Lead Poisoning

Lead poisoning can occur when lead builds up within the body, usually over a long period of time. Young children are vulnerable to lead poisoning and it is important to be aware of this due to lead poisoning being a factor in mental and physical development. Lead poisoning is a medical condition caused by increased levels of lead within the body that interferes with the normal processes of the body and is particularly toxic to children. This occurs because lead and calcium compete for the protein that is important for body functions, especially the nervous system. The lead can displace the calcium from that protein so the calcium will not be able to function properly.

bonelines

When simplifying the signs and symptoms of lead poisoning, we use the acronym “LEAD”. L represents the lines on the gingiva and long bones; E stands for Encephalopathy and erythrocyte (RBC) basophilic stippling (disease, damage, or malfunction of the brain), A signifies abdominal colic and anemia, and D which stands for drop foot and drop wrist.

Lead inhibits the enzymes that are needed to make Heme—preventing the production of hemoglobin. This causes basophilic stippling of the cells due to lead inhibiting the ribosomal RNA degradation. The red blood cells (RBC) will retain aggregates of ribosomal RNA that causes the stippling of the cells.

RNA

Lead poisoning will present itself with a “lead line” in the gingiva (gums) called the Burton’s line. This gray-blue line is visible at the margin of the gum at the base of the teeth. The long bones will also have lead lines in the metaphysis that appear like white bands on an x-ray because the lead is collected within these white bands. The width and density of these lines reflects chronic exposure.

 

At the RBC level, you will find anemia and basophilic stippling of the red blood cells.

dropfootwrist

The patient will also have encephalopathy associated with headache and memory loss. Lead poisoning may also cause abdominal colic—pain, cramps, and constipation. Another condition that may occur due to lead poisoning is “foot drop”. The patient may experience permanent damage to the central nervous system and the peripheral nerves.

 

This condition usually occurs from exposure to lead based paint, typically used in much older homes. Particles from the lead based paint can be inhaled through the air or from contaminated drinking water, as we have seen recently. Extended exposure can cause serious problems, with children being the most vulnerable. They will commonly show signs of: irritability, fatigue, lower IQ, and lack of attentiveness. The child may show signs of encephalopathy, nausea, vomiting, gait disturbances, and seizures. Exposure in adults is usually occupational related. Adults will experience personality changes, headaches, neuropathy, weakness, foot and wrist drop, and stomach aches. Both children and adults will experience pale skin due to anemia because lead interferes with the normal formation of hemoglobin.

When diagnosing lead poisoning, you have to take into consideration the history of exposure, cm lead levels are usually greater than 5—however, some people use higher numbers. If a complete blood count (CBC) test is done, microcytic anemia will be found and in a peripheral blood smear, you will find basophilic stippling (ribosomes). The serum iron will be normal.

basophil

When treating lead poisoning, the first step will be to eliminate the source of lead contamination. Next, a chelating agent will be used. During this step, various drugs may be used to help remove lead from the body. A chelating agent will bind the lead into a form that the body can excrete. It is used if lead levels are higher than 45µg/dL in children, and more than 70µg/dL in adults. Dimercaprol (oral chelating agent) is used in cases where patients present with encephalopathy. Succimer is used when there aren’t any signs of encephalopathy.

It is also possible to be contaminated by lead due to a bullet penetrating a joint or if it is introduced into the cerebral spinal fluid. This may cause severe synovitis and low grade lead poisoning. This condition is rare, however it can occur. Lead toxicity can also occur due to contamination of the ground water and soil. Lead poisoning can occur due to ingesting food grown in contaminated soil.

Salter-Harris Fracture Classifications

The Salter-Harris fracture is a common injury in children, involving the growth plates of the long bones. Approximately 15% to 30% of all childhood fractures are growth plate fractures and are common in the lower leg bones (tibia and fibula). It is important to detect these fractures as they may affect the growth of the bone if not treated properly.

There are five types of Salter-Harris fractures. The higher the type number, the more complications associated with the fracture.

typeIfx
Type I

Type I

Only 5% of fractures are Type I. It may be difficult to diagnose unless there is obvious displacement and sometimes the diagnosis is a clinical one. Type I fractures occur though the weak zone of the provisional calcification and are known for their fast healing and rare complication rate.

Type II:

typeIIfx
Type II

Approximately 75% of fractures are type II. These fractures occur at the physis (growth plate) and metaphysis – and when the corner of the metaphysis separates (Thurston-Holland Sign). The fragment usually stays with the epiphysis while the rest of the metaphysis will displace. Typically, healing is fast and growth is usually okay; however, distal femur fractures may result in growth deformity.

 

Type III:

10% of fractures are Type III, which are defined as fractures of the growth plate and epiphysis, or even a split of the epiphysis. The fractures extend into the articular surface of the bone and will require reduction of the joint. In distal femur fractures it may result in a growth deformity.

typeIIIfx
Type III

Type IV:

About 10% of fractures are Type IV fractures—which pass through the epiphysis, physis (growth plate), and the metaphysis. Type IV fractures can cause complications such as growth disturbance and angular deformity.

TYPEivfx
Type IV

Type V:

Type V fractures are uncommon, only occurring about 5% of the time. In type V fractures, compression or a crush injury of the growth plate takes place. This fracture has no association with the epiphysis or metaphysis and an initial diagnosis may be difficult. Despite being uncommon, these fractures have the highest incidence of growth deformity and disturbance.

typeVfx
Type V

Flail Chest

Flail Chest—Everything You Need to Know

In flail chest, three or more ribs are involved in segmental fractures. A segment of the rib cage breaks and then becomes separated or detached from the chest well. It usually requires a significant amount of violent force in order for the ribs to break in this way. Due to the nature of this injury, flail chest could be a life threatening condition.

flail

The fractured segment will sink into the chest with inspiration and expand out of the chest wall with expiration opposite to the normal chest wall mechanics. The segmented rib fractures work independently. If the segmented section moves right, then the rest of the ribs move left, and vice versa. The flail chest moves in the opposite direction of the chest wall. The fractured segment goes in while the rest of the chest goes out—this is called paradoxical breathing.

There may be a pulmonary contusion associated with the flail chest fracture segment, and this contusion could be more significant than the flail segment. There may also be a noticeable chest wall deformity with the presence of air in the subcutaneous tissue (crepitus). Trauma to the chest usually causes scapular fractures or a clavicle fracture.

Symptoms of Flail Chest:

  • Patient will have chest pain and shortness of breath
  • Paradoxical movement of the flail segment
    • The constant movement of the ribs is very painful
    • The broken rib may puncture the lung and cause pneumothorax

pneumo

Images

On an x-ray, it is difficult to see if the fractures are displaced or nondisplaced. A CT scan is probably the best method for visualizing these fractures.

The prognosis varies and it depends on the severity of the condition, however, the death rate ranges between 10-25% usually depending on the pulmonary injury. About 8% of patients who are admitted to the hospital with fractured ribs will have a flail chest.

Treatment

If there is no respiratory compromise and no flail chest segment, observation of the patient will be done. It is important to follow advanced trauma life support (ATLS) principles.

  • Airway
  • Breathing
  • Circulation

The patient’s pain will need to be managed—usually with intercostal nerve blocks. It is essential to avoid the suppression of breathing and if necessary, give the patient positive pressure ventilation (a chest tube if needed).

Surgery

Surgery may help in reducing the duration of the ventilator support and aid in the pulmonary function. The patient will need aggressive pulmonary toilet and physiotherapy.

An open reduction and internal fixation should be done when there is severe pain and displaced ribs, when there is a flail chest segment (three or more consecutive fractured ribs with segmental injury), the rib fractures are associated with failure to wean the patient off of ventilation, and/or when there are open rib fractures.  Usually a plate and screw system is used in addition to early range of motion of the shoulders.

Unbelievable Bacteria

One of the ways bacteria enters the body is through an open wound. When an open wound goes straight down to a fractured bone it is called and open fracture. When bacteria gains access to the deeper tissue beneath the open wound, the tissues become contaminated. Preoperative and prophylactic antibiotics are given to the patient to help decrease the infection rate with the hope of killing the bacteria in the contaminated field.

open fx bacteria

Additionally, a special treatment is done during an open fracture to further help prevent infection. This treatment consists of irrigating and washing the wound, as well as debridement of the dead tissue. Once the tissue has been adequately cleaned, the fracture needs to be reduced and stabilized. Three different ways to stabilize the fracture is with a plate, a rod, or an external fixator. The open wound is either left open for a variable amount of time and it is closed later on. At the time of wound closure, a skin graft will be needed. To promote healing of the fracture a bone graft will be needed usually four to six weeks after the injury.

skin graft

A bone graft is obtained from the pelvis as the pelvis has a large reserve of bone that can be utilized. The bone that is harvested is cut into pieces and then added to the fracture where needed. Despite the best care, a certain percentage of open fracture injuries will become infected. When the tissues become infected by bacteria, white blood cells are attracted to the infected site where the bacteria are multiplying and causing inflammation.

multiple bacteria

Bacteria multiply by replicating their DNA and then dividing into two identical bacterial cells. Due to the doubling of bacterial cells, the population of the bacteria grows rapidly. Once at the site of infection, the white blood cells begin to ingest the bacteria. These bacteria however, may survive and multiply within the white blood cells, causing the cells the burst. When this occurs, the bacteria is then released back into the tissues.

Other types of bacteria can also produce a thick capsule that prevents them from being engulfed. Engulfed bacteria may also produce toxins used to destroy cells that try to attack them. Bacteria can also hide in dead bone or bone cells. When this happens, antibiotics and white blood cells are unable to reach the bacteria, since the dead bone has no blood supply. In addition to the bacteria hiding in the bone, the bacteria grow rapidly.

engulf

During this growth period, the bacteria communicate with one another through a process known as quorum sensing. Quorum sensing is the use of a chemical signals from one bacteria to another. As the bacterial population grows, the concentration of the chemical signal. Once the concentration of the chemical signal reaches a certain threshold, the bacteria then begin their attack. The bacteria will attack the tissues causing it to break down and die which can lead to an abscess formation. The abscess must be drained and evacuated, followed by antibiotic treatment.

bacteria communuity

Antibiotics can kill bacteria in several different ways. One way is by disrupting the cell wall which ruptures the bacteria. Another way, is by preventing DNA replication by blocking the unwinding of the DNA. A third way is by inhibiting the ribosomes from making proteins needed for the cellular structure and function. The last way is by blocking the enzymes that produce folate. Folate is needed for DNA synthesis, and without it the cell will die.

When hardware is used to stabilize the fracture, the story can become much more complex.