Haemodynamic management of a patient with septic shock:

Coupled plasma filtration adsorption for the treatment of sepsis or septic shock: a systematic review and meta-analysis

BACKGROUND

The effect of coupled plasma filtration adsorption (CPFA) for the treatment of sepsis or septic shock is controversial. A systematic review and meta-analysis was performed to evaluate the impact of CPFA on all-cause mortality in patients with sepsis or septic shock.

METHODS

We searched the PubMed, Cochrane, and Embase databases for randomized controlled trials (RCTs) and cohort studies from inception to the 1st of May 2022. We included studies involving patients (˃ 14 years) with sepsis or septic shock. All authors reported our primary outcome of all-cause mortality (hospital mortality, 28-day mortality or 30-day mortality). Results were expressed as odds ratio (OR) with accompanying 95% confidence interval (CI).

RESULTS

Six studies including 537 patients were included. The primary outcome of this meta-analysis showed that the all-cause mortality was about 54.2% (119/243 in the CPFA group and 172/294 in the control group). There was no statistically significant difference in the all-cause mortality between two groups (odds ratio [OR] = 0.75; 95% CI 0.53 to 1.06; P = 0.11; Chi² = 14.04; I² = 64%).

CONCLUSIONS

The treatment of CPFA failed to decrease all-cause mortality of sepsis or septic shock patients. Further large-scale randomized controlled trials (RCTs) evaluating the ability of this therapy to improve clinical outcomes are still required to confirm these results.

Update on Vasopressors and Inotropes in Septic Shock

Vasopressors and inotropes are used in septic shock in patients who remain hypotensive despite adequate fluid resuscitation. The goal is to increase blood pressure to optimize perfusion to organs. Generally, goal-directed therapy to supra-normal oxygen transport variables cannot be recommended due to lack of benefit. Traditionally, vasopressors and inotropes in septic shock have been started in a step-wise fashion starting with dopamine. Recent data suggest that there may be true differences among vasopressors and inotropes on local tissue perfusion as measured by regional hemodynamic and oxygen transport. When started early in septic shock, norepinephrine decreases mortality, optimizes hemodynamic variables, and improves systemic and regional (eg, renal, gastric mucosal, splanchnic) perfusion. Epinephrine causes a greater increase in cardiac index (CI) and oxygen delivery (DO2 ) and increases gastric mucosal flow, but increases lactic acid and may not adequately preserve splanchnic circulation owing to its predominant vasoconstrictive alpha (α ) effects. Epinephrine may be particularly useful when used earlier in the course of septic shock in young patients and those who do not have any known cardiac abnormalities. Unlike epinephrine, dopamine does not preferentially increase the proportion of CI that preferentially goes to the splanchnic circulation. Dopamine is further limited because it cannot increase CI by more than 35% and is accompanied by tachycardia or tachydysrhythmias. Dopamine, as opposed to norepinephrine, may worsen splanchnic oxygen consumption (VO2 ) and oxygen extraction ratio (O2 ER). Low-dose dopamine has not been shown to consistently increase the glomerular filtration rate or prevent renal failure, and, indeed, worsens splanchnic tissue oxygen use. Routine use of concurrently administered dopamine with vasopressors is not recommended. Phenylephrine should be used when a pure vasoconstrictor is desired in patients who may not require or do not tolerate the beta (β ) effects of dopamine or norepinephrine with or without dobutamine. Patients with high filling pressure and hypotension may benefit from the combination of phenylephrine and dobutamine. Investigational approaches to vasopressor-refractory hypotension in septic shock include the use of vasopressin and corticosteroids.

Effect of Manual Hyperinflation on Hemodynamics, Gas Exchange, and Respiratory Mechanics in Ventilated Patients

The authors investigated the effect of manual hyperinflation (MHI) with set parameters applied to patients on mechanical ventilation on hemodynamics, respiratory mechanics, and gas exchange. Sixteen critically ill patients post-septic shock, with acute lung injury, were studied. Heart rate, arterial pressure, and mean pulmonary artery pressure were recorded every minute. Pulmonary artery occlusion pressure, cardiac output, arterial blood gases, and dynamic compliance (Cdyn) were recorded pre- and post-MHI. From this, systemic vascular resistance index (SVRI), cardiac index, oxygen delivery, and partial pressure of oxygen: fraction of inspired oxygen (PaO2:FiO2) ratio were calculated. There were significant increases in SVRI ( P < 0.05) post-MHI and diastolic arterial pressure ( P < 0.01) during MHI. Cdyn increased post-MHI ( P < 0.01) and was sustained at 20 minutes post-MHI ( P < 0.01). Subjects with an intrapulmonary cause of lung disease had a significant decrease ( P = 0.02) in PaO2:FiO2, and those with extrapulmonary causes of lung disease had a significant increase ( P < 0.001) in PaO2:FiO2 post-MHI. In critically ill patients, MHI resulted in an improvement in lung mechanics and an improvement in gas exchange in patients with lung disease due to extrapulmonary events and did not result in impairment of the cardiovascular system.

Coupled plasma filtration adsorption improves hemodynamics in septic shock

PURPOSE

Septic shock involves a dysregulation of the immune response to an infection. This may lead to hemodynamic dysfunction and multiple-organ failure. The main aim of this study was to evaluate the effect of coupled plasma filtration adsorption (CPFA) on the hemodynamic profile in patients with septic shock.

MATERIALS AND METHODS

We retrospectively analyzed data from 21 adult patients admitted to the intensive care unit with a diagnosis of septic shock, comparing data between pre-CPFA and post-CPFA treatment. They received a maximum of 5 cycles of treatment.

RESULTS

Coupled plasma filtration adsorption treatment was associated with a significant increase of mean arterial pressure (P < .001), reduction of the vasoactive/inotropic requirement (P = .007), and renal improvement. In patients with leukocytosis or leucopenia, the leukocyte count was restored to a reference range of values.

CONCLUSION

Treatment with CPFA improves hemodynamic parameters in septic shock patients, ameliorating organ failure.

Sympathetic overstimulation during critical illness: adverse effects of adrenergic stress

The term ''adrenergic'' originates from ''adrenaline'' and describes hormones or drugs whose effects are similar to those of epinephrine. Adrenergic stress is mediated by stimulation of adrenergic receptors and activation of post-receptor pathways. Critical illness is a potent stimulus of the sympathetic nervous system. It is undisputable that the adrenergic-driven ''fight-flight response'' is a physiologically meaningful reaction allowing humans to survive during evolution. However, in critical illness an overshooting stimulation of the sympathetic nervous system may well exceed in time and scope its beneficial effects. Comparable to the overwhelming immune response during sepsis, adrenergic stress in critical illness may get out of control and cause adverse effects. Several organ systems may be affected. The heart seems to be most susceptible to sympathetic overstimulation. Detrimental effects include impaired diastolic function, tachycardia and tachyarrhythmia, myocardial ischemia, stunning, apoptosis and necrosis. Adverse catecholamine effects have been observed in other organs such as the lungs (pulmonary edema, elevated pulmonary arterial pressures), the coagulation (hypercoagulability, thrombus formation), gastrointestinal (hypoperfusion, inhibition of peristalsis), endocrinologic (decreased prolactin, thyroid and growth hormone secretion) and immune systems (immunomodulation, stimulation of bacterial growth), and metabolism (increase in cell energy expenditure, hyperglycemia, catabolism, lipolysis, hyperlactatemia, electrolyte changes), bone marrow (anemia), and skeletal muscles (apoptosis). Potential therapeutic options to reduce excessive adrenergic stress comprise temperature and heart rate control, adequate use of sedative/analgesic drugs, and aiming for reasonable cardiovascular targets, adequate fluid therapy, use of levosimendan, hydrocortisone or supplementary arginine vasopressin.

Small volume of hypertonic saline as the initial fluid replacement in experimental hypodynamic sepsis

INTRODUCTION

We conducted the present study to examine the effects of hypertonic saline solution (7.5%) on cardiovascular function and splanchnic perfusion in experimental sepsis.

METHODS

Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over 30 minutes. After 30 minutes, they were randomized to receive lactated Ringer's solution 32 ml/kg (LR; n = 7) over 30 minutes or 7.5% hypertonic saline solution 4 ml/kg (HS; n = 8) over 5 minutes. They were observed without additional interventions for 120 minutes. Cardiac output (CO), mean arterial pressure (MAP), portal and renal blood flow (PBF and RBF, respectively), gastric partial pressure of CO2 (pCO2; gas tonometry), blood gases and lactate levels were assessed.

RESULTS

E. coli infusion promoted significant reductions in CO, MAP, PBF and RBF (approximately 45%, 12%, 45% and 25%, respectively) accompanied by an increase in lactate levels and systemic and mesenteric oxygen extraction (sO2ER and mO2ER). Widening of venous-arterial (approximately 15 mmHg), portal-arterial (approximately 18 mmHg) and gastric mucosal-arterial (approximately 55 mmHg) pCO2 gradients were also observed. LR and HS infusion transiently improved systemic and regional blood flow. However, HS infusion was associated with a significant and sustained reduction of systemic (18 +/- 2.6 versus 38 +/- 5.9%) and mesenteric oxygen extraction (18.5 +/- 1.9 versus 36.5 +/- 5.4%), without worsening other perfusional markers.

CONCLUSION

A large volume of LR or a small volume of HS promoted similar transient hemodynamic benefits in this sepsis model. However, a single bolus of HS did promote sustained reduction of systemic and mesenteric oxygen extraction, suggesting that hypertonic saline solution could be used as a salutary intervention during fluid resuscitation in septic patients.

Systemic and regional hemodynamic effects of enalaprilat infusion in experimental normotensive sepsis

Angiotensin-converting enzyme inhibitors have been shown to improve splanchnic perfusion in distinct shock states. We hypothesized that enalaprilat potentiates the benefits of early fluid resuscitation in severe experimental sepsis, particularly in the splanchnic region. Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over a period of 30 min. Thereafter, two interventions were performed: fluid infusion (normal saline, 32 mL/kg over 30 min) and enalaprilat infusion (0.02 mg kg(-1) min(-1) for 60 min) in randomized groups. The following groups were studied: controls (fluid infusion, N = 4), E1 (enalaprilat infusion followed by fluid infusion, N = 5) and E2 (fluid infusion followed by enalaprilat infusion, N = 5). All animals were observed for a 120 min after bacterial infusion. Mean arterial pressure, cardiac output (CO), portal vein blood flow (PVBF), systemic and regional oxygen-derived variables, and lactate levels were measured. Rapid and progressive reductions in CO and PVBF were induced by the infusion of live bacteria, while minor changes were observed in mean arterial pressure. Systemic and regional territories showed a significant increase in oxygen extraction and lactate levels. Widening venous-arterial and portal-arterial pCO2 gradients were also detected. Fluid replacement promoted transient benefits in CO and PVBF. Enalaprilat after fluid resuscitation did not affect systemic or regional hemodynamic variables. We conclude that in this model of normotensive sepsis inhibition of angiotensin-converting enzyme did not interfere with the course of systemic or regional hemodynamic and oxygen-derived variables.

Manual hyperinflation causes norepinephrine release

OBJECTIVE

To measure hemodynamics and plasma catecholamines during manual hyperinflation (MHI) in ventilated patients.

METHODS

MHI was performed with a Mapleson "C" circuit, 2l-reservoir bag; peak inspiratory pressure was standardized to 35 mL water; and positive expiratory-end pressure of 5 mL water was administered to seven mechanically ventilated patients with septic (6) and cardiogenic (1) shock (67.2 +/- 5.2 years, Acute Physiology Assessment and Chronic Health Evaluation II score 22.1 +/- 3.1). Diastolic (DAP) and mean arterial pressure (MAP), continuous cardiac index, pulmonary artery occlusion pressure, dynamic compliance, plasma norepinephrine and epinephrine, and arterial blood gases were recorded, and systemic vascular resistance index (SVRI) and oxygenation ratio were calculated.

RESULTS

There were no significant changes in pulmonary artery occlusion pressure, mean arterial pressure, or PaO2/FiO2. There were significant increases in SVRI (P < .001), DAP (P < .001), dynamic compliance (P < .01), and plasma norepinephrine (P < .001) and a decrease in cardiac index (P < .05) after MHI.

CONCLUSIONS

The increases in DAP, SVRI, and plasma norepinephrine suggest a sympathetic vasoconstrictive response during the application of MHI.

Terlipressin or norepinephrine in hyperdynamic septic shock: a prospective, randomized study

OBJECTIVE

To compare, in patients with hyperdynamic septic shock, the effects of norepinephrine or terlipressin on hemodynamic variables and renal function.

DESIGN

Prospective, randomized, open-label study.

SETTING

Intensive care unit of a university, tertiary, and referral center.

PATIENTS

Twenty adult patients with hyperdynamic septic shock, after fluid resuscitation.

INTERVENTIONS

Patients were randomized to receive norepinephrine or terlipressin. Global hemodynamic variables, oxygen consumption, urine flow, creatinine clearance, and arterial blood lactate levels were measured.

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressure, systemic vascular resistance, pulmonary vascular resistance, and left and right ventricular stroke work were significantly increased with both drugs. With terlipressin, but not with norepinephrine, a significant decrease in heart rate (from 113 +/- 17 to 104 +/- 11 beats.min(-1), p < .01) and cardiac index (from 5.1 +/- 1.7 to 4.2 +/- 1.6 L.min(-1).m(-2)) was observed, with no change in stroke volume. Oxygen delivery index (from 784 +/- 131 to 701 +/- 92 mL.min(-1).m(-2)) and consumption index (from 244 +/- 69 to 210 +/- 54 mL.min(-1).m(-2)) were significantly decreased with terlipressin, but not with norepinephrine. Blood lactate concentrations were significantly decreased with both drugs. Urine flow and creatinine clearance were increased with both drugs.

CONCLUSIONS

In patients with hyperdynamic septic shock, both norepinephrine and terlipressin were effective to raise mean arterial blood pressure. With terlipressin, but not norepinephrine, the improvement in blood pressure was achieved at the expense of cardiac index and oxygen consumption, which were significantly decreased. Renal function was improved with both drugs. In further studies, alternative strategies to maintain cardiac index should be explored, such as a synergy between low-dose terlipressin and dobutamine.

Short-lasting systemic and regional benefits of early crystalloid infusion after intravenous inoculation of dogs with live Escherichia coli

We investigated the systemic and regional hemodynamic effects of early crystalloid infusion in an experimental model of septic shock induced by intravenous inoculation with live Escherichia coli. Anesthetized dogs received an intravenous infusion of 1.2 x 10(10) cfu/kg live E. coli in 30 min. After 30 min of observation, they were randomized to controls (no fluids; N = 7), or fluid resuscitation with lactated Ringer's solution, 16 ml/kg (N = 7) or 32 ml/kg (N = 7) over 30 min and followed for 120 min. Cardiac index, portal blood flow, mean arterial pressure, systemic and regional oxygen-derived variables, blood lactate, and gastric PCO2 were assessed. Rapid and progressive cardiovascular deterioration with reduction in cardiac output, mean arterial pressure and portal blood flow (approximately 50, approximately 25 and approximately 70%, respectively) was induced by the live bacteria challenge. Systemic and regional territories showed significant increases in oxygen extraction and in lactate levels. Significant increases in venous-arterial (approximately 9.6 mmHg), portal-arterial (approximately 12.1 mmHg) and gastric mucosal-arterial (approximately 18.4 mmHg) PCO2 gradients were also observed. Early fluid replacement, especially with 32 ml/kg volumes of crystalloids, promoted only partial and transient benefits such as increases of approximately 76% in cardiac index, of approximately 50% in portal vein blood flow and decreases in venous-arterial, portal-arterial, gastric mucosal-arterial PCO2 gradients (7.2 +/- 1.0, 7.2 +/- 1.3 and 9.7 +/- 2.5 mmHg, respectively). The fluid infusion promoted only modest and transient benefits, unable to restore the systemic and regional perfusional and metabolic changes in this hypodynamic septic shock model.

Terlipressin in catecholamine-resistant septic shock patients

To determine the effects on hemodynamics, laboratory parameters, and renal function of terlipressin used in septic-shock patients with hypotension not responsive to high-dose norepinephrine (>2.0 microg x kg(-1) x min(-1)) and dopamine (25 microg x kg(-1) x min(-1)), a prospective, open-label study was carried out in 17 patients. Patients received one or two boluses of 1 mg of terlipressin. In all patients terlipressin induced a significant increase in mean arterial pressure (MAP), systemic vascular resistance, pulmonary vascular resistance, and left and right ventricular stroke work. The increase in MAP was accompanied by a significant decrease in heart rate and cardiac index, but stroke volume remained unchanged. Oxygen delivery and consumption were significantly decreased. Blood lactate concentrations significantly decreased over the study period. Bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly increased. Thrombocytes were significantly decreased. No change in prothrombin time was observed. Renal function, assessed by urine flow and creatinine clearance, was significantly improved. Pulmonary function assessed by Pao2/Fio2 ratio was not affected. A significant reduction in norepinephrine and dopamine infusion rates was observed in all patients. Eight patients died during their ICU stay from late multiple organ failure. Within the limitations of the present study (open-label design, small group of patients), it can be concluded that in septic shock patients with hypotension nonresponsive to fluid resuscitation and high-dose vasopressors, terlipressin can be effective to restore MAP. Cardiac index should be closely monitored because it was significantly decreased by terlipressin. Renal function was significantly improved. Mesenteric circulation was not evaluated, but hepatic function was altered during the study period. Further studies are required to determine whether terlipressin is safe in terms of outcome in septic shock patients.

Comparison of cardiac output measurements by arterial trans-cardiopulmonary and pulmonary arterial thermodilution with direct Fick in septic shock

BACKGROUND AND OBJECTIVE

The aim of this study was to compare cardiac output (CO) measurements by arterial trans-cardiopulmonary thermodilution (ATD) and pulmonary arterial thermodilution (PATD) with CO estimated on the basis of the Fick calculation via a metabolic monitor in septic shock.

METHODS

In a prospective animal study 20 anaesthetized, ventilated pigs (20.9 +/- 1.9 kg) were investigated. Septic shock was induced with faecal peritonitis. A pulmonary artery catheter was used for conventional measurement of CO. Simultaneously ATD was measured with a thermistor tipped catheter inserted into right carotid artery. Whole body oxygen consumption was measured by indirect calorimetry. Eighty data pairs of simultaneous CO measurements were analysed.

RESULTS

CO measured with Fick and that measured with PATD were significantly correlated (r = 0.94, r = 0.87, P < 0.001). Mean CO measured by PATD was 94.3 +/- 40.1 mL min(-1) kg(-1). Bias was 10.1 mL min(-1) kg(-1) (95% confidence interval (CI): 6.0-14.2 mL min(-1) kg(-1)) with limits of agreement of -26.8 to 47.0 mL min(-1) kg(-1). Correlation between Fick derived CO estimation and ATD CO was similar (r = 0.91, r2 = 0.83, P < 0.001). Mean CO measured by trans-cardiopulmonary thermodilution was 104.3 +/- 43.2 mL min(-1) kg(-1). Bias was 0.75 mL min(-1) kg(-1) (95% CI: -3.8 to 5.3 mL min(-1) kg(-1)) with limits of agreement of -39.7 to 41.2 mL min(-1) kg(-1).

CONCLUSIONS

Even during haemodynamic instability in septic shock the correlation of arterial trans-cardiopulmonary thermodilution and PATD derived CO with direct Fick was good. As arterial trans-cardiopulmonary thermodilution is less invasive than PATD, the former may offer practical advantages.

Exocrine pancreatic dysfunction in sepsis

BACKGROUND

Sepsis in critical illness is associated with the progressive failure of multiple organs. This study aims to establish a correlation between the severity of sepsis and exocrine pancreatic dysfunction.

MATERIALS AND METHODS

In a prospective cohort study pancreatic exocrine function was tested by means of a secretin-cholecystokinin test in 21 critically ill, mechanically ventilated patients with sepsis according to criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference Committee (ACCP/SCCM): 11 patients with shock and 10 patients without shock. Data were compared with seven healthy controls.

RESULTS

The volume of duodenal fluid was not statistically different in the three groups. Sepsis patients without shock had significantly reduced content of amylase and chymotrypsin in duodenal juice compared with healthy controls (P < 0.01). Secretion of amylase, chymotrypsin, trypsin (P < 0.01 each) and bicarbonate in duodenal fluid (P < 0.05) was impaired in the septic shock patients when compared with the healthy controls. The content of trypsin was different between sepsis patients and septic shock patients (P < 0.05). Spearman correlation analysis was significant between the amylase secretion and the APACHE III and SOFA scores (P < 0.01). The SOFA score was also related to secretion of trypsin (P < 0.05). In patients on pressor therapy, use of norepinephrine was associated with a significant decrease in bicarbonate secretion (P < 0.05).

CONCLUSIONS

Sepsis is associated with secretory pancreatic dysfunction that is worse in septic shock than in sepsis without shock. Impaired exocrine function was significantly correlated to the APACHE III and SOFA scores.