SEVOFLURANE ANESTHESIA WITHOUT MUSCLE RELAXANTS

FOR THORACOSCOPIC THYMECTOMY

IN MYASTHENIA GRAVIS

Vo Van HienNguyen Huu Tu

Mai Van Vien

Introduction Myasthenia gravis (MG) is a chronic autoimmune disorder

related to the thymus gland.

Thymectomy is one of the effective methods to treat MG.

Patients with myasthenia gravis did sentitivity to the drugs

were used in anesthesia → Choice drugs and anesthesia

technique plays an important role in the success of

operation.

Respiratory complications depend on anesthetic technique:

Mulder et al (1972): 50% of pts need ventilatory support.

Suwanchi (1995): Comparision general anesthesia vs

epidural anesthesia and iv. propofol: early extubation in

operating room 29%- 78%.

Catherine Chevalley et al (2001)(*):

+ Time need ventilation support : 2-48h

+ Propofol was used (1994): No need to ventilate

postoperative.

introduction

In Vietnam, Đo Tat Cuong (1996) reported postoperative

ventilation depend on method of anesthesia :

Anesthesia: 15.65%

Acupunture: 3.5%

Nguyen Van Thanh (1998) studied on 47 pts:

Required ventilation support: 15/47pts

Mortality: 3 patients due to respiratory infections.

introduction

Side effects of long-term ventilatory support on MG pts:

• Infections: respiratory, pneumonia, sepsis → death.

• Prolonged hospitalization days

• Increased treatment costs

Anesthesiologists’ recommendations:

introduction

“Avoid muscle relaxants in MG patients”

Choice drug ?Choice drug ?

Dose?Dose?

Intubation ?Intubation ?

Airways injuries?Airways injuries?

Hemodynamic change?Hemodynamic change?

Easy for surgeon?Easy for surgeon?

Early extubation?Early extubation?

Respiratory complication?Respiratory complication?

NO MUSCLE NO MUSCLE RELAXANTS RELAXANTS

!!!!!!

introduction

objectives

To evaluate the use of sevoflurane and

without muscle relaxants

for thoracoscopic thymectomy in MG patients

and post-operative respiratory status

methods

Subjects: Intervention study on 28 MG patients scheduled to

undergo thoracoscopic thymectomy

Monitor: Datex Omeda: ECG (DII), SpO2, EtCO2, invasive

aterial blood pressure (ABP), module Entropy (RE, SE), TOF.

Induction:

- Atropin: 0.5mg; Sufentanil: 0.5mcg/kg;

- Propofol 2.5-3 mg/kg

- Local anesthesia with 10 cc of lidocaine hydrochloride 2%

was sprayed on the vocal cords and into the trachea

Intubation Univent tube

- Loss eyelid reflex

- RE, SE<50

- Check tube and blocker’s position by endoscopy equipment

(Olympus)

Ventilate A/C mode : Vt = 10ml/kg; f=14l/ph; FiO2= 60%→

PetCO2= 28-32 mmHg.

OLV: Vt=5ml/kg, f=16-20; FiO2= 100% → Ppeak < 30 cm

H2O, PetCO2=30-35mmHg.

Sufentanil: 0.2mcg/kg/h

methods

Adjust concentration of sevoflurane

Criterial ABP > 130% baseline

70% < ABP <130%

ABP < 70% baseline

RE, SE>60 ↑ Sevorane ↑ Sevorane

Increase infusion and ephedrine iv

before ↑ Sevorane

40<RE,SE<60 Nicardipine ivAdequatedepth of

anesthesia

Increase infusion and ephedrine iv

RE, SE <40 Nicardipine iv ↓ Sevorane ↓ Sevorane

methods

Stop sufentanil 15 minutes before the end of surgery

Stop sevoflurane at the end of surgery.

Extubation when:

- Awake

- Head lift > 5 seconds

- RR < 30/min

- Inspiratory force > 25cmH2O

Assess respiratory status: breathing frequency; SpO2, blood gas.

Evaluate airway injuries at 24h postoperative.

methods

Medical equiments used in studyUnivent tube’s Univent tube’s

position position

in trachea in trachea

I- STAT portable I- STAT portable

clinical analyserclinical analyser

-pH-pH

-PaO2PaO2

-PaCO2PaCO2

-HCO3HCO3--

-BEBE

-BBBB

recorded Data General characteristics

Intubation conditions (Viby Mogensen Score), number of attemps to intubate.

Hemodynamic changes at induction, before and after intubation and intraoperative.

Neuromuscular effect of sevoflurane on MG: TOF

Surgeons’ satisfaction: VAS score

Time to extubation and respiratory status: f, SpO2 , PaO2,

PaCO2, pH,…

Clinical symtom due to airway injuries: sorethroat,

hoarseness and observe by laryngostroboscopy.

resultsGeneral characteristics

Characteristics Results

GenderMale 8 (28.6%)

Female 20 (71.4%)

Age (X±SD) (years) 39.5 ± 9.7

Classification (folow Osserman)

I 5 (17.9%)

IIa 16 (57.1%)

IIb 7 (25.0%)

Duration of disease (months)95.6 ± 8.73

3-121

Time in anesthesia

Time

Results

Loss eyelid reflex (seconds)112.6± 28.5

57- 140

Achive RE, SE <50 (seconds)149.5 ± 17.6

103 – 186

Intubation time (minutes)6.0± 1.5

3.5 – 12.8

results

Agent dose for induction and maintaining

Purpose Results

Propofol for induction (mg) 189,75±40,3110- 230

Total dose of sevoflurane for maintaining (ml) 125,35±59,6

Inspiratory concentration of sevorane for

maintaining (%)3,05± 2,4

results

Intubation condition

82.1

17.90

0

20

40

60

80

100

Rat

e (%

)

Excelent Good Poor

Intubation condition

results

Side effects intraoperative

Side Effects Results

Induction- Intubation

Coughing 2 (10,5%)

Involuntary movements

3 (15,8%)

Laryngospasm 0

MaintainingInvoluntary movements

4 (21,1%)

Awake 0

results

50

70

90

110

130

150

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14

Mea

n I

AB

P (

mm

Hg

)

InductionIntubation Surgery The

end

Mean IABP changes

results

Heart rate changes

results

50

70

90

110

130

150

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14

Hear

t rat

e (f/

min

)

Neuromuscular transmission intraoperative

92.179.3* 75.3* 76.5*

91.7

0

20

40

60

80

100

TO

F (

%)

Baseline 30 min 60 min 90 min The end

Time

results

Dù kiÕn kÕt luËn

Relative between myasthenia class and TOF at the 60th minute intraoperative

y = -10.6x + 97

R2 = 0.767; r= - 0.87579

50

60

70

80

90

100

1 2 3

Độ nhược cơ (1:I; 2: IIa; 3:IIb)

TO

F (

%)

results

Surgeons’ satisfaction

Level Results

Total satisfied 25 (89.3%)

Quite satisfied 3 (10.7%)

Medium 0

Poor 0

No satisfaction 0

results

Time in anesthesia

Duration Results

Duration of surgery (min)125.6 ± 20.3

85 - 145

Duration of anessthesia (min)143.7 ± 18.9

90 -180

∆ awake (min)11.2± 2.98.0 – 15.0

∆ extubation (min)12.7 ± 3.78.0 -17.0

Self-awareness (min)13.9 ± 1.9

8 -18

results

∆ awake (min)11.2± 2.98.0- 15.0

∆ extubation(min) 12.7 ± 3.78.0- 17.0

10

12

14

16

18

20

22

24

Beforeextubation

15 min 30 min 2h 6h 12h 24h 48h 72h

RR

(r/p

h)

95

96

97

98

99

100

Beforeextubation

15 min 30 min 2h 6h 12h 24h 48h 72h

Sp

O2

(%

)

spo2 and respiratory rate Changes after extubation

PaO2 changes

50

100

150

200

250

300

350

Pre-ope DLV OLV 2h afterextubation

1st daypost ope

2nd daypost-ope

3 rd daypost -ope

Arterial blood gas changes

PaCO2 changes

35

37

39

41

43

45

Pre-ope DLV OLV 2h afterextubation

1st daypost ope

2nd daypost ope

3rd postope

Arterial blood gas changes

pH changes

7.3

7.32

7.34

7.36

7.38

7.4

7.42

7.44

Pre-ope DLV OLV 2h afterextubation

1st daypost ope

2nd daypost ope

3rd postope

Arterial blood gas changes

Airway injuriesClinical symtoms

- ZHong and et al. 13%- 20%- 30%

- Heike K. 44% - 17%

Symtoms Results

Sore-throat 5 (17.8%)

Hoarseness 1(3.6%)

Both sore-throat and hoarseness 1(3.6%)

Total 7 (28.0%)

Injuries were observed by laryngostroboscopy

No injury 78.5%

laryngeal injuries14.3%

Both tracheal and larygeal injuries

3.6%

Tracheal injuries3.6%

Airway injuries

Sevoflurane anesthesia without muscular relaxants for thoracoscopic thymectomy in MG

Good intubating conditions

Stable hemodynamic

Faster recovery

100% of the patients successfully to extubate at operating room.

No patients required reintubation due to respiratory failure.

Airway injuries due to intubation: 28%

conclusions

Thank for your attention!