Change_in_Anesthesia_practices_-_Covid_times.pptx

Segmental spinal is a boon for high risk patients for GA, for laproscopic surgeries, and maintains hemodynamic stability.

1. Change in Anesthesia practices – Covid times { Segmental Spinal } DR. NEETA TANEJA HOD, DEPT. ANESTHESIA SBAMI

2. Types of Cases done Lap cholecystectomy using isobaric levo-bupivacaine 0.5%(7.5mg) mixed with 20mics fentanyl at T9-10 level Total laproscopic hysterectomy mix of hyperbaric bupiv(5mg)&isobaric bupiv(10mg) with 20mics fentanyl or in some cases combined with epidural Total lap colectomy under CSE at T9-10 level Modified radical mastectomy using 7.5mg isobaric levo-bupiv with 20mics fentanyl at T5 level

3. Thoracic spinal

4. Definition Segmental spinal is interchangeably used with Thoracic spinal anesthesia In real sense, “Blocking of the required dermatomes essential for the proposed surgical procedure with very low effective local anaesthetic drug” Necessitates dural puncture at high lumbar or mid to lower thoracic levels Lower the dose, more likely, true segmental block

5. Perspective Was being used only in high risk morbid patients for selective surgeries. Patients chosen for this technique need to be evaluated carefully and the technique is to be reserved for experienced clinicians it will establish itself as a routine procedure in day care anaesthesia.

6. Types of cases Practically all the abdominal surgeries : upper/lower, major /minor, daycare/or not, laparoscopic/open ) Superficial thoracic surgeries, Breast surgeries are possible with *Segmental spinal alone or *CSE (combined spinal epidural). If thats not all then *CSSA (continuous segmental spinal anaesthesia ) is also available.

7. History In 1909 ,Thomas Jonessco proposed the use of general spinal block for the surgeries of head , neck and thorax , puncturing the SAS between 1st and 2nd thoracic vertebra and succeeded to produce profound analgesia for the head , neck and upper limbs. He also punctured the SAS at mid thoracic and lower thoracic levels for thoracic and abdominal surgeries.

8. 1954 Segmental spinal anesthesia of the lower thoracic was used. The information that there is substantially more space in the dorsal subarachnoid space at thoracic level, might lead to potential application in regional anesthesia. The thoracic spinal puncture at T10 showed a rapid onset of action, regardless of baricity, decrease in the incidence of hypotension with faster recovery of the blockade, with low incidence of paresthesia and no spinal cord injuries in 636 patients If it were possible to limit anesthesia to the operative field and to use anesthetic agents in more diluted solutions and in smaller doses, certain undesirable effects of spinal anesthesia could also be avoided. This is the fundamental reason for using hemi anesthesia (posterior or unilateral) or segmental spinal anesthesia.

9. 2006 A new era of studies on segmental spinal anaesthesia, J Van Zundert punctured SAS at T10 for laparoscopic cholecystectomy, to anaesthetise a patient with severe obstructive lung disease. Since then there have been many studies about segmental spinals exploring its utility in many different surgical procedures like awake thoracoscopic / thoracic surgeries , laparoscopic cholecystectomy , breast surgeries etc.

10. Intrathecal block can be performed in three distinct zones 1st) a low zone, limited above by the 1st nerve segments of the lumbar region, for operations on the lower limbs and perineum; 2nd) a middle zone, limited above the 10th thoracic segment (belly button), for operations on the lower abdomen and pelvis and 3 rd) a high zone, limited above by the 4th thoracic segment (nipple area), for operations on the abdomen upper and lower thoracic.

11. Depending on the type of surgery, patients haemodynamic status and associated co-morbid conditions the dose of local anaesthetic agent and the site of injection along the neuraxis can be varied. For all abdominal surgeries with a adequate dose ,thoracic spinal above T10 is hardly required. Space between T10 and L1 is usually sufficient for all abdominal procedures. On an average a dose of 7.5 to 10 mg (1.5 to 2ml) of bupivaicaine/levobupivacaine with some additive ( fentanyl/clonidine) works well for 90 to 120 mins. This dose is exactly half the amount required when conventional spinal at lumber level to achieve a level of T3-T4 is used.

12. segmental spinal anaesthesia means “ Blocking of the required dermatomes essential for the proposed surgical procedure with very low effective local anaesthetic drug dose.” This often necessitates dural puncture at high lumber or thoracic levels apart from the conventional spinal below L1 . Lower the dose of local anaesthetic drug used more likely it to produce a true segmental block.

13. There are three main issues related to spinal at unconventional levels 1) risk of neuronal injury 2) respiratory embarrassment due to extensive thoracic nerve blockade and 3) cephalad spread of local anaesthetic drugs causing high or total block.

14. Advantages of segmental spinal over routine spinal or GA at times ? a) surgeries which were thought to be out of domain of spinal anaesthesia are possible with segmental spinal , like upper abdominal surgeries, superficial thoracic and breast surgeries, thoracoscopic procedures like bullectomy, thymectomy, lung volume reduction and wedge resection. b) higher levels of blocks can be achieved with just half the dose which would have required with spinal given at lumber levels. That means fewer haemodynamic fluctuations , early recovery, and voiding. c) special advantages over GA in patients with pre existing respiratory co morbidities. It can avoid postop pulmonary complications and patients going on ventilatory support. d) lower incidence of postop nausea and vomiting

15. which drugs can be used for segmental spinal ? Can hyperbaric drugs be used both isobaric and hyperbaric drugs can be used for segmental spinal and even a combination of both also can be used for some abdominopelvic surgeries. In general isobaric drugs are preferred for laparoscopic and thoracic surgeries and hyperbaric can be a choice in open surgeries specially in male muscular patients where relaxation can be a issue. Amongst the available drugs - Chlorprocaine 1%, Levobupivacaine 0.5%, Ropivacaine 0.5 & 0.75 % , Bupivacaine 0.5 % heavy all can be used as per need.

16. On an average one ml of isobaric drug spreads two to three segments above and below the site of injection. That means 2 to 2.5 ml of drug is sufficient to block segments from T2 to L5/S1 if spinal given at T10 In general for all lap abdominal surgeries of 60 to 90 mins duration , a dose of 2ml of isobaric levobupivacaine with fentanyl 25 mcg for Female patients and 2.5 ml levobupivacaine + 25 mcg fentanyl for male patients given at T10/12 level.

17. a combination of hyperbaric and isobaric drugs can be used. 0.5 ml of hyperbaric bupivacaine followed by 2ml of isobaric levobupivacaine from different syringe , in sitting position spinal at T 10/12 level. This can work for procedures like TLH or other abdominopelvic surgeries for upto 2 hrs or more depending on additive used. For prolonged surgeries and in patients with multiple co-morbidities where we want to use very minimal dose in spinal (just 1 to 1.5 ml ) , epidural can be placed at same level (CSE kit ) or one space above . Epidural can be helpful not only during surgery and postop analgesia but also by EVE (epidural volume extension technique ) low dose of spinal can be spread to more segments.

18. For thoracic and breast surgeries – spinal at midthoracic levels (T5/6/7) with 1 to 1.2 ml of isobaric levobupivacaine ( max 1.5 ml with additive ) with 25 mcg fentanyl can work for 60 minutes . For longer duration surgeries better to combine with epidural rather than increasing the intrathecal dose, to avoid haemodynamic and respiratory complications.

19. FACTORS RESPONSIBLE FOR SUCCESS WITH LOW DOSE AT THORACIC LEVELS The amount of CSF at thoracic levels is diminished compared to lumber and cervical levels. Thoracic nerve roots are very slight (thinner) compared to segments above and below. Thus there is less anaesthetic dilution per segmental unit of distance from the site of injection and roots are easily blocked due to small size. Onset time with isobaric solution in the lumber segments is longer than with the hyperbaric solution. When the injection is given in the thoracic segments the difference is not significant with solutions.

20. Accidental perforation of the dura mater during thoracic epidural block An anatomical explanation for the lack of damage was proposed by Imbelloni and Gouveia]. In MRI the following measures were found bet pot dura and spinal cord 5.19 mm in T 2 , 7.75 mm in T 5  and 5.88 mm in T 10 , or let us say, suficient distance to permit the careful advancement of a needle (accidentally of intenionally) without reaching the medula and administer anesthetic for a segmental spinal anesthesia .

21. Fact that anaesthetic technique is not usual does not mean that it is wrong. A concept has developed that regional anaesthetic should need no supplements and that if it does , it should be considered a failed block. This reasoning needs rethinking. Patient safety takes precedence over the unnecessary risks to be taken for the success of the procedure. This technique is reserved for experienced clinicians working in defined and approved evaluation programmes.

22. Low dose segmental spinal is associated with remarkable cardio-vascular stability. Patients with high BMI, cardiac and respiratory disease may be considered for day care surgery. Advantages demonstrated are – minimal haemodynamic fluctuations - minimal motor block - faster sensory recovery - early ambulation and voiding

23. Segmental Spinal Anesthesia: A Systematic Review Luiz Eduardo Imbelloni* , Jaime Weslei Sakamoto, Eduardo Piccinini Viana, Andre Augusto de Araujo, Davi Pöttker, Marcelo de Araujo Pistarino Department of Anesthesia, Hospital Clínicas Municipal São Bernardo do Campo, São Bernardo do Campo, SP, Brazil