Total Spinal Anesthesia Following Subarachnoid Injection of Local Anesthetic for Cesarean Section Two Case Reports

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2. Total Spinal AnesthesiaFollowing Subarachnoid Injection of Local Anesthetic for Cesarean Section(Two Case Reports) Dmitry Portnoy, MD Anesthesiology Department

3. Case # 1. Preoperative Assessment 21 y/o, G1, at 41 weeks induced for postdates, suspected chorioamnionitis. No previous medical or surgical history. System review was unrevealing, NKDA PE unremarkable, Wt-76 kg, Ht-5�3�� VS: BP-99/54, HR-82, RR-20, low FHR baseline AW: MP-I, TMD - 6 cm, neck - FROM, mouth opening - 4.5 cm.

4. Timeline 1740 Active labor, Cx - 7 cm. CSE � immediate pain relief. 2025 LEA activated after negative standard test dose. 0145 Called for c/s(failure to descend); Pump off; Pt reported some right-sided pain. LEC pulled back 1 cm. 0155 LEA activated with total of 15 cc of 3% chloroprocaine. Sensory block remains considerably inadequate on right side. 0210 To OR; LEC removed intact; SAH done at L2-L3, sitting with 1.2 cc(9,0 mg) of 0.75% Bup + 25 mcg Fentanyl + Epi 0214 Total spinal developed. EZ ventilation with cricoid pressure. Uneventful tracheal intubation following 250 mg of STP. 0234 Baby delivered without incident with Apgar 8 and 9. 0310 Extubated awake, in full strength, with airway reflexes intact. 0320 To PACU, VSS, sensory block at T3. POD # 2 Discharged home in good condition.

6. Spinal Following Epidural Controversy J.H.Waters compared epidural/spinal and spinal alone ( Anesthesia and Analgesia,1994;78:1029-35). Similar sensory level in both groups 20% less dose and volume in epidural/spinal group high spinal in 1 of 17 in epidural/spinal group �spinal anesthesia can be performed safely after inadequate epidural anesthetic�

7. Spinal Following Epidural Controversy T.Adams reported 61 cases of failed epidurals converted to spinal anesthesia(Anesth Analg1995;81:654-6) Standard dose of 0.75% hyperbaric bupivacaine used No high block or other complications noted Kestin IG. Spinal anaesthesia in obstetrics. ( British Journal of Anaesthesia 1991;66:596-607) � spinal technique may be used if an extradural block is inadequate after giving the maximum dose of local anesthetic�

8. Spinal Following Epidural Recommendations Caution is required in the presence of any fluid in extradural space( volume and time dependant). Reduction of spinal anesthetic dose/volume by 20%. Special considerations for patients with suspected difficult airway All patients who undergo RA warrant precautions for possible need of general anesthesia Catheter based intermittent technique Elective secure of the airway

9. Case # 2. Preoperative Assessment

11. Factors Influencing Distribution of Local Anesthetic Solutions (based on Dr. N. Green�s review) Patient characteristics Technique of injection Characteristics of spinal fluids Characteristics of anesthetic solution Vasoconstrictors Diffusion characteristics

12. Patient characteristics Age Height Gender Intraabdominal pressure Anatomical configuration of spinal column Position

13. Technique of injection Site of injection Direction of needle Direction of bevel Rate of injection Barbotage

14. Characteristics of anesthetic solution Density ( vs specific gravity vs baricity) Amount of anesthetic Concentration of anesthetic Volume of injected anesthetic Presence of vasoconstrictors

15. Characteristics of spinal fluids Composition Circulation Volume Pressure Density

16. Factors of great clinical significance Baricity of anesthetic solution. The dosage of anesthetic solution. The position of the patient (with hypo- or hyperbaric solutions)

17. Demonstrable factors of varying clinical significance Patient age Patient height Anatomical configuration of spinal column The direction of the needle during injection The volume and density of CSF The volume of anesthetic solution

18. Dosage of Spinal Anesthetic and Patients Variables in the Term Parturient Isobaric versus hyperbaric solutions. Standard versus variable dosage. No evidence that one way is better than another. No �golden standard� dose is known: dosages from 7.5 mg to 15.0 mg were successfully used.

19. Dosage of Spinal Anesthetic and Patients Variables in the Term Parturient(Dr. Ezzat I.Abouleish table)

20. Dosage of Spinal Anesthetic and Patients Variables in the Term Parturient Dr. R.Vadhera�s recommendations for spinal hyperbaric bupivacaine injections:

21. Dosage of Spinal Anesthetic and Patients Variables in the Term Parturient Mark C. Norris, M.D., Anesthesiology 72:478-482,1990

22. Dosage of Spinal Anesthetic and Patients Variables in the Term Parturient Mark Norris, M.D., Anesth Analg, 1988;67:555-8 Standard technique: 50 term parturients 12 mg of hyperbaric bupivacaine Lateral decubitus position

23. Dosage of Spinal Anesthetic and Patients Variables in the Term ParturientDr. M. Norris study conclusion Patients Variables: Age (20 � 42) Height (146 � 175 cm / 4�11�� � 6�0��) Weight (55 �136 kg) Body mass index (19 � 50 kg/m2) Did not correlate with the spread of sensory blockade �It is not necessary to vary the dose of injected hyperbaric bupivacaine�

24. Vertebral Column Length Variability and Spread of Hyperbaric Spinal Anesthetic B.Hartwell study � significant correlation exist M. Norris study � no clinically significant correlation

25. General Recommendations The incidence of high spinal block in obstetric anesthesia is probably higher. Careful monitoring of sensory level is advisable, particularly in patients with extreme variables. Be fully prepare to manage airway of any patient that undergo spinal anesthesia. Take special consideration for patients with potential difficult airway.