90 Upper Urinary Tract Trauma (Campbell 12th) Flashcards
Most commonly injured urologic organ from external trauma.
Kidney
Management of the majority of blunt and select penetrating injuries to the kidney.
Non-operative
Absolute indications for immediate renal intervention
Hemodynamic instability with no or transient response to resuscitation
Pulsatile or expanding retroperitoneal hematoma
Most important information to obtain in the history of blunt renal injury
Mechanism of injury
- the kidney is particularly vulnerable to deceleration injury
What happens to the kidney with significant deceleration?
- tear at the retroperitoneal points of fixation (hilum, upj) –> renal artery thrombosis, renal vein disruption, renal pedicle avulsion, upj disruption
How do high velocity wounds injure the kidneys without directly hitting them?
Blast effect –> causing delayed tissue necrosis.
What structures are injured in stab wounds on the anterior axillary line?
Renal hilum
Renal pedicle
What structures are injured in stab wounds on the posterior axillary line?
Renal parenchymal injury
Indicators of possible renal injury on PE
Flank ecchymoses Abdominal or flank tenderness Rib fractures Significant blow to the flank Penetrating injuries to the low thorax or flank
How many times does the risk of renal injury increase when there is ipsilateral rib fracture?
Threefold
Best indicators of significant urinary system injury
Gross and microscopic hematuria (>5 RBC/HPF or positive dipstick finding)
– especially when associated with acceleration/deceleration injury, penetrating trauma, hypotension at the ER (SBP <90)
The degree of hematuria and severity of the renal injury CONSISTENTLY CORRELATE.
True or false?
False
How do you collect urine samples in trauma patients?
Collect the FIRST ALIQUOT OF URINE OBTAINED BY CATHETERIZATION OR VOIDING.
Later urine samples may be diluted by diuresis from resuscitation fluids.
Will a very faint hint of pink be regarded as gross hematuria in trauma patients?
YES.
Any degree of visible blood in the urine is regarded as gross hematuria.
How is microscopic hematuria determined?
Dipstick or microanalysis.
Sensitivity and specificity of the dipstick method in determining microhematuria
97%
The presence or absence of hematuria should not be the sole determinant in the assessment of a patient with suspected renal trauma.
True or false
True
AAST Grade of:
Completely shattered kidney
V
AAST Grade of:
Avulsion of renal hilum, devascularizing the kidney
V
AAST Grade of:
Main renal artery or vein injury with contained hemorrhage
IV
AAST Grade of :
Parenchymal laceration EXTENDING THROUGH THE RENAL CORTEX, MEDULLA, AND COLLECTING SYSTEM.
IV
AAST Grade of:
> 1 cm parenchymal depth of renal cortex injury WITHOUT COLLECTING SYSTEM RUPTURE or WITHOUT URINARY EXTRAVASATION
III
AAST Grade of:
<1 cm parenchymal depth of renal cortex WITHOUT URINARY EXTRAVASATION
II
AAST Grade of:
NONEXPANDING PERIRENAL HEMATOMA confined to the renal retroperitoneum
II
AAST Grade of:
Microscopic or gross hematuria but with normal urologic studies
I
AAST Grade of:
Subcapsular, nonexpanding hematoma without parenchymal laceration
I
5 indications for renal imaging in trauma (AUA and EAU 2014 based pa tong sa Campbell)
- Penetrating trauma with a likelihood of renal injury (abdomen, flank, ipsilateral rib fracture, significant flank ecchynmosis, or low chest entry/exit wound) who are hemodynamically stable enough to have a CT.
- All patients with BLUNT TRAUMA with significant acceleration/deceleration mechanism of injury (specifically rapid deceleration), as would occur in a high speed MVA or fall from heights
- Blunt trauma + gross hematuria
- Blunt trauma + microhematuria AND hypotension (SBP <90 at any time during evaluation and resuscitation)
- ALL pediatric patients >5 RBC/HPF
Preferred imaging test for renal trauma
Abdominal/pelvic CT using IV contrast with immediate and delayed images.
Can patients with microscopic hematuria be observed only?
Yes. As long as they don’t or didn’t have hypotension.
True or false:
Penetrating injuries of ANY DEGREE OF HEMATURIA should be imaged.
True.
Why do children have higher risk for renal trauma?
Larger kidney size Less perirenal fat Non-ossified bones Less relative rib coverage Higher proportion of congenital renal abnormalities (severe hydronephrosis or UPJO)
Why do children often do not become hypotensive with major blood loss?
Children have a high catecholamine output after trauma, which maintains blood pressure until approximately 50% of blood volume has been lost.
What does lack of uptake of contrast material in the parenchyma suggest in the context of renal trauma?
Arterial thrombosis or transection
How many seconds after contrast injection is the nephrogenic phase?
80 seconds
In what phase of the CT scan can one identify parenchymal and collecting system injuries?
Delayed phase (10-15 mins after injection of contrast)
CT findings that may indicate major renal injuries
- Medial hematoma - vascular injury
- Medial urinary extravasation - renal pelvis or UPJ avulsion
- Global lack of parenchymal enhancement - renal artery occlusion
- Combination of two or more of the following:
- large hematoma greater than 3.5 cm
- medial renal laceration
- vascular contrast extravasation (brisk bleeding)
Major limitation of CT in renal injury imaging
Inability to define a renal venous injury adequately
How do you spot venous injury in CT scans of renal injury patients?
Normal arterial perfusion
Normal parenchyma
Normal delayed phase (collecting system)
but with medial hematoma
Scenario where a “one shot IVP” is warranted
When the surgeon encounters an UNEXPECTED RETROPERITONEAL HEMATOMA surrounding a kidney during ex-lap in an UNSTABLE trauma patient, WITHOUT a previous CT — AND, are contemplating renal exploration or nephrectomy.
The main purpose of the one shot IVP
To assess the presence of a functioning contralateral kidney.
Explain the one shot IVP technique
A single film is taken 10 minutes after IV push of 2 mL/kg of contrast material.
Dose of contrast material in one-shot IVP
2 mL/kg
FAST is limited in what situations?
Obese patients
Subcutaneous emphysema
Prior abdominal oeprations
What grades of renal injuries can nonoperative management be done in patients who are hemodynamically stable?
I to IVa
If “carefully staged and selected” can grade IV and V renal injuries be observed?
Yes.
What type of stab or gunshot wounds to the kidney can be managed nonoperatively?
Those isolated only to the kidney only.
The only absolute intraoperative indication for kidney exploration
A pulsatile and expanding retroperitoneal hematoma that suggests a life-threatening renal artery laceration.
