Comparison of Leg Elevation and Leg Wrapping in the Prevention of Propofol Induced Hypotension

Nitte University

Status: Unknown

Conditions: Propofol Induced Hypotension

Treatments: Other: control; Other: leg elevation; Other: leg wrapping

Study type: Interventional

Funder types: Other

Identifiers

NCT02845921

INST.EC/EC/066/2015-16

Details and patient eligibility

About

Propofol is an intravenous anaesthetic agent used for both induction and maintenance of anaesthesia. An important adverse effect is the significant fall in blood pressure. The current clinical study will be done to determine the efficacy of leg elevation and wrapping in reducing the incidence and severity of propofol induced hypotension in patients undergoing general anaesthesia.

Full description

Propofol is an intravenous anaesthetic agent used for both induction and maintenance of anaesthesia. It is widely employed due to its quick onset of action, short half life and rapid recovery. An important adverse effect is the significant fall in blood pressure. Although the exact mechanism of propofol induced hypotension is not known, venodilation, decreased peripheral resistance and decrease in cardiac output has been suggested.2 Though the hypotension is transient, it can produce devastating effects. Hence there is a need to prevent it. Moreover, several attempts at treating propofol induced hypotension have been met with variable and limited success.

Hypotension following spinal anaesthesia is also a frequent problem. It is generally treated with intravenous fluids and vasopressors. Simple and non pharmacological measures like leg elevation and leg wrapping with Esmarch bandage were reported to be successful.3 These reduce the incidence and severity of hypotension associated with spinal anaesthesia by improving the venous return.

The mechanisms of hypotension following intravenous propofol and spinal anaesthesia are almost similar. Therefore, the investigators hypothesize that leg elevation and wrapping can be attempted to reduce propofol induced hypotension. They are simple and cost effective techniques that will reduce the need for pharmacological measures to control hypotension. As the literature search did not reveal any information regarding the usefulness of these techniques in propofol induced hypotension, the current clinical study will be done to determine the efficacy of leg elevation and wrapping in reducing the incidence and severity of propofol induced hypotension in patients undergoing general anaesthesia.

The current study will compare the efficacy of leg elevation and leg wrapping in reducing the incidence and severity of propofol induced hypotension in terms of incidence of hypotension, magnitude of decrease in systolic, diastolic and mean arterial blood pressures, need for pharmacological measures to treat hypotension, changes in heart rate and adverse clinical outcomes, if any. It will be a prospective randomised controlled open label study from January 2016 to August 2017 involving 150 adult patients undergoing general anaesthesia.

For statistical analysis, descriptive statistics - minimum, maximum, mean and standard deviation will be used. Independent sample t test for data following normal distribution and for data not following normal distribution, Mann-Whitney U test will be used. P value less than 0.05 will be considered statistically significant. To study relationship between hypotension and other variables, Pearson's correlation will be used. Confidence interval will be calculated to 95%.

Enrollment: 150 estimated patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients belonging to ASA physical status I and II undergoing endotracheal general anaesthesia

Exclusion criteria

• Patient refusal
• Contraindication to application of bandage
• Partial or complete limb amputation
• Difficult airway
• Use of extraglottic airway device
• Pregnancy
• On antihypertensive or vasoactive medication
• Autonomic neuropathy

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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150 participants in 3 patient groups, including a placebo group

Group C Control

Placebo Comparator group

Description:

Patient will be shifted to operation theatre. Electrocardiography (ECG), pulse oximeter and non-invasive blood pressure (NIBP) monitors will be attached. Baseline vitals will be noted. Intravenous access will be secured and crystalloids at 100ml/hr will be given. Analgesia will be given by inj fentanyl 2µg/kg body weight. Lower limbs will be neither elevated or wrapped. Vitals will be recorded again. 3 minutes of pre-oxygenation will be done. Anaesthesia will be induced with inj. propofol 2mg/kg body weight injected over 30 seconds. Muscle relaxation will be achieved by inj. vecuronium 0.1mg/kg body weight. Patient will be ventilated with oxygen for 5 minutes. Orotracheal intubation will be performed with appropriate sized endotracheal tube.

Treatment:

Other: control

Group E Leg elevation

Experimental group

Description:

Patient will be shifted to operation theatre. Crystalloids at 100ml/hr will be given. Analgesia will be given by inj fentanyl 2µg/kg body weight. Lower limbs are elevated and supported on a stand making an angle of 30 degree to the horizontal. Vitals will be recorded again. 3 minutes of pre-oxygenation will be done. Anaesthesia will be induced with inj. propofol 2mg/kg body weight injected over 30 seconds. Muscle relaxation will be achieved by inj. vecuronium 0.1mg/kg body weight. Patient will be ventilated with oxygen for 5 minutes. Orotracheal intubation will be performed with appropriate sized endotracheal tube. Stand will be removed and legs will be brought to horizontal position 10 minutes after intubation.

Treatment:

Other: leg elevation

Group W Leg wrapping

Experimental group

Description:

Patient will be shifted to operation theatre. Crystalloids at 100ml/hr will be given. Analgesia will be given by inj fentanyl. Each lower limb will be elevated alternately and wrapped from toe to mid-thigh with Esmarch bandage. Care will be taken to avoid compressing the legs to greater than arterial pressure by confirming the presence of pulse using a saturation probe. Following wrapping, the lower limbs will be brought to horizontal position. 3 minutes of pre-oxygenation will be done. Anaesthesia will be induced with inj. propofol injected over 30 seconds. Muscle relaxation by inj. vecuronium. Patient will be ventilated with oxygen for 5 minutes. Orotracheal intubation will be performed with appropriate sized endotracheal tube. Esmarch bandage will be removed 10 minutes after intubation.

Treatment:

Other: leg wrapping