Girzadas Difficult Airway: Intubating the Morbidly Obese Patient
3 Major Concerns:
Rapid Oxygen Desaturation. This is due to patients with high BMI having smaller lung volumes and lower functional residual capacity. Patients with high BMI also have a higher metabolic rate and are using oxygen more rapidly. Because of these factors they desaturate much more quickly. Your safe apnea time is about 75% less than a patient with normal BMI. You need to counter this problem by obsessive pre-oxygenation using 15L Nasal cannula and Flush Rate O2 via a NRB mask or BVM or Bipap. Have the patient’s head up as much as possible during pre-oxygenation.
One option to pre-oxygenate. Other options are NRB with wall O2 open to Flush Rate. Bipap is another excellent option if you have time and the patient can tolerate.
2. More difficult airway management. This is due to larger tongue, more redundant tissue in the airway, thicker/less mobile neck. Patients have a smaller airway making visualization and intubation more difficult. Counter this problem with careful positioning. Elevate the head of the bed 25 degrees and put the patient in the sniffing position by elevating the head so the external ear canal is anterior to the sternum.
A is not good positioning. B and C both have the ear canal anterior to the sternum which will optimize your glotic view.
3. More difficult rescue of the failed airway. It is more difficult to BVM patients with high BMI. LMA is the preferred rescue device but airway pressures may cause the seal to fail. Finally cricothyrotomy is more difficult. You can counter this problem by planning your rescue prior to sedating the patient. Have an LMA at the bedside. Have a BVM with a Peep valve ready to go. Have an oral airway to facilitate bagging. Consider using ultrasound to identify where the cricothyroid membrane is and mark on the neck it’s location so if you have to perform a cric, you know exactly where to go.
Faculty members present felt that RSI after careful pre-oxygenation and positioning was still the best way to optimize your first pass success in the morbidly obese patient. Remember though that if you have significant concerns about how difficult the airway may be, you can always opt for topical anesthetic of the airway and ketamine sedation to avoid RSI.
Ahmad Study Guide Trauma
The safest initial therapy for symptomatic sucking chest wounds is the careful application of a petrolatum gauze–based dressing taped on three sides (Figure 53-4). Apply three or four layers of petrolatum gauze over the wound. The dressing should extend 6 to 8 cm beyond the margins of the wound so that it will not be sucked into the pleural cavity in the spontaneously breathing patient. Cover the petrolatum gauze with dry 4 × 4 gauze squares. Apply tincture of benzoin around three sides of the dressing. Apply tape to secure the three sides of the dressing to the chest wall. (Reichman’s EM Procedures 3rd Ed.) Editor’s note: Similar to the above picture, I would think that one of those pink defib conduction pads that you use for the hand-held defibrillator taped on three sides would work as well.
Small (<20%) pneumothoraces don’t necessarily need a chest tube. You can put the patient on supplemental oxygen and check another CXR in 6 hours. If it has improved, the patient can be discharged home.
Fracture of the sternum has been historically considered a marker of serious life-threatening injury, particularly cardiovascular injury. However, in clinical practice, it is the type of associated injury that determines morbidity and mortality. Patients with isolated sternal fractures and otherwise negative workup (including chest CT, echocardiogram, cardiac US, and cardiac enzymes at the time of presentation and 6 hours afterward) can safely be discharged home.42 Current experience with sternal fractures as a result of motor vehicle crashes notes a 1.5% incidence of cardiac dysrhythmias requiring treatment and a mortality rate of <1%.43 Such data suggest that sternal fractures are not an indicator of significant blunt myocardial injury. Patients with sternal fractures presenting with normal vital signs and an initial normal ECG should have a repeat ECG in 6 hours and, if unchanged, require no further workup for cardiac injury.44,4 (Tintinalli 8th edition)
Whether a normal chest radiograph excludes an aortic injury is a matter of controversy. One careful review of radiographs in patients with aortic injury did not find any normal radiographs. However, this study excluded technically suboptimal radiographs, was conducted by expert trauma radiologists, and the radiographic findings were subtle (Figures 14 and 15) (White et al. 1994). In two large clinical series, 5–7% of aortic injury cases had radiographs that were interpreted as negative for aortic injury (Fabian et al. 1997, Hunt et. al. 1996). However, the quality of the radiographic technique in these cases was not mentioned, and the radiographic criteria used to assess aortic injury were not stated. Several other case series also report normal mediastinal appearance in patients with aortic injury (Exadaktylos et al. 2001, Woodring 1990). Only when a chest radiograph is of sufficient quality to clearly determine that the mediastinal contours are normal could it be considered adequate to exclude a mediastinal hematoma (Mirvis 2006). However, in one study, 10% of aortic injury cases do not have a mediastinal hematoma on CT and so even a normal, technically optimal chest radiograph should not be used alone to exclude aortic injury (Cleverley et al. 2002).
Although of limited value in excluding aortic injury, the chest radiographic signs of mediastinal blood should be recognized and, when present, should prompt a rapid definitive investigation for aortic injury.
Definite signs of hemomediastinum in a patient with aortic injury.
The mediastinum is widened and the aortic knob is distorted by surrounding blood (arrow).
Mediastinal blood causes widening of the right paratracheal stripe (white arrowheads) and displacement of the left paraspinal line (black arrowheads), which extends up to the aortic knob.
The trachea is displaced to the right (white asterisks) and the left mainstem bronchus is displaced inferiorly (blackasterisks). This is due to blood surrounding the aorta. The faint shadow of the SVC is visible to the right of the paratracheal stripe. (The aortogram of this patient is shown in Figure 5.)
[From: Schwartz DT, Reisdorff EJ: Emergency Radiology. McGraw-Hill, 2000.]
Allam Chest Radiography
Calcified lung nodules are almost always benign.
Cavitary lesions can be lung cancer, metastasis, abscess, TB, Fungal or Wegener’s.
Opacities are bright areas on CXR. Lucencies are dark areas on CXR. Infiltrates is a term that is not well-defined and Dr. Allam advised us to avoid that term.
The causes of opacities on CXR include pus (pneumonia), blood, or water.
Lingular pneumonia. If the left heart border is obscured, it is due to lingular pneumonia. If the left diaphragm is obscured it is due to left lower lobe pneumonia or atelectasis.
Honeycombing pattern c/w Pulmonary Fibrosis. Interstitial pulmonary fibrosis (IPF), also called Usual Interstitial Pneumonitis, results in a restrictive lung disease that diminishes lung compliance and restricts diffusion of oxygen across the tissue to the blood. Over time, the disease leads to impaired exercise tolerance, chronic hypoxia, and cough. Treatment is aimed at immunomodulation through steroids and cytotoxic agents to halt disease. While late IPF is easily identified on chest radiographs, early disease is difficult to distinguish from other interstitial processes, such as CHF.
Pearls
Pulmonary fibrosis has a classic appearance of interstitial markings more prominent at the bases.
If pulmonary fibrosis is suspected, further evaluation should be done via high-resolution protocol chest CT to further determine the etiology. (Atlas of Emergency Radiology)
Deep sulcus sign
Deep sulcus sign indicative of pneumothorax in supine patients. The air accumulates inferiorly rather than superiorly as it would in an upright patient.
Humphrey/Delbar/Kentor Chest Trauma
East Guidelines for Blunt Cardiac Injury
Level 1
An admission electrocardiogram (ECG) should be performed on all patients in whom BCI is suspected (no change).
Level 2
If the admission ECG reveals a new abnormality (arrhythmia, ST changes, ischemia, heart block, and unexplained ST changes), the patient should be admitted for continuous ECG monitoring. For patients with preexisting abnormalities, comparison should be made to a previous ECG to determine need for monitoring (updated).
In patients with a normal ECG result and normal troponin I level, BCI is ruled out. The optimal timing of these measurements, however, has yet to be determined. Conversely, patients with normal ECG results but elevated troponin I level should be admitted to a monitored setting (new).
For patients with hemodynamic instability or persistent new arrhythmia, an echocardiogram should be obtained. If an optimal transthoracic echocardiogram cannot be performed, the patient should have a transesophageal echocardiogram (updated).
The presence of a sternal fracture alone does not predict the presence of BCI and thus should not prompt monitoring in the setting of normal ECG result and troponin I level (moved from Level 3).
Creatinine phosphokinase with isoenzyme analysis should not be performed because it is not useful in predicting which patients have or will have complications related to BCI (modified and moved from Level 3).
Nuclear medicine studies add little when compared with echocardiography and should not be routinely performed (no change).
Trauma attending comment: Not recommended to get a troponin unless there is a new EKG abnormality, arrhythmia, or hemodynamic changes. Editors comment: This is a controversial topic. I think many clinicians would consider getting a troponin in a patient with concern for possible blunt cardiac injury.
Trauma Attending comment: Treat hemothorax with a 32-36F chest tube. Indications for going to the OR is 1500ml of blood out immediately or 250ml/hr for four hours.
High flow nasal cannula O2 may benefit patients with flail chest by providing some level of Peep. Bipap can also be used to support alert, cooperative flail chest patients.
There are a few well-supported contraindications to performing an ED thoracotomy. A thoracotomy should not be performed in trauma patients who have no vital signs in the field.15,39,40 In the absence of field vitals, the survival rates are extremely low and the few who survive have severe neurologic impairment. Outside of patients who collapse in the ED, victims of blunt trauma with or without field vitals should not routinely undergo an ED thoracotomy.40,41 It is also contraindicated when prehospital CPR exceeds 10 minutes without a return of spontaneous circulation after blunt trauma, when prehospital CPR exceeds 15 minutes without a return of spontaneous circulation after penetrating trauma, and when the patient presents to the ED in asystole without a pericardial tamponade.39-43 An ED thoracotomy should not be performed regardless of the indications if a Trauma Surgeon or other qualified Surgeon is not available to take the patient to the Operating Room for definitive management. Do not perform an ED thoracotomy with the anticipation of transferring the patient to another facility if they can be resuscitated. In the near future, resuscitative endovascular balloon occlusion of the aorta (REBOA) may make some indications for a thoracotomy into contraindications (Chapter 74). (Reichman’s EM Procedures 3rd ED.)
Trauma Attending comment: It should be very rare for an emergency physician to perform an emergency thoracotomy. There are many risks to the patient and the physician when performing this procedure.
Harwood comment: Never do an emergency thoracotomy for blunt trauma or GSW to the chest, or non-chest trauma. But if there is an isolated stab wound to the region of the heart and patient has signs of life that may be the one time to go for it.
Trauma Attending comment: If you do open the chest and find a pericardial tamponade. Be very careful opening the pericardium to avoid cutting the phrenic nerve. Repair the ventricular injury with stables rather than sutures or foley balloon tamponade. Sutures are difficult to place in the heart and a foley balloon tends to tear through the hole making it larger.
Patients with aortic injuries that survive to the hospital get delayed repair. The Trauma surgeons fix all the other injuries first then a day or two later do an endovascular repair.