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NCT Number: NCT03809065

Effects of Nitroglycerin Versus Labetalol on Tissue Perfusion During Deliberate Hypotension

Deliberate hypotension is used to provide bloodless field during endoscopic sinus surgery; however, hypotension might impair perfusion of vital organs. The aim of this work is to compare the impact of nitroglycerin and labetalol on peripheral perfusion when used for induction of deliberate hypotension

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Key information

Conditions

Tissue Perfusion Deliberate Hypotension Sinus Endoscopic Surgery

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Kasr Al Ainy

Cairo, 11562, Egypt

About this study

Hypotensive anesthesia is associated with the risk of reduced tissue perfusion. The usual target mean arterial pressure during deliberate hypotension is 50- 65 mmHg; however, the status of peripheral perfusion under this target is not well investigated. Nitroglycerin and Labetalol are commonly used drugs to achieve deliberate hypotension. Nitroglycerin is a direct vasodilator and its main action is through venodilation, while labetalol combines a selective α1 and non selective beta-adrenergic blocking activity. Both drugs were previously compared during deliberate hypotension with regard to surgical field quality and blood loss. No study to date compared the effects of both drugs on peripheral perfusion when used for induction of deliberate hypotension. The Peripheral Perfusion Index (PPI) is the ratio between pulsatile and non-pulsatile components of peripheral circulation. Measurement of PPI is based on analysis of the pulse oximetry signal. PPI showed increasing popularity as a non invasive monitor of peripheral perfusion. Serum lactate is another frequently used marker of global tissue perfusion.The aim of this study is to compare the influence of nitroglycerin and labetalol on tissue perfusion when used for induction of deliberate hypotension during FESS operations. Tissue perfusion will be evaluated using PPI and serum lactate as markers of peripheral and global tissue perfusion respectively.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult male or female patients
  • 18-45 years
  • ASA physical status I-II
  • scheduled for FESS operations

Exclusion criteria

  • uncontrolled hypertension
  • cerebrovascular disorders
  • coagulation disorders
  • cardiovascular diseases
  • renal impairment
  • liver impairment
  • history of allergic reaction to any of the study medications

Treatment and study plan

Nitroglycerin

Drug

Nitroglycerin is a direct vasodilator and its main action is through venodilation. Nitroglycerin will be diluted by adding 3 mL (3 mg) to 47 mL normal saline in a 50 mL syringe and will be infused after endotracheal intubation with a starting dose of 0.5 mL/Kg/ hr to have a starting dose of 0.5 μg/Kg/min. The rate of nitroglycerin infusion will be 0.5-2 μg /kg/min .The infusion rate will be finely adjusted to maintain MAP around 55-65mmHg or till reaching adequate surgical field {defined as surgical field score (SFS) <3}.

labetalol

Drug

Labetalol is an α and β - adrenergic receptors competitive antagonist. Labetalol will be diluted by adding 10 mL (50 mg) to 40 mL normal saline in a 50 mL syringe and will be infused after endotracheal intubation with a starting dose of 0.5 mL/Kg/ hr. The rate of Labetalol infusion will be 0.5-2 mg/kg/h.The infusion rate will be finely adjusted to maintain MAP around 55-65mmHg or till reaching adequate surgical field {defined as surgical field score (SFS) <3}.

Primary outcomes

  1. Peripheral perfusion index

    Time frame: 4 hours

    Peripheral perfusion index will be used as a marker of peripheral perfusion.

Secondary outcomes

  1. Change in serum lactate concentration

    Time frame: Immediately before induction of anesthesia and after 60 minutes post recovery.

    Serum lactate concentration will be used as a marker of global tissue perfusion.Two samples will be obtained.

  2. Total blood loss

    Time frame: from beginning of surgery till the end of the procedure

    Total blood loss will be measured from the suction device and gauzes that will be used to dry the surgical field.

  3. Surgical field score (SFS)

    Time frame: from beginning of surgery till the end of the procedure.

    SFS ranges from 0 to 5 as follows: 0: No bleeding, 1: Slight bleeding-no suctioning of blood required, 2: Slight bleeding-occasional suctioning required. Surgical field not threatened. 3: Slight bleeding-frequent suctioning required. Bleeding threatens surgical field a few seconds after suction is removed, 4: Moderate bleeding-frequent suctioning required. Bleeding threatens surgical field directly after suction is removed, 5: Severe bleeding-constant suctioning required. Bleeding appears faster that can be removed by suction. Surgical field severely threatened and surgery not possible.

    Adequate surgical field is defined as SFS <3

  4. Mean arterial blood pressure

    Time frame: 4 hours

    Target mean arterial pressure during deliberate hypotension will be 55-65mmHg

  5. Heart rate

    Time frame: 4 hours

    Number of heart beats per minute

Sponsors and collaborators

Lead sponsor

Cairo University

Other

Registry information

Official study title

Effects of Nitroglycerin Versus Labetalol on Tissue Perfusion During Deliberate Hypotension for Sinus Endoscopic Surgery.

Important dates

Study start
2019
Primary completion
2019
Study completion
2019
First posted
Jan 18, 2019
Registry last updated
Apr 27, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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