The ETT can be used to investigate coronary heart disease (sometimes called coronary artery disease). This disease is due to narrowing of the coronary arteries. It can cause chest pains (angina) and other problems. So, if you develop chest pains you may be advised to have an ETT to help clarify the cause. However, different investigations (eg, coronary angiography or myocardial perfusion scintigraphy) are now preferred to diagnose whether you have coronary heart disease.
Many people with coronary heart disease have a normal ECG at rest. During exercise the heart beats faster and needs more oxygen. If one or more of your coronary arteries are narrowed, part or parts of the heart muscle do not get enough oxygen. This can cause the ECG tracing to become abnormal when you exercise. Therefore, if you have a positive ETT (an abnormal reading) you are likely to have coronary heart disease.
If you already have coronary heart disease, the degree of abnormality on the ECG tracing from the ETT can give a good idea of the severity of the disease.
How is an exercise tolerance test done?
Small electrodes are stuck on to your chest. Wires from the electrodes are connected to the electrocardiogram (ECG) machine. You will then be asked to exercise on a treadmill or on an exercise bike. The exercise starts at a very easy pace, and is gradually made more strenuous by increasing the speed and incline of the treadmill, or by putting some resistance on the bike wheel.
Whilst you exercise, ECG tracings are made and you will also have your blood pressure measured from time to time. The test lasts about 15-20 minutes.
What should I do to prepare for the test?
You should not have a heavy meal within one hour of the test. Otherwise, there is no special preparation needed. For the test, wear loose-fitting clothes and shoes that are comfortable to walk in. Continue to take your usual medication unless advised otherwise by a doctor.
Limitations
An ETT is a valuable investigation but it is not 100% accurate. Sometimes tracings show changes during exercise, even though the person has a completely normal heart. Also, some people with coronary heart disease have a normal ETT with no changes on the tracing. Doctors are aware of this and use the results of the test in conjunction with other information such as your symptoms, results of other tests, etc.
Nowadays it is common for scans of the heart to be done rather than an ETT. The scans that can be done for the heart include:
Risks
An ETT is done without any problems in the vast majority of cases. If you do not have coronary heart disease then complications are rare. However, serious complications occur in a small number of people who have coronary heart disease. The risk is to develop a heart attack (myocardial infarction) or a serious heart irregularity (an arrhythmia) during the test. Medical help is near to hand to deal with possible problems. However, there are reports of, very rarely, some people who have died during an ETT.
You have to weigh up the pros and cons before deciding on having this test. The test can give very valuable information about your condition, but with a small risk of serious problems developing.
FAQs
Steps of RSI (7 Ps)
- Preparation & Plan.
- Preoxygenation.
- Pre-treatment.
- Paralysis and induction.
- Protection and positioning.
- Placement with proof.
- Post-intubation management.
[5] The typical depth of the endotracheal tube is 23 cm for men and 21 cm for women, measured at the central incisors. The average size of the tube for an adult male is 8.0, and an adult female is 7.0, though this is somewhat an institution dependent practice.
What is the next step after failed ETT? ›
If unsuccessful, then there are suggestions to improve mask ventilation and successfully intubate. These include repositioning the patient's head or neck, administering a paralytic drug, applying external laryngeal manipulation, removing cricoid pressure, or using an adjunct such as a bougie.
What is the success rate of proper ETT placement after 1 failed attempt? ›
The success rate on first rescue intubation attempts declined as the number of preceding failed intubation attempts increased (81% [95% CI, 79%-84%] after one failed attempt; 71% [95% CI, 66%-76%] after two failed attempts; 67% [95% CI, 55%-78%] after three or more failed attempts; Ptrend <0.001; Figure 2).
What is the 3 finger rule for intubation? ›
3: The measurement of 3 fingers between the upper and lower teeth of a patient's open mouth indicates the ease of accessing the airway through the oral opening. In a typical patient, the ability to open their mouth wide enough to accommodate 3 fingers placed between the incisors indicates adequate mouth opening.
What is the rule of threes intubation? ›
According to the American Society of Anesthesiologists, intubation is determined to be difficult to secure when a proficient and skilled anesthesiologist requires more than 3 attempts or exceeds a duration of 10 minutes for successful endotracheal intubation.
What is the 332 rule for intubation? ›
The 3-3-2 rule uses three simple assessments to predict the difficulty of intubating a patient: 3: You should be able to fit three fingers between the upper and lower teeth of a patient with an open mouth. Ask the patient to open their mouth and place three fingers vertically between their incisors, or do it yourself.
What is the gold standard for ETT? ›
Waveform capnography is considered the gold standard for verification of proper endotracheal tube placement, but current guidelines caution that it is unreliable in low-perfusion states such as cardiac arrest.
What is a positive ETT test? ›
Therefore, if you have a positive ETT (an abnormal reading) you are likely to have coronary heart disease. If you already have coronary heart disease, the degree of abnormality on the ECG tracing from the ETT can give a good idea of the severity of the disease.
What is ETT results? ›
An exercise tolerance test (ETT) is helpful in evaluating a patient's heart function during exertion, and detecting the presence of coronary artery disease and arrhythmias.
Once the endotracheal tube is secured, obtain a chest x-ray, at earliest convenience, to confirm actual tube location and proper position (approximately 2-3 cm above the carina in an average size adult).
What is the first step to confirm ETT placement? ›
During intubation, direct visualization of the endotracheal tube passing through the vocal cords into the trachea, especially with the use of a videolaryngoscope, constitutes firm evidence of correct tube placement, but additional techniques should be used as objective findings to confirm proper endotracheal tube ...
What is the most reliable way to confirm ETT placement? ›
Conclusion: Capnography is the most reliable method to confirm endotracheal tube placement in emergency conditions in the prehospital setting.
How deep is an ETT tube insertion? ›
Most of the anaesthesia textbooks recommend depth of placement of ET to be 21 cm and 23 cm in adult females and males, respectively, from central incisors. [5,6] It is suggested that the tip of ET should be at least 4 cm from the carina, or the proximal part of the cuff should be 1.5 to 2.5 cm from the vocal cords.
What is the ETT route? ›
The endotracheal tube (ETT) route is used when I.V. or IO access isn't possible. Medi- cations administered via an ETT can be easi- ly remembered using the acronym NAVEL: naloxone, atropine, vasopressin, epinephrine, and lidocaine. Medications administered through an ETT must be 2 to 2.5 times the recommended I.V.
How do you assess ETT position? ›
Viewing the tube passing between the cords during direct laryngoscopy and visualization of the tracheal rings and carinae with a fiberoptic scope after intubation are the only fullproof methods of confirming tracheal intubation.
