A typical presenting symptom is a thunderclap headache. During a medical interview, patients usually call it the “worst headache of my life.” This problem should prompt further imaging. A headache often is associated with nausea, vomiting, and diplopia. Quite often signs of meningismus are present due to irritant blood spreading into the fourth ventricle and further down the spinal cord irritating nerves and causing neck and back pain. Cranial nerve deficits can occur. Practitioners should perform a detailed exam. The presence of a focal deficit increases the grade of subarachnoid hemorrhage and changes the perspective of post-event recovery. Patients with a high-grade subarachnoid hemorrhage quite often present in a state of coma that calls for a quick evaluation and urgent treatment, as the coma can be reversible. In addition to subarachnoid hemorrhage patients could have an intraocular hemorrhage, initially described and named after French ophthalmologist Albert Terson. When the physician identifies Terson syndrome, an ophthalmology service should be consulted to help with the care of the patient. Eighty percent of patients that develop Terson syndrome do not require further interventions other than regular follow-ups.

Initial evaluation of a patient suspected of having a subarachnoid hemorrhage should include head computed tomogram (CT). A CT angiography should be added if a subarachnoid hemorrhage is identified. If the initial CT is negative, but a physician has a very high suspicion for hemorrhage, a lumbar puncture should be performed and sent for laboratory evaluation of xanthochromia presence. Sometimes xanthochromia presence can be assessed at the bedside due to visible cerebrospinal fluid color change. A CT angiography diagnosis of an aneurysm or confirmation of negative CT angiography should be followed by cerebral angiography or digital subtraction angiography (DSA). A few factors should be considered in patients who are allergic to contrast or have decreased renal function. These patient populations need pre-procedure treatment to decrease the chances of an adverse reaction. Time-of-flight magnetic resonance angiography (TOF-MRA) is another acceptable mode of imaging that will not require contrast injection but due to the long time that is necessary to obtain complete examination is not always a feasible alternative in very sick patients with subarachnoid hemorrhage.[6][7][8]

Treatment of subarachnoid hemorrhage patients should occur in the intensive care unit. On the initial presentation, Hunt and Hess, as well as the World Federation of Neurological Surgeons scores, should be determined. If there is the presence of hydrocephalus, the placement of an external ventricular drain should be considered. Level one evidence supports the use of nimodipine and maintenance euvolemia as important factors to improve outcomes. Tight control of blood pressure until an aneurysm is also secured is necessary. Blood pressure should be less than 160 mmHg and more optimally within the 140-mmHg range. Seizure prophylaxis should be initiated, as 20% of these patients will seize within the first 24 hours post bleed. Seizure, while an aneurysm is unsecured, will worsen patient outcomes. Avoid hyponatremia and hypovolemia and initiate fluids as soon as intravascular access is obtained. Normal saline has shown slight benefits when compared to other fluids like Ringer's lactate solution. Monitor pulmonary status. Often the patient has been intubated in the field by emergency services, but if the patient has been not intubated and the Glasgow coma scale (GCS) score is less than eight, initiate steps to secure an airway. Consider an arterial line to have better control of patient hemodynamic status. Early intervention to secure an aneurysm will allow relaxing blood pressure goals and improving cerebral perfusion pressure which is severely compromised in these patients. The use of prothrombotic agents like aminocaproic acid is surgeon dependent and will need to be considered if an aneurysm cannot be secured within a short time.[9][10][11][12]

• Bacterial and tuberculous meningitis
• Granulomatous meningitis
• Neurosarcoidosis
• Pseudo-subarachnoid hemorrhage

The prognosis depends on the cause and grade of subarachnoid hemorrhage, and the presence of other complications.

• Seizures
• Vasospasm
• Rebleed
• Hydrocephalus
• Increased intracranial pressure
• Brain herniation
• Cerebral infarction
• Medical complications
• Neurogenic pulmonary edema[13]
• Death

A patient with an aneurysm, who is being conservatively managed should be advised on all the complications that can occur if it ruptures.

Any patient and relatives getting admitted with subarachnoid hemorrhage secondary to an aneurysm rupture should be aware of the chance of rebleed and the morbidity and mortality associated with any intervention.

The majority of patients with subarachnoid hemorrhage present to the emergency department. Thus, it is vital that the emergency department physician and nurse practitioner know the workup for these patients. Because of the very high mortality, an interprofessional team that includes a neurosurgeon, interventional radiologist, neurologist, intensivist, and Intensive Care Unit nurses is recommended. Unfortunately, despite the optimal case, the majority of patients die within 30 days. Even those who survive are left with severe complications that are disabling.[14][15] (Level V)