Delayed diagnosis of acute appendicitis in the first trimester of pregnancy leading to adverse pregnancy and maternal outcomes: a case report and literature review

¹Department of Obstetrics and Gynaecology, College of Health Sciences, University of Zimbabwe, Parirenyatwa Hospital, Mazowe Street, PO Box A168, Avondale, Harare, Zimbabwe, ²Department of Surgery, College of Health Sciences, University of Zimbabwe, Parirenyatwa Hospital, Mazowe Street, PO Box A168, Avondale, Harare, Zimbabwe

^&Corresponding author
Grant Murewanhema, Department of Obstetrics and Gynaecology, College of Health Sciences, University of Zimbabwe, Parirenyatwa Hospital, Mazowe Street, PO Box A168, Avondale, Harare, Zimbabwe

Introduction    

This case has been reported in accordance with the surgical case report guidelines (SCARE) criteria [1]. Acute appendicitis is the commonest non-gynaecological surgical emergency complicating pregnancy [2-5]. The incidence is about 1 in 800-1500 pregnancies [2,6-8]. About 30% of cases occur in the first trimester, 45% in the second trimester and the remaining 25% in the third trimester, with variations [2,7,8]. Obstruction of the appendiceal lumen due to lymphoid hyperplasia accounts for the majority of cases, though occasionally cases could be due to faecolith or other causes [9]. The diagnosis presents some challenges, owing to a shift in the position of the appendix from the right iliac fossa upwards as it is displaced by the gravid uterus, but also due to similarities in some of the symptoms of appendicitis and pregnancy [2,8,10]. Anorexia, vomiting and abdominal discomfort all occur quite frequently in patients with appendicitis and in pregnancy, particularly in the first trimester [2,11]. We present and discuss a case of a patient who was admitted into hospital with a working diagnosis of hyperemesis Gravidarum, but was later noted to have a gangrenous appendix at laparotomy.

Patient and observation     

A 28-year-old female patient, with two children and in her third pregnancy, presented to our institution, a tertiary teaching hospital in Zimbabwe´s capital city. She was 12 weeks pregnant, which she confirmed with a urinary pregnancy test. She had no obstetric ultrasound scan, and was not yet booked with any antenatal clinic. She however had a valid negative HIV test result. Her symptoms included non-bilious vomiting, generalised body weakness, and vague abdominal discomfort of a week´s duration. Prior to the onset of these symptoms, she had been well and had not experienced any significant early pregnancy symptoms save for intermittent fatigue and somnolence. She had no fever. She however reported reduced frequency of bowel motions. The rest of the systemic inquiry was non-contributory. Her previous pregnancies were uncomplicated, had no known chronic illnesses and had not undergone any previous surgery. She had no positive family history of multiple gestations. She was ill looking and lethargic, with sunken eyes. She was apyrexial, temperature 36.8, tachycardic, pulse 120 beats per minute and hypotensive, blood pressure 90/58mmHg. The respiratory, integumentary and neurological evaluations were normal. On abdominal examination, the abdomen was noted to be soft and slightly distended, with no guarding, rebound nor renal angle tenderness; neither did she have any dullness to percussion. The uterus was approximately 14 week sized, in keeping with her gestational age.

A clinical impression of hyperemesis Gravidarum was made, and patient was admitted into the gynaecological ward. Complete Blood Count (CBC) revealed a leucocytosis of 12000 cells/mm³, haemoglobin level of 13g/dl and a haematocrit of 40. She had normal urea and electrolytes. An obstetric ultrasound scan revealed a single viable intrauterine foetus at 12 weeks, in keeping with her dates. She was started on intravenous fluid resuscitation intravenous metoclopramide and oral feeds were discontinued. On the second day of admission, the abdominal pain worsened and patient went on to miscarry spontaneously on the ward. Evacuation of the uterus was performed on the same day. Despite the anti-emetic, she continued to vomit with worsening abdominal pain, which was localised to the suprapubic area. Her temperatures started spiking. Full infection screen, including blood cultures, urine and stool microscopy, culture and sensitivities, as well as malaria tests and Widal test, was performed and was negative. Empiric ceftriaxone and metronidazole were commenced, as well as intravenous paracetamol and opioid analgesia pro re nata. On the third day in the ward, the patient became very toxic, with hyperpyrexia of up to 40°C and tachypnoea of up to 28 breaths per minute. She developed septic shock. The white cell count went up to 26000 cells/mm³. A repeat ultrasound scan revealed gross ascites, and in consultation with the surgical team a diagnosis of pelvic abscess was made, and a decision was made to perform an exploratory laparotomy. At laparotomy, a gangrenous ruptured appendix was noted in association with 1500mls of formed pus. The pelvic organs were normal. Subsequently, saline peritoneal lavage was performed, followed by abdominal closure with a drain in-situ. The patient was admitted into the intensive care unit for 1 week for cardiopulmonary support, after which she was discharged to the surgical ward. She had a prolonged hospital stay of 28 days owing to surgical site infection and persistence of pyrexia. The patient had made a full recovery at 2-week review.

Ethics: patient gave verbal consent for publication of her case-report to be published. The Joint Research Ethics Committee and the Medical Research Council of Zimbabwe do not require approvals for publication of case reports.

Discussion     

We presented a case of ruptured appendicitis in pregnancy. The complexity concerning diagnosis of this entity is demonstrated in this case. Whilst the index of suspicion for acute appendicitis in the general population is high, the opposite applies for the pregnant woman. Mimicry between early pregnancy symptoms and those of appendicitis was evident in this case. Hyperemesis gravidarum must be a diagnosis of exclusion after exhaustive investigations; however, patients with severe emesis in the first trimester of pregnancy commonly have this condition [12]. Basing on epidemiological patterns, it is reasonable in our setting to admit patients and treat them as hyperemesis gravidarum before other explanations are found. Left untreated, the condition can result in debilitating dehydration with electrolyte imbalances including severe hypokalaemia and hypochloraemic metabolic alkalosis [13]. In the long run, hyperemesis can result in severe malnutrition in the expecting mother with resultant complications [12]. Diagnostic uncertainty may be compounded by a physiologic leucocytosis in pregnancy [2,14]. The parameters of the Alvarado score, which predicts the likelihood of acute appendicitis based on clinical symptoms and signs and laboratory evaluation, may be unreliable in pregnancy [14-16]. Right lower quadrant tenderness is often not elicited in pregnancy owing to a shift in the position of the appendix, particularly in advanced pregnancy [17]. Pain may not migrate from the peri-umbilical area to the right lower quadrant, and anorexia and nausea/emesis can occur in either pregnancy or appendicitis with relatively high frequency. Our patient was vomiting, but had no fever and no localisable abdominal pain prior to the miscarriage.

Ultrasound imaging is an important diagnostic modality [2,4,14]. However, the unsuspecting sonographer might miss the appendix in pregnancy due to a shift in the position. In a retrospective case analysis of 31 patients who underwent appendicectomy, Lin et al. noted that 25 had pathologically confirmed appendicitis [11]. They noted abdominal ultrasonography to have high sensitivity and specificity of 80% and 75% respectively, with an average diagnostic accuracy of 80.6% across the three trimesters. However, because of the small sample size, these results lack external validity, and operator skill was not considered. Moreover, because this was a retrospective analysis, without an original research objective, considerable bias exists concerning how the ultrasound scans were done. Higher imaging, such as computed tomography and magnetic resonance imaging, is rarely used for the diagnosis of acute appendicitis in our setting due to cost limitations. Appendiceal rupture occurs more frequently in pregnant women because of these diagnostic delays, but also due to the general reluctance to operate on pregnant women [2]. Many conditions mimic acute appendicitis in pregnancy and these include obstetric and non-obstetric conditions [2,8,16]. Obstetric conditions mimicking appendicitis include: ectopic pregnancy, threatened miscarriage, placental abruption, preterm labor, round ligament pain, red degeneration of uterine leiomyomas, chorioamnionitis and adnexal torsion [8]. Non-obstetric conditions mimicking acute appendicitis include acute pyelonephritis, cholecystitis, pancreatitis, gastroenteritis, renal calculus, intestinal obstruction, salpingitis and mesenteric adenitis [8]. Whilst evaluating a patient with suspected appendicitis, these conditions must be considered, but the converse is also true that whilst considering those conditions as possible diagnosis, appendicitis must also be considered.

In a literature review by de France Neto et al. it was noted that pregnant women are less likely to have a classical presentation of acute appendicitis, though they noted that pain around McBurney´s point was likely to occur in most pregnant women, irrespective of the stage of pregnancy [2]. They however noted that in the third trimester, the pain might be located in the flank or right upper quadrant. They recommended diagnostic imaging, with ultrasound scan as a modality of first choice, to avoid delays in diagnosing appendicitis in the pregnant population. A maximum diameter of greater than 6 mm of a tubular structure visualised in the right iliac fossa is diagnostic of acute appendicitis. A positive diagnosis on scan requires surgery. A sonographer must be specifically asked to examine the appendix; otherwise, like in the case we presented, the diagnosis can be missed. Nazir Mir et al. conducted a hospital-based study on the management and outcomes of acute appendicitis in pregnancy [7]. Out of 56 pregnant patients admitted with suspected appendicitis, 51 underwent surgery, and the remaining five were managed conservatively. Eighty-eight percent (45/51) of the operated patients were confirmed surgically and pathologically to have acute appendicitis. They noted that abdominal pain, nausea, vomiting, leucocyte count, temperature and C-reactive protein had a low yield for acute appendicitis. Thus, relying on these evaluations, some patients with acute appendicitis would have been missed. Considerable pregnancy wastage was observed in those who underwent surgery in the first and second trimesters; the rate of these complications was higher among those who had perforated appendix. It should, however be noted that the numbers in this study were small and therefore may not have been adequately powered to be conclusive.

Most of the evidence concerning the presentation, management and outcome of acute appendicitis in pregnancy comes from case studies and retrospective series. Nevertheless, sufficient evidence for early intervention in suspected cases of acute appendicitis in pregnancy now exists. In their small series of 10 patients, Mohan et al. reported significant differences in the rate of preterm labor (5.1% vs 1.3%) and fetal mortality (25% vs 1.7%) in patients with and without a perforated appendix [6]. However, as stated above, such numbers are too small to regard them as conclusive evidence. The choice of interventions in acute appendicitis now ranges from medical treatment with antibiotics, or operative surgery, either laparoscopically or via laparotomy [14]. Most surgeons still opt for surgical intervention, and the choice between laparoscopy and laparotomy is guided by resource availability and surgical skills. Delays in operation are associated with a higher rate of complications [2,7]. Masood et al. conducted a prospective cohort study of 118 patients who presented with appendicitis [10]. They divided the cases into uncomplicated and complicated appendicitis. Statistically significant differences were obtained between the rates of operative time, postoperative fever, surgical site infections and poor obstetric outcomes. The patient we presented had complicated appendicitis, which resulted in pregnancy loss, supraumbilical midline incision, ICU admission and prolonged hospital stay. In the future, most uncomplicated surgical appendectomies will probably be minimally invasive as laparoscopic equipment becomes more available and operator skills improve.

Conclusion     

Acute appendicitis, whilst rare in pregnancy, remains the commonest general surgical emergency in pregnancy. Non-specificity of symptoms and physiological changes of pregnancy complicate the diagnosis, resulting in delays. Ultrasound scan is a useful imaging modality. Surgical intervention, either laparoscopy or laparotomy, is the treatment of choice. However, surgical intervention may result in considerable pregnancy wastage.

Competing interests     

The authors declare no competing interests

Authors' contributions     

Grant Murewanhema admitted and followed up the patient, performed evacuation of the uterus and was part of the surgical team. He primarily prepared the manuscript. Linda Kumirayi helped in patient management and was part of the surgical team. Dennis Mazingi, Munyaradzi Nyakanda Muchabayiwa Francis Gidiri provided technical advice in case writing. All the authors have read and agreed to the final manuscript.

References