The Impact of Different Sedation Regimens on Hemodynamics in Patients Undergoing Mechanical Ventilation With Shock

Peking University

Status: Not yet enrolling

Conditions: Mechanically Ventilated Patients With Shock

Study type: Observational

Funder types: Other

Identifiers

NCT07037615

2025-Z-44

Details and patient eligibility

About

Mechanical ventilation is a common therapeutic intervention in the intensive care unit (ICU). However, patients undergoing mechanical ventilation often experience agitation, unplanned extubation, patient-ventilator asynchrony, and even neuroendocrine-immune dysregulation, sympathetic overexcitation, and organ dysfunction due to discomfort and pain. Sedation therapy mitigates patient stress, enhances comfort, and ensures the smooth implementation of mechanical ventilation, making it an essential component of treatment for ventilated patients. Nevertheless, sedation may impact peripheral vascular tone, leading to hemodynamic instability and exacerbating inadequate peripheral perfusion.

The precise implementation of sedation therapy to minimize adverse effects remains unclear. This prospective observational study will enroll critically ill patients with shock requiring mechanical ventilation. We will examine the effects of different sedation strategies-including sedation assessment protocols, sedative types, sedation duration, and daily awakening trials-on hemodynamics in this population. The study aims to explore optimized sedation regimens and provide evidence-based guidance for precision sedation therapy in clinical practice.

Full description

Critically ill patients requiring mechanical ventilation in the ICU frequently present with concurrent shock. The hemodynamic effects of sedative agents may further exacerbate circulatory instability. Studies indicate that 34% of ICU patients require simultaneous mechanical ventilation and vasoactive agent support. Among ARDS patients, over 60% develop shock, with approximately 65% necessitating vasopressor administration.

Common sedatives like propofol and dexmedetomidine, despite being first-line choices, exhibit significant hemodynamic side effects:

• **Propofol** induces hypotension (incidence: 20%) through vasodilation, sympathetic suppression, and bradycardia.
• **Dexmedetomidine** causes hypotension and bradycardia at low doses, while triggering vasoconstriction via peripheral α-2 receptor activation at high doses-both scenarios reduce cardiac output.

Additional factors affecting hemodynamic stability include sedation depth, duration, and daily awakening protocols. Deep sedation may mask dynamic assessment of fluid responsiveness, delaying shock resuscitation. Conversely, daily awakening-though reducing ventilation duration-may increase circulatory fluctuations through stress responses. These complex interactions necessitate balancing sedation efficacy and circulatory stability in shock patients, yet standardized protocols for this population remain lacking.

Enrollment: 50 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥ 18 years;
• Receiving invasive mechanical ventilation, with endotracheal intubation -performed <12 hours before enrollment;
• Patient requiring sedative and analgesic medications;
• Hemodynamic instability: Hypotension (systolic blood pressure <90 mmHg or mean arterial pressure <65 mmHg) occurring within 6 hours before intubation to 6 hours after intubation, requiring continuous vasoactive medication therapy for >1 hour.

Exclusion criteria

• Pregnant or breastfeeding patients;
• Patients with confirmed or suspected acute primary brain pathology (e.g., traumatic brain injury, intracranial hemorrhage, stroke, hypoxic brain injury);
• Patients with confirmed or suspected spinal cord injury or other pathologies likely to cause permanent or prolonged weakness;
• Patients with known allergy to the analgesic, sedative, or vasoactive medications used in the study protocol;
• Patients receiving palliative care or with an expected survival of ≤48 hours; Patients previously enrolled in this study.

Trial design

50 participants in 2 patient groups

Cumulative vasoactive support duration <1 hour/24h

Description:

On day 28 after ICU admission, patients were assessed for vasoactive drug independence, defined as vasoactive drug infusion not exceeding 60 minutes within any continuous 24-hour window.

Cumulative vasoactive support duration >1 hour/24h

Description:

On day 28 of ICU admission or thereafter, the patient underwent a vasoactive drug dependence assessment, defined as vasoactive drug infusion time exceeding 60 minutes within any continuous 24-hour window.