Recognizing the extent of blood loss based on vital sign and mental status abnormalities is a crucial skill. The Advanced Trauma Life Support (ATLS) classification for hemorrhagic shock correlates the amount of blood loss with expected physiological responses in a healthy individual weighing 70 kg. In terms of body weight, the total circulating blood volume accounts for approximately 7%, which is roughly equivalent to five liters in an average 70 kg male patient.

The ATLS classification for hemorrhagic shock is as follows:

CLASS I:
– Blood loss: Up to 750 mL
– Blood loss (% blood volume): Up to 15%
– Pulse rate: Less than 100 beats per minute (bpm)
– Systolic blood pressure: Normal
– Pulse pressure: Normal (or increased)
– Respiratory rate: 14-20 breaths per minute
– Urine output: Greater than 30 mL/hr
– CNS/mental status: Slightly anxious

CLASS II:
– Blood loss: 750-1500 mL
– Blood loss (% blood volume): 15-30%
– Pulse rate: 100-120 bpm
– Systolic blood pressure: Normal
– Pulse pressure: Decreased
– Respiratory rate: 20-30 breaths per minute
– Urine output: 20-30 mL/hr
– CNS/mental status: Mildly anxious

CLASS III:
– Blood loss: 1500-2000 mL
– Blood loss (% blood volume): 30-40%
– Pulse rate: 120-140 bpm
– Systolic blood pressure: Decreased
– Pulse pressure: Decreased
– Respiratory rate: 30-40 breaths per minute
– Urine output: 5-15 mL/hr
– CNS/mental status: Anxious, confused

CLASS IV:
– Blood loss: More than 2000 mL
– Blood loss (% blood volume): More than 40%
– Pulse rate: More than 140 bpm
– Systolic blood pressure: Decreased
– Pulse pressure: Decreased
– Respiratory rate: More than 40 breaths per minute
– Urine output: Negligible
– CNS/mental status: Confused, lethargic

Calcium-channel blocker overdose is a serious condition that can be life-threatening. The most dangerous types of calcium channel blockers in overdose are verapamil and diltiazem. These medications work by binding to the alpha-1 subunit of L-type calcium channels, which prevents the entry of calcium into cells. These channels are important for the functioning of cardiac myocytes, vascular smooth muscle cells, and islet beta-cells.

When managing a patient with calcium-channel blocker overdose, it is crucial to follow the standard ABC approach for resuscitation. If there is a risk of life-threatening toxicity, early intubation and ventilation should be considered. Invasive blood pressure monitoring is also necessary if hypotension and shock are developing.

The specific treatments for calcium-channel blocker overdose primarily focus on supporting the cardiovascular system. These treatments include:

1. Fluid resuscitation: Administer up to 20 mL/kg of crystalloid solution.

2. Calcium administration: This can temporarily increase blood pressure and heart rate. Options include 10% calcium gluconate (60 mL IV) or 10% calcium chloride (20 mL IV) via central venous access. Repeat boluses can be given up to three times, and a calcium infusion may be necessary to maintain serum calcium levels above 2.0 mEq/L.

3. Atropine: Consider administering 0.6 mg every 2 minutes, up to a total of 1.8 mg. However, atropine is often ineffective in these cases.

4. High dose insulin – euglycemic therapy (HIET): The use of HIET in managing cardiovascular toxicity has evolved. It used to be a last-resort measure, but early administration is now increasingly recommended. This involves giving a bolus of short-acting insulin (1 U/kg) and 50 mL of 50% glucose IV (unless there is marked hyperglycemia). Therapy should be continued with a short-acting insulin/dextrose infusion. Glucose levels should be monitored frequently, and potassium should be replaced if levels drop below 2.5 mmol/L.

5. Vasoactive infusions: Catecholamines such as dopamine, adrenaline, and/or noradrenaline can be titrated to achieve the desired inotropic and chronotropic effects.

6. Sodium bicarbonate: Consider using sodium bicarbonate in cases where a severe metabolic acidosis develops.

The intravascular volume of an infant is approximately 80 ml/kg. In older children, the intravascular volume is around 70 ml/kg.

Dehydration itself does not lead to death, but shock can. Shock can occur when there is a loss of 20 ml/kg from the intravascular space, while clinical dehydration is only noticeable after total losses of more than 25 ml/kg.

The maintenance fluid requirements for healthy, typical children are summarized in the table below:

Bodyweight:
– First 10 kg: Daily fluid requirement of 100 ml/kg, hourly fluid requirement of 4 ml/kg
– Second 10 kg: Daily fluid requirement of 50 ml/kg, hourly fluid requirement of 2 ml/kg
– Subsequent kg: Daily fluid requirement of 20 ml/kg, hourly fluid requirement of 1 ml/kg

Therefore, this child’s daily maintenance fluid requirement can be calculated as follows:

– First 10 kg: 100 ml/kg = 1000 ml
– Second 10 kg: 50 ml/kg = 500 ml
– Subsequent kg: 20 ml/kg = 40 ml

Total daily maintenance fluid requirement: 1540 ml

The recommended daily oral dose for adults is 900 mg, which should be taken in 2-3 divided doses. For severe asthma or COPD, the initial intravenous dose is 5 mg/kg and should be administered over 10-20 minutes. This can be followed by a continuous infusion of 0.5 mg/kg/hour. In the case of a 50 kg individual, the appropriate infusion rate would be 25 mg/hour. It is important to note that the therapeutic range for aminophylline is narrow, ranging from 10-20 microgram/ml. Therefore, it is beneficial to estimate the plasma concentration of aminophylline during long-term treatment.

The primary approach to managing nerve gas exposure through medication involves the repeated administration of antidotes. The two antidotes utilized for this purpose are atropine and pralidoxime.

Atropine is the standard anticholinergic medication employed to address the symptoms associated with nerve agent poisoning. It functions as an antagonist for muscarinic acetylcholine receptors, effectively blocking the effects caused by excessive acetylcholine. Initially, a 1.2 mg intravenous bolus of atropine is administered. This dosage is then repeated and doubled every 2-3 minutes until excessive bronchial secretion ceases and miosis (excessive constriction of the pupil) resolves. In some cases, as much as 100 mg of atropine may be necessary.

Pralidoxime (2-PAMCl) is the standard oxime used in the treatment of nerve agent poisoning. Its mechanism of action involves reactivating acetylcholinesterase by scavenging the phosphoryl group attached to the functional hydroxyl group of the enzyme, thereby counteracting the effects of the nerve agent itself. For patients who are moderately or severely poisoned, pralidoxime should be administered intravenously at a dosage of 30 mg/kg of body weight (or 2 g in the case of an adult) over a period of four minutes.

The CHA2DS2-VASc score is a tool used to predict the likelihood of future stroke in individuals with atrial fibrillation (AF). It is scored on a scale of 0-9, with higher scores indicating a higher risk of stroke. If a male has a score of 1 or more, or if a female has a score of 2 or more, it is recommended to start anticoagulation therapy to prevent future strokes. However, it is important to assess the risk of bleeding before initiating anticoagulation using the HAS-BLED score. The HAS-BLED score does not evaluate the risk of stroke, but rather the risk of bleeding. QRISK3, on the other hand, is a tool used to estimate the risk of cardiovascular disease over a 10-year period and is primarily used to determine the benefits of starting lipid lowering drugs. It is the preferred tool recommended by NICE over the Framingham risk score.

Further Reading:

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting around 5% of patients over the age of 70-75 years and 10% of patients aged 80-85 years. While AF can cause palpitations and inefficient cardiac function, the most important aspect of managing patients with AF is reducing the increased risk of stroke.

AF can be classified as first detected episode, paroxysmal, persistent, or permanent. First detected episode refers to the initial occurrence of AF, regardless of symptoms or duration. Paroxysmal AF occurs when a patient has 2 or more self-terminating episodes lasting less than 7 days. Persistent AF refers to episodes lasting more than 7 days that do not self-terminate. Permanent AF is continuous atrial fibrillation that cannot be cardioverted or if attempts to do so are deemed inappropriate. The treatment goals for permanent AF are rate control and anticoagulation if appropriate.

Symptoms of AF include palpitations, dyspnea, and chest pain. The most common sign is an irregularly irregular pulse. An electrocardiogram (ECG) is essential for diagnosing AF, as other conditions can also cause an irregular pulse.

Managing patients with AF involves two key parts: rate/rhythm control and reducing stroke risk. Rate control involves slowing down the irregular pulse to avoid negative effects on cardiac function. This is typically achieved using beta-blockers or rate-limiting calcium channel blockers. If one drug is not effective, combination therapy may be used. Rhythm control aims to restore and maintain normal sinus rhythm through pharmacological or electrical cardioversion. However, the majority of patients are managed with a rate control strategy.

Reducing stroke risk in patients with AF is crucial. Risk stratifying tools, such as the CHA2DS2-VASc score, are used to determine the most appropriate anticoagulation strategy. Anticoagulation is recommended for patients with a score of 2 or more. Clinicians can choose between warfarin and novel oral anticoagulants (NOACs) for anticoagulation.

Before starting anticoagulation, the patient’s bleeding risk should be assessed using tools like the HAS-BLED score or the ORBIT tool. These tools evaluate factors such as hypertension, abnormal renal or liver function, history of bleeding, age, and use of drugs that predispose to bleeding.

ATLS guidelines now suggest administering only 1 liter of crystalloid fluid during the initial assessment. If patients do not respond to the crystalloid, it is recommended to quickly transition to blood products. Studies have shown that infusing more than 1.5 liters of crystalloid fluid is associated with higher mortality rates in trauma cases. Therefore, it is advised to prioritize the early use of blood products and avoid large volumes of crystalloid fluid in trauma patients. In cases where it is necessary, massive transfusion should be considered, defined as the transfusion of more than 10 units of blood in 24 hours or more than 4 units of blood in one hour. For patients with evidence of Class III and IV hemorrhage, early resuscitation with blood and blood products in low ratios is recommended.

Based on the findings of significant trials, such as the CRASH-2 study, the use of tranexamic acid is now recommended within 3 hours. This involves administering a loading dose of 1 gram intravenously over 10 minutes, followed by an infusion of 1 gram over eight hours. In some regions, tranexamic acid is also being utilized in the prehospital setting.

Conjunctivitis is the most frequent occurrence of Chlamydia trachomatis infection in newborns. Ophthalmia neonatorum refers to any cause of conjunctivitis during the newborn period, regardless of the specific organism responsible. Chlamydia is now the leading cause, accounting for up to 40% of cases. Neisseria gonorrhoea, on the other hand, only accounts for less than 1% of reported cases. The remaining cases are caused by non-sexually transmitted bacteria like Staphylococcus, Streptococcus, Haemophilus species, and viruses.

Gonorrhoeal ophthalmia neonatorum typically presents within 1 to 5 days after birth. It is characterized by intense redness and swelling of the conjunctiva, eyelid swelling, and a severe discharge of pus. Corneal ulceration and perforation may also be present.

Chlamydial ophthalmia neonatorum, on the other hand, usually appears between 5 to 14 days after birth. It is characterized by a gradually increasing watery discharge that eventually becomes purulent. The inflammation in the eyes is usually less severe compared to gonococcal infection, and there is a lower risk of corneal ulceration and perforation.

The second most common manifestation of Chlamydia trachomatis infection in newborns is pneumonia. Approximately 5-30% of infected neonates will develop pneumonia. About half of these infants will also have a history of ophthalmia neonatorum.

A subarachnoid haemorrhage (SAH) occurs when there is spontaneous bleeding into the subarachnoid space and is often a catastrophic event. The incidence of SAH is 9 cases per 100,000 people per year, and it typically affects individuals between the ages of 35 and 65.

Approximately 80% of SAH cases are caused by the rupture of berry (saccular) aneurysms, while 15% are caused by arteriovenous malformations (AVM). In less than 5% of cases, no specific cause can be identified. Berry aneurysms are commonly associated with polycystic kidneys, Ehlers-Danlos Syndrome, and coarctation of the aorta.

There are several risk factors for SAH, including smoking, hypertension, bleeding disorders, alcohol misuse, and mycotic aneurysm. Additionally, a family history of SAH can increase the likelihood of developing the condition.

Patients with SAH typically experience a sudden and severe occipital headache, often described as the worst headache of my life. This may be accompanied by symptoms such as vomiting, collapse, seizures, and coma. Clinical signs of SAH include neck stiffness, a positive Kernig’s sign, and focal neurological abnormalities. Fundoscopy may reveal subhyaloid retinal haemorrhages in approximately 25% of patients.

Re-bleeding occurs in 30-40% of patients who survive the initial episode, with the highest risk occurring between 7 and 14 days after the initial bleed. If left untreated, SAH has a mortality rate of nearly 50% within the first eight weeks following presentation. Prolonged coma is associated with a 100% mortality rate.

The first-line investigation for SAH is a CT head scan, which can detect over 95% of cases if performed within the first 24 hours. The sensitivity of the CT scan increases to nearly 100% if performed within 6 hours of symptom onset. If the CT scan is negative, a lumbar puncture (LP) should be performed to diagnose SAH. The LP should be conducted at least 12 hours after the onset of headache, unless there are contraindications. Approximately 3% of patients with a negative CT scan will be confirmed to have had a SAH following an LP.

Conjunctivitis is the most common reason for red eyes, accounting for about 35% of all eye problems seen in general practice. It occurs when the conjunctiva, the thin layer covering the white part of the eye, becomes inflamed. Conjunctivitis can be caused by an infection or an allergic reaction.

Infective conjunctivitis is inflammation of the conjunctiva caused by a viral, bacterial, or parasitic infection. The most common type of infective conjunctivitis is viral, with adenoviruses being the main culprits. Bacterial conjunctivitis is also common and is usually caused by Streptococcus pneumoniae, Staphylococcus aureus, or Haemophilus influenzae.

The symptoms of infective conjunctivitis include sudden redness of the conjunctiva, discomfort described as a gritty or burning sensation, watering of the eyes, and discharge that may temporarily blurry vision. It can be challenging to differentiate between viral and bacterial conjunctivitis based on symptoms alone.

Here are some key features that can help distinguish between viral and bacterial conjunctivitis:

Features suggestive of viral conjunctivitis:
– Mild to moderate redness of the conjunctiva
– Presence of follicles on the inner surface of the eyelids
– Swelling of the eyelids
– Small, pinpoint bleeding under the conjunctiva
– Pseudomembranes (thin layers of tissue) may form on the inner surface of the eyelids in severe cases, often caused by adenovirus
– Less discharge (usually watery) compared to bacterial conjunctivitis
– Mild to moderate itching
– Symptoms of upper respiratory tract infection and swollen lymph nodes in front of the ears

Features suggestive of bacterial conjunctivitis:
– Purulent or mucopurulent discharge with crusting of the eyelids, which may cause them to stick together upon waking
– Mild or no itching
– Swollen lymph nodes in front of the ears, which are often present in severe bacterial conjunctivitis
– If the discharge is copious and mucopurulent, infection with Neisseria gonorrhoeae should be considered.

By considering these distinguishing features, healthcare professionals can better diagnose and manage cases of conjunctivitis.