The typical range for lactate levels in the body is 0.5-2.2 mmol/L, according to most UK trusts. However, it is important to mention that the RCEM sepsis guides consider a lactate level above 2 mmol/L to be abnormal.

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

Le Fort fractures are complex fractures of the midface that involve the maxillary bone and surrounding structures. These fractures can occur in a horizontal, pyramidal, or transverse direction. The distinguishing feature of Le Fort fractures is the traumatic separation of the pterygomaxillary region. They make up approximately 10% to 20% of all facial fractures and can have severe consequences, both in terms of potential life-threatening injuries and disfigurement.

The Le Fort classification system categorizes midface fractures into three groups based on the plane of injury. As the classification level increases, the location of the maxillary fracture moves from inferior to superior within the maxilla.

Le Fort I fractures are horizontal fractures that occur across the lower aspect of the maxilla. These fractures cause the teeth to separate from the upper face and extend through the lower nasal septum, the lateral wall of the maxillary sinus, and into the palatine bones and pterygoid plates. They are sometimes referred to as a floating palate because they often result in the mobility of the hard palate from the midface. Common accompanying symptoms include facial swelling, loose teeth, dental fractures, and misalignment of the teeth.

Le Fort II fractures are pyramidal-shaped fractures, with the base of the pyramid located at the level of the teeth and the apex at the nasofrontal suture. The fracture line extends from the nasal bridge and passes through the superior wall of the maxilla, the lacrimal bones, the inferior orbital floor and rim, and the anterior wall of the maxillary sinus. These fractures are sometimes called a floating maxilla because they typically result in the mobility of the maxilla from the midface. Common symptoms include facial swelling, nosebleeds, subconjunctival hemorrhage, cerebrospinal fluid leakage from the nose, and widening and flattening of the nasal bridge.

Le Fort III fractures are transverse fractures of the midface. The fracture line passes through the nasofrontal suture, the maxillo frontal suture, the orbital wall, and the zygomatic arch and zygomaticofrontal suture. These fractures cause separation of all facial bones from the cranial base, earning them the nickname craniofacial disjunction or floating face fractures. They are the rarest and most severe type of Le Fort fracture. Common symptoms include significant facial swelling, bruising around the eyes, facial flattening, and the entire face can be shifted.

Mallory-Weiss syndrome is a condition characterized by a tear in the lining of the esophagus, specifically near the junction where the esophagus meets the stomach. This tear is typically caused by forceful retching and vomiting and is often associated with behaviors such as binge drinking, eating disorders, and hyperemesis gravidarum. Fortunately, the bleeding usually stops within 24-48 hours and invasive procedures like endoscopy are rarely necessary.

It is important to note that Mallory-Weiss syndrome should not be confused with Boerhaave’s syndrome, which is the spontaneous rupture of a healthy esophagus, usually following intense vomiting. Patients with Boerhaave’s syndrome experience respiratory collapse, subcutaneous emphysema, and acute abdominal pain. While Boerhaave’s syndrome is rare, it is more commonly observed in individuals who abuse alcohol.

During the second and third trimesters of pregnancy, exposure to ACE inhibitors can lead to hypoperfusion, renal failure, and the oligohydramnios sequence. This sequence refers to the abnormal physical appearance of a fetus or newborn due to low levels of amniotic fluid in the uterus. It is also associated with malformations of the patient ductus arteriosus and aortic arch. These defects are believed to be caused by the inhibitory effects of ACE inhibitors on the renin-angiotensin-aldosterone system. To avoid these risks, it is recommended to discontinue ACE inhibitors before the second trimester.

Here is a list outlining the most commonly encountered drugs that have adverse effects during pregnancy:

Drug: ACE inhibitors
Adverse effects: If given in the second and third trimesters, can cause hypoperfusion, renal failure, and the oligohydramnios sequence.

Drug: Aminoglycosides
Adverse effects: Ototoxicity (damage to the ear) and deafness.

Drug: Aspirin
Adverse effects: High doses can cause first trimester abortions, delayed onset labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. Low doses (e.g. 75 mg) have no significant associated risk.

Drug: Benzodiazepines
Adverse effects: When given late in pregnancy, respiratory depression and a neonatal withdrawal syndrome can occur.

Drug: Calcium-channel blockers
Adverse effects: If given in the first trimester, can cause phalangeal abnormalities. If given in the second and third trimesters, can cause fetal growth retardation.

Croup, also known as laryngo-tracheo-bronchitis, is typically caused by the parainfluenza virus. Other viruses such as rhinovirus, influenza, and respiratory syncytial viruses can also be responsible. Before the onset of stridor, there is often a mild cold-like illness that lasts for 1-2 days. Symptoms usually reach their peak within 1-3 days, with the cough often being more troublesome at night. A milder cough may persist for another 7-10 days.

Since croup is caused by a viral infection, antibiotics are not effective unless there is a suspicion of a secondary bacterial infection. It is important to note that sedation should not be used in a child experiencing respiratory distress. To reduce airway swelling, dexamethasone and prednisolone are commonly prescribed, although they do not shorten the duration of the illness. In severe cases, nebulized adrenaline can be administered.

A barking cough is a characteristic symptom of croup, but it does not necessarily indicate the severity of the condition. Hospitalization for croup is rare and typically reserved for children who show worsening respiratory distress or signs of drowsiness/agitation.

The scoring system utilized to evaluate the severity of liver cirrhosis and predict mortality is the Child Pugh score. This scoring system takes into account several factors including the patient’s bilirubin levels, albumin levels, prothrombin time, presence of ascites, and hepatic encephalopathy. Each factor is assigned a score and the total score is used to classify the severity of liver cirrhosis into three categories: A, B, or C. The higher the score, the more severe the liver cirrhosis and the higher the risk of mortality.

Further Reading:

Cirrhosis is a condition where the liver undergoes structural changes, resulting in dysfunction of its normal functions. It can be classified as either compensated or decompensated. Compensated cirrhosis refers to a stage where the liver can still function effectively with minimal symptoms, while decompensated cirrhosis is when the liver damage is severe and clinical complications are present.

Cirrhosis develops over a period of several years due to repeated insults to the liver. Risk factors for cirrhosis include alcohol misuse, hepatitis B and C infection, obesity, type 2 diabetes, autoimmune liver disease, genetic conditions, certain medications, and other rare conditions.

The prognosis of cirrhosis can be assessed using the Child-Pugh score, which predicts mortality based on parameters such as bilirubin levels, albumin levels, INR, ascites, and encephalopathy. The score ranges from A to C, with higher scores indicating a poorer prognosis.

Complications of cirrhosis include portal hypertension, ascites, hepatic encephalopathy, variceal hemorrhage, increased infection risk, hepatocellular carcinoma, and cardiovascular complications.

Diagnosis of cirrhosis is typically done through liver function tests, blood tests, viral hepatitis screening, and imaging techniques such as transient elastography or acoustic radiation force impulse imaging. Liver biopsy may also be performed in some cases.

Management of cirrhosis involves treating the underlying cause, controlling risk factors, and monitoring for complications. Complications such as ascites, spontaneous bacterial peritonitis, oesophageal varices, and hepatic encephalopathy require specific management strategies.

Overall, cirrhosis is a progressive condition that requires ongoing monitoring and management to prevent further complications and improve outcomes for patients.

Psittacosis is a type of infection that can be transmitted from animals to humans, caused by a bacterium called Chlamydia psittaci. It is most commonly seen in people who own domestic birds, as well as those who work in pet shops or zoos. The typical symptoms of psittacosis include pneumonia that is acquired within the community, along with flu-like symptoms. Many patients also experience severe headaches and sensitivity to light. Enlargement of the spleen is a common finding in about two-thirds of individuals with this infection.

Infected individuals often develop a rash on their face, known as Horder’s spots, which appear as reddish macules. In some cases, erythema nodosum and erythema multiforme may also occur. The recommended treatment for psittacosis is a course of tetracycline or doxycycline for a period of 2-3 weeks.

On the other hand, rose spots are typically observed in cases of typhoid fever. These spots have a similar appearance to Horder’s spots but are usually found on the trunk rather than the face. Erythema marginatum is a pale red rash seen in rheumatic fever, while malar flush, also known as ‘mitral facies’, refers to the reddish discoloration of the cheeks commonly seen in individuals with mitral stenosis. Lastly, erythema chronicum migrans is the distinctive rash seen in Lyme disease, characterized by a circular rash with a central ‘bulls-eye’ appearance that spreads outward from the site of a tick bite.

The first heart sound (S1) is created by vibrations produced when the mitral and tricuspid valves close. It occurs at the end of diastole and the start of ventricular systole, coming before the upstroke of the carotid pulsation.

A sample of the normal heart sounds can be listened to here (courtesy of Littman stethoscopes).

A loud S1 can be associated with the following conditions:
– Increased transvalvular gradient (e.g. mitral stenosis, tricuspid stenosis)
– Increased force of ventricular contraction (e.g. tachycardia, hyperdynamic states like fever and thyrotoxicosis)
– Shortened PR interval (e.g. Wolff-Parkinson-White syndrome)
– Mitral valve prolapse
– Thin individuals

A soft S1 can be associated with the following conditions:
– Inappropriate apposition of the AV valves (e.g. mitral regurgitation, tricuspid regurgitation)
– Prolonged PR interval (e.g. heart block, digoxin toxicity)
– Decreased force of ventricular contraction (e.g. myocarditis, myocardial infarction)
– Increased distance from the heart (e.g. obesity, emphysema, pericardial effusion)

A split S1 can be associated with the following conditions:
– Right bundle branch block
– LV pacing
– Ebstein anomaly

Zygomaticomaxillary complex fractures, also known as quadramalar or tripod fractures, make up around 40% of all midface fractures and are the second most common facial bone fractures after nasal bone fractures.

These injuries typically occur when a direct blow is delivered to the malar eminence of the cheek. They consist of four components:

1. Widening of the zygomaticofrontal suture
2. Fracture of the zygomatic arch
3. Fracture of the inferior orbital rim and the walls of the anterior and posterior maxillary sinuses
4. Fracture of the lateral orbital rim.

Legionella pneumophila, a Gram-negative bacterium, can be found in natural water supplies and soil. It is responsible for causing Legionnaires’ disease, a serious illness. Outbreaks of this disease have been associated with poorly maintained air conditioning systems, whirlpool spas, and hot tubs.

The pneumonic form of Legionnaires’ disease presents with specific clinical features. Initially, there may be a mild flu-like prodrome lasting for 1-3 days. A non-productive cough, occurring in approximately 90% of cases, is also common. Pleuritic chest pain, haemoptysis, headache, nausea, vomiting, diarrhoea, and anorexia are other symptoms that may be experienced.

Fortunately, Legionella pneumophila infections can be effectively treated with macrolide antibiotics like erythromycin, or quinolones such as ciprofloxacin. Tetracyclines, including doxycycline, can also be used as a treatment option.

While the majority of Legionnaires’ disease cases are caused by Legionella pneumophila, there are several other species of Legionella that have been identified. One such species is Legionella longbeachae, which is less commonly encountered. It is primarily found in soil and potting compost and has been associated with outbreaks of Pontiac fever, a milder variant of Legionnaires’ disease that does not primarily affect the respiratory system.