90 Upper Urinary Tract Trauma (Campbell 12th)

Question 1

Most commonly injured urologic organ from external trauma.

Answer 1

Kidney

Question 2

Management of the majority of blunt and select penetrating injuries to the kidney.

Answer 2

Non-operative

Question 3

Absolute indications for immediate renal intervention

Answer 3

Hemodynamic instability with no or transient response to resuscitation

Pulsatile or expanding retroperitoneal hematoma

Question 4

Most important information to obtain in the history of blunt renal injury

Answer 4

Mechanism of injury

- the kidney is particularly vulnerable to deceleration injury

Question 5

What happens to the kidney with significant deceleration?

Answer 5

• tear at the retroperitoneal points of fixation (hilum, upj) –> renal artery thrombosis, renal vein disruption, renal pedicle avulsion, upj disruption

Question 6

How do high velocity wounds injure the kidneys without directly hitting them?

Answer 6

Blast effect –> causing delayed tissue necrosis.

Question 7

What structures are injured in stab wounds on the anterior axillary line?

Answer 7

Renal hilum

Renal pedicle

Question 8

What structures are injured in stab wounds on the posterior axillary line?

Answer 8

Renal parenchymal injury

Question 9

Indicators of possible renal injury on PE

Answer 9

Flank ecchymoses
Abdominal or flank tenderness
Rib fractures
Significant blow to the flank
Penetrating injuries to the low thorax or flank

Question 10

How many times does the risk of renal injury increase when there is ipsilateral rib fracture?

Answer 10

Threefold

Question 11

Best indicators of significant urinary system injury

Answer 11

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)

Question 12

The degree of hematuria and severity of the renal injury CONSISTENTLY CORRELATE.

True or false?

Answer 12

False

Question 13

How do you collect urine samples in trauma patients?

Answer 13

Collect the FIRST ALIQUOT OF URINE OBTAINED BY CATHETERIZATION OR VOIDING.

Later urine samples may be diluted by diuresis from resuscitation fluids.

Question 14

Will a very faint hint of pink be regarded as gross hematuria in trauma patients?

Answer 14

YES.

Any degree of visible blood in the urine is regarded as gross hematuria.

Question 15

How is microscopic hematuria determined?

Answer 15

Dipstick or microanalysis.

Question 16

Sensitivity and specificity of the dipstick method in determining microhematuria

Answer 16

97%

Question 17

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

Answer 17

True

Question 18

AAST Grade of:

Completely shattered kidney

Answer 18

V

Question 19

AAST Grade of:

Avulsion of renal hilum, devascularizing the kidney

Answer 19

V

Question 20

AAST Grade of:

Main renal artery or vein injury with contained hemorrhage

Answer 20

IV

Question 21

AAST Grade of :

Parenchymal laceration EXTENDING THROUGH THE RENAL CORTEX, MEDULLA, AND COLLECTING SYSTEM.

Answer 21

IV

Question 22

AAST Grade of:

> 1 cm parenchymal depth of renal cortex injury WITHOUT COLLECTING SYSTEM RUPTURE or WITHOUT URINARY EXTRAVASATION

Answer 22

III

Question 23

AAST Grade of:

<1 cm parenchymal depth of renal cortex WITHOUT URINARY EXTRAVASATION

Answer 23

II

Question 24

AAST Grade of:

NONEXPANDING PERIRENAL HEMATOMA confined to the renal retroperitoneum

Answer 24

II

Question 25

AAST Grade of: Microscopic or gross hematuria but with normal urologic studies

Answer 25

I

Question 26

AAST Grade of: Subcapsular, nonexpanding hematoma without parenchymal laceration

Answer 26

I

Question 27

5 indications for renal imaging in trauma (AUA and EAU 2014 based pa tong sa Campbell)

Answer 27

1. 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. 2. 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 3. Blunt trauma + gross hematuria 4. Blunt trauma + microhematuria AND hypotension (SBP <90 at any time during evaluation and resuscitation) 5. ALL pediatric patients >5 RBC/HPF

Question 28

Preferred imaging test for renal trauma

Answer 28

Abdominal/pelvic CT using IV contrast with immediate and delayed images.

Question 29

Can patients with microscopic hematuria be observed only?

Answer 29

Yes. As long as they don't or didn't have hypotension.

Question 30

True or false: Penetrating injuries of ANY DEGREE OF HEMATURIA should be imaged.

Answer 30

True.

Question 31

Why do children have higher risk for renal trauma?

Answer 31

``` Larger kidney size Less perirenal fat Non-ossified bones Less relative rib coverage Higher proportion of congenital renal abnormalities (severe hydronephrosis or UPJO) ```

Question 32

Why do children often do not become hypotensive with major blood loss?

Answer 32

Children have a high catecholamine output after trauma, which maintains blood pressure until approximately 50% of blood volume has been lost.

Question 33

What does lack of uptake of contrast material in the parenchyma suggest in the context of renal trauma?

Answer 33

Arterial thrombosis or transection

Question 34

How many seconds after contrast injection is the nephrogenic phase?

Answer 34

80 seconds

Question 35

In what phase of the CT scan can one identify parenchymal and collecting system injuries?

Answer 35

Delayed phase (10-15 mins after injection of contrast)

Question 36

CT findings that may indicate major renal injuries

Answer 36

1. Medial hematoma - vascular injury 2. Medial urinary extravasation - renal pelvis or UPJ avulsion 3. Global lack of parenchymal enhancement - renal artery occlusion 4. Combination of two or more of the following: - large hematoma greater than 3.5 cm - medial renal laceration - vascular contrast extravasation (brisk bleeding)

Question 37

Major limitation of CT in renal injury imaging

Answer 37

Inability to define a renal venous injury adequately

Question 38

How do you spot venous injury in CT scans of renal injury patients?

Answer 38

Normal arterial perfusion Normal parenchyma Normal delayed phase (collecting system) but with medial hematoma

Question 39

Scenario where a "one shot IVP" is warranted

Answer 39

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.

Question 40

The main purpose of the one shot IVP

Answer 40

To assess the presence of a functioning contralateral kidney.

Question 41

Explain the one shot IVP technique

Answer 41

A single film is taken 10 minutes after IV push of 2 mL/kg of contrast material.

Question 42

Dose of contrast material in one-shot IVP

Answer 42

2 mL/kg

Question 43

FAST is limited in what situations?

Answer 43

Obese patients Subcutaneous emphysema Prior abdominal oeprations

Question 44

What grades of renal injuries can nonoperative management be done in patients who are hemodynamically stable?

Answer 44

I to IVa

Question 45

If "carefully staged and selected" can grade IV and V renal injuries be observed?

Answer 45

Yes.

Question 46

What type of stab or gunshot wounds to the kidney can be managed nonoperatively?

Answer 46

Those isolated only to the kidney only.

Question 47

The only absolute intraoperative indication for kidney exploration

Answer 47

A pulsatile and expanding retroperitoneal hematoma that suggests a life-threatening renal artery laceration.