The object of this review is to convey new scientific information and resultant practical techniques applicable to the care of the severely injured patient.
The object of this review is to convey new scientific information and resultant practical techniques applicable to the care of the severely injured patient. One near death, severely injured patient is then briefly presented to exemplify A – airway, B-breathing C- cardiovascilar, D – disability, E – everything else techniques that contributed to her recovery.
Trauma can affect many body systems and a priority of need dictates the appropriate response. This priority concept is not new and is still based on the ABC's. However new experience has provided an increased emphasis on the importance of a clear airway, support of ventilation, early arrest or at least the augmentation of hemorrhage, and metabolic supportive techniques that are either designed to provide the oxygen and substrates that are necessary, or the augmentation of the bodies need of them. An example of this is use of hypothermia and induced coma or "anesthesia" that places the patient in a state of "suspended hibernation" for a period of time. This time allows the shocked cells to recover enough that they can resume a gradual return to normal function. At this time we are using mild hypothermia (93-98 degrees) in resuscitation when surgery is not required and moderate hypothermia (89-92 degrees) during resuscitation when surgery is required very commonly during the initial phases of trauma care. Then after restitution of the patient's oxygen debit and hypovolemia active rewarming is done slowly over 8 to 24 hours.
The following techniques have been developed by the author, or adapted by the author from techniques that are now used in the care of humans, which have been found to be critical importance in the care of seriously injured small animal patients:
1. A. Rapid and aggressive use of the tracheostomy including awake tracheostomy, tracheostomy use in the severely pulmonary traumatized patient that allows tracheal toiletry and direct support of ventilation;
2. AB. Jet-blow by oxygen stream ventilation, where, on arrival the spontaneously breathing trauma patient is provided a forceful stream of 100% oxygen delivered directly to their nose and mouth area. The stream is generated by attaching a 14 g IV 1-2 inch catheter to a commercial oxygen tubing line or to an IV solution administration set that is connected to a flow-meter regulator or to one arm of a Y connector that is placed in-line with the oxygen supply line of an anesthetic machine prior to it entering into the circle-system part of the machine. The jet stream delivered to an animal that is open mouth breathing will assist that animal's ability to take in the fresh gas on each inhalation effort. The jet stream will also provide a small level of positive airway pressure during exhalation and assist in increasing functional residual capacity. This will decrease the patient's level of work of breathing and be particularly beneficial in those patients with pulmonary contusion, intrapulmonic hemorrhage and edema. It is used during the initial phases of care when IV access is being obtained.
3. AB. Noninvasive ventilation by use of a bag-valve-mask and the attachment of a PEEP valve on the exhalation arm of the bag-valve. This provides the trauma team the ability to administer Bi-PAP ventilation on almost on a moment's notice whenever any patient arrives that is having difficulty with breathing. The Bi-PAP ventilation involves the squeezing of the bag with each breath the patient attempts to take thus giving an assisted ventilation which lowers the patient's work of breathing. When the patient exhales the exhaled breath is somewhat impeded by the peep valve which causes in retainment of some of the exhaled breath which increases functional residual capacity. Animals that arrive conscious enough to fight a mask are given an IM or IV injection of ketamine 1-2 mg/kg, butorphenol 0.1-0.2 mg/kg, acepromazine 0.01 – 0.02 mg/kg. It is then recommended to perform immediate ultrasound focused examination on the thoracic cavity to determine whether pneumothorax is present. If present then the thoracentesis or a chest tube may be needed as this noninvasive support ventilation may cause additional increases in pleural air. The mask can also be taped to the patient's head or placed into a cloth muzzle to continue the Non-Invasive Ventilation with a mechanical ventilator.
4. AB. The automatic "routine use" of mechanical ventilation for support of pulmonary function during the first 12 to 24 hours post admission in severely injured patients. This is in conjunction with the use of continuous rate infusion pentobarbital to induce a light barbiturate coma and allow the patient to tolerate can use mechanical pressure support ventilation with a lease of positive end expiratory pressure at the conclusion of the exhalation phase of each breath as a "protective lung strategy"
5. C. Hemostat assisted large-bore catheter venostotomy is performed at the onset of arrival of the severely injured patient.
An incision is made with an 18 gauge needle over the top of the intended peripheral vein, in most cases the cephalic vein. A curved Halstead mosquito hemostat is then used to quickly dissect out the vein. The hemostat is placed under the vein and pulled distally to stretch it out and place it under tension. Then a 14 to 18 gauge short intravenous catheter is inserted into the exposed and stretched vein with 14 gauge used in large dogs and 18 gauge used in small dogs or cats. Their use of the hemostat to expose and tense the vein is a key part of the technique that will allow placement of a catheter in less than a minute into vessels that are otherwise be difficult to catheterize.
6. C. Rapid determination of peripheral venous pressure is able to be performed utilizing gradual lowering of the fluid bag that is running at wide open during the initial fluid delivery phase. When the drips in the drip chamber stopped this indicates the peripheral venous pressure has been reached. The height of the drip column is then noted and measured. Any negative number indicates a low venous pressure below normal. If hemorrhage is controlled then the fluid support is continued until the venous pressure is positive. Not until hemorrhage is arrested should fluid support being given as a rapid rate to overcome the negative pressure as this would allow further continued hemorrhage to occur any more rapid rate. A peripheral venous pressure is used as a barometer to indicate venous volume however this is not the most ideal and is also recommended utilized thoracic ultrasound to assess the great vessels and heart filling to determine venous volume.
7. BCDE. Diagnostic ultrasonography of the thoracic cavity is no also highly recommend as well as examination of the abdominal cavity in most severely injured patients that are not immediately going to the operating room for surgery. Thoracic ultrasound is very useful in the detection of pneumothorax, by noting a loss of the "lung slipping sign", pulmonary interstitial edema, by noting, "comet tales" in the lung parenchyma, hemothorax, by noting the sigmoid sign on M mode and diaphragmatic hernia by noting the loops of bowel or liver or spleen within the thoracic cavity. It can be done very quickly and with less stress on the patient compared to thoracic radiographs. On short haired animals all that is generally necessary is wetting the hair was alcohol and the use of ultrasound jelly. Abdominal ultrasound, in the form of a focused abdominal systematic exam for trauma can also be completed within a matter of minutes and with the patient and the most positions of comfort, that of generally right or left lateral recumbency.
8. C. Augmentation of the rate of hemorrhage by the use of counter-pressure. When pressure is applied to an area of active hemorrhage four physical changes occur. A. The physical hole where the bleeding is coming from is made smaller. This greatly affects the flow of blood through the hole because of the physical law that applies [Q = r4 ] where Q = flow rate through the hole and r = the radius of the hole. B. Making the hole smaller increases the luminal tension on the hole via the Law of Laplace [T = l/r ] and this provides increased physical forces that tend to close the holeC. The hole "channel" becomes thicker which proportionally increases the resistance of flow through the hole. D. The pressure gradient or differential across the hole decreases where Delta P = vessel lumen pressure [Pvl] – pressure outside the vessel lumen [Pov], which also includes the tissue pressure of the hole itself [Pt]. Taking these physical changes into account, adding any amount of external pressure on the area hemorrhaging has the capability of make a substantial difference in the rate and amount of hemorrhage. Adding the external counter-pressure to a limb or abdominal cavity-pelvis and pelvic limbs can be done with simple materials such as the application of towels or bubble wrap and then tightening with duct tape. This also forces the patient to be immobilized which also decreases the chance for clot disruption. In some cases use of analgesics is required to prevent undue pain while the counter-pressure is applied. The amount of pressure needed to make a difference in blood loss has been found experimentally to be dependent on the pressure in the vessels that are hemorrhaging.
From clinical experience it has been noted most canine and feline patients that arrive at a veterinary hospital hemorrhaging are hemorrhaging from non-high pressure vessels. Those in which hemorrhage is coming from a high pressure vessel like the aorta, for the most part, never arrive alive. Therefore the type of external pressure that is generally used for those animals with suspected or confirmed internal hemorrhage is 10 to 15 centimeters of water. This amount of pressure is quite capable of slowing or stopping most hemorrhaging sites. It is left in place for from 2 to 8 hours and then gradually decreased. Those not stabilizing are provided with additional supportive care such as blood transfusions etc., and taken to the operating room or placed in significant hypothermia the hypotension allowed to continue for four hours. Then the counter-pressure is gradually released over 2 – 4 hours.
Those patients that are candidates for immediate surgery and internal counter-pressure are those in which it is clinically apparent that massive hemorrhage has occurred in either or both of these cavities. These animals require immediate exposure of one or both body cavities and the application of the counter-pressure over the exposed bleeding sources. Aortic cross clamping is performed prior to opening the abdominal cavity if blood pressure is nonexistent as this provides necessary flow to the brain and heart.
9. C. Use of hemostatic agents such as the methocellulose bead products, the shelf-fish exoskeleton based chitosan containing materials like Celox or HemCon, the thrombin and collagen based mixtures, and the tissue bonding cyanoacrylic glue materials have all have helped in the control of severe hemorrhage, at the scene, in the ER and in the OR. Although only approved for use externally, some have been used internally without adverse effects. Temporary inflow occlusion of blood into the bleeding sight, the physical whiping of the blood away from the bleeding site, and the placement of the hemostatic agent into the bleeding site, have been important techniques to do to stop the hemorrhage. Ultrasound instrumentation to provide hemorrhage control has also been used.
10. C. Use of intralumenal occlusion balloon typed catheters have also been used effectively for the control of hemorrhage in both cats and dogs to a limited extent. They are routinely used in large trauma centers to provide "non'operative" invasive means of controlling bleeding sites particularly in difficult to expose and control areas. Interventional radiologists work as part of the trauma team and are "on call" when needed to provide occlusion to the vessels feeding the bleeding site. In some cases the site is completely controlled and requires no further intervention. In some cases however this technique is used to provide a temporary control until surgical exposure can be accomplished.
11. C. Based on oxygen demand of the various tissues and "bleed out rate and total accumulation" most severely hemorrhaging trauma patients will require autotransfusion of the accumulated blood from either or both the thoracic and abdominal cavity for them to survive. This is best accomplished with commercial autotransfusion systems, however in emergency conditions the blood can be aspirated into a reservoir (suction canister, 60 ml syringe) and simply administered back to the patient immediately using a basic 170 micro blood filter. A series of trauma cases has proven this technique viable and life-saving. The accumulated blood can be directly collected from a body cavity, via a large bore thoracic cannula placed by a non-styling method that dissects a small hole into the thoracic or abdominal cavity. In most cases anticoagulant is not needed. Use of hypertonic saline and hetastarch at 2-3 ml/kg boluses one to three times as needed to provide pulsitile perfusion as determined by Doppler Flow blood flow monitoring and the g-r-a-d-u-a-l increase of pressures back to normal after a given time in the lower flow states.. generally aiming for just enough time for clotting to become just firm enough not to blow as pressures go on to normal. The patients MUST also be immobilized and continued to be such until hours go buy, again the reason is to prevent clots from blowing. Mild abdominal pressure with a towel or bubble wrap around the abdomen and pelvis and pelvic limbs and held in place with duct tape is a splinting maneuver that has worked in selected cases. Of course if the patient is bleeding so rapidly that this strategy would not work open resuscitation must be rapidly attempted. Obviously there is a much higher mortality in these cases. In these cases or in those that fail to stop hemorrhaging in some cases rapid exposure of both the thoracic cavity and the abdominal cavity using Mayo scissors, the use of encircling Miller's knots for rapid ligation of liver and lung lobes, kidney and closures also with auto-suture devices and with body cavity closure using continuous polypropylene or again, using auto-suture devices has been and continues to be life-saving.
12. ABCDE. Use of supplemental oxygen beginning early in the course of resuscitation, prior to the onset of fluid support, and following through with the use of oxygen carrying colloid substances such as Oxyglobin (a hemoglobin based oxygen carrier (HBOC), and hyperbaric oxygen (HBO) are also recommended as "new techniques" to use in the care of the trauma patient. There are multiple veterinary centers currently involved in a patient registry that has been set up by the Veterinary Hyperbaric Society. There are many trauma cases in human medicine that have been documented to have significantly benefited from hyperbaric oxygen therapy. There also have been experimental studies concerning the used of HBO in trauma and shock that have demonstrated their effectiveness in carrying and off loading oxygen better than homologous blood transfusions by a factor of 4. Research has suggested that providing oxygen supplementation prior to fluid resuscitation is associated with less reperfusion injury and continuing the use of it postoperatively is associated with less wound complications including infection.
13. ABCDE. Monitoring and assessing perfusion using infrared laser guided or non-guided thermometry. The devices are relatively inexpensive and provide a digital read-out of the temperature within one second. The difference between the surface temperature of the buccal area in the oral cavity and the toe web space in a pelvic limb is dependent on perfusion and, although the concept is not new, the technology is and this allows for the rapid and accurate determination of the differential temperature. The infrared devices can be easily purchased at such stores such as Radio-Shack.
14. ABCDE - Support of the gastrointestinal track with glutamine containing fluids that are given in small amounts by the enteral route and followed by gradual increases has been a main factor in survival.
15. In the head injured patient if deterioration is observed following emergency medical care then the patient should be taken to surgery and the cranium or spinal canal opened and hematoma, ruptured disc removed and the surgical site left with only a muscle - fat covering over it to allow for further decompression.
One severe trauma case that recovered with the use of these techniques was Sara: A middle aged FeS Golden Retriever that was hit by an automobile. She sustained a very severe blow to the head which caused her frontal bones to shatter and her left eye to rupture, both externally and internally with eye contents being expressed into the depths of the sinuses. She arrived breathing but with a struggle and was barely conscious. A large opening in the frontal sinus was spewing blood in a steady rate and her breathing was being done principally through the opening in her sinus. I was not able to determined what other injuries were possibly present as her face was covered with blood. The following were performed:. Jet blow-by O2 to the face and "blow hole" in the sinus. Hemostat enhanced 14 g venostomy catheter placement in the right cephalic vein. A rapid "awake" tracheotomy & ventilation with 100% O2. Assessment of venous pressure via bag-drop-technique. Assessment of blood flow and pressure with a Doppler flow detector. Venous pressure and flow were very poor. Hypertonic saline/Hetastarch 50-50 combination bolused at 5 ml/kg. HBOC (Oxyglobin) and FFP 5 ml/kg (each) were started to provide pressures enough for Doppler flows to be heard well. Plasmalyte 15 ml/kg then 2 ml/kg/ hr and Hetastarch 2 ml/kg/hr during all of anesthesia. Ketamine 2 ml/kg with ace (0.2 mg), Hydromorphone 0.02mg/kg provided for pain relief, Acepromazine 0.02 mg/kg. Atricarium 0.25/kg IV to paralyze then ½ doses as needed were given during the surgery. Clipped the entire head and neck, applied a block with lidocaine /bupivicaine /bicarbonate. Sara was in surgery room within 20 minutes of arrival with the head clipped and the head and elevated with care taken not to placed compression on the jugular veins. IV cephazolin and enrofloxacin were provided. An incision over entire nasal and frontal region was accomplished. As I started to remove the bone fragments the severe bleeding resumed. The bleed was stopped with counter-pressure and a pack was left in as exposure of and carotid occlusion was needed. Bone fragments and eye contents were removed. ACell was applied to the nasal defect and sutured to bone and periostium. Temperature was 90 at conclusion of surgery. Ventilator support was continued for 14 hours with a CRI of pentobarbital, morphine, lidocaine and ketamine. Gradual rewarming was done during this time after 4 hours of continued hypothermia –monitored by thermometery. ICU monitoring, trickle feeding via an E tube, residual assessments Q 4 hr, tracheostomy care and physical therapy (range of motion activity, massage, standing, walking w/ assistance) was done Q 4 hr. HBOTx (½ ATA at 100% oxygen for brain contusion was completed. Tracheotomy care as required, (suctioning, humidification, tube changes Q 4-8 hrs) was done and following five days of continued care Sara was able to be discharged. She made a full recovery other than the loss of her left eye.