Aneasthesia Pearls August 2017


Memoirs of an Anaesthetist

Memoirs of an Anaesthetist

Prof.Dr. M.Suresh MD, DA.  KAPVGMC, TRICHY

 As I sit back with a cup of coffee slowly inching towards the twilight years of my life I am reminiscing about the path I have traversed in life’s journey. Not very long ago when I started Anaesthesia practice rarely have I had the luxury of calling time my own. Now twenty-five years down, it makes me wonder if I have done the right thing by devoting so many hours of my life to the profession.Today it is just my wife and I at home. The children are all grown up and have flown the nest. Have I erred in life for not having spent more quality time with my children? Well in any case it is too late regret now.

I sent my boys to good schools. Gave them tennis lessons in reputed clubs, music classes, nice clothes and shoes, but I was never available to drop or pick them up from school.

I still remember the day when we were getting ready to go out for a dinner over the weekend and the look on the face of my son when I received a phone call at that moment. Disappointment was written all over his face. His words “Oops there goes our weekend” said it all. Such was my commitment to Anaesthesia that I was ready to sacrifice my family time for it. Was it to make a few rupees more or was it really commitment? Or was it the fear in my mind that I would lose my practice if I do not respond to an emergency call. Well it could be any of these. I leave it to you to decide which.

Today sitting alone at home I have realized that family should be given the due importance it deserves. Time is something that once lost can never be retrieved. So please spend quality time with your children and family. Teach them their lessons; help them with their homework and assignments. These moments will be cherished by both you and your offspring.

I have never attended a parent-teacher meet. Always managed to miss the annual day celebrations even when the children were getting a prize or be it performing at the cultural event. Here I am indebted to my better half who took care of all these things while I was busy saving patients (making money).

Well talking of money let me tell you this “As an Anaesthetist you can never be a millionaire but then you will also not be a pauper”. This I mean by practising Anaesthesia alone. Of course a number of our Anaesthetist colleagues have left behind Anaesthesia to become entrepreneurs and I feel their success in their excellent management of hospitals should be attributed to their anaesthesia background.

Now let me get to what I have felt being an Anaesthetist. Was giving twenty five years of my youth to the profession justifiable enough to warrant this sacrifice? Well I guess I still am passionate about my profession. The one look of relief and a word of thanks that the patients in labour give you after giving the first dose of epidural is enough to justify the hard work put in over many years. I am a Professor of Anaesthesia in a teaching institution. And it gives me great satisfaction to pass on the knowledge and skills garnered over the years on to the next generation.

Many a time the work of the anaesthetist goes unrecognised. The ways by which recognition can be gained is to establish your presence and impress upon the patients the importance of your role in surgery, intensive care, painless labour, etc. It is also important to make the Hospital and the surgeon understand your role in team work. Step out of the closed confines of the operation theatre and make yourselves visible to the patients and their families.

So how is it possible to balance your family and profession?  This is possible when we work for a Government institution or for a corporate hospital with fixed duty hours. In this scenario we will end up with a fixed income as well. In today’s world one cannot quantify what is enough money. It is not enough to have a house, a car and a nice trip with your family once in a while. One has to make enough to make a foreign trip at least once every couple of years. Children seem to have become more demanding these days. Peer pressure seems to play havoc on the young minds. Leave alone foreign trips, making a trip to the annual ISA conference is proving to be a costly affair. Traveling expenses and accommodation for three days easily notches up not less than fifty thousand rupees.

I feel the need of the hour is unity among the fraternity. Group practice is one solution to a fine balance between family and profession. Here we can have a good income and at the same time quality time with the family. What we need is a good team with good cooperation and skills. All must be like minded. Be willing to share the income equally. Take holidays and week off keeping in mind the need of others. Share the work load. Maintain quality and maintain proper records. Team should have a leader to allocate work and his word shall be final. All places of work should have minimum standards of monitoring. There should be scope for expanding our operations. New members should be recruited. The project should be managed professionally.

Now let me tell you what I should not have done. I am a government employee. I am also allowed to have a private practice. Like I   said earlier one never realises as to what is enough money. And so I ran around to wherever I was summoned. From one hospital to another and from there to another and so forth. Anaesthetising patients was never an issue. My prime concern was to reach my destination on time. I would like to confess here that I   may have not done justice to my profession on a number of occasions. This I have realised is what should not be done at any cost. After all our primary concern and responsibility should be to keep the safety of our patients uppermost in mind. So to avoid these kind of events I suggest that do not bite more than what you can chew.

At the start of a doctor’s career, he has all the time in the world. Later on in life he has all the money he needs, but no time. So when the time is ripe ask yourself “do I spend all the money I make”. Well if not so why go running around making more. Save for a comfortable retired life. Get adequate health insurance. Go around and see the world. Don’t spoil the kids by leaving too much for them to flaunt and throw away. Just as you made your livelihood they too will make theirs.

Now to summarise I would suggest that you limit your practice, spend quality time with friends and family, enjoy life to the fullest, be content in life and experience the joy of being an anaesthetist to the fullest.

After all” You live only once so live it in style”  

Paramedian Lumbar Epidural Technique - Why You Should Adopt It?

 Paramedian Lumbar Epidural Technique – Why You Should Adopt It?

Jeremy Collins, MD, FRCA, M.B.,Ch.B .Stanford University School of Medicine

The para median approach for lumbar epidural was first described by  John Bonica, whose is a wrestler turning in to Anaesthesiologit and pioneer in pain management in 1956. A survey conducted in UK (2006)[1] states that 96% of anaesthetist followed midline approach as against 4% para median approach.
Why mid line is popular?
– Most teach midline

– Requires less three dimensional spatial awareness

– Ligamentum flavum is widest in midline

– Faster ( Chestnuts Obstetric Anaesthesia)

– Less painful

But Kopacz et al[2] found that the learning curve in regional anaesthesia for paramedian approach need 1.76 ± 1.29 attempts as against 1.22 ± 0.31 attempts.



The paramedian approach is associated with fewer technical problems compared to the midline approach, and because it avoids the supraspinous and interspinous ligaments, the procedure is less painful and ideal in elderly patients with calcified ligaments. This approach penetrates the ligamentum flavum directly after passing through the paraspinal muscles.
The Tuohy needle is inserted through the skin at a point about 1.5 cm lateral to the mid point of the spinous process immediately below the level of the desired block. Needle insertion will be in a cephalad and medial direction, with the needle angled 10°–15° toward the midline and 10°–15° in the cephalad direction. If contact is made with the lamina, the needle should be adjusted in a cephalad direction so that you are walking up the bone . It is then withdrawn slightly, redirected cephalad and medially, and walked off the lamina until it pierces the ligamentum flavum and enters the epidural space.
From the above X ray you note the inter-laminar space is narrower in the midline and as you move laterally it widens that means clinically the midline approach depends upon the degree of flexion of the patient.

Paramedian Vs Midline  anatomy

– Less reliant on flextion

– Great anatomic tolerance

– Avoids supra spinous and inter spinous ligaments

– Can be done in patients who can’t be flexed

– Because it avoids the supraspinous and interspinous ligaments, the procedure is less painful and ideal in elderly patients with calcified ligaments

Advantages of Paramedian approach:
The cervical and high thoracic ligamentum flavum fails to fuse in the midline.

The MRI of spine shows the following anatomy:

  1. Lamina 5. Ligamentum Flavum 6. Epidural space 8. Spinal canal. White line midline approach and Red line paramedian approach.

From the above picture one can understand why the epidural localization is difficult in midline approach in upper thoracic since ligamentum flavum is thin in midline and chances of dural puncture is more as it straightly pierces the dura. But in lateral approach the tuohy needle glide over the dura and avoid dural puncture. (see the fig below)

Paramedian approach may be painful as the needle has to pass long distance in the soft tissue and it may hit periostium of lamina. But Holdcraft et al found that there is no difference between midline approach and paramedian approach in terms of pain (assessed by VAS) and tissue damage (assessed by MRI)

The Tuohy needle is inserted through the skin at a point about 1.5 cm lateral to the mid point of the spinous process immediately below the level of the desired block.

The midline approach is limited by bony channels and more degree of flextion.

But in paramedian approach the bony channel is wide and you have to pass the needle straight until it hits the lamina and tilt the needle cephaloid 10- 150

Advantages of needle entering oblique angle is less chance of PDPH in CSE as the needle raise a flap in the arachnoid membrane which acts as flap and prevent CSF leakage. Since the point of entry of spinal  needle in dura and arachnoid are not in straight line there is no tract for the CSF to leak.

Another advantage is reduction in wet tap, ease of threading the catheter and catheter can travel long without kinking. The cephaloid advancement is more and lateral or caudal deviation is less.

But the chance of intravascular catheter placement in obstetric patients are 5 times more common  in paramedian approach as compared to midline approach. The parasthesia also more common in paramedian approach.

  • Anatomical advantage
  • Less flexion required
  • A back up technique for difficult blocks
  • Potential for less wet tap
  • Easy threading of catheter
  • Catheter stays cephaloid and midline
  • Standardise for transition to thoracic epidural space


  1. Wantman, A., Hancox, N. and Howell, P. R. (2006), Techniques for identifying the epidural space: a survey of practice amongst anaesthetists in the UK. Anaesthesia, 61: 370–375.
  2. Kopacz, Dan J. M.D.; Neal, Joseph M. M.D.; Pollock, Julia E. M.D. The Regional Anesthesia “Learning Curve”: What Is the Minimum Number of Epidural and Spinal Blocks to Reach Consistency? Regional Anesthesia . 21(3):182-190, May/June 1996.
  3. Browns atlas of Regional Anaesthesia.
  4. Boon, Johannes M. M.Med.; Prinsloo, E. B.Sc.; Raath, Russell P. M.Med. A Paramedian Approach for Epidural Block: An Anatomic and Radiologic Description. Regional Anesthesia & Pain Medicine: May/June 2003 – Volume 28 – Issue 3 – p 221–227.
  5. J.M.Boon Lumbar puncture: Anatomical review of a clinical skill. Clinical Anatomy  Volume 17, issue 7 2004 Pages 544–553.
  6. A. Holdcroft, G. Samsoon, R.A. Fernando, C. Baudouin . Acute tissue damage following epidural cannulation: A comparison between the midline and paramedian approach in obstetric patients. Int J Obstet Anesth  January 1994 Volume 3, Issue 1, p35-8.
  7. Jeremy Collins, MD, FRCA, M.B.,Ch.B .Stanford University School of Medicine. SOAP. March 3, 2017, Sol Shnider 2017 San Francisco.
Courtesy:  SOAP – Paramedian Lumbar Epidural Technique Why You Should Adopt It – Jeremy Collins, MD

Perioperative Management of Patients With Coronary Stents

 Perioperative Management of Patients With Coronary Stents
Dr.J.Edward Johnson. M.D. (Anaes),D.C.H.                                                                                            Associate Professor, KGMCH.


Perioperative coronary stent thrombosis is a catastrophic complication that can occur in patients receiving both bare-metal and drug-eluting stents. Noncardiac surgery appears to increase the risk that recently-placed stents thrombose, especially when surgery is performed early after stenting, and particularly if dual antiplatelet therapy is discontinued.

Both the safe timing of noncardiac surgery and the need for continuing chronic antiplatelet therapy for coronary artery stents to mitigate a perioperative major adverse cardiac event (MACE) remains controversial.

Stent Implantation
 Bare-metal stents, introduced in 1986, were thought to be a solution to abrupt coronary vessel closure (arterial recoil and constrictive remodeling) associated with percutaneous coronary angioplasty.[1,2] However, restenosis due to neointimal hyperplasia is observed in 10–30% of patients with bare-metal stents.[3]  In 2003, drug-eluting stents were introduced as a solution to this problem. Nevertheless, stent thrombosis is still seen in 5–10% of patients with drug-eluting stents.[4]

Stent implantation causes injury to the endothelial surface, which initiates interactions between the stent surface, blood, and vessel wall. This leads to neointimal hyperplasia and increased thrombogenicity. Various coatings have been applied to stents to reduce neointimal hyperplasia and subsequent stenosis. [5,6] Drug-eluting stents are composed of three components: the platform (stent), a carrier (a polymer), and a drug to reduce the incidence of neointimal hyperplasia. In order to prevent stent thrombosis, patients with coronary stents also require dual antiplatelet therapy with clopidogrel and aspirin. The predominant drug-eluting stents in use today are the sirolimus and paclitaxel families of stents. Sirolimus is a naturally occurring immunosuppressive, cytostatic compound that arrests the cell cycle and reduces neointimal hyperplasia. Paclitaxel is an antiproliferative and cytotoxic agent. Drug elution off the sirolimus platform is thought to be complete in 6 weeks; for paclitaxel, 10% of the drug is released in the first 10 days and the remainder is slowly eluted over an indefinite period. [7,8]

Acute stent thrombosis occurs within the first 24 h after percutaneous coronary intervention: sub-acute stent thrombosis occurs between 24 h and 30 days; late stent thrombosis occurs between 31 days and 1 yr; and very late stent thrombosis occurs more than 1 yr mafter intervention. Early stent thrombosis is usually mechanical in origin (coronary artery dissection or under expansion of the stent).[2] In contrast, late stent thrombosis is related to stent malposition, abnormal re-endothelization,[3] or hypersensitivity. Incomplete intimal healing after percutaneous coronary intervention increases the period of time during which thrombosis can occur.[9]

Patients with a coronary stent present a significant risk regardless of the type of non-cardiac operation undertaken. In a study involving patients with either bare-metal stents or drug-eluting stents, 44.7% of the patients sustained a complication with 4.9% mortality.[10]

Perioperative management

The rates of coronary stent-related complications in patients undergoing non-cardiac surgery range from 0.6% to 45%, with a mortality rate of 2.6–4.9%.[11] The adverse events rate is 2.1 times more in patients with recently implanted stents (30 days) than in those in whom stents were inserted 90 days before operation. [10]

The risk of late stent thrombosis in relation to dual antiplatelet therapy withdrawal:
Highest risk of LST is represented by premature complete discontinuation of DAPT, whereas lowest risk is seen when patients are on DAPT. DAPT, dual antiplatelet therapy; LST, late stent thrombosis.

Perioperative risk factors for stent thrombosis:

Clinical risk factors

  • Advanced age
  • Acute coronary syndrome
  • Diabetes
  • Low ejection fraction
  • Prior brachytherapy
  • Renal failure

Angiographic risk factors

  • Long stents
  • Multiple lesions
  • Overlapping stents
  • Ostial or bifurcation lesions
  • Small vessels
  • Suboptimal stent results

Perioperative management issues for patients with a coronary stent:

  • Management of anticoagulation
  • Appropriate duration from percutaneous coronary intervention to
  • surgical procedure
  • Choice of anaesthetic technique
  • Perioperative monitoring
  • Immediate access to a cardiac catheterization laboratory

Perioperative Stent Thrombosis Prevention Strategies

2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery: Recommondations:  [12]

Coronary Revascularization Before Noncardiac Surgery

Class I

  1. Revascularization before noncardiac surgery is recommended in circumstances in which revascularization is indicated according to existing CPGs. (Level of Evidence: C)

Class III: No Benefit

  1. It is not recommended that routine coronary revascularization be performed before noncardiac surgery exclusively to reduce perioperative cardiac events.

PCI before noncardiac surgery should be limited to

1) Patients with left main disease whose comorbidities preclude bypass surgery without undue risk and 2) Patients with unstable coronary artery disease who would be appropriate candidates for emergency or urgent revascularization.

Patients with ST-elevation MI or non–ST-elevation acute coronary syndrome benefit from early invasive management. In such patients, in whom noncardiac surgery is time sensitive despite an increased risk in the perioperative period, a strategy of balloon angioplasty or bare-metal stent (BMS) implantation should be considered.


Choosing Appropriate PCI Intervention:

  • Urgent Surgery

Consider CABG combined with noncardiac surgery

  • Surgery 2-6 weeks with high bleeding risk

Consider balloon angioplasty with provisional BMS

  • Surgery in 1-12 months

Consider BMS and 4-6 weeks of ASA and P2Y12 inhibitor with continuation of ASA perioperatively

  • Surgery > 12 Months or low bleeding risk

PCI and DES with prolonged aspirin and P2Y12 platelet receptor-inhibitor


Timing of Elective Noncardiac Surgery in Patients With Previous PCI

Class I

  1. Elective noncardiac surgery should be delayed 14 days after balloon angioplasty (Level of Evidence: C) and 30 days after BMS implantation (Level of Evidence B).
  2. Elective noncardiac surgery should optimally be delayed 365 days after drug-eluting stent (DES) implantation. (Level of Evidence: B)

Class IIa

  1. In patients in whom noncardiac surgery is required, a consensus decision among treating clinicians as to the relative risks of surgery and discontinuation or continuation of antiplatelet therapy can be useful. (Level of Evidence: C)

Class IIb*

  1. Elective noncardiac surgery after DES implantation may be considered after 180 days if the risk of further delay is greater than the expected risks of ischemia and stent thrombosis. (Level of Evidence: B)

Class III: Harm

  1. Elective noncardiac surgery should not be performed within 30 days after BMS implantation or within 12 months after DES implantation in patients in whom dual antiplatelet therapy will need to be discontinued perioperatively. (Level of Evidence: B)
  2. Elective noncardiac surgery should not be performed within 14 days of balloon angioplasty in patients in whom aspirin will need to be discontinued perioperatively. (Level of Evidence: C)

Antiplatelet therapy in the perioperative period

Dual antiplatelet therapy is the cornerstone of stent thrombosis prevention [13]. The current recommendations that clopidogrel be administered for 3 months after placement of a Sirolimus-eluting stent (SES) and 6 months after placement of a Paclitaxel-eluting stent(PES) are based on the duration of time that a thienopyridine was required in the pivotal trials of these stents that led to their approval.

Antiplatelet treatment strategies to minimize perioperative stent thrombosis include[14]:

      • Continue dual antiplatelet therapy during and after surgery
      • Discontinue clopidogrel but “bridge” the patient to surgery using a short-acting antiplatelet agent with a glycoprotein IIb/IIIa inhibitor or an antithrombin, and restart clopidogrel as soon as possible after surgery
      • Discontinue clopidogrel before surgery and restart it as soon as possible after surgery


This option is especially in patients undergoing surgery early after stent implantation. Surgeons who are concerned about the risk of perioperative bleeding may need help weighing the risk of bleeding with the particular operation planned against the benefits of continuing dual antiplatelet therapy throughout the perioperative period. In some procedures, such as dental extractions, cataract surgery, or routine dermatologic surgery, bleeding almost always can be controlled with local measures, and discontinuation of antiplatelet therapy is not necessary. Even in procedures with higher bleeding risk, when surgeons are informed that stent thrombosis leads to death or a large MI in the majority of patients, they often can be persuaded that the risk of thrombosis outweighs the risk of bleeding.  This strategy would not be appropriate for patients in whom any excess bleeding could have catastrophic consequences, such as neurosurgery patients.


If surgery is needed early after stent placement and clopidogrel needs to be stopped, some clinicians “bridge” the patient to surgery using a short-acting antiplatelet agent or an anticoagulant. Because stent thrombosis is primarily a platelet-mediated phenomenon, platelet inhibitors might be a more logical choice if such a strategy is pursued. Furthermore, the cessation of heparin in a patient not on aspirin or other antiplatelet agents has been shown to cause platelet activation and a rebound phenomenon which may actually increase the likelihood of perioperative stent thrombosis compared to if no heparin bridging had been performed.


This strategy may be sufficient when the stent is believed to be fully endothelialized and the risk of stent thrombosis is very low. It also should be used whenever clopidogrel cannot be continued throughout the perioperative period, such as in patients undergoing neurosurgery, in whom bleeding would likely be catastrophic. Once the surgeon permits the re-initiation of clopidogrel, it might be wisest to administer a 600-mg loading, which not only reduces the time required to achieve maximal inhibition of platelet aggregation to 2 to 4 h, but also reduces the frequency of hyporesponsiveness to clopidogrel, particularly among patients with activated platelets as is uniformly the case among patients who have just undergone surgery.

Management algorithm for patients with Drug-Eluting Stents presenting for noncardiac surgery [15]

 Recently Gro Egholm et al [16] conducted a study to evaluate the surgical risk associated with DES-PCI compared with that in nonstented patients without ischemic heart disease (IHD)between 2005 and 2012, a total of 22,590 patients who underwent DES-PCI in western Denmark. They found that surgery within 30 days after implantation of DES increases the risk of MI, cardiac death, and all-cause mortality and surgery performed beyond this period but within 12 months after DES implantation demonstrated a 30-day mortality equivalent to that of patients without IHD. Further studies are needed to define the optimal approach to antithrombotic therapy in patients undergoing noncardiac surgery in the 12 months after DES implantation.



  1. Serruys PW, Kutryk MJ, Ong AT. Coronary-artery stents. N Engl J Med 2006; 354: 483–95
  2. Camenzind E, Steg PG, Wijns W. Stent thrombosis late after implantation of first-generation drug-eluting stents: a cause for concern. Circulation 2007; 115: 1440–55.
  3. Metzler H, Huber K, Kozek-Langenecker S. Anaesthesia in patients with drug-eluting stents. Curr Opin Anaesthesiol 2008; 21: 55–9
  4. Motovska Z, Knot J, Widimsky P. Stent thrombosis-risk assessment and prevention. Cardiovasc Ther 2010 (epub ahead of print)
  5. Acharya G, Park K. Mechanisms of controlled drug release from drug-eluting stents. Adv Drug Deliv Rev 2006; 58: 387–401
  6. Daemen J, Serruys PW. Drug-eluting stent update 2007: Part I. A survey of current and future generation drug-eluting stents: meaningful advances or more of the same? Circulation 2007; 116: 316–28
  7. Howard-Alpe GM, de Bono J, Hudsmith L, Orr WP, Foex P, Sear JW. Coronary artery stents and non-cardiac surgery. Br J Anaesth 2007; 98: 560–74
  8. Farb A, Boam AB. Stent thrombosis redux—the FDA perspective. N Engl J Med 2007; 356: 984–7
  9. Farb A, Burke AP, Kolodgie FD, Virmani R. Pathological mechanisms of fatal late coronary stent thrombosis in humans. Circulation 2003; 108: 1701–6
  10. Vicenzi MN, Meislitzer T, Heitzinger B, Halaj M, Fleisher LA, Metzler H. Coronary artery stenting and non-cardiac surgery—a prospective outcome study. Br J Anaesth 2006; 96: 686–93.
  11. Schouten O, van Domburg RT, Bax JJ, et al. Noncardiac surgery after coronary stenting: early surgery and interruption of antiplatelet therapy are associated with an increase in major adverse cardiac events. J Am Coll Cardiol 2007; 49: 122–4.
  12. Fleisher LA, Beckman JA, Brown KA, Calkins H, Chaikof E, Fleischmann KE, Freeman WK, Froehlich JB, Kasper EK, Kersten JR, Riegel B, Robb JF: ACC/AHA guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: Executive summary. Circulation 2007; 116:1971–96.
  13. Leon MB, Baim DS, Popma JJ, et al. A clinical trial comparing three antithrombotic-drug regimens after coronary-artery stenting. Stent Anticoagulation Restenosis Study Investigators. N Engl J Med 1998; 339:1665–71.
  14. Emmanouil S. Brilakis, MD, PHD, FACC, Subhash Banerjee, MD, FACC, Peter B. Berger, MD, FACC. Perioperative Management of Patients With Coronary Stents. Journal of the American College of Cardiology Vol. 49, No. 22, 2007.
  15. Wanda M. Popescu. Perioperative management of the patient with a coronary stent. Current Opinion in Anaesthesiology 2010, 23:109–115.
  16. Gro Egholm, MD, PHD, Steen Dalby Kristensen, MD, DMSC, Troels Thim, MD, PHD, Kevin K.W. Olesen, MD et al. Risk Associated With Surgery Within 12 Months After Coronary Drug-Eluting Stent Implantation. J A C C. Vol  . 6 8 , NO . 2 4 , 2 0 1 6

Anaesthesia This Month

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Founder President of our branch Dr.S.Subramoniam is elected as First President of South Zone ISA.

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