Circulatory disorders comprise e.g. blood pressure abnormalities and blocked arteries or veins of different organs.
Risk factors for arterial hypertension are higher age, renal damage, smoking, stress as well as some drugs (“pill”). Arteriosclerosis may also elicit high blood pressure. Patients with arterial hypertension often suffer from dyspnoea after slight effort, high and often irregular pulse, lack of physical capacity, blue lips, swollen feet, headache, nausea and dizziness.
Patients with hypertensive crisis should stay in bed and the blood pressure has to be repeatedly monitored. According to medical instructions nitrolingual spray should be given. In the next port the seaman needs to be referred to a medical doctor to determine the cause of hypertension and to optimize treatment.
Predominantly young, slim people sometimes have a low blood pressure. Many of these patients have blackouts if they stand for a longer time or stand up quickly from a lying position.
After lying the patients flat they will recover rapidly. A further treatment including long-lasting rest is normally not necessary. Physical training on board may help to raise the pulse rate as a long-term effect. Differential diagnostics should be done if symptoms repeatedly occur.
Pathogenetically, a stroke is caused by a complete occlusion of an artery supplying blood to the brain (ischemic stroke). It is triggered by a plaque or clot (thrombus) in 65-75% of strokes or by a clot formed in a vessel elsewhere in the body and swept by the bloodstream until it occludes a blood vessel in the brain (5-10% of strokes). The bleeding into the brain (hemorrhagic stroke) from a ruptured artery supplying blood to the brain occurs in 20% of strokes.
Stroke patients develop symptoms gradually over hours or days. They often get complete or partial paralysis of one side predominantly affecting face and arm. A weakness of the face is shown by dropping of one corner of the mouth. Further, they have headache and an abnormal speech with difficulties to find words.
In case of suspected stroke the patient has to be carefully examined to find out any weakness or other stroke symptoms. (Thus, the inexperienced examiner on board should be aware about the typical symptoms and must be able to judge the patient’s power in the bilateral extremities’ comparison. This might be demanding for several health officers).
Before seeking for medical advice the pulse rate, blood pressure, level of consciousness and some history data (about age, taken medicines, known diabetes/ epilepsy or evidence of cocaine or amphetamine use) have to be noted. An urgent hospital admission is essential, even if there has only been slight and transient paralysis because first the cause of the stroke should be professionally clarified and second these patients are at risk to develop a massive stroke in the course of time.
The patient should lie in bed with the body, shoulders and head at the same level for at least the first 24 hours. In case of unconsciousness the patient should put in stable lateral position; it must be avoided to give anything by mouth until it is ensured that the patient can swallow water normally. In unconsciousness an intravenous cannula has to be inserted and normal saline administered. According to the International Medical Guide for Ships (3rd edition) it is recommended to give docusate with senna and acetylsalicylic acid if shipboard evacuation is likely to be delayed for more than 24 hours.
Acute arterial obliteration in the limbs
Arteries of the limbs can be obliterated by a clot coming from the heart or from another diseased artery (by arterial embolism or arterial thrombosis). Common risk factors are cardiac arrhythmia, aortic aneurysm, smoking and an age above 50 years.
The patients normally have a long history of sudden, exertion-related pain in the muscles of the affected limbs becoming pale, cold and without a pulse. In most cases the arteries of the legs are affected leading to pain in the calf muscles during walking in terms of the so-called intermittent claudication. Sometimes, in severe cases, shock with a rise in pulse or fall of blood pressure as well as fever appears. On rest the symptoms normally disappear.
The affected limbs must be in a low position in warming clothing. The patient has to stay in bed and the pain must be killed by strong drugs (preferably morphine). The immediate evacuation and hospitalization are required because the affected limbs could otherwise die off and then have to be amputated. The health officer should be able to distinguish embolism from thrombosis because of therapeutic consequences.
When thrombi from major veins swept on with the bloodstream to the blood vessels of the lung they may occlude a lung artery. This is often caused by deep vein thrombosis. Massive pulmonary embolism may elicit a serious state of shock and is often fatal. These patients suffer from sudden weakness, breathlessness, anxiety and pain in the chest.
First at all, the patient’s shock needs to be treated. The patient sits with raised upper body by strictest bed rest. As pulmonary embolism poses a serious life-threatening event immediate hospital treatment is required.
A venous thrombosis initially starts with an inflammation of the vain wall (phlebitis), predominantly in varicose vein of the lower legs. Venous thrombosis occurs especially in patients who had a surgery during the previous four weeks or who have been immobile for more than 10 hours (probably a seaman arriving the ship after a long plane flight).
The affected limbs become red, hot and pressure-sensitive. Further, the limbs are swollen and lifting the foot becomes painful. Some days later the symptoms abate and the vain scleroses.
The patient should rest for at least 10 days in bed since a risk of embolism exist. The limbs should be raised (in contrast to the treatment of embolism), cooled and alcohol compresses should be administered. Further, anti-inflammatory drugs should be given. After inflammation has abated elastic bandage to limbs should be applied and the patient is permitted to walk.