Splenic Infarction in a High-Altitude Traveler with Undiagnosed Sickle Cell Trait

To the Editor:

In March 2007, I was the doctor on a high-altitude expedition in Peru, when a young man with undiagnosed sickle cell trait (SCT) suffered a splenic infarction. Although SCT-related splenic infarction at altitude is a well-documented phenomenon, ^{1 –}3 it is a relatively rare event, and, therefore, this is a worthwhile case to share among relevant health professionals.

Shortly after arriving in Cusco, Peru, a physically fit, 23-year-old white male with an unremarkable medical history developed acute abdominal pain. He had flown from the UK in a commercial, pressurized aircraft. Cusco is situated at an altitude of 3300 m. This was the patient's first trip to such a high altitude; previously he had not ventured above 1500 m.

The initial symptom was a mild-moderate, continuous epigastric pain. Abdominal examination revealed a soft abdomen, tender in the epigastric region with no guarding and normal bowel sounds. Half an hour later the patient began vomiting, and over the course of the next couple of hours the upper abdominal pain progressively worsened. The patient had not overtly exerted himself, having only undertaken gentle walking during the time between the flight landing and the onset of the pain. The expedition group had journeyed about an hour from Cusco by bus, so taxi transfer of the patient back to a hospital in Cusco was urgently arranged.

On arrival at the hospital, the patient's vital signs were as follows: pulse 78 beats per minute, blood pressure 140/80 mm Hg, temperature 36.5°C, respiratory rate 22 breaths per minute, oxygen saturation 91% in room air. He was managed with oxygen, opioid analgesia, and intravenous fluids. A surgical consult was obtained. Abdominal examination at that time revealed generalized tenderness, worst in the upper abdomen, with marked pain on percussion over the spleen. A surgical consultation was obtained. Within approximately 6 hours of symptom onset, the patient was mildly clinically jaundiced.

Laboratory blood test results are detailed in Tables 1 and 2. An ultrasound scan revealed splenic enlargement, and a diagnosis of probable splenic infarction was made. A decision for surgical management was made immediately after the ultrasound scan, and a total splenectomy was completed within 11 hours of symptom onset. The patient made a good recovery, and was transferred 4 days after surgery to a hospital in Lima to benefit from the lower altitude.

Table 1

Hematological laboratory results at presentation

Table 2

Biochemical laboratory results at presentation

Upon return to the UK, the patient was referred to a hematologist, and hemoglobin electrophoresis revealed SCT with 37.9% of structurally abnormal hemoglobin (35–45% of hemoglobin is structurally abnormal in SCT). This patient was born in the UK and has some Greek ancestry (his maternal grandfather was Greek), although he was unaware of any family history of SCT or disease. Screening for other hemoglobinopathies and thrombophilias was undertaken, and all results were negative (Table 3). Histological examination of the spleen revealed extensive areas of ischemic infarction in an enlarged spleen (19 × 14 × 9 cm), with sickled erythrocytes within the clots and some of the blood vessels.

Table 3

Hematological investigations (3 months after splenectomy)

This case was typical of the presentation of SCT-related splenic infarction: initial epigastric pain that soon localizes to the left hypochondrium. ^{1 –}3 Vomiting is common, and breathing may become shallow and difficult, often with end-inspiratory pain. ^{1 –}3 A left pleural effusion may also develop.^1,2

Conservative management with analgesia, fluids, oxygen, and descent has been found to be effective in the management of splenic infarction in SCT. ^{1 –}3 Blood transfusion may also be necessary. Use of the hyperbaric chamber may also aid management by normalizing oxygen tensions. According to the literature, splenectomy is often unnecessary in SCT-related splenic infarction and can be avoided with good conservative management.^1,3 However, surgical intervention (partial or complete splenectomy) may be needed if conservative management fails or complications arise.^3,4 Hemorrhage, overwhelming sepsis, and abscess or pseudocyst formation are indications for surgical intervention. ⁴

In this particular case, if the clinicians involved had been aware of the patient's sickle cell status and of the appropriate management of SCT-related splenic infarction, greater emphasis could have been placed on the conservative management and splenectomy may have been avoided. I would therefore suggest screening at-risk individuals for SCT prior to high-altitude travel. Should patients with known SCT develop symptoms consistent with splenic infarction, the diagnosis can be expedited and prompt, appropriate management initiated.

Travel and expedition companies organizing trips to high altitude should provide pre-departure guidance to their clients to ensure they are aware of the health risks associated with high-altitude travel. Ideally, clients should receive a pre-departure health questionnaire that includes questions relating to ethnicity and personal/ family history of sickle cell disease/trait. Doctors involved with predeparture health assessments need to be aware of this risk associated with SCT and advise their patients accordingly. Individuals deemed at risk of SCT should be offered a screening test prior to high-altitude travel. Sickle cell trait carriers can then make informed decisions as to whether to risk traveling to high altitudes.

A careful family history and determination of ethnicity, along with knowledge of the global distribution and prevalence of SCT, will aid risk assessment for SCT carriage. Sickle cell trait has a wide geographic distribution: although it is most common in Sub-Saharan Africa, it is also found in people of Mediterranean, Caribbean, Middle-Eastern, Asian, and Indian origin. Country-specific estimates of SCT prevalence are available. ⁵ Nowadays, some countries have newborn screening programs that detect SCT; however, many adults traveling to high altitude will not have undergone screening.

Quantification of the risk of splenic infarction at altitude in SCT carriers is difficult because the incidence of the phenomenon is unknown. However, patients should be advised that altitudes above 5000 ft (1524 m) (that would include many ski resorts around the world) are hazardous. ³ Exertion increases the risk of splenic infarction in SCT. ² There is also an association between sudden death in SCT and exertional heat illness and rhabdomyolysis.^2,3 It is therefore prudent to warn SCT carriers traveling to high altitude about dehydration and overexertion. Because people with SCT are also at risk of hyposthenuria ³ (inability to concentrate the urine), they can easily become volume depleted and should be warned that urine color is not a reliable marker of hydration status.

With increasing numbers of people participating in high-altitude travel, it is important that travelers, tour operators, and doctors are aware of this complication of SCT. Increased awareness of the phenomenon and predeparture screening in at-risk individuals may reduce the occurrence of SCT-related splenic infarction, promote appropriate management, and reduce the number of unnecessary splenectomies.