Unintentional Plastic Blister Ingestion Leading to Intestinal Perforation: A Report of Two Cases

Introduction

The ingestion of foreign bodies is a common reason for emergency department visits. Bone fragments, chicken bones, teeth, and cocktail sticks are among the most commonly swallowed foreign bodies [1]. Children, older individuals, those with concomitant psychiatric conditions, intoxicated persons, individuals with visual impairments, and those with dentures are particularly susceptible due to reduced palatal sensitivity [1,2]. Complications arising from foreign body ingestion, such as bleeding or perforation, requiring endoscopic or surgical intervention, occur in approximately 1% of cases [2]. Despite their low ingestion rates, tablet blister packs pose an increased risk of injury and perforation due to their sharp-edged shape.

The diagnosis of blister ingestion can be challenging due to the often vague clinical presentation and the limited visibility of blister packs in initial imaging studies [1,3]. Therefore, it is important to consider the possibility of blister ingestion in cases of unclear throat or abdominal complaints, especially in patients at higher risk.

In the current context of an aging society, this topic is pertinent. Due to its rarity, limited references in the literature, and difficulty in diagnosis, raising awareness about this clinical situation is crucial to avoid possible fatal events due to late or non-identification of blister ingestion.

Case Reports

CASE 1:

A 75-year-old man presented to the emergency department of the Cantonal Hospital St. Gallen in Switzerland, with acute onset of constant abdominal pain in the right upper quadrant and epigastric regions. He reported having taken 3 painkillers that morning. The patient had undergone abdominal surgeries and an endovascular aortic repair in 2015 for a ruptured abdominal aortic aneurysm. Despite suffering from mild cognitive impairment, he lived alone at home.

Upon examination, he was hypotensive (64/44 mmHg) but otherwise hemodynamically stable. He had marked tenderness and guarding in the right upper abdominal quadrant. Non-contrast abdominal computed tomography (CT) was un-remarkable (Figure 1A). Thus, the cause of abdominalgia remained unclear.

The patient developed an acute abdomen on the first day after admission. A second CT of the abdomen was performed with angiography. This revealed short-stretched wall thickening of the small intestine in the right mid-abdomen, as well as a small intraluminal hyperdense structure 2 cm in length (Figure 1B). Strong clinical suspicion of perforation prompted an exploratory laparotomy.

Midline upper abdominal laparotomy was performed. Upon exploration of the right hemiabdomen, a loop of the small intestine was dislodged, revealing a 3-mm perforation 50 cm proximal to Bauhin’s valve in the mesentery region. A foreign body could be palpated (Figure 2A). The perforation site was dilated through an enterotomy, and the foreign body was extracted. The foreign body was identified as an empty medication blister (Figure 2B). During the patient’s inpatient stay, he was asked if he could recall swallowing the blister, which he denied.

CASE 2:

A 55-year-old man was brought to our emergency department of the Cantonal Hospital St. Gallen in Switzerland with unexplained unconsciousness, a Glasgow Coma Scale score of 3, and respiratory depression. The patient had a history of polytoxicomania, including heroin abuse and persistent use of ethyl alcohol, nicotine, and hashish.

The intubated patient exhibited cardiopulmonary stability, a soft abdomen, and various contusion marks upon physical examination. A non-contrast CT of the skull showed an acute subdural hematoma in the right hemisphere, which could explain the reduced vigilance. A contrast-enhanced CT of the lungs showed aspiration in the right lung and an unidentified foreign body in the stomach (Figure 3A). Retrospectively, a foreign body is also visible in the esophagus, which was initially overlooked (Figure 3B).

First, an emergency craniotomy was performed. Gastroscopy was performed to retrieve the foreign body, an empty drug blister, in the esophagus 20 cm from the dentition (Figure 4A). The blister caused mild mucosal injury with bleeding; however, there was no evidence of perforation. A second empty tablet blister, measuring approximately 2 cm in length, was found in the stomach corpus. No mucosal lesions were observed (Figure 4B). After further improvement in the patient’s breathing and neurological condition, he was extubated uneventfully.

The patient’s daughter reported that he had been experiencing confusion and a noticeable decline in his usual mental faculties over the preceding weeks. She further mentioned that he had been engaging in repetitive swallowing of objects, such as foam shavings or cigarettes. A psychosomatic assessment revealed no evidence of psychosis or suicide. The patient stated that he could not remember these events and denied consuming any additional substances. The circumstances leading to ingestion remained unclear throughout the study period.

Discussion

Foreign bodies are usually released through defecation. However, complications, such as bleeding or perforation, occur in approximately 1% of cases, which necessitate surgical or endoscopic intervention [2], as was the case for both of our patients. Our first patient was at increased risk of swallowing a foreign body because of his age and mild cognitive impairment, as noted in his medical history. In the case of our second patient, polytoxicomania, with its often-associated cognitive decline, was the most likely causative factor.

In the case of swallowed tablet blisters, the risk of injury is increased by sharp edges, which occur particularly in individually cut blisters. This risk is further exacerbated by the fact that small injuries to the intestinal mucosa caused by blister edges can lead to swelling of the intestinal mucosa with consecutive blister impaction. The most common sites of foreign body perforations are the ileum and jejunum [2,3].

To date, there have only been a few case reports on the frequency of intestinal perforations due to blister impaction. Based on these limited data and the assumption that there is a high number of undiagnosed blister ingestions, we assume that the risk of perforation after tablet blister ingestion is substantial.

This condition necessitates an early diagnosis. However, as demonstrated in our cases, this can be difficult to achieve for several reasons. First, a history of abdominal pain is often non-specific, and patients often cannot recall the ingestion of tablet blisters, as in both of our cases [4]. Second, tablet blisters are often difficult to recognize on initial imaging depending on the gating plane [5]. In the lateral view, the plastic blisters with their aluminum foil closure and the tablets, surrounded by a small air gap, often appear like small “unidentifiable flying objects” [6]. As in both our cases, blisters can often only be recognized in a retrospective review of the images, with knowledge of the clinical course [7]. The challenges in radiological diagnosis, even for experienced radiologists, are also reflected in our 2 cases. At our center, radiological images are initially assessed by a resident physician or a junior consultant, and are subsequently reviewed and verified daily by a senior consultant or head physician. In the first case, contrast enhancement was not applied for the initial imaging study despite the fact that the patient had renal insufficiency requiring dialysis; thus, according to the literature, contrast administration could have been applied [8]. This may have facilitated the initial diagnosis. In the second case, despite the CT, a second blister in the esophagus remained undetected until gastroscopy. The possibility of blister ingestion should be considered in patients with unclear abdominal complaints and no clear imaging findings.

Prophylactic measures are of great importance because diagnosis may be difficult. Tamura et al showed that blister packs with rounded edges and softer materials can reduce the risk of esophageal perforation after blister ingestion. Industrial efforts to create new packaging forms are well known in Japan [9]. However, we argue that blister packs should be avoided wherever possible, and efforts should be made to explore alternative forms of packaging. In routine clinical practice, the preparation of medications in blisters before dispensing them to the patient is established for safety (control of medication according to the dual control principle) and practical reasons (protecting medications from environmental influences); the tablets are only to be pressed out of the blisters immediately before dispensing. The instructions provided at our hospital were similar to this. Nevertheless, if medication is administered in a blister pack, it should be done under the supervision of a specialist. In the case of unsupervised administration, the cognitive state of the patient should be taken into account [3,10]. However, instances of accidental ingestion of medication blisters have also been documented in patients who exhibited no signs of cognitive impairment prior to the incident [10]. In 2016, Prokop et al presented a case report that prompted the issuance of hospital staff guidelines on tablet handling, prohibiting the provision of oral medicines in blisters [3]. In our first case, it remained unclear whether the patient had received the medication. However, it can be assumed that it is hardly feasible for caregivers in the nursing service or relatives to be present when the patient consumes each tablet, particularly in the case of outpatients. This is especially true regarding medication that the patient takes only as needed. If possible, cutting of the medication blisters in the outpatient setting should only be carried out with simultaneous rounding of the corners. Furthermore, we consider good patient training on medication intake as an essential measure for cognitively impaired patients.

The limitation of this case report lies in the lack of denominator data essential for calculating disease rates. Additionally, the lack of a comparison or control group compromises statistical validity, posing a risk of bias in the outcomes.

Conclusions

The ingestion of tablet blisters is rare. Often, these events are not recalled by patients. Nevertheless, this should be considered in patients with unclear abdominal complaints and one or more risk factors for blister ingestion. If blister ingestion is suspected, a rapid diagnosis should be made to enable early detection of perforation, and the medical team should react accordingly. In the future, additional research could enhance the accuracy of radiological detection for blister ingestion, thereby preventing delays in response. Therefore, prophylactic measures are essential. If possible, cutting medication blisters and subsequent unsupervised medication intake should be avoided. Early identification of at-risk patients and implementation of prophylactic measures is of great importance.