Sepsis and Septic Shock: Symptoms, Causes, Treatment & Prevention (Complete Guide)

Sepsis and Septic shock

Infographic of Septic Shock Pathophysiology and Management according to 2026 Surviving Sepsis Campaign Guidelines.

The pathophysiology of sepsis involves a series of interacting pathways involving immune stimulation, immune suppression, hypercoagulation, and hypofibrinolysis. Cardiovascular management plays an important role in the treatment of septic shock. Hypotension occurs because of failure of vasoconstriction by vascular smooth muscle resulting in peripheral vasodilation Goal-directed cardiovascular resuscitation has been demonstrated to be an important determinant of survival in patients with septic shock. In addition to cardiovascular management, appropriate initial antimicrobial treatment of patients with severe sepsis also appears to be an important determinant of patient outcome. 

The unscrambling of the complex pathophysiology associated with severe sepsis and septic shock has made much progress, and current understanding of this process is no longer rudimentary. Novel drug entities and new therapeutic strategies targeting these pathways have demonstrated efficacy in reducing patient mortality.

Medications commonly used in septic shock and their effects on cardiac output (CO), mean arterial pressure (MAP), and systemic vascular resistance (SVR). Vasopressors are the first group and include norepinephrine, dopamine, epinephrine, phenylephrine, and vasopressin. Norepinephrine is given at a dose of 0.05–0.5 µg/kg/min and has minimal to slight effect on cardiac output, while it increases MAP and markedly increases SVR. Dopamine is administered at 5–20 µg/kg/min and increases cardiac output as well as MAP, with a strong increase in SVR. Epinephrine, given at 0.05–2 µg/kg/min, increases cardiac output and SVR and moderately raises MAP. Phenylephrine is administered at 2–10 µg/kg/min and significantly increases MAP and SVR with minimal effect on cardiac output. Vasopressin is given at 0.04 units/min and has no significant effect on cardiac output but strongly increases MAP and SVR.

The second group is inotropes, represented by dobutamine, which is administered at 2.5–10 µg/kg/min and markedly increases cardiac output while having little or slightly positive effect on MAP and little to no effect on SVR.

The third medication activated protein C is  a hopeful therapy, modern management focuses entirely on early antibiotics and hemodynamic stability.

The fourth category is corticosteroids, where hydrocortisone is commonly used at a dose of 50 mg every 6 hours, sometimes combined with fludrocortisone 50 µg daily.

Finally, antibiotic management is also an essential component in septic shock treatment and follows a specific treatment.

Antibiotic management of severe sepsis and septic shock begins by determining whether the patient is immunocompromised. This includes conditions such as HIV positivity, neutropenia, chronic corticosteroid use, malnutrition, or receiving chemotherapy. If the patient is immunocompromised, consultation with an infectious disease expert should be considered because antimicrobial therapy may need to cover opportunistic pathogens in addition to bacterial infections. If the patient is not immunocompromised, clinicians should consider the likely cause of infection based on clinical presentation, noting that viral, fungal, bacterial infections may also lead to severe sepsis or septic shock.

Next, clinicians should assess for risk factors of healthcare-associated infection, including recent hospitalization, residence in a nursing home or rehabilitation facility, regular visits to hospital clinics or dialysis centers, or receiving home infusion or wound therapy. If such risk factors are present, treatment should cover potentially antibiotic-resistant nosocomial pathogens such as MRSA, Pseudomonas aeruginosa, Acinetobacter species, Klebsiella pneumoniae (ESBL positive), and Escherichia coli (ESBL positive). Recommended therapy may include a broad-spectrum cephalosporin (such as cefepime or ceftazidime), a carbapenem (imipenem, meropenem, or doripenem), or a beta-lactam/beta-lactamase inhibitor combination (piperacillin-tazobactam), combined with a fluoroquinolone (ciprofloxacin or levofloxacin) or an aminoglycoside (gentamicin, tobramycin, or amikacin), along with an MRSA-directed agent such as vancomycin, linezolid, or tigecycline.

If there are no healthcare-associated infection risk factors, clinicians should consider community-acquired bacterial pathogens that are typically antibiotic-sensitive, including Streptococcus pneumoniae, Escherichia coli, Legionella pneumophila, methicillin-susceptible Staphylococcus aureus, Haemophilus influenzae, and Klebsiella pneumoniae. In such cases, single-agent therapy may be selected, including ceftriaxone, a fluoroquinolone (levofloxacin, moxifloxacin, or ciprofloxacin), ampicillin/sulbactam, ertapenem, or macrolides such as azithromycin, clarithromycin, or telithromycin. Finally, once the causative organism is identified and susceptibility testing results are available, the antibiotic regimen should be modified or narrowed accordingly.

The significance of early, aggressive, volume resuscitation and hemodynamic stabilization was demonstrated in a randomized, controlled, single-center trial in patients who presented to the emergency department with signs of the systemic inflammatory response syndrome and hypotension. Administration of crystalloids, red blood cell transfusions, vasopressors, and inotropes based on aggressive monitoring of intravascular volume and a tissue oxygen marker within 6 hours of

presentation to the emergency department resulted in a 16% decrease in absolute 28- day mortality. The major differences in treatment between the intervention and control groups were in the volume of intravenous fluids received, the number of patients trans- fused packed red blood, the use of dobutamine, and the presence of a dedicated study team for the first 6 hours of care. 

Fluid Management of Septic Shock:

In the clinical management of septic shock, treatment begins when a patient presents with signs of sepsis along with hypotension or hypoperfusion, such as systolic blood pressure (SBP) below 90 mmHg, mean arterial pressure (MAP) below 60 mmHg, or elevated lactate levels. The first step is to administer an initial fluid bolus of at least 20 mL/kg of 0.9% sodium chloride (normal saline) or lactated Ringer’s solution. If the patient continues to have SBP < 90 mmHg or MAP < 60 mmHg, a central venous pressure (CVP) catheter should be inserted to guide further resuscitation. When CVP is less than 8 mmHg, additional fluid boluses of at least 20 mL/kg of normal saline or lactated Ringer’s solution should be repeated until the CVP reaches ≥ 8 mmHg.

Once adequate CVP is achieved, MAP should be measured. If MAP remains below 60 mmHg, vasopressors such as norepinephrine (NE) or dopamine (DA) should be administered to maintain perfusion. If MAP is ≥ 60 mmHg, the next step is to measure central venous oxygen saturation (ScvO₂). If ScvO₂ is less than 70%, further interventions are required, including blood transfusion if hematocrit (HCT) is below 30% and administration of dobutamine if the cardiac index (CI) is below 3.5 L/min/m².

The overall therapeutic goals during resuscitation are MAP ≥ 60 mmHg, SBP ≥ 90 mmHg, CVP ≥ 8 mmHg, and ScvO₂ ≥ 70%. If these goals are achieved, clinicians should determine whether vasopressors are still required. If vasopressors remain necessary, adjunctive therapies may be considered; if not, resuscitation is considered complete.

Adjunctive therapies in septic shock begins with a patient who has a clinical picture of sepsis and requires vasopressors despite achieving fluid management goals. At this stage, the APACHE (acute physiology and chronic health evaluation)II score is considered. If the patient has an increased risk of bleeding, is moribund, is not expected to survive 28 days, or has a DNR (do-not-resuscitate) order, then drotrecogin alfa (activated) should not be administered. If none of these conditions are present, drotrecogin alfa (activated) may be administered.

Next, a randomly timed cortisol level should be measured. If the cortisol level is less than 15 µg/mL, physiologic corticosteroid replacement should be considered. If the level is between 15 and 34 µg/mL, a corticotropin stimulation test should be performed to assess the increase in cortisol. If the increase is less than 9 µg/mL, corticosteroid replacement should be considered; however, if the increase is 9 µg/mL or greater, corticosteroid therapy is unlikely to provide benefit. If the initial cortisol level is greater than 34 µg/mL, corticosteroid treatment is also unlikely to be beneficial.

Plan:

Intravenous fluid administration and the appropriateness of initial antimicrobial therapy for severe sepsis and septic shock. Patients managed in this manner were more likely to receive intravenous fluids >20 mL/kg of body weight prior to 2- vasopressor administration, and consequently were less likely to require vasopressor administration at the time of transfer to the intensive care unit. Patients managed with this approach were also more likely to be treated with an appropriate initial antimi- crobial regimen. As a result of the aggressive management initiated in the emergency department and continued in the intensive care unit, patients managed via the severe sepsis order sets had statistically shorter hospital lengths of stay and a lower risk for 28-day mortality. 

In summary, the initial management of patients with septic shock appears to be critical in terms of determining outcome. Institution of standardized physician order sets, or some other systematic approach, for the management of patients with severe infections appears to consistently improve the delivery of recommended therapies and, as a result, may improve patient outcomes.

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