ソース: ジェームズ ・ W Bonz、MD、救急医学、エール大学院医学系、ニューヘブン、コネチカット、米国
気管内挿管の他の形態が失敗し、換気が悪化または可能ではない場合、外科的気道確保の手順が示されます。これは恐れられていた「ことはできません挿管、換気できない」シナリオと緊急時の設定で輪状甲状膜切開は外科的治療選択。
輪状甲状膜切開は合併症のリスクが低い、輪状甲状間膜や手順を実行ことができます比較速度の予測可能な解剖学のため気管切開術を優先 — 少ないでも実務を経験します。輪状甲状膜切開が伝統的に「オープン」形式で行われています。ただし、関連する解剖学的ランドマークの識別がより困難なより成功したアプローチとして標準セルジンガー法を用いた経皮的輪状甲状膜切開を進められています。Seldinger 法にはイントロデューサ針、ガイドワイヤーを使用して体に装置の導入が含まれます。ターゲットを見つけるために針を使用します。ガイドワイヤーは、ガイドワイヤーとターゲットにされ、デバイスの「プレース ホルダー」としてターゲットに薄肉針を介して供給されます。
経皮的輪状甲状膜切開の場合開業医はまず物理的なランドマークで輪状甲状間膜を識別し、小さな縦皮膚切開を行います。薄肉 18 ゲージ針 (注射器に添付) を貫き、膜と注射器で空気を吸気時気道を確実に識別します。ガイドワイヤー針を介して供給されます。標準的な輪状甲状膜切開セットには、そのルーメン内で硬い散大と (気管カニューレに類似) 気道カテーテルが含まれます。ガイドワイヤーをカテーテル/散大組み合わせを供給、カテーテル ・ ガイドワイヤーが気道内に配置されます。散大とガイド線は削除後と換気用バッグ-バルブ-デバイスにカテーテルを接続します。
Percutaneous cricothyrotomy using Seldinger technique is a critical and life saving procedure. It was first described by Melker and is also referred to as “Melker technique.” The decision to place a surgical airway must be made quickly. The procedure itself should be completed in less than a minute. Percutaneous cricothyrotomy with needle and guide wire has been advocated over open cricothyrotomy because the potential complications in an open cricothyrotomy can prove disastrous for the patient.
The benefit of Seldinger technique in performing cricothyrotomy is that the airway is located with a needle, and its access is “held” with the guide wire until the airway catheter is in place. If the cricothyroid membrane is not encountered with the first needle insertion, the location may be re-adjusted and there is less likely to be a life-threatening complication than if the location were misidentified with a scalpel blade. An open cricothyrotomy, by contrast, relies on identification of the cricothyroid membrane and airway by visual inspection after a vertical incision is made with a scalpel. In the event of hemorrhage, visualization can become impossible. Additionally, in obese patients and those with otherwise poor anatomic landmarks, identifying the midline can be a challenge.
Although there are a variety of commercially available percutaneous cricothyrotomy kits, this technique can be done easily with supplies commonly found in the emergency department. There are many procedures that rely on Seldinger technique. A central venous catheter kit could be utilized, for example. It should be noted that other versions of this technique have been described. Some feel that identification of the airway using a needle without the subsequent use of Seldinger technique is the best strategy, combining elements of open cricothyrotomy and needle identification of the airway.
Cricothyrotomy is a surgical airway procedure indicated when other forms of endotracheal intubation have failed and patient ventilation is declining or not possible.
The two forms of this procedure are open or surgical cricothyrotomy – discussed in a different video – and percutaneous cricothyrotomy, which will be discussed here. The latter is the method of choice for many practitioners especially when identification of the relevant anatomic landmarks is more difficult, such as in the patients with short neck and excessive soft tissue.
In this presentation, we will outline how to conduct the percutaneous cricothyrotomy procedure using a pre-packaged kit and when kit is not available.
Start by gathering the necessary supplies for the procedure including: chlorhexadine, a bag valve mask device, suction and oxygen supply equipment, and the pre-packaged percutaneous cricothyrotomy kit. A standard pre-packaged kit should include: a 18 gauge introducer needle, a 5 milliliter syringe, scalpel, guide wire, a dilator, an airway catheter and a neck-tie.
After opening the kit, attach the introducer needle to the syringe, make sure that the catheter and dilator are assembled, and lay out the guidewire and scalpel for easy access. The patient in this situation has likely undergone attempted endotracheal intubation and should already be lying supine. Stand at the patient’s head, extend the neck (2.4.2) and palpate to locate the cricothyroid membrane. This membrane is located below the laryngeal prominence — the “Adam’s Apple”. After locating the membrane, grab the paratracheal structures and move them around. They will move as a unit and create a depression. The needle insertion landmark is in the midline of this depression. If time allows, the area should be cleaned with chlorhexadine, and ideally, the exam gloves should be traded for sterile gloves. However, as with all emergent procedures, true sterile technique may be sacrificed for rapidity.
Make a small 5-millimeter vertical incision with the scalpel at the identified midline. Then, advance the introducer needle at a 45° angle into the incision and through the cricothyroid membrane toward the patient’s feet. Withdraw on the plunger while advancing the needle. When the needle enters into the airway, you will be able to aspirate air easily. Next, brace your hand against the patient’s neck and remove the syringe from the needle. Be sure to keep the needle opening within the air filled lumen.
Now, advance the guidewire through the needle approximately 15 centimeters to assure the wire is well within the airway. Then, remove the needle, keeping the guidewire in place. Next, thread the catheter-dilator assembly over the wire and push it through the patient’s skin. While doing so, anatomically orient the device with the airway such the curve of the catheter matches the curve needed from its entry point into the trachea. Keep pushing until the catheter is fully in place — that is till the plastic flange is against the patient’s neck. Next, remove the dilator and the wire from the assembly and attach the catheter to the bag-valve manual resuscitator. Confirm correct placement by auscultating for breath sounds, and monitoring the end tidal CO2 — the normal range for which is 35-45 mmHg.
Finally, secure the airway catheter with appropriate necktie.
Now let’s review how to conduct the percutaneous cricothyrotomy procedure without a kit, which is not ideal, but may be the most preferable option in an emergency situation.
For supplies, open the central venous catheter tray and remove the following items : a 5-milliliter syringe, an introducer needle, a guidewire, and a scalpel. In addition, obtain a tracheostomy tube .
Attach the introducer needle to the empty 5-milliliter syringe. Then, prepare the guidewire by retracting it in its sheath and straightening out the J tip. Locate the cricothyroid membrane by palpating as shown previously and prep the neck with chlorhexadine if time allows. Grab the laryngeal structures as a unit to be certain that the midline is identified. Next, while applying gentle pressure to the plunger, advance the introducer needle at a 45° angle in caudal direction. Once the needle tip reaches the trachea, air can be easily aspirated into the syringe. Now, with your non-dominant hand, hold the needle steady and remove the syringe with your dominant hand. Then advance the guide wire 15 centimeters through the introducer needle. Next, with a number 11-scalpel blade make a horizontal incision at the level of the needle — approximately 2 centimeter in length and 2 cm deep –, cutting through the skin and cricothyroid membrane. Now, remove the needle and leave the guidewire in place and load the tracheostomy tube onto the guidewire.
Next, to dilate the incision open, retract the scalpel blade and advance the handle of the scalpel through the incision. With the handle is firmly inside the incision, rotate it by 90° so that it is oriented parallel with the patient’s neck and perpendicular to the horizontal incision. This will hold the aperture open and allow for easier passage of the tracheostomy tube. Advance the tube over the guidewire and through the opening created by the scalpel handle. This will assure that the tube follows the correct tract into the airway. After the tube is in position, remove the guide wire, attach the tube to the ventilator device and secure it in place with neckties.
Cricothyrotomy is a critical and life saving procedure. The decision to place a surgical airway must be made quickly, and the procedure itself should be completed in less than a minute. The procedure shown in this video on percutaneous cricothyrotomy using the Seldinger technique has been advocated over open cricothyrotomy, because of the potential for bleeding with open cricothyrotomy.
A major advantage of using a needle to locate the airway is that if the cricothyroid membrane is not encountered with the first needle insertion, the location may be re-adjusted and there is less likely to be a life threatening complication.
On the contrary, the open cricothyrotomy procedure relies on identification of the cricothyroid membrane and airway by visual inspection after a vertical incision is made with a scalpel. If there is a hemorrhage, visualization can become impossible. Furthermore, in the obese and in those with otherwise poor anatomic landmarks, identifying midline can be a challenge.
You have just watched a JoVE video demonstrating the percutaneous cricothyrotomy procedure, with and without a pre-packaged kit. As always, thanks for watching!
