1. What are the stages of hemorrhagic shock?
Trauma - 5th Ed. (2004),
The clinical and physiologic response to hemorrhage has been classified according to the magnitude of volume loss. Loss of up to 15% of the circulating volume (700 to 750 mL for a 70-kg patient) may produce little in terms of obvious symptoms while loss of up to 30% of the circulating volume (1.5 L) may result in mild tachycardia, tachypnea, and anxiety. Hypotension, marked tachycardia (pulse > 110 to 120 beats/min) and confusion may not be evident until more than 30% of the blood volume has been lost, while loss of 40% of circulating volume (2 L) is immediately life-threatening. Young healthy patients with vigorous compensatory mechanisms may tolerate larger volumes of blood loss while manifesting fewer clinical signs despite significant peripheral hypoperfusion being present. These patients may maintain a near-normal blood pressure until a precipitous cardiovascular collapse occurs. Elderly patients may be taking medications that either promote bleeding (warfarin, aspirin) or mask the compensatory response to hypovolemia (beta blockers). In addition, atherosclerotic vascular disease, diminished cardiac compliance with age, inability to elevate heart rate or cardiac contractility in response to hemorrhage, and overall decline in physiologic reserve decrease the elderly patient's ability to tolerate hemorrhage.
2. What are the hemodynamic changes associated with septic shock?
Current Critical Care Diagnosis & Treatment - 2nd Ed. (2003)
The distinguishing hemodynamic features of septic shock are elevated cardiac output, decreased systemic vascular resistance, and decreased blood pressure. Tachycardia is partially responsible for maintaining the blood pressure. [NB the ventricles become dilated so as to increase output according to the Frank-starling curve, this is how the heart compensates for the myocardial depression that septic mediators often cause]. More recent investigations have shown that cardiac output remains elevated until decreased output develops as a preterminal event. A normal or elevated mixed venous oxygen saturation and decreased arterial-venous oxygen content difference is present.
3. What are the hemodynamic changes associated with cardiogenic shock?
Schwartz's Principles of Surgery - 8th Ed. (2005)
Emergency Medicine: A Comprehensive Study Guide - 6th Ed.
Hemodynamic criteria include sustained hypotension, reduced cardiac index (< 2.2 L/min per square meter), and elevated pulmonary artery wedge pressure (> 15 mm Hg). Clinical signs of cardiogenic shock include evidence of poor CO with tissue hypoperfusion (hypotension, mental status changes, cool mottled skin) and evidence of volume overload (jugular venous distention, rales, and an S3 gallop).
4. What are the hemodynamic changes associated with hypovolemic shock?
Harrison's Principles of Internal Medicine - 16th Ed. (2005)
Reduced cardiac output and a compensatory sympathetic mediated response characterized by tachycardia and elevated systemic vascular resistance.
5. A 30 y.o. pt. arrives s/p fall from a tree. He is noted to be hypotensive on arrival. Invasive hemodynamic monitoring shows him to have a CVP of 1 mm Hg (nl 2-8 mm Hg), a cardiac output of 3 L/min (nl 4-6 L/min), an SVR of 450 dyne/sec/cm-5 (nl 900-1200 dyne/sec/cm-5), and a mixed venous oxygen saturation of 55% (nl 70-80%). Characterize his shock state.
Schwartz's Principles of Surgery - 8th Ed. (2005)
Neurogenic Shock - Loss of vasoconstrictor impulses results in increased vascular capacitance, decreased venous return, and decreased cardiac output. Neurogenic shock is usually secondary to spinal cord injuries from vertebral body fractures of the cervical or high thoracic region that disrupt sympathetic regulation of peripheral vascular tone. Rarely, a spinal cord injury without bony fracture, such as an epidural hematoma impinging on the spinal cord, can produce neurogenic shock. Sympathetic input to the heart, which normally increases heart rate and cardiac contractility, and input to the adrenal medulla, which increases catecholamine release, may also be disrupted, preventing the typical reflex tachycardia that occurs with hypovolemia. Acute spinal cord injury results in activation of multiple secondary injury mechanisms: (1) vascular compromise to the spinal cord with loss of autoregulation, vasospasm, and thrombosis, (2) loss of cellular membrane integrity and impaired energy metabolism, and (3) neurotransmitter accumulation and release of free radicals. Importantly, hypotension contributes to the worsening of acute spinal cord injury as the result of further reduction in blood flow to the spinal cord. Management of acute spinal cord injury with attention to blood pressure control, oxygenation, and hemodynamics, essentially optimizing perfusion of an already ischemic spinal cord, seems to result in improved neurologic outcome. Patients with hypotension from spinal cord injury are best monitored in an intensive care unit, and carefully followed for evidence of cardiac or respiratory dysfunction.
6. When should a pulmonary artery wedge pressure be recorded? Is it any different in a ventilated versus a non-ventilated patient?
Emedicine
The timing of PCWP measurement is critical because intrathoracic pressures can vary widely with inspiration and expiration and are transmitted to the pulmonary vasculature. During spontaneous inspiration, the intrathoracic pressures decrease (more negative); during expiration, intrathoracic pressures increase (more positive). Positive pressure ventilation (eg, in an intubated patient) reverses this situation. To minimize the effect of the respiratory cycle on intrathoracic pressures, measurements are obtained at end-expiration, when intrathoracic pressure is closest to zero. [NB this is the same in ventilated and non-ventilated patients. The difference is how the pressure tracing looks].
7. What are some indications for placement of a pulmonary artery catheter?
Emedicine, Uptodate.com - Swan-Ganz catheterization: Indications and complications.
No study has definitively demonstrated improved outcome in critically ill patients managed using pulmonary artery catheters. Thus, the accepted indications for pulmonary artery catheterization have been generated largely on the basis of expert opinion. Fundamentally, the decision to place a Swan-Ganz catheter should be based on a specific question regarding a patient's hemodynamic status that cannot be satisfactorily answered by clinical or noninvasive assessment; if the answer could change management, then placement of the catheter is indicated [NB remember this principle for the ABSITE!] Common indications are listed
• Diagnosis of shock states
• Differentiation of high- versus low-pressure pulmonary edema
• Diagnosis of primary pulmonary hypertension (PPH)
• Diagnosis of valvular disease, intracardiac shunts, cardiac tamponade, and pulmonary embolus (PE)
• Monitoring and management of complicated AMI
• Assessing hemodynamic response to therapies
• Management of multiorgan system failure and/or severe burns
• Management of hemodynamic instability after cardiac surgery
• Assessment of response to treatment in patients with PPH (Primary pulmonary hypertension)
8. What are some indicators of endpoints of resuscitation? What are their benefits
and drawbacks?
Schwartz's Principles of Surgery - 8th Ed. (2005)
Lactate - Elevated serum lactate is an indirect measure of the oxygen debt, and therefore an approximation of the magnitude and duration of the severity of shock. The admission lactate level, highest lactate level, and time interval to normalize the serum lactate are important prognostic indicators for survival.
Base deficit - Base deficit can be stratified into mild (3 to 5), moderate (6 to 14) and severe (≥15) categories, with a trend toward higher mortality with worsening base deficit in patients with trauma. Both the magnitude of the perfusion deficit as indicated by the base deficit and the time required to correct it are major factors determining outcome in shock. [NB Both lactate and base deficit are global measures of perfusion, and thus may miss regional hypoperfusion. They may be confounded by underlying organ dysfunction as well, and may not fully reflect the oxygen debt of underlying tissue. Nevertheless, they are useful indetermining both response and mortality]
Gastric tonometry - Goal-directed human studies, with gastric mucosal pH (pHi) as an endpoint in resuscitation, have shown normalization of pHi to correlate with improved outcome in several studies, and with contradictory findings in other studies. Utility of pHi as a singular endpoint in the resuscitation of critically-ill patients remains controversial.
Tissue pH, oxygen, carbon dioxide levels - Tissue probes with optical sensors have been used to measure tissue pH and partial pressure of oxygen and carbon dioxide in subcutaneous sites, muscle, and the bladder. These probes may utilize transcutaneous methodology with Clark electrodes or direct percutaneous probes. The percutaneous probes can be inserted through an 18-gauge catheter and hold promise as continuous monitors of tissue perfusion.
Near infrared spectroscopy - Trauma patients with decoupled oxyhemoglobin and cytochrome a,a3 have redox dysfunction and have been shown to have a higher incidence of organ failure (89 vs. 13%). Not widely used in clinical practice
9. How do you calculate oxygen delivery? Systemic vascular resistance?
Current Critical Care Diagnosis & Treatment - 2nd Ed. (2003)
The delivery of oxygen is dependent upon the quantity of oxygen present in the blood and the cardiac output. The oxygen content, is calculated as follows:
. Multiply by cardiac output to get oxygen delivery. The last term is often negligible.
Systemic Vascular resistance is calculated as follows:
10. Where on the EKG tracing should the CVP be measured? Where should the pulmonary artery wedge pressure be measured?
Saturday, November 1, 2008
Trauma Surgery Review
1. Describe the management of rib fractures with an associated traumatic hemothorax.
[Townsend: Sabiston Textbook of Surgery, 17th ed., 506-509]
Rib fractures are the most common injuries after blunt chest injuries. Ribs 4 through 10 are usually fractured. One or two rib fractures without pleural or lung involvement are usually treated on an outpatient basis. However, in the elderly, owing to decreased bone density, reduced chest wall compliance, and increased incidence of underlying parenchymal disease, rib fractures may lead to decreased ability to cough, reduced vital capacity, and infectious complications. Pain on inspiration is usually the primary clinical manifestation after rib fractures. Epidural analgesia is adequate for patients with multiple or bilateral fractures and provides adequate pain control and appropriate pulmonary toilette, decreasing the number of complications. [NB: There is a body of literature suggesting that epidurals are the gold standard of pain control and there is a diminished rate of severe complications with them, particularly with elderly patients. Patient controlled analgesia is another promising approach, may supplement with rib bocks. My personal practice is also to add non-steroidal anti-inflammatory meds and muscle relaxants when able to, and send patients home on a mixture of medications]
Hemothoraces are initially treated by chest tube placement (36 French), and in approximately 85% of the cases, the bleeding will stop as the lung is re-expanded owing to the low pressure in the systemic circulation. A small number of cases will have continued bleeding and will require a thoracotomy. [NB: generally those injuries that produce >1500 cc output initially or >200 cc/hr for more than two or more hours.] These are usually injuries in systemic arteries (intercostal arteries or internal mammary artery) or veins or major pulmonary vessels or are cardiac in origin. Autotransfusion should be considered in these circumstances.
2. What are the indications and techniques for operation in renal trauma (both blunt and penetrating) [Trauma - 5th Ed. (2004)]
Indications: Hemodynamic instability, ongoing hemorrhage requiring significant transfusion, pulsatile or expanding hematoma on exploration, or avulsion of the pedicle. Relative indications for surgical intervention have included high-grade injuries, large perirenal hematoma, presence of urinary extravasation on contrast studies, significant devitalized fragments of parenchyma, and presence in the operating room during laparotomy with an incompletely staged injury.
Techniques: (Trauma 5th ed. 2004)
A number of indications for renal exploration following injury have been suggested by McAninch and Carroll.
1. hemodynamic instability
2. ongoing hemorrhage requiring significant transfusion
3. pulsatile or expanding hematoma on exploration
4. avulsion of the pedicle.
Relative indications for surgical intervention have included:
1. high-grade injuries
2. large perirenal hematoma
3. presence of urinary extravasation on contrast studies
4. significant devitalized fragments of parenchyma
5. presence in the operating room during laparotomy with an incompletely staged injury.
Renal exploration for trauma begins with prioritization of the injuries and determining that the initial operation is in fact the appropriate time to embark on the renal exploration. intraoperative IVP can be performed by administering 1 to 2 mL/kg of iodinated contrast intravenously and then obtaining a 10-min excretion film. This can occur while other general surgical tasks are being accomplished to avoid wasting time. There has been some controversy regarding the importance of first obtaining vascular control of the renal pedicle prior to renal exploration as previously described. Some proponents claim a markedly reduced nephrectomy rate if the renal vessels are first dissected and controlled with vessel loops. Others claim that this maneuver is unnecessary to successful renal exploration and repair. If there is an injury to the pedicle, central vascular control should be the initial maneuver. If, based on the anatomy of the injury, the kidney is not considered reconstructible, a nephrectomy is performed. It is preferable to separately ligate the renal artery and vein to avoid the potential for arteriovenous fistula. For trauma nephrectomies, the ureter and adjoining vessels are ligated near the kidney, while the gonadal vein is ligated and divided when necessary, with no need for concern for adverse impact on the gonadal structures. Technique involves incising the posterior peritoneum lateral to the aorta [NB incise MEDIAL to the inferior mesenteric vein, a generally recognizable landmark] and individually dissecting and looping the renal vessels on the side of injury. Following pedicle control or access, the colon and mesocolon on the side of injury is reflected medially following incision of the peritoneal reflection. When the anterior surface of Gerota's fascia is fully exposed, a generous, vertical, anterior incision is made through the fascia, and the kidney is fully mobilized.
. If the kidney is felt to be reconstructible in an unstable patient, the kidney can be packed off with laparotomy pads as other surgical injuries are treated. After repair of other injuries, or at the time of a secondary surgical procedure, formal exploration and reconstruction of the kidney is performed. If, based on the anatomy of the injury, the kidney is not considered reconstructible, a nephrectomy is performed.
3. How is a gunshot wound to the left flank treated in a stable patient? [Trauma - 5th Ed. (2004)]
Below is an algorithm suggested by Trauma - 5th Ed. (2004). Depending on the CT findings, possible treatments could include; observation, laparoscopy or laparotomy. [NB I would not call a labile patient ‘stable’. Furthermore I would get a CT scan first in a stable patient specifically to assess the ipsilateral kidney even if I had made the decision to operate. Otherwise, see previous question].
4. What might be some injuries associated with the previous GSW and how would they be treated?
Bowel injuries – Operative resection or repair
Solid organ injuries – Depending on extent of injury, treatment could range from removal of the organ to hemorrhage control and ICU observation. [NB: Differentiate renal injuries, which may not require exploration, with ureteral injuries which should always be repaired or diverted if repair is not feasible, as in damage control]
Pneumothorax – Chest tube
Hemothorax – Chest tube [NB: Diaphragm injuries may be present, and should be repaired. That is why I made the question a LEFT GSW. If in doubt and no formal indication for laparotomy exists, a laparoscopy can be done to assess the diaphragm]
Injury to Vascular structures – Operative exploration with repair or ligation
Injury to spinal cord – MRI with possible Operative intervention by neurosurgery [NB MRI may not be feasible in the patient with a bullet in him or her; operative intervention is controversial. Role of the trauma surgeon is basically supportive]
5. Describe the workup and management of a gunshot wound to the thigh.
[Trauma - 5th Ed. (2004)]
The location and extent of the injury will guide our work up and interventions. After stabilizing the patient, one should focus on all anatomical structures in the area of injury. Evaluation for vascular trauma should be assessed first following the below mentioned algorithm. Open fractures need to be irrigated and repaired in the OR. Injury to nerves can be assessed by physical exam and possible surgical intervention by neurosurgery. Soft tissue and muscle injuries can be washed out and approximated with the skin left open. Because of the wide range of guns (22 – shotgun) there is a wide variance in surgical management.
Figure 43-8. Algorithm for evaluation of injured extremities for vascular trauma. Dotted lines indicate possible alternative modalities that require further study.
[NB: I particularly want everyone to focus on the right and left side of the algorithm. Dr. Frykberg, in his bipolar style, has made it quite clear that normal physical examination is quite reliable to rule out the presence of a significant vascular injury, and, conversely the presence of hard signs requires urgent intervention, and, in fact recommends on table arteriography in the OR followed by whatever procedure is necessary ]
6. What are the grades of pancreatic injury & describe the operative approach to each?
[ACS Surgery]
Table 1 - AAST Organ Injury Scales for Pancreas and Duodenum
Injured Structure
AAST Grade*
Characteristics of Injury
AIS-90 Score
Pancreas
I
Small hematoma without duct injury; superficial laceration without duct injury
2
II
Large hematoma without duct injury or tissue loss; major laceration without duct injury or tissue loss
2; 3
III
Distal transection or parenchymal laceration with duct injury
3
IV
Proximal† transection or parenchymal laceration involving ampulla
4
V
Massive disruption of pancreatic head
5
Duodenum
I
Single-segment hematoma; partial-thickness laceration without perforation
2; 3
II
Multiple-segment hematoma; small (< 50% of circumference) laceration
2; 4
III
Large laceration (50%–75% of circumference of segment D2 or 50%–100% of circumference of segment D1, D3, or D4)
4
IV
Very large (75%–100%) laceration of segment D2; rupture of ampulla or distal CBD
5
V
Massive duodenopancreatic injury; devascularization of duodenum
5
[NB: Management of grade 5 injuries is not universally accepted and should be tempered by common sense, like wide drainage may be the most appropriate initial intervention followed by delayed reconstruction, with Whipple procedures being reserved for the stable patient with destruction of the pancreatic head accompanied by destruction of the ampulla]
7. What is the sequence of approach used to decrease intracranial pressure in patients with severe closed head injury? [Trauma - 5th Ed. (2004)]
TABLE 19-3. CONTROL OF ELEVATED INTRACRANIAL PRESSURE
EEliminate factors that can elevate ICP
• Straighten head to prevent kinking of jugular vein, raise head of bed slightly (no more than 30), eliminate hypercarbia, etc.
• Repeat CT (if not done recently) to look for mass lesion requiring surgical intervention.
T Treat pain with narcotics, e.g., morphine 2-10 mg IV for adults. Sedating effects may also help lower ICP. If response inadequate: consider benzodiazepines or propofol infusion (watch blood pressure).
I If ICP still elevated: neuromuscular blockade. Monitor depth of paralysis with nerve stimulator.
Note: try to hold sedation and paralysis at least once a day (such as before morning rounds) so that a valid neurologic examination can be performed.
If ICP still elevated: drainage of cerebrospinal fluid (CSF) via ventriculostomy.
If CSF drainage fails or is not possible: mannitol 0.25-1.0 g/kg bolus. May repeat prn as long as fluid balance is followed closely and serum osmolality stays below 320 mOsm/L.
If ICP elevation persists: may try mild hyperventilation (keeping Paco2 > 30 mmHg), especially if cerebral oxygenation is monitored by Sjvo2 catheter and/or by Pbto2 monitor.
Next step: pentobarbital-induced coma. Meticulous attention must be paid to avoiding arterial hypotension. Consider having pressors hanging and ready to be infused as pentobarbital is given.
Other treatments:
• Hypothermia was not beneficial when tested in a multicenter trial, but it is possible that select subgroups of patients may benefit.
• Decompressive craniectomy may be an option in some cases (especially with unilateral pathology), but this treatment still awaits validation in a rigorous trial.
8. What are some indications for Emergency Department thoracotomy? (www.trauma.org) [NB: ED thoracotomy is a costly and drastic episode of drama best reserved for patients with rapid deterioration in the ED, or who have undergone cardiac arrest just before arrival with signs of life still present. Patients who have undergone prolonged CPR or patients with blunt trauma who sustain cardiac arrest at the scene should not have this procedure done. I prefer to teach residents on live patients, not dead ones].
1. Penetrating thoracic injury &;
- Traumatic arrest with previously witnessed cardiac activity (pre-hospital or in-
hospital)
- Unresponsive hypotension (BP < 70mmHg)
2. Blunt thoracic injury
- Unresponsive hypotension (BP < 70mmHg)
- Rapid exsanguination from chest tube (>1500ml). [NB These patients should be expediently transported to the OR. The results of ED thoractomy for blunt trauma patients are uniformly dismal. See previous comment]
9. Describe the management options in a patient with a grade 4 splenic injury?
[Trauma - 5th Ed. (2004)]
Grade IV splenic injury =
Hematoma: ruptured intraparenchymal hematoma with active bleeding
Laceration: laceration involving segmental or hilar vessels producing major devascularization (> 25% of spleen)
Treatment options include:
1. Operative management – Pre-op abx. Trauma laparotomy. Pack off the abdomen in all 4 quadrants and localize injuries and bleeding. Splenectomy or splenorrhaphy for injured spleen. Postoperative immunizations to reduce incidence of OPSI.
2. Non – Operative management – Appropriate patient selection is the most important element of nonoperative management. Although it is certainly true that nonoperative management is possible in a large number of patients with splenic injury, emergency surgery is still sometimes necessary to stop life-threatening hemorrhage. Of paramount importance is the hemodynamic stability of the patient. Assuming hemodynamic stability, the other important prerequisite is the patient's abdominal examination. In patients who are awake and alert and can cooperate with a physical exam and provide feedback, it is important that they not have diffuse, persistent peritonitis. Nonoperative management should only be undertaken if it will be possible to closely follow the patient. ICU admission with serial blood draws, checking Hematocrit and serial abdominal exams is best. Reported success rates for nonoperative management are 95% or higher for pediatric patients and approximately 80% or higher in adults
[NB: CT scanning is mandatory in these patients and should be repeated if there is any suspicion of a bowel injury]
10. Name some late complications of non-operative treatment of blunt hepatic injuries. How are they managed? [Trauma - 5th Ed. (2004)]
Bile Leaks: Bilomas or bile leak can occur in 3 to 20% of nonoperatively managed patients. Evidence of bile leak by HIDA scan does not mandate intervention. Abnormal liver function tests, abdominal distention, and intolerance to feeding may all indicate a bile leak. CT scan evaluation with drainage percutaneously usually remedies the problem completely. Bile leaks or bilomas are drained percutaneously, sometimes for up to 4 to 6 weeks, and they nearly always resolve without ERC or other decompressive maneuvers.
Abscess: Abscesses, such as biliary collections, can often be managed by CT-guided drainage catheters. However, if the patient fails to improve with drainage and antibiotics, wide surgical drainage should be performed.
Hemorrhage: Using the same criteria that was originally utilized to manage these patients nonoperatively, namely hemodynamic stability without ongoing blood loss, patients with delayed hemorrhage can undergo hepatic angiographic embolization and observation with success. Therefore, it seems that delayed hemorrhage is actually a rare and manageable complication.
Compartment syndrome of the liver: Operative drainage
Hemobilia: The authors concluded that hepatic artery pseudoaneurysm with hemobilia is predisposed by a bile leak and that angiographic embolization was appropriate for patients without sepsis and with small cavities. However, formal hepatic resection or drainage, after angiographic vascular control, may be necessary for septic patients or those with large cavities. Hemobilia is much less common with the prevalence of nonoperative management. With operative interventions of the past including large parenchymal suturing and vessel ligation, communications between vessels and bile ducts often occurred iatrogenically. Now that nonoperative care is practiced, hemobilia is rare.
[Townsend: Sabiston Textbook of Surgery, 17th ed., 506-509]
Rib fractures are the most common injuries after blunt chest injuries. Ribs 4 through 10 are usually fractured. One or two rib fractures without pleural or lung involvement are usually treated on an outpatient basis. However, in the elderly, owing to decreased bone density, reduced chest wall compliance, and increased incidence of underlying parenchymal disease, rib fractures may lead to decreased ability to cough, reduced vital capacity, and infectious complications. Pain on inspiration is usually the primary clinical manifestation after rib fractures. Epidural analgesia is adequate for patients with multiple or bilateral fractures and provides adequate pain control and appropriate pulmonary toilette, decreasing the number of complications. [NB: There is a body of literature suggesting that epidurals are the gold standard of pain control and there is a diminished rate of severe complications with them, particularly with elderly patients. Patient controlled analgesia is another promising approach, may supplement with rib bocks. My personal practice is also to add non-steroidal anti-inflammatory meds and muscle relaxants when able to, and send patients home on a mixture of medications]
Hemothoraces are initially treated by chest tube placement (36 French), and in approximately 85% of the cases, the bleeding will stop as the lung is re-expanded owing to the low pressure in the systemic circulation. A small number of cases will have continued bleeding and will require a thoracotomy. [NB: generally those injuries that produce >1500 cc output initially or >200 cc/hr for more than two or more hours.] These are usually injuries in systemic arteries (intercostal arteries or internal mammary artery) or veins or major pulmonary vessels or are cardiac in origin. Autotransfusion should be considered in these circumstances.
2. What are the indications and techniques for operation in renal trauma (both blunt and penetrating) [Trauma - 5th Ed. (2004)]
Indications: Hemodynamic instability, ongoing hemorrhage requiring significant transfusion, pulsatile or expanding hematoma on exploration, or avulsion of the pedicle. Relative indications for surgical intervention have included high-grade injuries, large perirenal hematoma, presence of urinary extravasation on contrast studies, significant devitalized fragments of parenchyma, and presence in the operating room during laparotomy with an incompletely staged injury.
Techniques: (Trauma 5th ed. 2004)
A number of indications for renal exploration following injury have been suggested by McAninch and Carroll.
1. hemodynamic instability
2. ongoing hemorrhage requiring significant transfusion
3. pulsatile or expanding hematoma on exploration
4. avulsion of the pedicle.
Relative indications for surgical intervention have included:
1. high-grade injuries
2. large perirenal hematoma
3. presence of urinary extravasation on contrast studies
4. significant devitalized fragments of parenchyma
5. presence in the operating room during laparotomy with an incompletely staged injury.
Renal exploration for trauma begins with prioritization of the injuries and determining that the initial operation is in fact the appropriate time to embark on the renal exploration. intraoperative IVP can be performed by administering 1 to 2 mL/kg of iodinated contrast intravenously and then obtaining a 10-min excretion film. This can occur while other general surgical tasks are being accomplished to avoid wasting time. There has been some controversy regarding the importance of first obtaining vascular control of the renal pedicle prior to renal exploration as previously described. Some proponents claim a markedly reduced nephrectomy rate if the renal vessels are first dissected and controlled with vessel loops. Others claim that this maneuver is unnecessary to successful renal exploration and repair. If there is an injury to the pedicle, central vascular control should be the initial maneuver. If, based on the anatomy of the injury, the kidney is not considered reconstructible, a nephrectomy is performed. It is preferable to separately ligate the renal artery and vein to avoid the potential for arteriovenous fistula. For trauma nephrectomies, the ureter and adjoining vessels are ligated near the kidney, while the gonadal vein is ligated and divided when necessary, with no need for concern for adverse impact on the gonadal structures. Technique involves incising the posterior peritoneum lateral to the aorta [NB incise MEDIAL to the inferior mesenteric vein, a generally recognizable landmark] and individually dissecting and looping the renal vessels on the side of injury. Following pedicle control or access, the colon and mesocolon on the side of injury is reflected medially following incision of the peritoneal reflection. When the anterior surface of Gerota's fascia is fully exposed, a generous, vertical, anterior incision is made through the fascia, and the kidney is fully mobilized.
. If the kidney is felt to be reconstructible in an unstable patient, the kidney can be packed off with laparotomy pads as other surgical injuries are treated. After repair of other injuries, or at the time of a secondary surgical procedure, formal exploration and reconstruction of the kidney is performed. If, based on the anatomy of the injury, the kidney is not considered reconstructible, a nephrectomy is performed.
3. How is a gunshot wound to the left flank treated in a stable patient? [Trauma - 5th Ed. (2004)]
Below is an algorithm suggested by Trauma - 5th Ed. (2004). Depending on the CT findings, possible treatments could include; observation, laparoscopy or laparotomy. [NB I would not call a labile patient ‘stable’. Furthermore I would get a CT scan first in a stable patient specifically to assess the ipsilateral kidney even if I had made the decision to operate. Otherwise, see previous question].
4. What might be some injuries associated with the previous GSW and how would they be treated?
Bowel injuries – Operative resection or repair
Solid organ injuries – Depending on extent of injury, treatment could range from removal of the organ to hemorrhage control and ICU observation. [NB: Differentiate renal injuries, which may not require exploration, with ureteral injuries which should always be repaired or diverted if repair is not feasible, as in damage control]
Pneumothorax – Chest tube
Hemothorax – Chest tube [NB: Diaphragm injuries may be present, and should be repaired. That is why I made the question a LEFT GSW. If in doubt and no formal indication for laparotomy exists, a laparoscopy can be done to assess the diaphragm]
Injury to Vascular structures – Operative exploration with repair or ligation
Injury to spinal cord – MRI with possible Operative intervention by neurosurgery [NB MRI may not be feasible in the patient with a bullet in him or her; operative intervention is controversial. Role of the trauma surgeon is basically supportive]
5. Describe the workup and management of a gunshot wound to the thigh.
[Trauma - 5th Ed. (2004)]
The location and extent of the injury will guide our work up and interventions. After stabilizing the patient, one should focus on all anatomical structures in the area of injury. Evaluation for vascular trauma should be assessed first following the below mentioned algorithm. Open fractures need to be irrigated and repaired in the OR. Injury to nerves can be assessed by physical exam and possible surgical intervention by neurosurgery. Soft tissue and muscle injuries can be washed out and approximated with the skin left open. Because of the wide range of guns (22 – shotgun) there is a wide variance in surgical management.
Figure 43-8. Algorithm for evaluation of injured extremities for vascular trauma. Dotted lines indicate possible alternative modalities that require further study.
[NB: I particularly want everyone to focus on the right and left side of the algorithm. Dr. Frykberg, in his bipolar style, has made it quite clear that normal physical examination is quite reliable to rule out the presence of a significant vascular injury, and, conversely the presence of hard signs requires urgent intervention, and, in fact recommends on table arteriography in the OR followed by whatever procedure is necessary ]
6. What are the grades of pancreatic injury & describe the operative approach to each?
[ACS Surgery]
Table 1 - AAST Organ Injury Scales for Pancreas and Duodenum
Injured Structure
AAST Grade*
Characteristics of Injury
AIS-90 Score
Pancreas
I
Small hematoma without duct injury; superficial laceration without duct injury
2
II
Large hematoma without duct injury or tissue loss; major laceration without duct injury or tissue loss
2; 3
III
Distal transection or parenchymal laceration with duct injury
3
IV
Proximal† transection or parenchymal laceration involving ampulla
4
V
Massive disruption of pancreatic head
5
Duodenum
I
Single-segment hematoma; partial-thickness laceration without perforation
2; 3
II
Multiple-segment hematoma; small (< 50% of circumference) laceration
2; 4
III
Large laceration (50%–75% of circumference of segment D2 or 50%–100% of circumference of segment D1, D3, or D4)
4
IV
Very large (75%–100%) laceration of segment D2; rupture of ampulla or distal CBD
5
V
Massive duodenopancreatic injury; devascularization of duodenum
5
[NB: Management of grade 5 injuries is not universally accepted and should be tempered by common sense, like wide drainage may be the most appropriate initial intervention followed by delayed reconstruction, with Whipple procedures being reserved for the stable patient with destruction of the pancreatic head accompanied by destruction of the ampulla]
7. What is the sequence of approach used to decrease intracranial pressure in patients with severe closed head injury? [Trauma - 5th Ed. (2004)]
TABLE 19-3. CONTROL OF ELEVATED INTRACRANIAL PRESSURE
EEliminate factors that can elevate ICP
• Straighten head to prevent kinking of jugular vein, raise head of bed slightly (no more than 30), eliminate hypercarbia, etc.
• Repeat CT (if not done recently) to look for mass lesion requiring surgical intervention.
T Treat pain with narcotics, e.g., morphine 2-10 mg IV for adults. Sedating effects may also help lower ICP. If response inadequate: consider benzodiazepines or propofol infusion (watch blood pressure).
I If ICP still elevated: neuromuscular blockade. Monitor depth of paralysis with nerve stimulator.
Note: try to hold sedation and paralysis at least once a day (such as before morning rounds) so that a valid neurologic examination can be performed.
If ICP still elevated: drainage of cerebrospinal fluid (CSF) via ventriculostomy.
If CSF drainage fails or is not possible: mannitol 0.25-1.0 g/kg bolus. May repeat prn as long as fluid balance is followed closely and serum osmolality stays below 320 mOsm/L.
If ICP elevation persists: may try mild hyperventilation (keeping Paco2 > 30 mmHg), especially if cerebral oxygenation is monitored by Sjvo2 catheter and/or by Pbto2 monitor.
Next step: pentobarbital-induced coma. Meticulous attention must be paid to avoiding arterial hypotension. Consider having pressors hanging and ready to be infused as pentobarbital is given.
Other treatments:
• Hypothermia was not beneficial when tested in a multicenter trial, but it is possible that select subgroups of patients may benefit.
• Decompressive craniectomy may be an option in some cases (especially with unilateral pathology), but this treatment still awaits validation in a rigorous trial.
8. What are some indications for Emergency Department thoracotomy? (www.trauma.org) [NB: ED thoracotomy is a costly and drastic episode of drama best reserved for patients with rapid deterioration in the ED, or who have undergone cardiac arrest just before arrival with signs of life still present. Patients who have undergone prolonged CPR or patients with blunt trauma who sustain cardiac arrest at the scene should not have this procedure done. I prefer to teach residents on live patients, not dead ones].
1. Penetrating thoracic injury &;
- Traumatic arrest with previously witnessed cardiac activity (pre-hospital or in-
hospital)
- Unresponsive hypotension (BP < 70mmHg)
2. Blunt thoracic injury
- Unresponsive hypotension (BP < 70mmHg)
- Rapid exsanguination from chest tube (>1500ml). [NB These patients should be expediently transported to the OR. The results of ED thoractomy for blunt trauma patients are uniformly dismal. See previous comment]
9. Describe the management options in a patient with a grade 4 splenic injury?
[Trauma - 5th Ed. (2004)]
Grade IV splenic injury =
Hematoma: ruptured intraparenchymal hematoma with active bleeding
Laceration: laceration involving segmental or hilar vessels producing major devascularization (> 25% of spleen)
Treatment options include:
1. Operative management – Pre-op abx. Trauma laparotomy. Pack off the abdomen in all 4 quadrants and localize injuries and bleeding. Splenectomy or splenorrhaphy for injured spleen. Postoperative immunizations to reduce incidence of OPSI.
2. Non – Operative management – Appropriate patient selection is the most important element of nonoperative management. Although it is certainly true that nonoperative management is possible in a large number of patients with splenic injury, emergency surgery is still sometimes necessary to stop life-threatening hemorrhage. Of paramount importance is the hemodynamic stability of the patient. Assuming hemodynamic stability, the other important prerequisite is the patient's abdominal examination. In patients who are awake and alert and can cooperate with a physical exam and provide feedback, it is important that they not have diffuse, persistent peritonitis. Nonoperative management should only be undertaken if it will be possible to closely follow the patient. ICU admission with serial blood draws, checking Hematocrit and serial abdominal exams is best. Reported success rates for nonoperative management are 95% or higher for pediatric patients and approximately 80% or higher in adults
[NB: CT scanning is mandatory in these patients and should be repeated if there is any suspicion of a bowel injury]
10. Name some late complications of non-operative treatment of blunt hepatic injuries. How are they managed? [Trauma - 5th Ed. (2004)]
Bile Leaks: Bilomas or bile leak can occur in 3 to 20% of nonoperatively managed patients. Evidence of bile leak by HIDA scan does not mandate intervention. Abnormal liver function tests, abdominal distention, and intolerance to feeding may all indicate a bile leak. CT scan evaluation with drainage percutaneously usually remedies the problem completely. Bile leaks or bilomas are drained percutaneously, sometimes for up to 4 to 6 weeks, and they nearly always resolve without ERC or other decompressive maneuvers.
Abscess: Abscesses, such as biliary collections, can often be managed by CT-guided drainage catheters. However, if the patient fails to improve with drainage and antibiotics, wide surgical drainage should be performed.
Hemorrhage: Using the same criteria that was originally utilized to manage these patients nonoperatively, namely hemodynamic stability without ongoing blood loss, patients with delayed hemorrhage can undergo hepatic angiographic embolization and observation with success. Therefore, it seems that delayed hemorrhage is actually a rare and manageable complication.
Compartment syndrome of the liver: Operative drainage
Hemobilia: The authors concluded that hepatic artery pseudoaneurysm with hemobilia is predisposed by a bile leak and that angiographic embolization was appropriate for patients without sepsis and with small cavities. However, formal hepatic resection or drainage, after angiographic vascular control, may be necessary for septic patients or those with large cavities. Hemobilia is much less common with the prevalence of nonoperative management. With operative interventions of the past including large parenchymal suturing and vessel ligation, communications between vessels and bile ducts often occurred iatrogenically. Now that nonoperative care is practiced, hemobilia is rare.
Thursday, October 16, 2008
ABSITE Review Questions
A 76 year old male undergoing a trauma laparotomy is found to be significantly hypothermic when a temperature probe foley catheter is placed. Warm IV fluids are started, a heating blanket is placed, the room temperature is increased, and warm intraabdominal irrigation is started. What additional step will also lead to an improvement in this patient's condition?
a. Close the patient and go to the ICU
b. Change propofol to diazepam
c. Wake the patient up
d. Go to cardiopulmonary bypass
e. Start ECMO
Want to know the right answer? Find out at the ABSITE Review Course
Wednesday, October 8, 2008
USMLE Score Calculator
USMLE Score Calculator
The data used to create the calculators is obtained from the public domain and from our own pool of students who have completed the entire USMLE Review course. The sample size is approximately 4,000 and consists of US Medical Graduates and Foreign Medical Graduates. The score estimate provided above is based on a complex multivariate weighted regression analysis and estimated continuous probability distribution.
With the calculator, you are able to enter one or more test scores to estimate your performance on the USMLE. If you have taken the NBME Comprehensive Basic Science Self-Assessment (CBSSA), choose either your most recent score or the average of your most recent scores if the exams are within the same timeframe. Enter only your raw score (out of 800), not the converted score (out of 300). Other testing services offer a 3 digit score or an overall percentage of correct answers. Enter your average percent based off a large (over 250 questions) pool of timed, single-use questions with no repeats.
As you move the sliders to the appropriate numbers, small icons on the graph will move to show your estimated performance as an overlay on a normal distribution. Your estimated three digit score is the X-axis, while the Y-axis is the Gaussian function. As you enter more scores, you will note that your score estimate (the black icon) will move around accordingly.
Both the estimator and calculator provide a USMLE 3 digit score, USMLE 2 digit score, and estimated percentile. The calculator also provides an overall standard deviation, which will vary depending on the number of testing services you have used. For information purposes only, an estimated pass indicator will glow red, yellow, or green depending on your overall performance. The yellow box to the right will provide some basic hints.
You are permitted to reset all of the data in the calculator, and to print its data for later use. We hope that you will enjoy the USMLE Score Calculator.
The data used to create the calculators is obtained from the public domain and from our own pool of students who have completed the entire USMLE Review course. The sample size is approximately 4,000 and consists of US Medical Graduates and Foreign Medical Graduates. The score estimate provided above is based on a complex multivariate weighted regression analysis and estimated continuous probability distribution.
With the calculator, you are able to enter one or more test scores to estimate your performance on the USMLE. If you have taken the NBME Comprehensive Basic Science Self-Assessment (CBSSA), choose either your most recent score or the average of your most recent scores if the exams are within the same timeframe. Enter only your raw score (out of 800), not the converted score (out of 300). Other testing services offer a 3 digit score or an overall percentage of correct answers. Enter your average percent based off a large (over 250 questions) pool of timed, single-use questions with no repeats.
As you move the sliders to the appropriate numbers, small icons on the graph will move to show your estimated performance as an overlay on a normal distribution. Your estimated three digit score is the X-axis, while the Y-axis is the Gaussian function. As you enter more scores, you will note that your score estimate (the black icon) will move around accordingly.
Both the estimator and calculator provide a USMLE 3 digit score, USMLE 2 digit score, and estimated percentile. The calculator also provides an overall standard deviation, which will vary depending on the number of testing services you have used. For information purposes only, an estimated pass indicator will glow red, yellow, or green depending on your overall performance. The yellow box to the right will provide some basic hints.
You are permitted to reset all of the data in the calculator, and to print its data for later use. We hope that you will enjoy the USMLE Score Calculator.
Monday, October 6, 2008
Great ABSITE Review Course♦
ABSITE Review Course
- #1 selling ABSITE review course in the world and on Amazon.com.
- Over 1,000 practice questions with detailed explanations - UPDATED AND REVISED.
- The ONLY comprehensive surgery and ABSITE review course that follows the American Board of Surgery content outline.
- Reviewed and trusted by program directors, faculty, and residents from top surgery programs.
- Covers all major topics on the ABSITE and surgery boards with the high-yield review textbook and a comprehensive online review course.
- New weekly reading course in surgery that follows key reference books in surgery (i.e. Sabiston’s, Cameron’s, and Greenfield’s). Includes reading summary, practice exams, slide presentations, and streaming lectures.
Wednesday, October 1, 2008
www.clinicalreview.com
ABSITE Study Tips
How you study for the ABSITE depends on how much time you have available. Motivated residents who prepare in advance will benefit the most from the online review program and the enormous body of information available on the website. Regardless of how much time you have available, this entire review program is designed to be done piecemeal using the short periods of time you have available on call nights and in between cases. Each topic is designed to be covered in just a few minutes, and many residents report making good progress on the question bank by doing a few questions over lunch each day. Those who are on night float rotations or taking call report making good progress on the high-yield PowerPoint reviews.
Based on resident feedback, our recommendation is to keep the pocket version of the book with you at all times. It is a handy book to go through whenever a few minutes are available. This larger book is seen more and more in the hospital as the exam draws closer, but most residents recommend spending an hour every evening months in advance to review this book. While each individual study plan will be different, there are a few trends that we have noticed with high scorers:
- Use this book in conjunction with the online questions and your existing reference books
- Do at least a dozen questions and read through several topics every night
- Review the high-yield PowerPoint presentations a week in advance of your exam
- Take note of your strengths and weaknesses and focus on them accordingly
- Keep your notes and review material from year to year
Whether you are preparing for the junior ABSITE or the senior ABSITE, we recommend going through this resource in its entirety. Topics that have appeared on one exam more than another are marked appropriately. Topics that have appeared on recent exams or more than once are marked by stars. In addition, topics that the reviewers have deemed to be particularly worthwhile are also highlighted. It is important to reiterate that the purpose of this book is to help you become a better doctor and surgeon – your score on this exam should reflect your mastery of basic science and clinical medicine, and their application to the field of surgery.
Learn more about our high quality review courses for the USMLE and ABSITE. Our review courses include access to thousands of practice questions with detailed explanations, high-yield online and published textbooks, slide reviews, and audio/video lectures. Learn more about the USMLE review and ABSITE review, and visit our exam preparation website.
ABSITE Practice Questions - www.ClinicalReview.com
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