August 20, 2009
ROYAL PAINS MEDICAL BLOG
By Dr. Irving Danesh

Hi, this is Dr. Irv and I hope you have had a happy and healthy week.

In this week's episode of Royal Pains ("Nobody's Perfect"), Divya and Evan encounter a very serious medical problem in the field. Divya has to make life and death decisions based only on her clinical exam and medical judgment since she has no sophisticated medical equipment or hospital back up. Ultimately, she treats Captain Bryan for two major medical problems: tension pneumothorax and flail chest. These types of chest trauma cause death in 20-25% of cases.

Tension pneumothorax occurs when air escapes the lung and accumulates within the chest cavity. Normally, the chest cavity has a negative pressure, thus allowing the lung to stay inflated. When air escapes from the lung, it spills into the chest cavity allowing this space to go from negative pressure to a positive pressure. The lung deflates or collapses. This is a problem as air now has problems getting into the lung, yet blood is still circulating in this lung waiting for oxygen that is not coming. Hypoxia (low oxygen content of blood) begins. As we have discussed previously, blood is vital for all cells' survival.

A tension pneumothorax occurs when the chest cavity develops so much pressure that it starts pushing on the great vessels of the heart: the aorta and the vena cava. The aorta is the great artery that leaves the heart carrying blood rich in oxygen and the vena cava is the great vein coming into the heart carrying blood that has had most of its oxygen removed by the cell. When the pressure in the chest gets to a certain point, it starts pinching the great vessels and doesn't allow blood to flow into the heart. If blood can't flow into the heart, cardiac arrest ensues.

Divya knows that chest trauma--especially by blunt major force impact--will fracture ribs. The broken ends of the ribs are very sharp and can easily lacerate the lung. Divya comes up with the snap diagnosis of a tension pneumothorax. There is only one solution: she must relieve the increased pressure build up and allow the great vessels to un-kink.

Divya places a hollow needle in the chest, allowing air to escape. While this instantly solves the problem of the kinked vessels, she now has to relieve the collapsed lung. Divya creates a homemade Heimlich valve or flutter valve, which lets air out but not in. As the lung partially expands, it forces air through the needle and through the flutter valve. Eventually, negative pressure is re-created in the chest cavity and the lung re-inflates.

The second problem Divya faces is the flail chest. If a blow to the chest breaks two or more ribs in two different places per rib, that section of the chest wall becomes disconnected from the rest of the chest wall. The flail segment then acts independently from the rest of the ribcage.

Normally when you inhale, the chest expands. When you exhale, your chest contracts. In flail chest, this mechanism is still in place, except for the flail segment. During inhalation the flail segment contracts into the chest and when the patient lets the breath go the flail expands. This is called paradoxical breathing.

The flail segment is not only very painful but it makes it much harder to breath. Usually with a flail chest the lung underneath the segment is either contused or lacerated decreasing the ability to oxygenate further.

Treatment of the flail chest is controversial. In some cases of flail chest where there is no hypoxia and the patient is stable, pain control and the manual cleaning out of secretions in the lungs may be effective. The patient is given narcotic pain medications and a respiratory therapist will help the patient clear his secretions. This is done by putting a small catheter down the nose or mouth into the lungs and removing accumulated mucous and other fluids that are there. This opens the passages in the lung, allowing better oxygenation.

Finally, if a patient is having problems with oxygenation, the patient may be intubated and put on a respirator to keep the small air passages in the lung (bronchioles) open. The respirator keeps the bronchioles open by using positive pressure. Surgery to repair the ribs has long been thought to not help this situation. Recently there have been scientific papers showing that surgical repair of the ribs may in fact help decrease pain and increase oxygenation.

Till next blog have a happy and healthy week.

Doctor Irv