regard to resuscitating patients with abdominal pain and suspected or known intra‐abdominal hemorrhage, such as ruptured aortic aneurysm or ruptured ectopic pregnancy, attempts to restore normotensive states may not be possible in the prehospital environment. In fact, it may be harmful. These conclusions are drawn from animal and clinical studies of hemorrhagic shock that demonstrate that some level of “permissive hypotension” may improve outcomes [22–24]. Animal research showed no differences in organ perfusion, cardiac output, and lactic acid levels between permissive hypotension and normotensive resuscitation groups. It defined permissive hypotension as 60% of baseline mean arterial pressure [25].
Urinary catheters serve as both a management tool and source of some abdominal pain. Their presence and functionality should be noted during patient examination. Patients with both indwelling urethral and suprapubic catheters are at risk for urinary tract infections, mechanical obstruction, or catheter displacement. EMS clinicians may be trained to place urinary catheters, observing sterile technique, to relieve bladder distention. They should be educated that patients with recent urethral procedures or bleeding from the urethral meatus should not be catheterized due to risk of urethral injury.
Disposition
It is difficult for EMS personnel to identify patients who do not require transport and to make a decision regarding the need for medical evaluation in an ED. It is possible that a patient may not require EMS transport but may still require medical evaluation. Researchers have previously evaluated the accuracy of such decisions. When EMS clinicians were compared with physicians regarding need for patients to be transported, EMS clinician judgment was 22.1% sensitive and 80.5% specific [26]. The presence of abdominal pain was found to be highly associated with the need for transport as judged by the physicians. On the other hand, one study found 84% over‐triage with regard to provision of ALS care to patients with abdominal pain [27]. Significant under‐triage may also occur; 11% in one investigation [28]. Multiple evaluations have confirmed significant under‐triage by EMS personnel for a variety of medical conditions [29–31]. These studies reaffirm the need to exercise caution in approaching transport decisions in patients with abdominal complaints.
Special populations
There are certain populations who are at particular risk for poor outcomes and require an attentive approach.
Elderly
In 2016, there were 49.2 million people age 65 and over in the United States, accounting for 15% of the population [32]. By 2030, the number is projected to represent nearly 21% of the total U.S. population [33]. This population represents high‐volume users of the EMS system [34]. Compared to younger patients, geriatric patients have higher mortality when admitted to a hospital with abdominal pain and a higher rate of surgical intervention [34–36]. One third of elderly patients who present with abdominal pain require surgery, as compared with 10% for other adult patients [37].
The higher mortality rate in geriatric patients is due to several factors. Elderly patients delay seeking medical care for abdominal complaints and will often present later in their disease processes than younger patients. They tend to have more vague symptoms, which can make the evaluation difficult. The elderly have a decreased perception of abdominal pain [38]. Because of this, many elderly patients with significant underlying pathology are misdiagnosed with benign conditions.
Use of medications such as beta‐blockers, nonsteroidal anti‐inflammatory drugs, pain medications, anticoagulants, and steroids are more common in this population. In addition, other physiologic responses including fever, immune responsiveness, rebound tenderness, and laboratory abnormalities may not be as prominent in the older patient. Complex medical problems predispose this population to certain conditions, such as abdominal aortic aneurysm and mesenteric ischemia.
Common diagnoses found in the geriatric population with abdominal pain include diverticulitis, diverticulosis, small bowel obstruction, volvulus, malignancy, perforated viscous, urinary tract infection, appendicitis, and biliary tract disease. This list is not all‐inclusive. As mentioned previously, cardiac or pulmonary pathology can also present as abdominal pain, and must be entertained based on the patient’s history and physical exam. Additional historical information about abdominal pain as related to food intake, vomiting and/or diarrhea, melena or bright red blood per rectum, previous abdominal surgeries, fever, sick contacts, and other areas of pain should be elicited. Focus is necessary on the cardiac, pulmonary, and abdominal components of the physical exam. Cardiac and pulse oximetry monitoring is recommended.
Females of Childbearing Age
Females of childbearing age represent a particular challenge because the number of problems that cause abdominal pain in this population must be expanded to include conditions involving the pelvic organs. Specifically, ectopic pregnancy, ovarian torsion, ruptured ovarian cyst, and tubo‐ovarian abscess (TOA) as a consequence of pelvic inflammatory disease are significant causes of pain in this population. The difficulty in evaluating these possibilities lies in the fact that neither pelvic examination nor pregnancy testing are routinely available in the prehospital setting. Many patients do not know they are pregnant, and the physical exam is not reliable in establishing the diagnosis of pregnancy.
Ectopic pregnancy is one of the leading causes of pregnancy‐related deaths in women. Hemorrhagic shock from a ruptured ectopic pregnancy should be considered in any female of appropriate age with hypotension and abdominal pain. A past history of PID, known tubal pregnancy, prior tubal surgery, or intrauterine device use increases the likelihood of ectopic pregnancy.
Pelvic pain caused by ovarian torsion tends to be sudden in onset in reproductive‐age females. It is typically described as sharp and knife‐like. Right‐sided torsion is more common. The signs and symptoms of a ruptured ovarian cyst are difficult to distinguish from torsion. TOA occurs in approximately 1%‐4% of patients with PID [39]. The pain is more insidious in onset, and rupture of the abscess causes signs of peritonitis. Rupture of a TOA carries a mortality of approximately 10% [40].
Children
Pediatric patients present a challenge to EMS clinicians for a variety of reasons. As a rule, pediatric patients are not high‐volume users of the EMS system. In addition, infants and children may be unable to describe their symptoms, which is particularly problematic given the importance of historical data in establishing a cause. It is important to discuss the history of the patient’s symptoms and the reason why EMS was called with a parent or guardian familiar with the situation. Nonspecific findings such as irritability, inability to be consoled, and poor feeding may be the only signs of an abdominal problem in the very young. Vomiting, oral intake, urine output, last bowel movement, presence of fever, sick contacts, and vaccination status are useful points from the history. The birth history is important when treating a neonate. Questions that should be asked include whether the pregnancy was at term at the time of birth, did the mother receive prenatal care, were there any complications during the delivery, did the patient require an extended hospital stay after the birth, and have there been any subsequent hospitalizations since birth for any reason. Vital signs can be difficult to interpret in the pediatric population due to age‐related variations and the tremendous physiologic reserve that these patients possess. The examination can be compromised by the patient’s fear of pain and of the unfamiliar examiner. Finally, abdominal pain is a particularly common complaint in many extra‐abdominal conditions, as discussed above [41].
Age is a key factor in the evaluation of abdominal pain in the pediatric patient. For patients up to 1 year old, some of the considerations include infantile colic, Hirschsprung’s disease, necrotizing enterocolitis, intussusception, pyloric stenosis, volvulus, and incarcerated hernia. Bilious vomiting accompanying abdominal pain in an infant is particularly
