Advaced-Trauma And Ortho Flashcards
Trauma fluid resuscitation: LR va saline, colloids vs crystalloids?
The crystalloid versus colloid argument is forever unresolved and except in specific populations, no difference in meaningful outcome has been proven (answer C). Lactated ringers is slightly hypotonic, whereas normal saline is slightly hypertonic, but again, this has not led to a clinically significant outcome difference (answer B). The lactate in lactated ringers is converted to bicarbonate in the liver, thus preventing the hyperchloraemic acidosis seen with normal saline.
Following an abdominal stab wound, a patient has a 30% reduction in blood volume. Which of the following physiologic processes are true:
A. Baroreceptors in the carotid sinus and aortic arch increase discharges (action potentials)
B. Atrial natreutic peptide (ANP)is released by the myocytes
C. Glucagon and cortisol levels increase
D. Corticotrophin (ACTH) release is inhibited
E. Insulin levels increase
Explain each one
C: Glucagon and cortisol levels increase
In the setting of hypovolaemia, the hypothalamus releases vasopressin and ACTH. Vasopressin (anti-diuretic hormone) is vasoconstrictor and leads to increased water absorption in the renal collecting duct (thus increasing blood volume). ACTH results in increased cortisol and glucagon levels, which among other things, leads to an catabolic effect with glucose release and synthesis (increasing blood glucose). Insulin levels, which have a anabolic effects, decrease. Baroreceptor discharges lead to inhibition of the sympathetic nervous system. In the setting of hypovolaemia, baroreceptors DECREASE discharges thus lessening the inhibition on the sympathetic system (answer A, see Cardiac physiology question 14). ANP is released with atrial stretch, which occurs with hypervolaemia, not hypovolaemia (answer B).
Hypothermia can result in a functional coagulopathy, but the effects are typically not clinically significant until around:
33.0 C
Blood transfusion ratios:
Finally, transfusion of blood in a 1:1 ratio of RBC: FFP has strong evidence for improved outcome, and 1:1:1 RBC: FFP: Platelet may theoretically be even better (answer A). Note that 1:1:1 means that one unit of platelets are given for every six pBRCS and FFPs.
Following a motor vehicle accident, a 50 year-old woman with ruptured spleen and lacerated liver has lost 7 liters of blood in the operating room and has received numerous blood products. The surgeons inform you that there is diffuse and extensive oozing. Which of the following reasons are most likely contributing to the uncontrolled bleeding:
A. RBC: FFP: Platelets were administered in a 1:1:1 ratio
B. The patient was previously taking ginseng supplements
C. The patient has a temperature of 35.0 C
D. Increased release of inflammatory cytokines
E. Decreased levels of tissue plasminogen activator (TPA)
D: Increased release of inflammatory cytokines
Trauma is a proinflammatory state, leading to massive release of cytokines and interleukins, leading to multiple undesirable effects. One of these effects include endothelial dysfunction and damage, with systemic tissue factor release and consumption of coagulation factors (disseminated intravascular coagulopathy) (see haematology 9). Tissue damage results in release of TPA and hence fibrinolysis (answer E) (as well as of course tissue factor and initiation of the extrinsic clotting pathway)
30 year old man has suffered three stab wounds to the chest following dinner with his wife. The patient is extremely hypotensive and tachycardic. Physical exam reveals a bilateral breath sounds, normal heart sounds, no distention of neck veins, but pulsus paradoxus is present. Chest X-ray (CXR) demonstrated a small pneumothorax on the left, left haemothorax, and mildly widened mediastinum. ECG showed decreased amplitude sinus tachycardia without any other abnormality. In the ED a left chest tube was placed.
The surgeon informs you that he believes the patient has cardiac tamponade and wants to proceed to the OR immediately. The patient’s vitals are: BP 65/50, HR 130, Sat 90%. You recommend:
A. Alternative diagnosis as the patient does not have distended neck veins
B. Alternative diagnosis as the patient does not have muffled heart sounds
C. Flushing of the chest tube
D. Pericardiocentesis in the ED
E. Immediate transfer to the OR
is: D: Pericardiocentesis in the ED
The patient is unstable with possible tamponade, pericardiocentesis should be performed immediately. Currently the patient is likely too unstable to tolerate anesthetic induction and pericardiocentesis may increase diastolic filling and increase cardiac output until sternotomy can be performed. Beck’s triad (muffled heart sounds, distended neck veins, and hypotension) is found in less than 10% of patients. Equalization of the diastolic pressures of the heart is also not terribly common. Kussmaul’s sign (neck vein swelling with inspiration) is unreliable, especially with hypovolaemia. Pulses paradoxicus is also not reliable for diagnosis. Electrical alternans may also not be present in small volume, acute tamponade (as it represents the pendulum swinging of the heart in the pericardial sac
Cardiac tamponade:
Following aspiration of 100 cc of blood from pericardiocentesis, the patient’s blood pressure increased to 80/50, and you proceed to the OR. Which of the following is the best induction plan:
A. Ketamine and succinylcholine
B. Thiopental and succinylcholine
C. Mask induction, maintenance of spontaneous ventilation
D. High dose fentanyl and succinylcholine
E. Propofol and rocuronium
A: Ketamine and succinylcholine
Of the following choices, ketamine and succinylcholine is the best in this situation. Ketamine activates sympathetic outflow, preserving venous tone (preload) and heart rate. Ketamine is a myocardial depressant, but in patients without impaired myocardiums (CHF, etc), it is rarely a problem. The second issue is positive pressure versus spontaneous ventilation. In tamponade, spontaneous ventilation has distinct advantages as positive intrathoracic pressure can decrease venous return. However, in this case the patient is a full stomach and risk of aspiration with answer C is too great. One can intubate without muscle relaxant in the setting of ketamine, but the choice was not given. Thiopental is a preload reducer (answer B), and propofol decreases afterload and can lead to significant hypotension (answer E). High dose fentanyl can lead to bradycardia, which is counter to the goals of tamponade management (full & fast) (answer D).
Note that in this stem, the ultimate board answer of spontaneous ventilation is outweighed by other clinical factors. On the oral board you could choose answer C and defend it successfully, but on the written exam there’s only one right answer.
Following a motor vehicle accident, a 20 year old has flail chest and is intubated in the ED. Two minutes later, the patient is hypotensive, tachycardic, and hypoxic. Breath sounds are decreased on the left, and heart sounds are difficult to discern. Which of the following is the next BEST step:
A. Needle thorocostomy placed just superior to the second rib at the midclavicular line on the left
B. Needle thoracostomy placed just inferior to the second rib at the midclavicular line on the left
C. Needle thoracostomy placed just superior to the third rib at the midclavicular line on the left
D. Needle thoracostomy placed just inferior to the third rib at the midclavicular line on the left
E. Needle pericardiocentesis with the subxiphoid approach
C: Needle thoracostomy placed just superior to the third rib at the midclavicular line on the left
The patient most likely has a pneumothorax and immediate needle thoracostomy or chest tube placement is needed. For needle thoracostomy, the second intercostal space at the midclavicular line is commonly chosen when in the supine position. The second intercostal space is the area below the second rib and above the third rib. Approach just inferior to the rib risks intercostal artery (or vein) injury and bleeding. Since the hypotension worsened with positive pressure ventilation in the setting of flail chest (which almost always has underlying pneumothorax), pneumothorax is the most likely diagnosis. Answer E is a treatment option for cardiac tamponade.
How is it that a T4 epidural could cause less hypotension than a T8?
T4 epidural would likely be more effective and associated with less hypotension (at the T8 epidural would have to be run at a much higher rate to cover the majority of pain).
Vertebral artery dissection treatment:
The underlying pathophysiology usually involves intramural haemorrhage and often without neurologic sequelae. The risk, however, is that posterior blood flow (vertebral-basilar) can be compromised (due to decreased flow through the VAD), so anticoagulation is often started for these patients baring significant intracranial bleeding or change in the appearance of the VAD.
Patients on the borderline of abdominal compartment syndrome can be pushed over the edge with excessive
Crystalloid administration
Which of the following is true regarding abdominal compartment syndrome:
A. Bladder pressure significantly overestimates abdominal pressure
B. Oliguria is the most specific sign of abdominal compartment syndrome
C. Functional reserve capacity (FRC) is increased
D. Cardiac preload is increased
E. Intracranial pressure (ICP) can increase secondary to abdominal pressure
Explain each
Increased abdominal pressures push the diaphragm up towards the thorax, increasing intrathoracic pressures, increasing peak and plateau pressures, decreasing FRC (answer C), decreasing cardiac preload (answer D), and increasing afterload. Furthermore, high abdominal pressures impede blood flow to abdominal organs including the gut and kidneys. Oliguria is common, but has many etiologies in trauma patients, and is thus not very specific for abdominal compartment syndrome (answer B). Increase intrathoracic pressures increase jugular pressures, and thus can decrease cerebral venous runoff leading to increased ICP (answer E). Bladder pressures are considered an accurate, less invasive method to measure abdominal pressures.
A 16 year old boy is pulled from a fire with first and second degree burns on his chest and portions of his face. In the ED, he is following commands and sating 100% on facemask. Over the following hour he is increasingly dyspneic and striderous, yet still sating 100% on nasal cannula. Which of the following is the BEST plan:
A. Admit to the ICU for observation
B. Rapid sequence intubation and mechanical ventilation
C. Inhalation induction and intubation, followed by mechanical ventilation
D. Awake fiberoptic intubation and mechanical ventilation
E. Noninvasive continuous positive airway pressure (CPAP)
D: Awake fiberoptic intubation and mechanical ventilation
Following burn, especially with evidence of facial involvement, singed nasal hair, and soot in the sputum, upper airway oedema often occurs. Complete and partial airway obstruction are not uncommon and there should be a low threshold for intubation. In any burn patient, unrecognized swelling can lead to very difficult intubation and ventilation. In this patient in particular, there is evidence of underlying airway obstruction and awake fiberoptic intubation should be employed.
Which of the following is true regarding recombinant factor 7:
A. It complexes with the active form of factor 8
B. Factor 7 is also referred to as tissue factor
C. Recombinant factor 7 administration can overcome a relative deficiency of factors in the intrinsic pathway
D. Recombinant factor 7 administration can overcome a relative deficiency of platelets
E. Recombinant factor 7 (Novoseven) and factor 9 complex (Profilin) both work by decreasing the active form of factor 10
The intrinsic pathway’s primary function is to synergistically support the continued formation of thrombin once the extrinsic pathway has been initiated. In the setting of coagulopathy associated with trauma (DIC, dilutional, etc) a relative lack of important factors of the intrinsic pathway (factors 8, 9, & 11) can be overcome by continually supplying exogenous (recombinant) factor 7 (answer C). Factor 7 complexes with tissue factor, activating the common pathway (10 → 5→ 2 → 1) (answer A). Factor 9 complex supplies additional factors of the intrinsic and common pathway (and even extrinsic pathway at low levels), whereas r7 is specific for the extrinsic pathway.
Fat embolism syndrome vs massive fat embolism:
Respiratory failure, right heart failure, cerebral manifestations (mental status changes), and coagulopathic changes are common. Petechiae are uncommon but supposedly pathognomonic. FES presents postoperatively (usually 1-3 days), whereas massive fat embolism (not FES) can present with immediate cardiopulmonary collapse, just like venous thromboembolism (VTE). Diagnosis of FES is one of exclusion, although the clinical manifestations with evidence of fat droplets inside alveolar macrophages makes the diagnosis more likely.
Cerebral involvement with FES!
