Journal Anesthesia

7/24/2019 Journal Anesthesia

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JournalAnesthesia for cesarean section

in a patient with

achondroplasiaPresented by:Fathin Amirah binti Aminnuddin

Reviewed by:Dr. Nunung,Sp.An


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Introduction:Cesarean section under general anesthesia is recommendedin achondroplastic, pregnant patients; however, the use of conductivetechniques has been recently reported, with acceptable results.

Objective:To describe the anesthesia management in an achondroplasticpatient scheduled for C-section under combined spinalepiduralanesthesia.

Methods and results:We present the case of a first pregnancy in a patientwith achondroplasia, height 110cm and 37 weeks of gestation. The

patient underwent cesarean section under ultrasound-guidedconductive anesthesia, using a titrated mixture of local anesthetic andopiate, with good results for the mother and child.

Conclusions:Conductive anesthesia is an option in C-section in patientswith achondroplasia. Although there are no clear recommendations toguide a safe access to the neuroaxis or to administer anesthetic agents atthis level, ultrasound and the titrated administration of neuraxial drugs(epidural, epiduralspinal and continuous spinal) for improved safetyand efficacy of the technique in this type of patients may be considered

Abstract


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Case Description


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First pregnancy in anachondroplastic29-year oldwith 37 weeks of gestation was scheduled for

Cesarean section. Personal history of acid-pepticdisease and ultrasound finding of fetus withachondroplasia was given; the results of thephysical examination were: height 110cm bloodpressure (BP): 120/70, heart rate (HR): 75 min,

weight 41 kg and BMI: 33,9: short limbs andthoracolumbar kyphoscoliosis. No predictors ofdifficult airway or cardiopulmonary/neurologicalfindings.

The patientrequested to be awakeduring the birthof the baby.


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Fig 1: Thepatient. Note hershort stature andlimbs

After discussing the risk and benefit of anesthesiaprocedures, a combinedspinalepidural techniqueis considered.

Prior to administering the anesthesia, the patientreceived 50mg of ranitidine and 10mg ofmetoclopramide IV under basic ASA monitoring,including preparation of a difficult airway kit.

With the patient in sitting position, followingultrasound measurement, the epidural space L2L3is identified at 3.5cm from the skin; using a tuohy #18needle and continuous loss of resistance with salinesolution, the epidural space was accessed free ofcomplications. A multi-orifice epidural #20 catheter

was introduced and fixed to the skin. The catheteraspiration test was negative and the decision is madenot to perform a test dose.


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After three WhitacreTM 25-needle taps the subarachnoid spacein L3L4 was identified.

5mg of hyperbaric bupivacaine with 64g of morphine and 16gof fentanyl were injected. The patient did not experience anynumbness during the procedure.

Sensory block was verified up to T4. BP at 5min was 80/40 and HR 72/min. 8mg of etilephrine were required to maintain the systolic BP >90mmHg and the mean BP > 50mmHg.

The patient experienced discomfort during peritoneal tractionand hence 60mg of epidural lidocaine without epinephrine wereadministered and a slow IV bolus of 48g of remifentanyl.

The newborn had an apgar score of 8 at one minute and 10 at5min

In total, 1000 cc of crystalloids were administered and theprocedure was completed free from complications.


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Discussion


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Dwarfism is defined as the failure to reach astature over 148cm and achondroplasia is the

most frequent cause.

This is a hereditary bone metabolism disorderwith a prevalence of 1/26,000 live births.

It is an autosomal dominant transmission andin 80% of the cases is a spontaneous geneticmutation.

Definition


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Achondroplasia is characterized byshort stature, macrocephalus with

prominent forehead, depressed nasalbridge, protuberant buttocks andabdomen, short limbs, particularlythe proximal segment, lumbarhyperlordosis and thoracic

kyphoscoliosis Symptomatic spinalstenosis usually does not manifestitself before the fourth or fifth decadeof life, when osteophytes, kyphosis,scoliosis and disc hernias cause

additional narrowing of the spinalcanal.


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Women are often affected and have low fertilityrates. Delivery is usually through Cesarean sectionbecause of the cephalopelvic disproportion.

The choice of anesthesia for C-section inachondroplastic patients has been controversial,but general anesthesia is usually preferred, thoughit is particularly challenging since the anatomicalterations further compound the typicalmorphological changes during pregnancy.


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The Risks


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General anesthesia presents specific risks such as: tendency to obstruct the airway; cervical instability, difficulties for direct laryngoscopy as a result of rigid temporomadibularjoints, macroglossia and pharyngeal stenosis.

The passage of the endotracheal tube may be difficult and there is aneed to choose a small tube, in accordance with the weight of thepatient rather than age.

Odontoid process dysplasia is a frequent finding and is accompaniedin some cases by atlanto-axial instability and bone marrowcompression that may deteriorate with orotracheal intubationmaneuvers.

Additionally, dystrophy and thoracic kyphoscoliosis predispose for thedevelopment of restrictive lung disease.

Heart abnormalities predispose to ischemic events.


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Subarachnoidal anesthesia may prove technically challengingand its distribution may be inappropriate due to lumbar

hyperlordosis, marked thoracic kyphoscoliosis, progressivenarrowing of the inter-peduncular space and generalizedstenosis of the spinal or epidural space. Some authors do notrecommend this approach to prevent blaming the anesthetictechnique for any neurological abnormality caused by the

spinal deformity.

There are no literature reports of neurologic injury inachondroplastic patients with conductive anesthesia; however,the risk is undeniable and any neurological disorders must beappropriately registered in the clinical record and post-blockevaluations should be performed for early detection.


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Whichever the technique, aorta-caval compression may be severeresulting in hypotension that requires uterine displacement, fluids co-load and rapid administration of vasopressants.

Short limbs and obesity may hinder non-invasive BP measurement andhence occasionally intra-arterial measurements are needed.

Due to existing reports of failed subarachnoidal anesthesia for the

management of Cesarean sections in patients with achondroplasia,excellent results were achieved with the use of a combined spinalepidural technique to enable epidural titration of the anesthetic agent ifneeded.


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Conclusion


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Conductive anesthesia is an option for the management ofachondroplastic patients undergoing Cesarean section; however,

in the light of inter-individual anatomic variations of the spine,ultrasound guided lumbar tap should be considered to facilitatethe approach and reduce the risk of neurological complications.

Likewise, neuraxial titration of local anesthetic agents with

techniques such as epidural, combined spinalepidural orcontinuous spinal is needed.

Finally, even when selecting regional techniques, do not everrule out the possibility of general anesthesia and always be

prepared for difficult airway management.

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Journal Anesthesia