The Response Patterns to the Electrical Stimulation of Epidural Catheters With Varying Pulse Widths in Term Pregnant Women
Epidural analgesia is commonly used for labor pain relief due to its safety and effectiveness. Despite a very high success rate, the epidural technique remains a somewhat blind technique and failures continue to occur. Unfortunately, there are no imaging techniques that can be used at the bedside to determine the proper positioning of the epidural catheter. The trans-catheter electric stimulation test (TCEST) has been successfully used for this purpose. This test is occasionally performed in situations where the immediate confirmation of the proper epidural catheter location is deemed necessary. The test helps to predict which epidurals might fail so that appropriate measures could be immediately implemented.
There has been one duration of electrical stimulus (0.2 milliseconds) that has been used in the majority of studies and in clinical practice. With this duration of stimulation, the vast majority of cases show a unilateral motor response of the lower limbs during the TCEST. Studies on the stimulation of peripheral nerves (nerves in the arms and legs) have shown that an electrical stimulus with a longer duration is able to stimulate nerves which are farther away. Since nerves in the epidural space are similar in composition to peripheral nerves, the investigators expect to see a higher rate of bilateral response with the longer duration of stimulus. The investigators also hope to show that this bilateral response is predictive of a better functioning epidural.
The investigators hypothesize that the incidence of a bilateral response to the TCEST will be higher with the 1.0 ms pulse width compared to 0.1 ms pulse width. Furthermore, the investigators hypothesize that a bilateral motor response associated with the 1.0 ms pulse width will be predictive of symmetry of sensory and motor block and of lower consumption of local anesthetic.
調査の概要
詳細な説明
This will be a randomized double-blind controlled study. After recruitment of the patient, epidural anesthesia will be performed in the standard fashion employed in the investigators' institution by a fellow or staff. Spinal ultrasound will be used prior to performing the epidural catheter insertion. The trans-catheter electric stimulation test (TCEST) will be performed at both a 0.1ms pulse width and a 1ms pulse width. The order in which the two pulse widths are applied will be randomly decided by computer. The test dose of local anesthetic will then be administered, and the TCEST will be repeated 5 minutes later. Again, both pulse widths (0.1ms, 1ms) will be used, and the order in which they are applied will be decided randomly.
Following the second testing, a loading dose of the standard anesthetic solution will be administered. The sensory level to ice will be tested at 20 minutes following injection of the loading dose of bupivacaine and fentanyl. The sensory level will be assessed from the sacral to the thoracic levels, bilaterally. The motor response pattern will be recorded for all TCESTs performed, and any relationship between pulse width and response pattern will be determined.
研究の種類
入学 (実際)
段階
- 適用できない
連絡先と場所
研究場所
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Ontario
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Toronto、Ontario、カナダ、M5G1X5
- Mount Sinai Hospital
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-
参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
Inclusion Criteria:
- Women 16 years of age and older requesting an epidural for labour analgesia
- Ability to communicate in English
- Informed consent
Exclusion criteria:
- Refusal to provide written informed consent
- Inability to communicate in English
- Abnormal vertebral anatomy, including but not limited to previous spine surgery and scoliosis
- Allergy or hypersensitivity to lidocaine, bupivacaine or fentanyl
- Coexisting neurological disorders
- Implanted electronic devices
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：処理
- 割り当て：ランダム化
- 介入モデル：並列代入
- マスキング：ダブル
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
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アクティブコンパレータ：0.1ms pulse width
The nerve stimulator will be connected to the epidural catheter through an adapter, which will be primed with a standard volume of 3 ml of sterile normal saline to allow for effective electrical conduction.
The cathode terminal of the stimulator will then be attached to the metal hub of the adapter and the anode terminal will be connected to the electrode placed over the deltoid muscle.
All patients will have the trans-catheter electric stimulation test (TCEST) performed with both a 1 ms pulse width and 0.1 ms pulse width and the order of administration will be randomized.
|
The nerve stimulator (Stimpod NMS 450: Xavant technology (PTY) Ltd; Pretoria, South Africa or similar nerve stimulator) will be connected to the epidural catheter through an adapter (Johans ECG Adapter, Arrow International Inc., Reading).
The epidural catheter and the adapter will be primed with a standard volume of 3 ml of sterile normal saline to allow for effective electrical conduction.
Secured connections and avoidance of any air within in the system must be ensured to avoid high impedance in the circuit, which could result in false negatives.
The cathode terminal of the stimulator will then be attached to the metal hub of the adapter and the anode terminal will be connected to the electrode placed over the deltoid muscle.
他の名前：
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アクティブコンパレータ：1ms pulse width
The nerve stimulator will be connected to the epidural catheter through an adapter, which will be primed with a standard volume of 3 ml of sterile normal saline to allow for effective electrical conduction.
The cathode terminal of the stimulator will then be attached to the metal hub of the adapter and the anode terminal will be connected to the electrode placed over the deltoid muscle.
All patients will have the trans-catheter electric stimulation test (TCEST) performed with both a 1 ms pulse width and 0.1 ms pulse width and the order of administration will be randomized.
|
The nerve stimulator (Stimpod NMS 450: Xavant technology (PTY) Ltd; Pretoria, South Africa or similar nerve stimulator) will be connected to the epidural catheter through an adapter (Johans ECG Adapter, Arrow International Inc., Reading).
The epidural catheter and the adapter will be primed with a standard volume of 3 ml of sterile normal saline to allow for effective electrical conduction.
Secured connections and avoidance of any air within in the system must be ensured to avoid high impedance in the circuit, which could result in false negatives.
The cathode terminal of the stimulator will then be attached to the metal hub of the adapter and the anode terminal will be connected to the electrode placed over the deltoid muscle.
他の名前：
|
この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Motor response pattern
時間枠：5 minutes
|
Motor response pattern to the electrical stimulation of the epidural catheter, either unilateral or bilateral.
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5 minutes
|
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Sensory level
時間枠：2 hours
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The sensory level to ice at 20 minutes and 2 hours following injection of the standard epidural loading dose.
The sensory level will be assessed from the sacral to the thoracic levels, bilaterally.
|
2 hours
|
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Motor block
時間枠：2 hours
|
Lower extremity motor block as assessed by the Bromage score (Range: 0-3) bilaterally at 20 minutes and 2 hours following the loading dose. 0 = No motor block (full flexion of knees and feet)
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2 hours
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Current (mA)
時間枠：5 minutes
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The current required to elicit a motor response on the initial TCEST and at 5 minutes after the test dose
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5 minutes
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Consumption of local anesthetic
時間枠：2 hours
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Amount of local anesthetic consumed as measured on the pump in the first 2 hours.
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2 hours
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Epidural block failure
時間枠：2 hours
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Failure of the epidural analgesia, defined as no evidence of a sensory block to ice and absent pain relief in the first 20 minutes, OR the need for epidural catheter replacement within 2 hours of the loading dose.
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2 hours
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協力者と研究者
出版物と役立つリンク
研究記録日
主要日程の研究
研究開始 (実際)
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
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