Intramuscular Phenylephrine HCL for Prevention of Spinal Anesthesia Induced Hypotension

Anesthesia Clinical Trial

Official title:

Comparison of Two Different Doses of Intramuscular Phenylephrine HCL for Prevention of Spinal Anesthesia Induced Hypotension During Cesarean Section: A Prospective Randomized Double-blinded Parallel Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05348980
• Other study ID #: RMI/RMI-REC/Approval/57
• Status: Completed
• Phase: Phase 4
• Start date: January 1, 2020
• Est. completion date: July 31, 2020

Study information

• Verified date: April 2022
• Source: Rehman Medical Institute - RMI
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Background: Spinal anesthesia (SA) is preferred over general anesthesia in Cesarean section (CS) due to its better safety profile but SA induced hypotension remains a big challenge for the clinical Anesthetist. Different methods including 15° left lateral table tilt, leftward uterine manual displacement, fluid pre-and co-loading have been used but drop in Systolic Blood Pressure (SBP) jeopardizing maternal and fetal well-being still occurs. Timely administered Phenylephrine HCL, an α-1 adrenergic agonist, is a recommended remedy.

Subjects and methods: Sixty parturients of American Society of Anaesthesiologists (ASA) physical status 1 and 2, scheduled for elective CS under SA were enrolled in this prospective double-blinded study and randomly divided into two equal groups, P4 and P8. They received intramuscular (IM) Phenylephrine HCL 04 mg and 08 mg respectively before SA. Spinal block up to T6 was achieved with 12.5 mg 0.5% Bupivacaine HCl heavy. The incidence and intensity of hypotension, rescue doses of Phenylephrine HCL and any adverse event, were recorded. Data collected was analyzed using Epi lnfo ™ version 7.2.

Description:

Introduction: World Health Organization (WHO) defines maternal death as a death while pregnant or within 42 days of the end of gestation, from any cause related to or aggravated by the pregnancy or its management (excluding accidental or incidental causes). In 2017 global Maternal Mortality Ratio (MMR) reported by United Nations (UN) is 211 deaths per 100,000 live births. MMR in Pakistan, with inter-provincial variability, is 186 deaths per 100,000 live births according to the latest Pakistan Maternal Mortality Survey (PMMS) report published in August, 2020 by United Nations Population Fund (UNFPA), a subsidiary organ of United Nations General Assembly.

CS requires general anesthesia, SA or epidural anesthesia; however, SA is preferred. SA is believed to be safe, though severe complications like profound hypotension compounded by aorto-caval compression might happen . World Health Organization (WHO) defines ideal CS rate below 10 to 15 %. According to 1990-91 and 2017-18 Pakistan Demographic and Health Survey data, rate of C-section has been raised from 3.2 % to 19.6 - 22.3 % . Higher rate of anesthesia and surgery in a developing country like Pakistan has a direct bearing on MMR, patient's morbidity, cost of medical services and siphoning scarce resources.

The first case of cardiac arrest occurring after SA was reported in 1940 and since then, the ability of SA to cause cardio-pulmonary arrest was considered. Hypotension and bradycardia are the most common side effects of SA. SA induced hypotension, which is a substantial clinical challenge, is caused by pharmacological sympathectomy. The incidence is reported around 80 %. Hypotension occurs despite fluid preload, left lateral uterine displacement and left lateral table tilt.

Duration and severity of hypotension is responsible for maternal ill effects like nausea/vomiting initially and later culminating to dyspnoea, apnea and circulatory arrest if poorly managed. Additionally there will be poor apgar score or even fetal demise depending upon the severity. Energetic use of strong vasopressors has been recommended. Phenylephrine HCL is considered to be the vasopressor of choice in parturients due to its propensity to cause less fetal acidosis. Phenylephrine HCL being an α-1adrenergic agonist counters the decrease in Systemic Vascular Resistance (SVR) induced by SA and can be administered by subcutaneous, intravenous and IM routes. Its onset and duration of action are 1-3 minutes and 5- 20 minutes respectively, when given intravenously (IV); and 10-20 minutes and an hour respectively when given IM. Clinically, 50-100 microgram boluses of Phenylephrine HCL is used intravenously to address hypotension. The investigators, in the current study exploited its lesser reported IM route.

Rationale: IM Phenylephrine HCL shortly before administering SA can prove a better option to prevent hypotension even for longer duration due to its slower absorption and can provide longer hemodynamic stability, lesser drop in fetal pH and apgar score.

Objectives: The primary objective of the study was to determine appropriate dose of IM Phenylephrine HCL in preventing hypotension due to SA administered for CS in ASA 1 and 2 parturients. Secondary objectives were to determine the need for total rescue doses of Phenylephrine HCL, measure drop in SBP in the two trial groups; and observe any side effects associated with IM injection of Phenylephrine HCL.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: July 31, 2020
• Est. primary completion date: July 31, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 45 Years

Eligibility

Inclusion Criteria:

• All pregnant ladies of American Society of Anesthesiologists (ASA) physical status 1 or 2 with

• Singleton Pregnancy,

• Full term pregnancy, and

• Admitted for elective CS

Exclusion Criteria:

All those participants having;

• Blood pressure =140/90 mm of Hg,

• ASA 3 or above status,

• Contraindication to spinal anesthesia

• Fetal anomalies/

• Abnormal placentae

• Refusal to consent

Related Conditions & MeSH terms

• Anesthesia
• Hypotension

Intervention

Drug:
• Phenylephrine Hydrochloride 4 mg
Intramuscular Phenylephrine HCL 04 mg were administered as prophylactic stat dose in Vastus lateralis muscle of thigh 05 minutes before giving spinal anesthesia.
• Phenylephrine Hydrochloride 8 mg
Intramuscular Phenylephrine HCL 08 mg were administered as prophylactic stat dose in Vastus lateralis muscle of thigh 05 minutes before giving spinal anesthesia.

Locations

Country	Name	City	State
Pakistan	Rehman Medical Institute	Peshawar	Khyber Pakhtunkhwa

Sponsors (1)

Lead Sponsor	Collaborator
Rehman Medical Institute - RMI

Country where clinical trial is conducted

Pakistan, 

References & Publications (15)

Amjad A, Imran A, Shahram N, Zakar R, Usman A, Zakar MZ, Fischer F. Trends of caesarean section deliveries in Pakistan: secondary data analysis from Demographic and Health Surveys, 1990-2018. BMC Pregnancy Childbirth. 2020 Dec 2;20(1):753. doi: 10.1186/s1 — View Citation

EVALUATION OF PREEMPTIVE INTRAMUSCULAR EPHEDRINE VS PHENYLEPHRINE IN PREVENTION OF HYPOTENSION INDUCED BY SPINAL ANESTHESIA IN LOWER SEGMENT CAESAREAN SECTION. [cited 2021 Dec 18]; Available from: www.ijmedicines.com

Ferré F, Martin C, Bosch L, Kurrek M, Lairez O, Minville V. Control of Spinal Anesthesia-Induced Hypotension in Adults. Local Reg Anesth. 2020 Jun 3;13:39-46. doi: 10.2147/LRA.S240753. eCollection 2020. Review. — View Citation

GBD 2015 Maternal Mortality Collaborators. Global, regional, and national levels of maternal mortality, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016 Oct 8;388(10053):1775-1812. doi: 10.1016/S0140-6736(16)31470 — View Citation

Hasanin AM, Amin SM, Agiza NA, Elsayed MK, Refaat S, Hussein HA, Rouk TI, Alrahmany M, Elsayad ME, Elshafaei KA, Refaie A. Norepinephrine Infusion for Preventing Postspinal Anesthesia Hypotension during Cesarean Delivery: A Randomized Dose-finding Trial. — View Citation

Kinsella SM, Carvalho B, Dyer RA, Fernando R, McDonnell N, Mercier FJ, Palanisamy A, Sia ATH, Van de Velde M, Vercueil A; Consensus Statement Collaborators. International consensus statement on the management of hypotension with vasopressors during caesar — View Citation

Michelsen TM, Tronstad C, Rosseland LA. Blood pressure and cardiac output during caesarean delivery under spinal anaesthesia: a prospective cohort study. BMJ Open. 2021 Jun 14;11(6):e046102. doi: 10.1136/bmjopen-2020-046102. — View Citation

Ngan Kee WD, Lee SW, Ng FF, Tan PE, Khaw KS. Randomized double-blinded comparison of norepinephrine and phenylephrine for maintenance of blood pressure during spinal anesthesia for cesarean delivery. Anesthesiology. 2015 Apr;122(4):736-45. doi: 10.1097/AL — View Citation

Oh AY, Hwang JW, Song IA, Kim MH, Ryu JH, Park HP, Jeon YT, Do SH. Influence of the timing of administration of crystalloid on maternal hypotension during spinal anesthesia for cesarean delivery: preload versus coload. BMC Anesthesiol. 2014 May 16;14:36. — View Citation

Richards E, Lopez MJ, Maani C V. Phenylephrine. xPharm Compr Pharmacol Ref [Internet]. 2021 Jul 13 [cited 2022 Jan 17];1-5. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534801/

Rijs K, Mercier FJ, Lucas DN, Rossaint R, Klimek M, Heesen M. Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section: Network meta-analysis, trial sequential analysis and meta-regression. Eur J Anaesthesiol. 202 — View Citation

Shitemaw T, Jemal B, Mamo T, Akalu L. Incidence and associated factors for hypotension after spinal anesthesia during cesarean section at Gandhi Memorial Hospital Addis Ababa, Ethiopia. PLoS One. 2020 Aug 13;15(8):e0236755. doi: 10.1371/journal.pone.0236755. eCollection 2020. — View Citation

Wang X, Shen X, Liu S, Yang J, Xu S. The Efficacy and Safety of Norepinephrine and Its Feasibility as a Replacement for Phenylephrine to Manage Maternal Hypotension during Elective Cesarean Delivery under Spinal Anesthesia. Biomed Res Int. 2018 Dec 31;201 — View Citation

Xu C, Liu S, Huang Y, Guo X, Xiao H, Qi D. Phenylephrine vs ephedrine in cesarean delivery under spinal anesthesia: A systematic literature review and meta-analysis. Int J Surg. 2018 Dec;60:48-59. doi: 10.1016/j.ijsu.2018.10.039. Epub 2018 Oct 31. — View Citation

Xu C, Liu S, Qian D, Liu A, Liu C, Chen Y, Qi D. Preventive intramuscular phenylephrine in elective cesarean section under spinal anesthesia: A randomized controlled trial. Int J Surg. 2019 Feb;62:5-11. doi: 10.1016/j.ijsu.2018.12.014. Epub 2019 Jan 11. — View Citation

* Note: There are 15 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Incidence of hypotension in both groups	The primary outcome is to find incidence of hypotension in each group P4 and P8 i.e. number of participants who develop hypotension in the relevant group multiplied by 100.; Incidence= number of participants who develop hypotension/ total participants in the group *100.; Hypotension is defined as a decrease of more than 20 % from baseline systolic blood pressure measured through non-invasive method.	One and half hour post spinal anesthesia
Secondary	To find the rescue dose/ doses of intravenous Phenylephrine HCL.	To find the rescue dose/ doses of intravenous Phenylephrine in the two groups P4 and P8.	One and half hour post spinal anesthesia
Secondary	Onset of hypotension	Determine the onset of hypotension in the two groups P4 and P8 (keeping starting time 0 minute at the administration of intrathecal hyperbaric Bupivacaine).	Half hour/ 30 minutes post spinal anesthesia
Secondary	Adverse events associated with any groups	Record any adverse event associated with any groups e.g. bradycardia, hypotension, Nausea, Vomiting, Hypertension, Cardiac arrest.	One and half hour post spinal anesthesia
Secondary	Neonatal APGAR Score	Neonatal APGAR (Appearance, Pulse, Grimace response, Activity, and Respiration)Score from 0 - 10 will be measured at 01 and 05 minutes for each neonate delivered. The higher score is considered good i.e. 10 while lower score is considered bad/ worse e.g. 0 -3.; The Apgar score measures five things to check a baby's health. Each is scored on a scale of 0 to 2, with 2 being the best score: Appearance (skin color) Pulse (heart rate) Grimace response (reflexes) Activity (muscle tone) Respiration (breathing rate and effort)	5 minutes post delivery