Above: the tip of a hypodermic syringe needle. Below: the tip of a fang from the cobra Naja kaouthia.
Both are designed to pierce the skin and admit fluids into the bloodstream, although it is often the case that the intended effects are polar opposites.
Artificial designs frequently imitate those of nature; in this case, mankind was approximately 25 million years late.
A 3-year-old girl presented to the emergency department after she had ingested a metal pendant. She had not vomited and had no pain in her chest. A physical examination was unremarkable. A radiograph of the chest confirmed a heart-shaped foreign body in the proximal thoracic esophagus. Ingestions of foreign bodies are most commonly reported in children 1 to 3 years of age. Ingested items that warrant immediate endoscopic removal from the esophagus include sharp objects, button batteries, and foreign bodies that have been present for longer than 24 hours. Asymptomatic children who have ingested items that do not have potentially dangerous features may be observed without intervention to allow the foreign body to pass spontaneously. In this patient, the position of the foreign body appeared to be unchanged on repeat radiographs of the chest. The patient was taken to the operating room to undergo rigid endoscopy, and a gold heart-shaped pendant was removed (inset). Reinspection of the esophagus showed minor abrasions of the esophageal mucosa. After the procedure, the patient recovered well and was discharged home.
Your brain is a network of billions of neurones, all somehow connected to each other. At this very second, millions of impulses are being transmitted through these connections carrying information about what you can see and hear, as well as your emotional state. It’s an incredibly complex system but sometimes things go wrong. Despite extensive research, we are still not certain on the biology that underlies mental illnesses- including depression. However, we have come pretty far in developing effective treatments.
We have a lot to owe to neurotransmitters, they are the driving force behind every chemical process that occurs in your body. This infographic shows the most common, and the roles they have.
Hypovolemic shock = not enough blood volume to maintain blood pressure Cardiogenic shock = heart is too weak to maintain cardiac output; often occurs after a heart attack, heart can’t pump strongly enough Obstructive shock = a blockage somewhere prevents blood from circulating Distributive shock = blood vessels leak or dilate too much to maintain blood pressure; systemic shock, all vessels are dilated
Examples
Hypovolaemic shock: dehydration (prolonged poor water intake, diabetic polyuria both mellitus and insipidus, burns); haemorrhage (trauma, clotting factor deficiencies, ruptures/perforations of organs and vessels)
Cardiogenic shock: poor cardiac output (congestive heart failure, arrhythmias, valvular diseases, ventricular outflow tract stenosis,
ischaemic heart disease, myocardial contusions), neurogenic causes (hypofunction of cardioexcitatory centre/hyperfunction of cardioinhibitory centre of medulla)
Obstructive shock: thromboemboli, coarctation of the aorta, cardiac tamponade, pneumothorax
Distributive shock: neurogenic shock (hypofunction of the vasomotor centre in the medulla), anaphylaxis (histamine induced systemic vasodilation w/ increased vascular permeability leading to widespread oedema)
Septic shock: histaminergic effects like anaphylactic shock + reduced cardiac contractility like cardiogenic shock + thrombotic thrombocytopoenia/DIC leading to haemorrhagic shock
A man who was completely paralysed from the waist down can walk again after a British-funded surgical breakthrough which offers hope to millions of people who are disabled by spinal cord injuries.
Polish surgeons used nerve-supporting cells from the nose of Darek Fidyka, a Bulgarian man who was injured four years ago, to provide pathways along which the broken tissue was able to grow. The 38-year-old, who is believed to be the first person in the world to recover from complete severing of the spinal nerves, can now walk with a frame and has been able to resume an independent life, even to the extent of driving a car, while sensation has returned to his lower limbs.
The cells from the patient’s olfactory bulb in the brain were removed and grown in the lab. The olfactory bulb is on the inferior side of the brain and it transmits smell information from the nose to the brain, and is thus necessary for a proper sense of smell. The olfactory bulb is, with the subventricular zone, one of only two structures in the brain observed to undergo continuing neurogenesis in adult mammals. In most mammals, new neurons are born from neural stem cells in the sub-ventricular zone and migrate rostrally towards the main and accessory olfactory bulbs.
The cells taken from the nasal cavity were injected into the spinal cord above and below the damaged site and strips of nerve fibres were taken from the patient’s ankle to form a bridge for the cells to grow across.
Professor Geoffrey Raisman, whose team at University College London’s institute of neurology discovered the technique, said: “We believe that this procedure is the breakthrough which, as it is further developed, will result in a historic change in the currently hopeless outlook for people disabled by spinal cord injury.” Raisman said he had never believed the “observed wisdom” that the central nervous system cannot regenerate damaged connections. He added: “Nerve fibres are trying to regenerate all the time. But there are two problems – crash barriers, which are scars, and a great big hole in the road. “In order for the nerve fibres to express that ability they’ve always had to repair themselves, first the scar has to be opened up, and then you have to provide a channel that will lead them where they need to go.”
He stressed that what had been achieved was a leap forward beyond promoting “plasticity” – the rewiring of remaining connections. The professor added: “The number of patients who are completely paralysed is enormous. There are millions of them in the world. “If we can convince the global neurosurgeon community that this works then it will develop very rapidly indeed.”
Although posterior hip dislocation is an uncommon injury, the consequences of delayed recognition or treatment can be dire. The majority are caused by head-on car crashes, and 90% of these are posterior dislocations. The femoral head is forced across the back wall of the acetabulum, either by the knee striking the dash, or by forces moving up the leg when the knee is locked. This occurs most commonly on the right side when the driver is standing on the brake pedal, desperately trying to stop.
On exam, the patient presents with the hip flexed, internally rotated and somewhat adducted. Range of motion is limited, and increasing resistance is felt when you try to move it out of position. An AP pelvic X-ray will show the femoral head out of the socket, but it may take a lateral or Judet view to tell if it is posterior vs anterior.
These injuries need to be reduced as soon as possible to decrease the chance of avascular necrosis of the femoral head. Procedural sedation is required for all reductions, since it makes the patient much more comfortable and reduces muscle tone. The ED cart needs to be able to handle both the patient’s weight and your own. I also recommend a spotter on each side of the cart.
Standing on the cart near the patient’s feet, begin to apply traction to the femur and slowly flex the hip to about 90 degrees. Then gently adduct the thigh to help jump the femoral head over the acetabular rim. You will feel a satisfying clunk as the head drops into place. Straighten the leg and keep it adducted. If you are unsuccessful after two tries, there is probably a bony fragment keeping the head out of the socket. See an instructional video on this tomorrow.
Regardless of success, consult your orthopedic surgeon for further instructions. And be sure to thoroughly evaluate the rest of the patient. It takes a lot of energy to cause this injury, and it is flowing through the rest of the patient, breaking other things as well.
