The Major Players of the RUQ

Of the 4 abdominal quadrants, the right upper quadrant is particularly challenging because it houses:

• a large portion of large bowel (the upper ascending and initial transverse colon);
• most of the liver;
• the gallbladder;
• peritoneum that covers these structures; and it is roofed over by the
• right hemidiaphragm.

Therefore, problems arising in the RUQ include, respectively:

• obstruction, spasm, or distention of the ascending colon or transverse colon;
• pain from liver conditions, such as hepatitis, mononucleosis, hepatic malignancy (usually metastatic), and liver capsule swelling;
• liver swelling from right-side heart failure;
• gallbladder infection ("cholecystitis") or obstruction (usually from stones, "cholelithiasis);
• diaphragmatic muscle strain, and
• pain arising from the distension or inflammation of the peritoneum covering or in close proximity to these organs.

The liver, gallbladder, and large colon are covered by a serosa of peritoneum origin, so any distention of their capsules can cause severe, sharp pain.

 

Referred Pain of RUQ Origin

Pain originating from problems in the RUQ can cause "referred pain" to the right shoulder blade. Referred pain is a confusion in the spinal cord of identifying the primary location of pain.

NOTE: "Afferent" (toward the spine) pain signals from the RUQ can cause firing of other afferent nerves going to that same spinal segment and flip pain signals back out ("efferent") to those areas, making it seem like the distant areas are primarily painful, too.

NOTE: pain from the RUQ can be referred to the right shoulder blade when deep breaths that depress the diaphragm push down on an inflamed organ in this area, creating a sudden exacerbation of its pain and worsening of any referred pain.

One must also be aware that lung conditions can also cause shoulder blade pain, either unilateral or bilateral,: pleurisy (pleuritis), pneumonia, or atelectasis (collapsed lung with pneumothorax).

Liver failure does not usually represent a pain syndrome in the RUQ; instead, it more likely presents as a progression from asymptomatic elevated laboratory liver enzymes all the way to somnolence, coma, and death.

 

Peritonitis

PERITONITIS: rupture of any of these organs can cause a diffuse peritonitis, with

• diffuse pain,
• rebound tenderness, and
• guarding,

which indicates surgical emergencies requiring immediate transport.

 

Pregnancy + RUQ Pain

►Call to Action: TRANSPORT

Any woman pregnant in her 2nd or 3rd trimester with RUQ pain warrants immediate transport, because this may represent HELLP Syndrome (Hemolysis, Elevated Liver enzymes, and Low Platelets), a life-threatening endpoint of pre-eclampsia ("toxemia" or "pregnancy-induced hypertension") with a high mortality rate. HELLP syndrome causes capsular swelling in the liver severe enough to rupture it. 

Pregnant women, because of their increased levels of progesterone, are prone to its slowing effects on peristalsis of the

• intestines (leading to constipation) and of the
• gallbladder (leading to stone formation and subsequent obstruction).

 

Child and Adolescent RUQ

Pain due to the liver is usually of viral origin, from pathogens that cause hepatosplenomegaly (swelling of the liver and spleen).

Epstein-Barr virus causes infectious mononucleosis, a cause for this type of organ swelling.

Fitzhugh-Curtis Syndrome: another cause of RUQ pain in sexually active adolescents is scarring around the liver from gonorrhea, called "Fitz-Hugh Syndrome." Fitz-Hugh Syndrome is probably scarring around the liver from free pus in the abdomen because of previous gonorrhea (active or resolved gonorrhea).

Toxins can cause liver failure with swelling, which is a consideration with adolescents engaging in high-risk behavior, such as abuse of hydrocarbon "snorting." This is an acute situation and may be life-threatening.

TORCH: infants and young children with hepatomegaly may have secondary syphilis (congenital) or have one of the other TORCH infections (Toxoplasmosis, "Other," including syphilis, Rubella, Cytomegalovirus, or Herpes infection)

CHOLECYSTITIS

Usually not seen in young women or children, except with the use of birth control pills. BCPs can slow down turnover in the gallbladder, resulting in stones that can be a surgical emergency.