The symptoms and signs of PE are highly variable and non-specific and a high index of suspicion is critical in the diagnosis of this potentially lethal condition. The most common symptoms of PE are dyspnea at rest or on exertion (73%), pleuritic chest pain (44%), and cough (34%) with calf pain (44%) and calf or thigh swelling(41%) indicating DVT preceding PE.35, 36
Patients with such symptoms or signs often need additional testing to confirm or exclude the diagnosis. Hiccups on the other hand are rarely associated with PE. Patients may also be completely asymptomatic, making the diagnosis more challenging. A meta-analysis of 28 studies found that among 5,233 patients who had DVT, 1,665 (32%) had asymptomatic PE, highlighting the importance of a high index of suspicion.37
Risk stratification or pretest probability assessment thus becomes paramount in raising awareness of a possible diagnosis of PE.
All patients with chest pain or shortness of breath should have CXR and ECG. In patients with high pretest probability and non-specific symptoms, even if CXR and EKG are normal d-dimer level, lower extremity duplex scan, ventilation-perfusion (VQ) scans and CT angiogram may be needed.35, 37–40
Numerous prediction models and algorithms have been developed for assessment of patients with possible PE, including the Geneva, Kline, Pulmonary Embolism Rule-out Criteria (PERC), Pisa and Wells systems.41–46
Of these the Wells criteria and the PERC rules are the most popular. The different elements included in these scoring systems are clinical history, physical examination, and diagnostic tests, such as arterial blood gas, D-dimer, ECG, and CXR with points ascribed to each element. Based on the total score and the clinical picture, the need for additional testing, such as VQ scans and CT angiograms, is determined by the clinician. Thus, by PERC rules if a patient meets all 8 criteria and falls into a low-risk category the probability of PE is < 2% and further testing may not be required. By Wells’ criteria, a patient with low probability of PE and a negative D-dimer test may be discharged home without more testing.
Zylicz reported a case of intractable hiccups due to PE suggesting that a thrombus in the inferior vena cava (shown on ultrasound) caused PE and then hiccups, but no objective evidence of PE is presented.33
Hiccups resolved with low molecular weight heparin, but recurred when heparin was discontinued. The patient also had underlying non-small cell lung cancer and it is unclear if lung cancer was the source of the hiccups. All of our patients had CT-documented PE and 2 had the risk factor of recent surgery.
Patient # 1 had a low Wells score of 1.5 (HR > 100), making him low risk, but he failed 3 of 8 PERC criteria and the CXR and overall gestalt raised suspicion for PE. Also the Kline decision rule (age/hypoxemia) put him in the unsafe category with a pretest probability of 45.2%. The revised Geneva score placed him in a moderate risk group based on tachycardia alone. Patient # 2 had a score of 3 on Wells criteria (HR > 100; recent surgery) and failed 2 of 8 PERC categories. In patient #3 Wells score was 1.5 (recent surgery), and he failed only 1 of 8 PERC categories.
Different scoring systems put patients in different risk categories highlighting the difficulty in relying only on one scoring system. Intractable hiccups in 2 patients raised our level of suspicion after our experience with patient #1, although both of these patients had recent surgery. CXR in patient #1 and EKG in patient # 2 also helped point us in the right direction. Our series of 3 patients with PE who had hiccups as a presenting symptom highlights the importance of including hiccups in the constellation of symptoms and signs associated with PE. If pretest probability testing is also taken into account, it will help us decide which patients need more advanced imaging and testing to confirm or exclude the diagnosis.