- Definition of Meningitis Infection
A call to provide emergency medical attention comes quite early in the morning. The patient is a 24 year old who has fallen unconscious on the floor and presents with multiple muscle dysfunction. The arms are folded facing the chest and the head and neck region rigid and aching. This 24 year old patient must have been suffering from meningitis, a type of inflammatory reaction that affects the meninges, the membranes that cover the spinal cord and the brain. It is caused by various microorganisms and the resulting infection is potentially fatal. The most common causative agent is the virus, but infections of viral cause may be resolved without therapeutic intervention. It must, however, be noted that meningitis can cause brain damage or even death if not treated on time It is the reason why an immediate intervention was necessary for the 24 year old patient as it would significantly save his life (Connie 2007). This paper investigates the clinical signs, differential diagnosis as well as the pathophysiology of meningitis. In addition, it elucidates the relationship between head injury and the causation of meningitis infection.
Clinical Signs and Medical Assessment
The most common symptom of meningitis is severe headache accompanied with fever and head stiffness. These occur in almost 90 per cent of patients who have contracted the disease. Thus, when one presents with this combination of symptoms in a region that is known for meningitis, it is advisable to seek urgent medical attention so that the situation does not get out of hand. In fact, the combination or the triad is usually is so obvious that one would not misdiagnose the disease (Corrigan & Selassie & Orman 2010). For example, neck stiffness or Nuchal rigidity is quite pronounced because one completely loses the ability to move the neck forward or backward. The onset of the disease can also be used to identify it as it usually begins suddenly. In addition, the meningital fever is usually severe so that body temperature may shoot beyond 42 degrees centigrade. According to literature, nuchal rigidity occurs in about 70 percent of the patients. This implies that additional criteria should be used for definitive diagnosis. This could be Kernig’s sign that is usually assessed while the patient assumes a supine position. In this position, the knees are made to be in 90 degrees from each other (Andreu & Rizo 1998). When extreme pain seems to be limiting the extent of passive extension of the knees, then it confirms that the person has a meningitis infection.
These symptoms only manifest in infected adults, as children show completely different signs. In most cases, children only look more irritable than normal. In addition, the top of the child’s head may show a bulge, especially at the soft point at the top of the head. Although these are enough to make a diagnosis, manifestation of cold extremities, leg pain as well as skin color may be present as well. Meningitis infection should be treated as an emergency, especially in children as they have not developed a strong immune system to contain the attacking agent. The other common signs that may be seen in both children and adults include photophobia, where patients find it difficult to tolerate light of certain brightness (Eagleton 2010). Phonophobia, intolerance to high pitched noise, has also been noted as a leading symptom in meningitis infection. Generally, it should be easy to predict an infection with meningitis from these signs since they are quite unique. The fact that the infection comes suddenly makes it hard to confuse the infection with other infections that are accompanied with fever and myalgia.
Practical Steps in Differential Diagnosis
The patient’s clinical signs point to several possibilities. For example, extreme fever is associated with several infections by microorganisms like bacteria and viruses. This type of fever occurs together with severe headache because the two signs have a similar point of stimulus. On the other hand, headache alone can occur in cases of head injury or any kind of psychological trauma. However, the occurrence of the triad composed of fever, headache and neck stiffness eliminates these possibilities (McAllister & Yudofsky 2011). This triad is typical of an infection of the meninges and usually renders one completely immovable. Diagnosis of meningitis is based on these three cardinal signs; fever, headache and stiff neck. Yet still, there are several possible causative agents of meningitis that have to be elucidated. The differential diagnosis is mainly done through blood tests as they help to determine the exact agent that causes the disease so that definite therapy can be started. There are several agents that can cause meningitis infection and all present similar symptoms. For example, the most common causative agents include bacteria, viruses and fungal agents. The first things to look for in blood tests are markers for inflammation like a complete blood profile or count, C-reactive proteins or a blood culture. However, cerebrospinal fluid is usually used for tests as compared to blood samples because it is much cheaper and gives more specific diagnosis. In order to obtain the cerebrospinal fluid, a lumbar puncture should be carried out to obtain sufficient amount of fluid for the test. It is only in situations of brain tumor or extreme intracranial pressure that lumber puncture can be contraindicated (Leon-Carrion 2006).
Gram staining is usually done on the cerebrospinal fluid in order to demonstrate the type of bacteria that could be causing the infection. In case it is found to be gram negative bacteria, then immediate intervention has to be made because this type of bacteria usually causes dangerous infections. However, the absence of bacteria should not be interpreted to mean no infection as the disease has other causative agents that are not bacteria. In fact, even in bacterial infection bacteria are only found in 60 percent of the cases. This percentage could even be reduced much further if any doze of antibiotics was given shortly before the test was done. In addition, gram staining has been found to be less sensitive with certain classes of bacteria, for example the Listeria species. Thus, blood cells should be a significant adjunct in the diagnosis. For instance, elevated levels of eosinophils should get one suspicious when it is associated with the aforementioned symptoms. They basically suggest acute forms of fungal or viral infections. In some instances, the presence of acetate in cerebrospinal fluid may be an important pointer to bacterial infection. An appropriate diagnosis will enable the medical personnel to initiate therapy as soon as possible (Nathan & Katz & Ross)
The disease results from inflammation of the three membranes of the spinal cord. These membranes enclose and protect the brain from mechanical injury of any nature. Usually, microorganisms do not have access to these membranes and therefore to the brain. However, bacteria can reach the meninges through the blood stream because blood flows to these membranes as well. It basically starts as an infection somewhere far away from the brain, but the bacteria eventually get to the brain due to compromised barriers to blood flow. The other route through which microorganisms can get to the brain is the central nervous system. Although this is extremely rare, it is highly possible especially when bacteria or the viral agents are transported by neurons through a retrograde system. In addition, it is possible to have the bacteria reaching the brain by first adsorbing to the mucus membranes and then being swept away by blood to the brain cavity. However, this must be preceded by viral infections that break down the normal physiological barriers provided by the mucus membranes (Lovell & Barth & Collins & Echemendia). While in blood circulation, the bacteria get to the subarachnoid space at points of weakness in the blood brain barrier. Some of the major contributors to such kind of infections include skull fractures or congenital defects of the meninges. The inflammatory reaction usually occurs as a result of immune response to the presence of the microorganisms in the subarachnoid space rather than a direct effect of the microorganisms. For example, the components of the immune system are known to respond by releasing a large amount of cytokines that in turn initiate the inflammatory cascade. This causes the membrane to be more permeable, thereby letting in more bacteria or infective agents to cause further damage to the meninges (Varney & Roberts 1999). In the end, cerebral edema that is marked by highly increased intracranial pressure ensures and this is known to cause headache. Fever usually results from the release of pyrogens by the inflammatory cells. When this is allowed to persist for long, blood supply to the brain may be cut off completely and this would result in death of brain cells and eventually death of the patient. It must also be noted that patients’ conditions may be worsened by giving antibiotics because the drugs will kill the bacteria and the resultant debris may cause further inflammatory reactions that may worsen the patients’ conditions (William 2009)
Practical Steps in Disease Management
The current management of meningitis infection focuses on the mode of manifestation by the disease. In most cases, the disease may manifest as meningitis or as meningococcal septicemia, which affects the entire systemic circulation. The mode of infections usually determines the type of treatment that should be adopted for the disease and the urgency of initiating treatment. For example, septicemia is known to be more lethal as it can cause multi-organ failure and death in a few hours (Parker & Thompson 1998). However, meningitis without septicemia is not as lethal and may easier to be managed. Nonetheless, it should be treated as soon as possible before it degenerates into a meningococcal septicemia. Generally, meningitis is viewed as a medical emergency and therapy should be instituted within the shortest time possible. Thus, even before definite diagnosis can be done patients are supposed to be put on empirical therapy. This implies the administration of antibiotics with very wide spectra, (Michael 2012). The most commonly used drugs for empirical therapy is chloramphenicol and ceftriaxone. These antibiotics are able to kill a very wide range of bacteria and are given to patients for this reason. Although the two drugs have unpleasant side effects like nausea and vomiting, patients should be encouraged to take them nonetheless. However, if the patient is not in a position to take the drugs on his or her own, parenteral means should be used to give the drugs (Houllis & Karachalios 2011). In fact, this route is preferred to the oral route as it gives immediate therapy and reduces chances of mortality. Empirical therapy should, however, be stopped as soon as results from tests on cerebrospinal fluid have been obtained. At this point, the patient should be given drugs that target the specific causative agents so that the disease is cured fast enough.
The definitive treatment for meningitis targets specific agents that cause the disease. For example, Neisseria meningitidis should be treated with a short course antibiotic regimen of penicillin or ampicillin. For patients who are resistant to penicillin, ampicillin gives better results as it is not easily metabolized by the beta lactamases produced by the bacterial agents. But for patients, who are allergic to penicillin, ceftriaxone should be instituted immediately as it is not a derivative of penicillin(Saas Drugs & Pharmacology). Prophylactic therapy should also be instituted for children who may come into contact with fluids from the infected patients. This will significantly prevent them from being infected since there infections are more difficult to manage. As for Streptococcus pneumonia infections, the preferred drug is intravenous ceftriaxone or any fluoroquinolone. These are the most common causes of meningitis, which should be given an immediate attention. At the moment, there is a vaccine called Pneumovax that provides long term immunity against meningitis infections.
Critique on the Evidence of Effective Management
It has been argued that empirical therapy should not apply for meningitis because it predisposes the patient to drug resistance. The particular drug that has been singled out for criticism is ceftriaxone because it is popularly used in both empirical and definitive therapy. Indeed, it is true that most meningitis infections are caused by bacteria, against which ceftriaxone is effective. This implies that at the time definitive therapy is given, the patient has had several dozes of the antibiotic, and chances that resistance is developing are quite high (Polland & Maiden 2001). However, this argument has been ruled out on technicality basis considering that the drug is quite effective and clears the bacteria before the resistance is developed. Thus, fears of drug resistance should not deter doctors from putting their patients on this empirical treatment as diagnosis is done to determine the actual causative agent.
2. Definition of Head Injury
Head injury denotes any form of trauma of the head, even if it does not affect the brain. This is not a popular disease condition and affects only 3 percent of the global population. However, it has been noted in cases of road accidents or some of the dangerous sports like safari rallies the mortality rates for the head injury currently stand at 25 percent in the United States and Britain, where it is common among children below the age of 15. In most cases, head injury is considered to entail trauma to the scalp, the skull or penetration into the brain. It can either be closed where the dura mater remains in place or open where it disassociates from the brain (Lambert 1988). Head injuries of any nature are known to cause fracture of the skull or just compress it. Either way, they cause considerable amount of pain or serious hemorrhage in the subdural cavity, also called subdural hematoma.
Medical Assessment of Clinical Symptoms
There are no specific symptoms for head injury, but depend on the extent of brain damage. For example, excessive subdural hemorrhage may result in a state of anemia or inadequate blood supply to the brain. These usually cause a restlessness, general fatigue or irritability. The other common symptoms may include mental confusion, blood vision or headaches (Parker 2004). Depending on the part of the brain that is damaged, the patient may experience amnesia, dizziness, memory loss or even unconsciousness. However, these conditions are associated with severe damages that also affect the brain.
Practical Steps in Differential Diagnosis
The diagnosis can only help in determining the part of the brain that has been adversely affected by the injury. It must, however, be noted that brain injury is a serious predisposing factor to meningitis infections and associated tests should be done to confirm if there is an infection. Blood tests help to determine the exact agent that causes the disease so that the definite therapy can be started (Silverstein 1971). There are several agents that can cause meningitis infection and all present with almost similar symptoms. For example, the most common causative agents include bacteria, viruses and fungal agents. The first things to look for in blood tests are markers for inflammation like a complete blood profile or count, C-reactive proteins or a blood culture. However, cerebrospinal fluid is usually used for tests as compared to blood samples because it is much cheaper and gives more specific diagnosis. In order to obtain the cerebrospinal fluid, a lumbar puncture should be carried out to obtain sufficient amount of fluid for the test. It is only in situations of brain tumor or extreme intracranial pressure that lumber puncture can be contraindicated. In addition, instrumental imaging can also be done using CT scans or MRI scans (Granacher 2007). They usually give a clear image of the inflamed spinal membranes, but cannot elucidate the cause. Thus, they should be used together with the tests on cerebrospinal fluid as well as clinical symptoms.
Pathophysiology and Clinical Assessment
This is related to the head injury and the associated complications. Generally, head injury causes trauma to the head that may in turn compromise the integrity of the blood brain barrier. This will leave the patient more susceptible to meningitis infections by the various causative agents (Ashton 2012). Head trauma can also manifest as severe headache that can only be controlled with analgesic/antipyretic drugs. However, the presence of wounds or swellings on the head would confirm a case of head injury.
Practical Steps in Management of Head Injury
The first intervention would be to eliminate headache caused by head trauma. There are strong drugs like aspirin that block the prostaglandin pathway, thus effectively inhibits sensation of pain. In case of wounds or swellings, properly cleaning of the site would be ideal in order prevent microbial infections of the head and eventually into the brain (Leon-Carrion 2006). This would be satisfactory to effectively manage head trauma.
In conclusion, meningitis infections are closely related to head trauma. Usually, injuries to the head significantly compromise the effectiveness of the blood brain barrier and this enables infective microorganisms to get to the brain. Such infections are lethal and should therefore be treated as medical emergencies. This implies that empirical treatment should be instituted as soon as possible to stem further complications. However, focus should shift to the definitive treatment as soon as laboratory results identify the causative agent of the disease condition.