ANESTHESIA FOR SURGERY OF THYMECTOMY TO TREAT MYASTHENIA GRAVIS

AT CHORAY HOSPITAL FROM 2004 – 2012.

PhD.MD. Dong Pham VanDr. Thao Trang Nguyen Thi

THE ANESTHETIC DEPARTEMENT

OVERVIEW

OVERVIEW

An autoimmune disease.An autoimmune disease. Ages, both sexes, female > male.Ages, both sexes, female > male. History of muscle weakness, move is History of muscle weakness, move is

fatigue, rest is gradually improved.fatigue, rest is gradually improved. 10 - 15% for thymomas, 75% for thymic 10 - 15% for thymomas, 75% for thymic

abnormalities.abnormalities. Thymectomy: one of efficacious therapies.Thymectomy: one of efficacious therapies.

OVERVIEW

General anesthesia with double-lumen endotracheal tube, with or without NMBDs.

Some drugs cause weak muscle. Vietnam hasn’t a lot of study topics like

this yet.

Purposes:

To investigate the correlation between 2 groups

patients with and without using NMBDs vs post-op

respiratory failure ratio and recoverable time after

anesthesia.

PHYSIOLOGY OF NEUROMUSCULAR TRANSMISSIONS

MOTOR UNIT

PHYSIOLOGY OF NEUROMUSCULAR TRANSMISSION

Stimulated neuron openning Calci channel Ach from synaptic vesicles in presynapse terminal go out.

Ach – AchR openning channel

Na, Ca flows enter depolarizing motor end plate.

Action potential across on cell membrane surface.

MECHANISM OF NMBDs

Depolarizing NMBDs: linking AChR Depolarize the end plate phase I block prolonged connection of succinylcholin Deforming AchR structure phase II block.

Non-depolarizing NMBDs: linking with 1 unit abnormalities of Ach-AChR no depolarize the end plate.

SITES OF NEUROMUSCULAR SITES OF NEUROMUSCULAR TRANSMISSIBLE DYSFUNCTIONTRANSMISSIBLE DYSFUNCTION

EFFECTS OF NMBDs IN NEUROMUSCULAR DYSFUNCTIONS

Decreasing the number of AChRs Decreasing the number of AChRs because of:because of:

• Changing the function of AChRs .Changing the function of AChRs .• Increasing the degradation of AChRs.Increasing the degradation of AChRs.• Destroying the surface of postsynapse.Destroying the surface of postsynapse.

Resistance with depolarizing NMBDs.Resistance with depolarizing NMBDs.

Sensitivity with non-depolarizing NMBDs.Sensitivity with non-depolarizing NMBDs.

SUBJECTS AND RESEARCH METHODS

SUBJECTS AND RESEARCH METHODS

Research design: retrospection, description with analysis.

Time, place: at Cho Ray hospital from 03/2004 to 06/2012.

Surgical methods:Thymectomy by endoscopic surgery.

SUBJECTS AND RESEARCH METHODS

Research methods:Research methods:Inclusion criteriaInclusion criteria: IIA, IIB (Osserman), 2 : IIA, IIB (Osserman), 2 groups, 1groups, 1stst group: use NMBDs; 2 group: use NMBDs; 2ndnd group: no use group: no use NMBDs.NMBDs.

Exclusion criteriaExclusion criteria: : patients with respiratory patients with respiratory failure, MG crisis, pre-op pyridostigmine failure, MG crisis, pre-op pyridostigmine bromide > 750 mg/d; I, III, IV grade; IIA, IIB with bromide > 750 mg/d; I, III, IV grade; IIA, IIB with cardiac, chronic pulmonary disease, sequela of cardiac, chronic pulmonary disease, sequela of stroke.stroke.

SUBJECTS AND RESEARCH METHODS

Research process:Research process:Preanesthetic examinationPreanesthetic examinationPreanesthetic drugs: Preanesthetic drugs: nonoInductionInduction: Propofol or sevoflurane, : Propofol or sevoflurane, SufentanilSufentanil, , or fentanyl (IV). Use or no use: or fentanyl (IV). Use or no use: suxamethoniume, atracurium, rocuronium. suxamethoniume, atracurium, rocuronium. Intubating double-lumen tube..Intubating double-lumen tube..MaintenanceMaintenance: : Sevoflurane, isoflurane, TIVA Sevoflurane, isoflurane, TIVA or TCI, sufentanil or fentanyl (IV). In end of or TCI, sufentanil or fentanyl (IV). In end of surgery, stop drugs & change endotracheal surgery, stop drugs & change endotracheal tube.tube.Post-op: Post-op: monitoringmonitoring vital signs, ABG, SPOvital signs, ABG, SPO22, , MG crisis…analgesia: tramadol, perfalgan, or MG crisis…analgesia: tramadol, perfalgan, or nisidol.nisidol.

SUBJECTS AND RESEARCH METHODS

Collected variables:Collected variables:

- Age, sex, MG degree, pulse, BP, SpO- Age, sex, MG degree, pulse, BP, SpO22..

- Surgical time, time of spontaneous - Surgical time, time of spontaneous ventilation via endotracheal tube, recovery ventilation via endotracheal tube, recovery room, in hospital. Ratio of respiratory failure, room, in hospital. Ratio of respiratory failure, post-op mechanism ventilation. post-op mechanism ventilation. - Perioperative drugs: fentanyl, sufentanil; - Perioperative drugs: fentanyl, sufentanil; propofol, isoflurane, sevoflurane; propofol, isoflurane, sevoflurane; suxamethonium, atracurium, rocuronium.suxamethonium, atracurium, rocuronium.- Post-op drugs: tramadol.- Post-op drugs: tramadol.

RESULTS & DISCUSSIONS

RESULTS & DISCUSSIONS

Table 1: Ratio of patients using of relaxant drugs and no.

124 patients

Table 2. Ratio of relaxant drugs.

Comments: 70.2% female, 29,8% male, this difference was statistically significant, with p < 0.001. Average age was 32.16 ± 11.23, this difference wasn’t statistically significant between 2 groups. p > 0.05.

DISTRIBUTION OF AGES, SEXES IN 02 GROUPS

Characterizations

1st Groupn = 43 (%)

2nd Groupn = 81 (%)

Totaln= 124(%)

P

Age X ± SD Min Max

30.33 ± 11.071355

34.30 ± 11.651462

32.16 ± 11.231362

0.069

Sex Male Female

10 (23.3%)33 (76.7%)

27 (33.3%)54 (66.7%)

37 (29.8%)87 (70.2%)

< 0.001

SURGICAL TIME.

Time (minute) 1st group

(n = 43)

2nd group

(n = 81)

p

X ± SD

Min

Max

104 ± 52.11

45

190

96 ± 52.52

30

200

0.672

Comments: The surgical time wasn’t statictically significant difference between 2 groups, with p > 0.05.

TIME OF SPONTANEOUS VENTILATION VIA ENDOTRACHEAL TUBE IN

RECOVERY ROOM

Comments: 1st group 21.61 ± 11.40 was longer 2nd group 5.69 ± 5.13, the difference was statictically significant, with p < 0.001.

1st Group 2nd Group

RATIO OF MECHANISM VENTILATION IN RECOVERY ROOM

Mechanism

Ventilation

1st group

(n = 43)

2nd group

(n = 81)

p

Yes

No

9 (20.9)

34 (79.1)

6 (7.4)

75 (92.6)

0.028

Comments: : 1st group 20.9% was higher than 2nd group 7.4%, the difference was statictically significant, with p < 0.05.

TIME OF POST-OP MECHANISM TIME OF POST-OP MECHANISM VENTILATION BETWEEN 02 VENTILATION BETWEEN 02

GROUPSGROUPS

Comments : 1st group 56.06 ± 57.98 was longer than 2nd group 3.50 ± 1.33, the difference was statictically significant, with p < 0.05.

56.06 ± 57.98

1st Group 2nd Group

POST-OP RESPIRATORY FAILURE RATIO BETWEEN 02 GROUPS.

Comments: : 1st group 60.5% was higher than 2nd group 7.4%, the difference was statictically significant, with p < 0.001.

1st Group 2nd Group Total

TIME IN RECOVERY ROOM OF 02 GROUPS.

Comments: : 1st group 30.94 ± 34.81 was longer than 2nd group 9.77 ± 9.38, the difference was statictically significant, with p < 0.001.

1st Group 2nd Group

CONCLUSIONCONCLUSION

MG patients have the same status, general anesthesia, surgical time, using the same anesthetic and analgesic drugs during and post-op the patients, who use NMBDs were the time of post-op spontaneous ventilation via endotrachea, of mechanism ventilation, of staying recovery room longer and ratio of post-op mechanism ventilation, respiratory faillure higher than the ones no use NMBDs.