Particular attention should be paid to cardiac, diabetic, steroid, and immunosuppressive agents. Medications such as beta‐blockers, anti‐inflammatory agents, and over‐the‐counter medications can affect the patient’s response to infection and inflammation, limiting early vital sign abnormalities. The past medical history may provide clues to the underlying condition. Past surgical history may point toward recurrent pathology such as diverticulitis or a complication of prior procedures such as abdominal wall hernias or bowel obstructions. History taking should include information about previous episodes of similar pain, diagnosis, and management. The patient should be questioned about his/her last oral intake and menstrual period. Finally, the events leading up to the current illness and EMS activation should be elicited.
Box 19.4 OPQRST questions in abdominal pain
Onset: When did your pain begin?
Palliation/Provocation: What were you doing when your pain started? What makes your pain better or worse? If you have taken anything for the pain, has it changed your symptoms? Are you more comfortable in a certain position?
Quality: Can you describe what your pain feels like?
Radiation: Do you feel pain anywhere else? Does the pain move to any other place?
Severity: How bad is your pain on a scale from 1 to 10, if 10 is the worst pain you can imagine?
Timing: Since it started, has your pain changed in quality, severity, or location?
The patient’s general appearance should be assessed. Seasoned EMS clinicians develop an immediate impression of those who are “sick.” A patient who limits his or her movement due to abdominal pain may have peritonitis, as opposed to one who cannot find a position of comfort (e.g., kidney stones or aneurismal pain).
The focus of the physical examination should be to identify potentially life‐threatening conditions. Assessment and monitoring of vital signs is crucial. Indications of shock, including hypotension, tachycardia, narrow pulse pressure, tachypnea, or low end‐tidal CO2 should be recognized. A hypotensive patient should be presumed to have a serious medical condition requiring immediate intervention.
A careful examination of the heart and lungs should be completed. Abnormal or diminished lung sounds may indicate pneumonia or pleural effusion, which may present as ipsilateral upper abdominal pain. Cardiac auscultation may detect murmurs or gallop rhythms, which may be associated with an acute myocardial infarction or heart failure presenting with vague abdominal pain or GI symptoms as the chief complaint.
EMS clinicians should perform a brief, directed examination of the abdomen. Inspection of the abdomen should be performed to detect distention, skin lesions, or bruising. The presence of therapeutic appliances such as cardiac assist devices, feeding tubes, dialysis access ports, ostomies, and urinary catheters should be noted, as well as their appearance and the condition of surrounding skin. Auscultation of bowel sounds is neither accurate nor productive in the out‐of‐hospital setting. Similarly, percussion does not yield any important findings in these patients.
Palpation should first be performed in the areas away from the region of discomfort. The area of pain should be assessed last with gradually increased pressure to allow some qualification of the level of discomfort (e.g., pain with gentle palpation). Specific findings such as Murphy’s sign, Rovsing’s sign, obturator sign, and psoas sign are neither sensitive nor specific. Percussion of the patient’s heel while the leg is fully extended, or noting pain with movement of the ambulance, may be more effective than depressing and releasing the abdominal wall to detect rebound tenderness. Deep palpation to detect a pulsatile mass in the abdomen is discouraged due to its low yield and theoretical potential for exacerbating the patient’s condition if an aortic aneurysm is present.
Management
Management of the patient with abdominal pain begins with attention to the patient’s airway, ventilation, and hemodynamic stability. Patients in profound shock may benefit from a secure airway and positive‐pressure ventilation. Vascular access is indicated in some abdominal pain patients for fluid and medication administration. If the patient has experienced significant fluid loss or has evidence of shock, two large bore IVs should be established. If IV access is difficult or unobtainable, intraosseous access may be indicated. Resuscitation with crystalloid solution (normal saline or Ringer’s lactate) is generally indicated for prehospital hemodynamic instability. The increasing availability of blood products in the out‐of‐hospital environment is enabling their administration for nontraumatic indications such as massive gastrointestinal hemorrhage or aneurysmal rupture. However, evidence‐based indications and outcome data are lacking [4, 5]. Vasopressors such as norepinephrine may be indicated if septic shock from an abdominal source is suspected and the mean arterial pressure is below 65 mmHg despite adequate volume resuscitation. While such medications are often not available to prehospital EMS personnel, they may be available to EMS physicians or to personnel providing an interfacility transport for more advanced care. Any patient with hemodynamic compromise should have continuous cardiac monitoring; the same may be true for all patients over 50 years of age, though again, evidence is lacking. A 12‐lead ECG should be obtained and interpreted to rule out acute myocardial infarction in patients with cardiac risk factors such as age, diabetes, or hypertension. Continuous pulse oximetry should be used in critically ill patients or those with suspected pulmonary etiologies. Supplemental oxygen should be administered to patients with respiratory distress or hypoxia.
There are reports describing the use of ultrasound in the prehospital setting. New ultrasound technology is lightweight, provides high‐quality resolution, and can withstand a wider range of environmental conditions. Some paramedics have been trained in the focused assessment with sonography in trauma (FAST) exam as well as abdominal aortic ultrasound to evaluate for aneurysm. Multiple studies have shown that under close physician supervision, the point‐of‐care FAST exam and abdominal aorta ultrasound are feasible and useful in the prehospital setting [6–8]. They can provide earlier information regarding the patient’s condition, leading to more informed triage decisions, reduced time to diagnosis, and improved delivery to definitive care (see Chapter 69).
Several studies have evaluated prehospital lactic acid measurement in nontrauma patients. There may be potential benefit for undifferentiated patients with abdominal pain. Elevation in prehospital lactate has been linked to mortality and may provide information superior to that of the patient’s vital signs in detecting occult shock, as well as facilitating resuscitation at an earlier stage in patient care [9–11].
Historically, there have been eloquent expressions of concern regarding analgesic administration to not‐yet‐diagnosed patients with abdominal pain [12–15]. The general foundation for reluctance to pursue pain relief is belief that pain provides an important diagnostic clue, and any attenuation could lead to delayed or missed diagnosis of important pathology. Proponents of treating abdominal pain with analgesics stress that a more comfortable patient is better able to participate in a reliable physical examination, and diagnostic tools and accuracy have improved greatly since concerns were articulated. They further point out that adverse outcomes related to diagnostic efficiency are not directly associated with analgesic administration [15–20]. Thus, the goal for EMS has generally evolved. Pain should be treated to the extent that it facilitates a detailed history and physical exam from a patient who is alert and able to cooperate. Opioids have been the mainstay of pain management. However, other agents may also provide value in specific circumstances and, barring general contraindications, include nonsteroidal anti‐inflammatory drugs (e.g., ketorolac), acetaminophen, and nondissociative doses of ketamine [21].
