Chapter 15 Acute back pain

Case 15.1

1. Using only this information, list the possible causes of Caitlyn’s pain. Justify your answers.

Possible diagnosis	Reasons likely	Reasons unlikely
DDx 1: gynaecological problem (eg: ovarian cyst, ovarian torsion)	• Low back pain, history of abdominal pain • Pain diffuse and poorly localised • Episodic history related to menstrual cycle • Dyspareunia • Pressure during urination/bowel movements • Abnormal menstruation • Abdominal bloating • Unable to become pregnant
DDx 2: musculoskeletal problem (eg: lumbar joint sprain, lumbar disc injury)	• Onset after exercise • Low back pain • Her pain is diffuse and poorly localised Pain aggravated with sneezing, straining (Valsalva)
DDx 3: other type of gynaecological problem (eg: polycystic ovarian syndrome, pelvic inflammatory disease, endometriosis)	• Lower abdominal pain, back pain • Irregular menstrual cycle • Bloating	• No hirsutism, acne or obesity: polycystic ovarian syndrome less likely (but still possible) • No dysmenorrhoea
DDx 4: ectopic pregnancy or threatened abortion	• Lower abdominal pain, amenorrhea and vaginal bleeding are classic triad of symptoms. May or may not have all symptoms. This patient presents with abdominal pain and cannot recall last menstrual cycle so this is a possible diagnosis	• No vaginal bleeding so threatened abortion less likely • Pregnancy test was negative
DDx 5: gastrointestinal problem (unlikely)	• Abdominal pain	• Appetite and weight normal • No GIT symptoms
DDx 6: neoplasm (unlikely)	• Usually asymptomatic in early disease • Abdominal pain and bloating • Irregular menses • Other features may include: altered bowel habit, vaginal bleeding, abdominal distension, pelvic mass, bowel obstruction	• Less common in women younger than 40 • No symptoms suggestive of this diagnosis
DDx 7: renal problem (unlikely)	• Usually presents with flank pain that is diffuse and severe • Pressure with urination	• No frequency, urgency or blood in urine

2. Why was Caitlyn asked about:

a the quality of the pain

The quality of the pain helps determine the underlying structure that may be involved in causing the pain. In this case, the quality of the pain is diffuse and poorly localised. This can indicate either referred pain from another structure, including somato–somatic referral or viscero–somatic referral, or may indicate and underlying inflammatory response is occurring.

b the nature of the onset of the pain

The nature of the onset of pain also helps determine which underlying structure may be involved, and also which pathophysiological process may be occurring to the involved structures, and helps to establish a timeframe. For example, a traumatic onset is more likely to cause traumatic injuries such as fractures, dislocations and tearing, and can involve structures such as bones, ligaments and muscles. This is usually an acute pain scenario. An insidious onset may indicate that a less obvious but potentially more serious problem is occurring.

c pain at rest and pain affecting sleep

When a person is resting, the pressures and impact of movement, posture and external environmental influences are lessened, giving the body time to recover and heal, and as such, often providing relief from pain. When rest does not provide relief from pain, the diagnostician must consider this to be a red flag; persistent pain may represent a dangerous diagnosis that requires further medical investigation. Pain that worsens at night or does not allow sleep may also indicate serious underlying pathology, although it is usually a reflection of the severity of the pain.

d the significance of sneezing and straining

The Valsalva manoeuvre is a test performed to determine the effects of increased pressure on the spinal cord and meningeal tissue. The patient is asked to take a deep breath, and to hold it while bearing down as if to pass a bowel movement. This test causes increased intrathecal pressure, as well as an increase in intra-abdominal pressure due to the action of breath-holding with bearing down. If a space occupying lesion exists within the spinal canal (such as a herniated disc, tumour or osteophytic bony outgrowths), this increase in pressure can irritate the neural and thecal tissue at the site. Increasing intra-abdominal pressure causes compression of the visceral contents within the abdomen; if any inflammation or underlying pathology/injury exists, compressing the involved organs may result in pain or discomfort. Sneezing and straining to go to the toilet are both events that naturally cause a Valsalva manoeuvre, and thus may cause pain.

e the pattern of pain

Establishing the pattern of pain will show whether the pain follows an episodic or relapsing/remitting course, or if it is constant. This allows you to see how the problem began and developed over the course of time. This may give a clearer insight into which structures and processes are involved in the underlying problem.

f her menstrual history

This is particularly relevant to female patients who present with low back or abdominal pain, or who complain of genitourinary or possible endocrine symptoms. Reproductive function may be altered by endocrine conditions, and anatomically the reproductive structures are situated within the pelvic cavity or lower abdomen.

g her genitourinary history

This is relevant to a patient who complains of low back or abdominal pain, as neurologically the genitourinary system is supplied by the thoracolumbar and sacral spinal levels, and anatomically the genitourinary organs are positioned within the low abdomen and pelvis.

3. What do you need to examine in this patient?

Examination	Justification
Inspection	• Overall body habitus, posture, appearance, wellness, level of discomfort
Vitals	• Blood pressure/heart rate/respiration: a measure of general health • Temperature: to exclude fever, underlying infection
Abdominal examination	• To exclude gastrointestinal, genitourinary and gynaecological involvement, look for masses, tenderness, guarding and rebound tenderness
Musculoskeletal examination	• Thoracolumbar, lumbar spine and hip for range of motion (ROM) and pain provocation. This should include: • slump test/ straight leg raise *: to determine the possibility of dural tension which may be due to intervertebral disc extrusion/prolapsed • Kemp’s test: to exclude lumbar facet joint involvement • sacroiliac joint provocation tests: to exclude sacroiliac joint involvement

(* The absence of positive findings with straight leg raising does not absolutely exclude disc involvement.)

4. What information can you obtain from these findings? Can you narrow your differential diagnosis?

Positive findings include abdominal distension, tenderness in the right iliac fossa with a possible mild ovarian enlargement being detected by palpation, and associated mechanical findings in the lumbar spine and sacroiliac region.

The slump test and Valsalva manoeuvre are negative, which lessens the likelihood of lumbar intervertebral disc involvement. These tests were, however, positive for pain provocation in the abdominal lower right quadrant and sacroiliac joint. There is a possibility that the increased intra-abdominal pressure caused by this test may have some type of effect on abdominal or pelvic viscera.

Kemp’s test was also negative, making lumbar facet joint involvement less likely.

5. Explain the significance of the following signs, in context of your differential diagnosis:

a no clubbing of the digits

Usually indicates involvement of the gastrointestinal, cardiovascular or respiratory systems.

b No conjunctival pallor

May indicate anaemia, which may occur via blood loss or dietary restrictions.

c kidneys not palpable

Exclude urinary involvement in back pain and abdominal pain, even though urinary pressure was felt during palpation of the ovary.

d no rebound tenderness

This test stretches the peritoneum and causes increased abdominal pain, and usually requires emergency assessment. An acute gastrointestinal problem such as appendicitis, peritonitis or haemorrhage is thus highly unlikely.

e abdominal bloating

Distension and bloating is a common complaint, but can indicate serious underlying conditions such as ascites caused by congestive heart failure, portal hypertension or kidney damage, as well as others such as bowel cancer, bowel obstruction or intraabdominal bleeding. It is mild in this case, so consider pregnancy, constipation, flatus, benign ovarian mass, irritable bowel syndrome.

f right lower quadrant tenderness

Includes conditions such as appendicitis, diverticulitis, endometriosis, ectopic pregnancy, ovarian cyst with or without haemorrhage/rupture, renal calculus. Some of these may be ruled out for other reasons already stated.

g hypertonic right psoas and lumbar erector spinae muscles and tender sacral sulcus

h absence of acne and hirsutism

These symptoms are typical of polycystic ovarian syndrome (PCOS), although not essential for its diagnosis. The lack of these symptoms make the diagnosis of PCOS a little less likely.

6. Caitlyn is referred to a medical practitioner. What investigations are required? Why? What would you expect, based on the physical examination findings?

Laboratory tests are not diagnostic for ovarian cysts but are useful for the exclusion of other differential considerations.

Investigation	Justification	Expectations based on differential diagnosis
Urinary or blood pregnancy test	To exclude pregnancy in any woman of child-bearing age with irregular menses	As she has no symptoms of pregnancy, it would be expected that this would be negative. However, ectopic pregnancy may present with abdominal and lumbar pain and a negative test
Full blood count	Screen for anaemia or infections	Expect a normal blood count, unless anaemia or infection is present. The white blood cell count may be elevated in presence of ovarian torsion or abdominal infection
CA125	Cancer antigen 125 for ovarian cancer	This protein is found on both normal ovarian and ovarian cancer cells. A serum level of less than 35U/mL is considered normal
Urinalysis	General screen for urinary conditions	Expect negative findings
Pelvic ultrasound	To assess for ovarian cysts, ovarian torsion, ovarian masses	Ovarian cysts vary considerably in size, but are commonly between 2.5–15cm in diameter, with thin rounded walls and hypoechoic appearance. If haemorrhage occurs due to rupture, appearance is anechoic on ultrasound. Ovarian torsion may present with an enlarged ovary and oedema