhospital helicopter transfer of ventilated COVID-19 patients. No clinical relevant changes in vital signs including non-invasive cardiac output

BackgroundDuring the COVID-19 pandemic in The Netherlands, critically ill ventilated COVID-19 patients were transferred not only between hospitals by ambulance but also by the Helicopter Emergency Medical Service (HEMS). To date, little is known about the physiological impact of helicopter transport on critically ill patients and COVID-19 patients in particular. This study was conducted to explore the impact of inter-hospital helicopter transfer on vital signs of mechanically ventilated patients with severe COVID-19, with special focus on take-off, midflight, and landing.MethodsAll ventilated critically ill COVID-19 patients who were transported between April 2020 and June 2021 by the Dutch ‘Lifeliner 5’ HEMS team and who were fully monitored, including noninvasive cardiac output, were included in this study. Three 10-min timeframes (take-off, midflight and landing) were defined for analysis. Continuous data on the vital parameters heart rate, peripheral oxygen saturation, arterial blood pressure, end-tidal CO2 and noninvasive cardiac output using electrical cardiometry were collected and stored at 1-min intervals. Data were analyzed for differences over time within the timeframes using one-way analysis of variance. Significant differences were checked for clinical relevance.ResultsNinety-eight patients were included in the analysis. During take-off, an increase was noticed in cardiac output (from 6.7 to 8.2 L min−1; P < 0.0001), which was determined by a decrease in systemic vascular resistance (from 1071 to 739 dyne·s·cm−5, P < 0.0001) accompanied by an increase in stroke volume (from 88.8 to 113.7 mL, P < 0.0001). Other parameters were unchanged during take-off and mid-flight. During landing, cardiac output and stroke volume slightly decreased (from 8.0 to 6.8 L min−1, P < 0.0001 and from 110.1 to 84.4 mL, P < 0.0001, respectively), and total systemic vascular resistance increased (P < 0.0001). Though statistically significant, the found changes were small and not clinically relevant to the medical status of the patients as judged by the attending physicians.ConclusionsInterhospital helicopter transfer of ventilated intensive care patients with COVID-19 can be performed safely and does not result in clinically relevant changes in vital signs.

443 Arterial hypertension in aortic valve stenosis: a critical update

Abstract Aims Aortic stenosis (AS) is a very common valve disease and is associated with high mortality once it becomes symptomatic. Arterial hypertension (HT) has a high prevalence among patients with AS leading to worst left ventricle remodelling and faster degeneration of the valve. HT also seems to interfere with the assessment of the severity of AS leading to an underestimation of the real degree of stenosis. Treatment of HT in AS has historically been associated with reluctance due to both the lack of clear guidelines and the fear of adverse effects, but the most recent evidence shows as several drugs that can be used. Methods The pathophysiology of the combination of AS and HT is the association of a first fixed mechanical obstruction of the aortic root and a second obstruction due to systemic vascular resistance. Consequently, a decrease in systemic vascular resistance through, for example, the administration of vasodilators could theoretically cause a drop in systemic pressure due to the fixed mechanical obstruction given by the stenosis which prevents an increase in cardiac output. This theory was the basis for avoiding vasodilators in patients with AS. Results There is a unanimous opinion on maintaining blood pressure values of 130–139 mmHg of systolic and 70–90 mmHg of diastolic, but there is not the same agreement on which drugs to adopt to achieve the aforementioned values. Renin-Angiotensin-Aldosterone system inhibitors are certainly the first-line treatment thanks to their cardioprotective, plaque stabilizing, and antiarrhythmic effect since they are also associated with increased survival rates and greater left ventricular mass reduction in patients after surgical or transcatheter aortic valve replacement for severe AS. If blood pressure is not yet controlled, the addition of a beta-blocker should be considered: metoprolol has the greatest literature, showing not only an improvement in haemodynamic and metabolic performance but also a reduction in mortality in patients who already presented with coronary artery disease. Mineralocorticoid receptor antagonist can be used, among them eplerenone has been studied and can be useful to relieve symptoms of patients with a flare-up of heart failure by reducing the preload, provided that a close fluid and echocardiographic monitoring is implemented. Conclusions The use of phosphodiesterase 5 inhibitors can improve the haemodynamic status of patients with aortic stenosis and reduce the level of left ventricular hypertrophy, as well as improve pulmonary circulation and exercise tolerability of patients with AS, however it should be considered that in other studies sildenafil was associated with a worse clinical outcome. Calcium channel blocker are one the most used medications in patients with HT, but their use was associated with a 7-fold relative risk of all-cause mortality independent of known confounders and was also associated with an adverse effect on treadmill exercise and higher risk of all-cause mortality in patients with AS.

Development and characterization of a new swine model of invasive pneumococcal pneumonia.

Streptococcus pneumoniae is the most common microbial cause of community-acquired pneumonia. Currently, there are no available models of severe pneumococcal pneumonia in mechanically ventilated animals to mimic clinical conditions of critically ill patients. We studied endogenous pulmonary flora in 4 healthy pigs and in an additional 10 pigs in which we intra-bronchially instilled S. pneumoniae serotype 19 A, characterized by its resistance to penicillin, macrolides and tetracyclines. The pigs underwent ventilation for 72 h. All pigs that were not challenged with S. pneumoniae completed the 72-h study, whereas 30% of infected pigs did not. At 24 h, we clinically confirmed pneumonia in the infected pigs; upon necropsy, we sampled lung tissue for microbiological/histological confirmation of pneumococcal pneumonia. In control pigs, Streptococcus suis and Staphylococcus aureus were the most commonly encountered pathogens, and their lung tissue mean ± s.e.m. concentration was 7.94 ± 20 c.f.u./g. In infected pigs, S. pneumoniae was found in the lungs of all pigs (mean ± s.e.m. pulmonary concentration of 1.26 × 105 ± 2 × 102 c.f.u./g). Bacteremia was found in 50% of infected pigs. Pneumococcal pneumonia was confirmed in all infected pigs at 24 h. Pneumonia was associated with thrombocytopenia, an increase in prothrombin time, cardiac output and vasopressor dependency index and a decrease in systemic vascular resistance. Upon necropsy, microbiological/histological pneumococcal pneumonia was confirmed in 8 of 10 pigs. We have therefore developed a novel model of penicillin- and macrolide-resistant pneumococcal pneumonia in mechanically ventilated pigs with bacteremia and severe hemodynamic compromise. The model could prove valuable for appraising the pathogenesis of pneumococcal pneumonia, the effects associated with macrolide resistance and the outcomes related to the use of new diagnostic strategies and antibiotic or complementary therapies.

PREGNANCY MANAGEMENT AND OUTCOME IN A WOMAN WITH CONGENITAL UNILATERAL LUNG AGENESIS: A CASE REPORT

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Congenital unilateral lung agenesis is a rare condition characterized by the complete absence of a lung and the bronchovascular tree. It is often associated with cardiac and bronchopulmonary malformations, resulting in significant morbidity and mortality. Pregnancy, due to the physiologic changes during gestation and childbirth, poses additional risks to these patients. We report a case of a woman with congenital right lung agenesis (CRLA) whose successful pregnancy could offer guidance to clinicians in the interdisciplinary management of a high-risk condition (1). CASE PRESENTATION: A 26-year-old G1P0 was referred to our Maternal Fetal Medicine (MFM) clinic for her CRLA with resultant dextrocardia and left lung hyperinflation. She was asymptomatic and was able to tolerate daily activities without concerns. Pre-conceptional imaging studies showed results consistent with her medical history.There were no obstetric concerns with normal prenatal labs and normal fetal anatomy ultrasound. She was recommended to undergo cardiopulmonary evaluation and follow up with the relevant specialists.The patient remained clinically stable throughout the gestation. Delivery and postpartum planning was done in the early third trimester at a multidisciplinary conference with the MFM, Anesthesia, Cardiology, Pulmonology, Obstetrics, and Critical Care teams.The patient was electively induced at 39 weeks resulting in an uncomplicated vaginal delivery. Careful monitoring of the patient's hemodynamic status was performed during the intra- and postpartum periods due to the concern of volume overload from intravenous fluid infusions during and autotransfusion following delivery. Her postpartum course was uncomplicated. DISCUSSION: Several cardiopulmonary physiological changes occur in pregnancy to accommodate the growing fetus. An increase in cardiac output with a decrease in pulmonary and systemic vascular resistance leads to an increase in pre-load and increased pulmonary capillary permeability. The risk of pulmonary edema is highest in the second stage of labor due to the autotransfusion into the systemic circulation and the relief of pressure on the inferior vena cava (2). During pregnancy, there is a 40% increased oxygen requirement by the growing fetus, placenta, and maternal organs with a decreased reserve secondary to the increased consumption and decreased functional residual capacity. These changes are often the source of significant morbidity and mortality in women with compromised systems (3). For these reasons, a multidisciplinary care approach was of utmost importance for this patient. CONCLUSIONS: We advocate for the utility of a multidisciplinary approach with frequent follow-up and testing with each specialty to ensure the best care for a successful pregnancy outcome in this patient with CRLA. REFERENCE #1: Wert S. E. (2016). Normal and Abnormal Structural Development of the Lung. In Polin R. A., Abman S. H., Rowitch D. H., Benitz W. E., & Fox W. W., Fetal and Neonatal Physiology (pp. 627-641). Elsevier. https://doi.org/10.1016/B978-0-323-35214-7.00061-5 REFERENCE #2: Silversides C. K. & Colman J. M. (2007). Physiological changes in pregnancy. Oakley, C. & Warnes C. A. (2007). Heart Disease in Pregnancy (pp. 6-16). Blackwell Publishing Limited. REFERENCE #3: Gabbe, S. G., Niebyl, J. R., Simpson, J. L., Landon, M. B., Galan, H. L., Jauniaux, E. R., ... & Grobman, W. A. (2016). Obstetrics: normal and problem pregnancies e-book. Elsevier Health Sciences. DISCLOSURES: No relevant relationships by Kajal Angras, source=Web Response No relevant relationships by Kelly Ca, source=Web Response No relevant relationships by Cherise Hatch, source=Web Response No relevant relationships by VANI MOVVA, source=Web Response