Dose Down for the Extra Pounds Continuous Spinal Anesthesia for the Cesarean Section of a Super Obese Obstetric Patient

Authors: Patricia Amolenda, M.D

Citation: PatriciaAmolenda,NatesanManimekalai,HarrisBaig,”DoseDownfortheExtraPounds:Continuous SpinalAnesthesiafortheCesareanSectionofaSuperObeseObstetricPatient(BMI-98)”,GlobalScientificResearch JournalofAnesthesiology,1(1),2018,pp.1-4

Copyright: Copyright © 2018 Patricia Amolenda, Natesan Manimekalai, Harris Baig, This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.



Morbidly obese obstetric patients pose clinical challenges to anesthesiologists. We present a case of a super obese (body mass index (BMI) >50 kg/m2 )obstetric patient with a BMI of 98 who underwent cesarean section under continuous spinal anesthesia.


A37-year-old African American female, gravida5, para3, at 33 weeks gestation, presented inactive labor with signs of chorioamnionitis. She was 63 inches tall (5foot3inches) and weighed 553lbs (251 kg,BMI:98). Sheunder went cesarean section with bilateral tuballi gation under continuous spinal an esthesia. The patient was initially given 2.5 mg is obaric bupivacaine and 20 mcg fentanyl, which gave a T4 sensory block. In the 75-minute surgery, patient required a total of 5mg of bupivacaine. She remained stable intraoperatively andpostoperativelyandwasdischargedwithoutcomplications.


Continuousspinalanesthesiaisareliableandeffectiveoptionforthecesareansectionofmorbidly obesepatients.Inthesepatients,itisimportanttocarefullytitratethelocalanestheticdosetopreventunwanted complications.


continuous spinal anesthesia, morbid obesity, difficult neuraxial, cesarean section



Obesity is an ever-growing health problem, which has an increasing incidence in women of the reproductive age.1 The World Health Organization classified obesity into three (Table 1), wherein class III was further categorized as either morbid obesity (BMI > 40kg/m2 ) or super obesity (BMI > 50 kg/m2 ).2The anatomic and physiologicchangesassociatedwithincreasedbodymassindex(BMI)haveclinicalimplicationsthatposeclinical challenges both to the obstetrician and anesthesiologist (Table 2).3 These complications have been shown to rise with increasing BMI.4Therefore, the anesthetic management of these patients require careful planning, communication,specialequipment,andexpertisewithneuraxialplacementandairwaymanagement.Thiscase report focuses on the pros and cons of different anesthetic techniques for a super obese obstetric patient for elective cesarean section and the benefit of continuous spinalanesthesia.

Table1. Obesity scale using body mass index (BMI) 


Table2. Challenges associated withsuper obese patients undergoing cesarean section


Case Presentation:

A 37-year-old African American female gravida 5 para 3, presented at 33 weeks gestation, in active labor,with fever and chills with the provisional diagnosis of chorioamnionitis. The obstetrician decided to proceed with a cesarean section and bilateral tubal ligation.The patient’s past medical history included hypertension, obstructivesleepapnea,chronicbronchitisandgestationaldiabetes.Shereportedverylimitedmobilityathome due to shortness of breath with activity. Her surgical history revealed two previous cesarean sections were doneunderspinalanesthesiawithoutanycomplications.Shealsohadanopencholecystectomyundergeneral anesthesia with awake fiberoptic intubation and unremarkable intraoperative and postoperative course. On her physical examination, she was 63 inches tall (5 foot 3 inches) and weighed 553 lbs (251 kg, BMI: 98). Her airway assessment was Mallampati classification 3. She had short, thick neck, with good range of motion of neckandjaw.Cardiovascularandpulmonaryphysicalexaminationswereunremarkable.Significantlaboratory results included a white blood cell count of 15,600 cells permicroliter.

Ouranestheticplanforthisrepeatcesareansectionwithbilateraltuballigationwastoplaceaspinal(intrathecal) catheter and titrate the local anesthetic as required. The backup plan wasan awake fiberoptic intubation and proceed under general anesthesia. Both anesthetic options, along with risks and benefits of each were discussedwiththepatient. Pre-operatively, thepatientreceived50mgofranitidineintravenouslyand30mlof sodium citrate orally. The patient was brought to the operating room and standard monitors were placed. The patientwasplacedinasittingposition;sterilepreparationofthelowerbackwithchlorhexidinewasdone.After identification of L3-L4 interspace, a 5 inch 18 gauge Touhy epidural needle was inserted via midline approach. Dura was punctured and clear cerebrospinal fluid (CSF) was visualized from the needle. A 20-gauge catheter was then advanced into the subarachnoid space. Before the catheter was secured, the patient was placed in a left lateral position and the intrathecal placement of the catheter was confirmed with aspiration of clear CSF. Patient was then placed in a supine position. 2.5 mg (1 ml) of isobaric (a formulation with a specific gravity or density equal to cerebrospinal fluid) bupivacaine and 20 mcg of fentanyl was given through the catheter.After 3 minutes, sensory level was checked by skin prick testing and the patient had a T4 block. Antibiotics which included 2 grams of cefazolin, 2 grams of ampicillin, and 500 mg of azithromycin were administered.

Thesurgerystartedviaamidlineverticalsupra-umbilicalincisionandthebabywasdeliveredviaatransverse lower uterine incision. The Apgar scores were 6 and 8 at 1 and 5 minutes, respectively. The patient required anotherbolusdoseof1.25mg(0.5ml)ofisobaricbupivacaine45minutesafterthefirstbolus,andanother 1.25 mg 30 minutes after the second bolus. The additional bolus dose were given because patient complained ofpain.Thepatient’sbloodpressureremainedstablethroughoutsurgeryanddidnotrequireanyvasopressor. A total of 2,000 ml of lactated Ringer solution was given and total urine output was 200 ml. The surgery was completeduneventfullyafter75minutes,withanestimatedbloodlossof1,000ml.Attheendofthesurgery,the intrathecal catheter was removed and the patient was brought in stable condition to the post-anesthesia care unit (PACU). Thepatientdidwellpostpartumandwasdischargedonthe3rdpost-operativeday.


This case report details the successful management of a super obese patient who had an elective cesarean section under continuous spinal anesthesia (CSA). This case demonstrates that continuous spinal anesthesia can be a reliable and effective option for the cesarean section of morbidly obese patients. Interestingly, this patient required a very low dose of bupivacaine to achieve adequate sensory block. This case emphasizes the importance of adjusting the dose of local anesthetics in these morbidly obese patients.

Regional anesthesia is favored over general anesthesia in the anesthetic management of morbidly obese obstetric patients undergoing elective cesarean delivery because there is a greater risk of difficult or failed intubation and aspiration with general anesthesia.5 Other options for regional anesthesia for these parturients include single-shot spinal, epidural, combined spinal-epidural, and continuous spinal anesthesia. Because this surgery was deemed to be prolonged and difficult, single-shot spinal was not considered. Additionally, obese patientshavedecreasedCSFvolumethatresultsfromincreasedabdominalpressure,whichmayproducemore extensive neuraxial blockade resulting in high or total spinal anesthesia.6Epidural anesthesia has the risk of inadequate sensory block, with one study revealing that the rate of epidural failure is more in morbidly obese parturients.7 Continuous spinal technique has the advantage of providing effective and immediate analgesia as wellasthebenefitoftitratingthelocalanesthetictomaintainanadequatelevelofsensoryblock.8Thepresence ofCSFconfirmsintrathecalplacementandincreasesthechanceofasuccessfulblock.Carefulincrementaldosing through intrathecal catheter results in less abrupt and dramatic hemodynamic changes. Isobaric solutions are preferredincontinuousspinalanesthesiabecauseoftheirpredictability

Currently, no randomized clinical trials have been done to compare the different medications for continuous spinal anesthesia inces are an section, but case report shave helped us with dosing. 8 Continuous spinal anesthesia has been reported to be successfully utilized inpatients with previous spinal surgery, significant cardiac disease and those known to have difficult epidural placement. The failure rate of CSA with 20 gauge catheters is very low as placement of the Tuohy needle in the sub arachnoid space is easily ascertained by the escape of CSF. 9 The risks associated with CSA include post-dural puncture headache, and cauda equina syndrome and some problems with the catheters such as kinking and getting dislodged. 

Complications of continuous spinal technique includes cauda equina syndrome which has been previously reported with the use of micro catheters and large doses of hyperbaric (a formulation with density heavier than cerebrospinal fluid) lidocaine local anesthetic, which resulted in mal distribution of high concentration of local anesthetic around the cauda equina.10The mal distribution of local anesthetic associated with the use of the small intrathecal catheters led to drug overdose, which resulted in neurotoxicity and cauda equine syndrome. These micro catheters had been withdrawn from clinical practice in the United States.We gave 1 ml of 0.25% isobaric bupivacaine at a time with a total of 2ml and also used a 20 gaugeregul are piduralcatheter.

Post-dural puncture headache (PDPH) is another complication of CSA. This complication is one of the reason, this technique has been under-utilized in younger parturients. In morbidly obese parturients however, the incidence of post-dural puncture headache is found to be lower.11Post-dural puncture headache incidence after unintentional dural puncture with an epidural needle has shown to be significantly decreased after an intrathecal catheter is placed and reduced to a greater extent when removed 24 hours post-delivery.12Our patient did not develop headache or any other complication. 


In summary, continuous spinal anesthesia is one of the few techniques that can be used in cesarean delivery of super morbidly obese obstetric patients. The advantages include reliable anesthesia, immediate onset and titratability. This case demonstrates the necessity of further studies to determine the proper dosing of local anesthetics specific for super obesepatients.


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