Ridryder 911

Yes, you can meet a helicopter to meet you, as long as they (Hospital) has not made contact or accepted patient as such. You are using the pad as a meeting place only. This has been thoroughly discussed with EMS helicopters and EMTALA and they agree. There is no contract or agreement between hospital and patient. The "outside" areas are involving parking lot and centers owned by the hospital such as clinics etc. R/r 911

I do agree there are more tamponade related injuries from penetrating injuries but with the indications of Beck's Triad in trauma one cannot exempt it. Yes, myocardial contusions will cause tamponade too as well and not as higher incidence of myocardial rupture. I agree there is a higher incident of myocardial rupture, but doubtful any symptomology will resemble Becks configuration. Since the papillary muscles are usually torn and a possible ventricular wall disruption occurs, as well as more than one chamber is usually involved, one usually sees a dead patient. I disagree however not being able to auscultate heart tones, ones needs to possible choose better devices or use a doppler system if too much ambient noise is present. Personally, I have no problems auscultating heart tones as well as bruit's, bowel sounds etc... in the field setting. We do carry doppler for determination of true PEA as well as vasculature perfusion and of course a flat head for fetal heart tones in the event of inability to auscultate. R/r 911

Very good points and + 5 for a good comments. I like to add, one should give a verbal report to staff. Until there has been such report and you leave the patient without formally addressing to the staff, one could be charged with abandonment. Yes, even if the patient is in the hospital. The same if you dropped the patient in the lobby without telling and giving a report to another equal or higher trained. The key word is they assume care ...not that you just have the patient in the hospital setting... you can book out of there. One can only imagine, if you place a cardiac in the hall and no one assumed care and was not informed about it.. only later to find that patient had coded.. there would be less medics. R/r 911

How ironic, to see the meatwagon next to a fire engine... R/r 911

Geez.. I thought the 70's was over ! Collar brass.. what's next EMT letter bars, back to lapel pins from CPR to storks, to Extrication Specialist.. Just when we were getting over being a whacker !.. and attempting to be medical. Sorry, if you just have to have a badge to impress yourself.. purchase one. But there is no reason or event that is helpful, or deemed warranted. Photo I.D'.'s should be required with special labeling. With the new national DMAT and MRC guidelines in the event of a disaster, only those with photo ID's will be able to pass through the perimeter, so you can keep your badges at home.. R/r 911

I don't have the stats.. but the 12 + that was shot and killed last year in self defense (thoroughly investigated and deemed such) will never harm or break into another person's home again. So yes, it may not lower the crime rate over all, but there is 12+ less this year! ... Again, we are not discussing running around with a 6 shooter on your hip. In fact, I cannot publicly display my weapon and there are several factors where and how it can be used. As well, you are automatically placed into a data base etc.. so, they know your fingerprints, DNA, etc.. It is not a free ride or pass to shoot someone. Ironically, I have yet heard of an accidental shooting or "raged" shooter attempting to use this law. The case is very scrutinized and investigated. R/r 911

I would complain to the college anyway. They may want to cancel his contract and do away with a half arse class. Besides, chances are they don't want their name on it, if it is flawed. Good luck! R/r 911

First. Beck's triad is occurring from tamponade in the pericardium. It can be produced as little as additional 10 ml and V-fib can be caused as little as 30ml of blood or fluid. Remember, what is occurring when this happens. The heart is being confined, thus pressure is being induced or ejection and refill. Remember Starling's Law ? Becks triad will have a "narrow pulse pressure" with lowering arterial pressure, because the inability to fill and JVD will occur due to increased venous pressure from right heart problems as will you have potential muffled heart tones. I have seen Beck's Triad and the main point of catching it is M.O.I. , D.O.R.F. sign (Ford spelt backwards..steering wheel imprintl...lol) sternal bruising or echymoses of ribs as well, and muffled heart tones, JVD, and narrowing pulse pressure. Usually, if you see the pulse pressure changed, it is getting very serious and they need pericardialcentesis in a hurry. As well, you might see ECG changes of ischemia and ectopi. Since most services do not perform such, recognition of it is the crucial part to notify ahead for the receiving ER to be prepared. Tension Pneumo is occurence of the lung. It inly affects the heart in the later stages (if one makes it that far) by pushing the mediastianal area (heart, trachea, etc..) over from the increased air in lung pleuritic area. Now, it can produce JVD because again, it is compromising the filling of the heart by pushing it to the side. So, yes they are completely different and yet, they may have a tension pneumo and a tamonade at the same time.. we can correct a tension pneumo easy enough. p.s. the respiratory breathing in ICP is sometimes referred to as Biot's respiratory pattern...no to be confused with central neurogenic hyperventilation pattern. R/r 911

Okay, how does one own a college program?.. Something is not right here ? Did you complain to the college officials, if it is through the college then they have oversight.. again, this is not clear. R/r 911

I do not see the problem either. In fact in OK. have a similar law called "make my day" law, that gives the citizen the right to arm and protect themselves. I personally carry a concealed weapon (one of course has to go through a course and qualify and be licensed) for that main reason. I have caught robbers in the act of breaking into and robbing my home. I personally would have no problem shooting them and ending their lives. I can assure you, if I had a weapon on me at that time, they would not had been alive today. Now, you have to remember in rural area, you may call 911 but do to the area covered the response may be up to 40 minutes or more before an officer arrives, if you are even that lucky. It is not like in metro area where there is a cop every 4 to 6 blocks. We have four sheriff deputies covering over 787 square miles... so what do you think your chance is of having an officer rescuing you is? We have had about a dozen people or more that was shot and was declared justified by this law. Some of the idiots were actually inside the home making threatening gestures. Too bad so sad.. I call it adding to the natural selection committee, of eliminating idiots out there. Our carjackings have went down as well as some of the violent crimes.. again the adage.. Don't worry about good people with guns. Gang bangers, lower lives will always get and have weapons, it just gives the others the right and protection to have an equal chance. Nor has there been an increase of shootings of "Billy Bob's" at bars, etc. as gun control activists claim would happen, nor kids accidentally shot from those that were legally carrying and storing a weapon. Remember, ones that are attempting kidnapping, murder, sexual assault are not doing it because they are nice people. These are violent crimes, and I have no problem ending the situation, nor would I have for any caring citizen that wants to end that situation. The victim would have less harm or loss of life, the state would save tons of money attempting to capture these assailants, court costs, prison costs, less crowding at prison, and then costs on appeals.. etc. No it is not vigilante, they are not seeking justice, just providing protection and action of harmful crimes. If you are not doing anything wrong, then you don't have to worry. Normal Joe is not going to come after you, the same way as it is now... except if gives the normal Joe some legal protection. R/r 911

Good points Doc! KISS.. Keep it short and simple. Where everyone will understand it. R/r 911

I have been doing CNS test for at least 25+ years, after reading Bledsoe's advanced paramedic skills book, (when he was in med school). It is simplistic and definitely not as detail as a good exam, but is better than nothing. I got tired of not knowing early signs of neuro porblems, I don't want to wait for my patient to crash. Basically, it can be performed in < 1 minute, but can tell you a life's worth ! It is so simple, we should be teaching this in Basic EMT !!! Cranial Nerve Examination 1. Cranial nerve I Olfactory: Ask patient about smelling. Keep eyes closed one nare pushed closed, smell w/each nostril Test with different smells such as alcohol pad and cologne or other fragrance Cranial nerve II.: Optic nerve This is when we check for pupillary reflexes. Light should be shined from outside corner to pupil noting reflex (brisk,etc) I keep a small Snellen, eye chart with me, that has colors and different size print. But I used to keep a colored paper advertisement, I laminated and have them read it & tell the colors. visual acuity visual field color vision optic disc appearance III Occulomotor - eye movement. Look for ptosis (drooping eyelid), note the appearance of the eyes, and check for ocular alignment (the light source reflection should fall at the same location on each eyeball). IV Trochlear Nerve: Next, test extraocular range of motion by having the patient follow one of your fingers through the six principal positions (called Cardinal movements) of gaze (make an "H" pattern). Note any misalignment of the eyes or complaints of diplopia or unable to focus. When specifically evaluating CN 3 during testing, note adduction (medial rectus) Moving eye inwards, depression while abducting (inferior oblique) moving eye towards the side, and elevation (superior rectus and inferior oblique) moving eye up and down, ptosis (III nerve) droopy eyelid. This can be done simply by and pupil reaction to light (II & III nerve) Light should be shined from outside corner to pupil noting reflex (brisk,etc) and if the opposite pupil reacts as well. V. Trigeminal Nerve The trigeminal nerve supplies both sensory and motor fibers to the face and periorbital (around the eyes) area. The afferent sensory fibers separate into three divisions and carry touch, pressure, pain, and temperature sense from the oral and nasal cavities, and the face. Motor efferent fibers function to innervate several facial muscles, including the muscles of mastication (chewing). The sensory portion of the trigeminal nerve is commonly tested by examining the how intact and sensitive of pain and light touch sensation from all areas of the face (forehead, cheek, and jaw). Ask the patient to close his/her eyes, a 4 X 4 or the cotton from your baby asprin bottle, it is lightly touched to one side of the forehead. The 4X4 or cotton is then touched to the opposite side and the patient is asked to compare sensations. A sharp object can be used (cap of an ink pen) in the same manner when testing for pain symmetry. The test is then repeated on the cheek and jaw line. Testing the sensory distribution of the trigeminal nerve. Ask your patient to compare the sensation of light touch on both sides of the forehead, cheek, and chin. An another test used to evaluate the trigeminal nerve is the corneal reflex test. Evaluate the reflex by gently touching each cornea with a sterile edge of a 4 X 4, and observing any asymmetries in the blink response This tests both the sensory fifth nerve and the motor portion of the seventh nerve, which is responsible for lid closure. VI. Abducens Nerve The abducens nerve supplies somatic efferent motor fibers to the lateral rectus muscle, which functions to abduct the eye. Have the patient follow your finger and tracing an "H" pattern tests the abducens nerve. Inability to abduct (move the eye outwards from midline) the eye indicates a possible deficit. Aneurysms, tumors, meningitis, trauma, and cavernous sinus problems. VII. Facial Nerve The facial nerve supplies efferent motor innervation to the muscles of facial expression, and carries sensory afferent fibers from the anterior two thirds of the tongue for taste. To test the motor division of the facial nerve, start from the top and work down. First, have the patient wrinkle their forehead and check for asymmetry. Next, have the patient shut the eyes tightly while you attempt to open them. Note any weakness on one side. Finally, have the patient smile big or snarl at you to show his/her teeth and compare the nasolabial folds on either side of the face. To detect droope VIII: Vestibulocochlear NerveThe eighth cranial nerve carries two special sensory afferent fibers, one for audition (hearing) and one for vestibular function (balance). The cochlear division of CN 8 is tested by screening for auditory/hearing. This can be done in the field by the medic lightly rubbing his/her fingers together next to each of the patient's ears and comparing the left and right side responses. FYI: In addition, you may see in ER a Rhinne and Weber tests. This is why they have tuning forks (no, there not for musicals )These are easy to perform and can help differentiate conductive deficits from neurosensory lesions. The Weber test consists of placing a vibrating tuning fork on the middle of the forehead and asking if the patient feels or hears it best on one side or the other. In a normal patient, they will say that it is the same on both sides. The patient with unilateral neurosensory hearing loss will hear it best in the normal ear, and the patient with unilateral conductive hearing loss will hear it best in the abnormal ear. The Rinne test consists of comparing bone conduction, assessed by placing the tuning fork on the mastoid process behind the ear, versus air conduction, assessed by holding the tuning fork in air near the front of the ear. Remember normally, air conduction volume is greater than bone conduction sound volume which will be dull). For neurosensory hearing loss, air conduction volume is still greater than bone conduction, but for conduction hearing loss, bone conduction sound volume will be greater than air conduction volume. Testing of the vestibulocochlear nerve. The Weber test. The tuning fork is struck and placed in the middle of the patient's forehead. The patient compares the loudness on both sides. The Rinne test. A tuning fork is held against the mastoid process until it can no longer be heard. It is then brought to the ear to evaluate patient response. Vestibular testing is can be used to assess brainstem function in comatose patients or in patients who report vertigo/dizziness. Negative results can be for damage to CN 8 which can be caused by trauma, tumors, or infection and can lead to hearing loss, dizziness, loss of balance, tinnitis, and deafness. IX: Glossopharyngeal Nerve The ninth cranial nerve supplies motor fibers to the parotid gland and the pharynx. It also carries sensory fibers from the carotid body and taste sensation fibers from the posterior third of the tongue. Check for a gag reflex, this can tests both the sensory and motor components of CN 9 and CN 10. This involuntary reflex is obtained by stroking the back of the pharynx with a tongue depressor or oral airway and watching the elevation of the palate (as well as causing the patient to gag). The motor division of CN 9 and CN 10 is tested by having the patient say "ahh" or "kah. The palate should rise symmetrically and equally in the back of the oral cavity . Paralysis of the ninth nerve causes a pulling of the uvula (that thing that hangs down) to the unaffected side. The ninth, tenth, and eleventh cranial nerve pathways are close together. So basically in the field testing the glossopharyngeal and vagus nerve. The patient sticks out her tongue and says "ahh." The palate and uvula should elevate symmetrically without deviation. X.Vagus Nerve The vagus nerve carries sensory afferent fibers from the larynx, trachea, esophagus, pharynx, and abdominal viscera. It also sends efferent motor fibers to the pharynx, tongue, thoracic and abdominal viscera, and the larynx. Testing of the vagus nerve is performed by the gag reflex and "ahh" test as described above. Have the patient swallow, difficulties can be resulted from unilateral lesions affecting the vagus nerve can produce hoarseness and difficulty swallowing due to a loss of laryngeal function. Causes of unilateral lesions include trauma and from surgical procedures of the neck, aortic aneurysm, and compression due to enlarged paratracheal lymph nodes from metastatic carcinoma. XI: Accessory NerveThe accessory nerve carries efferent motor fibers to innervate the sternomastoid (sternum) and trapezius muscles (neck muscles). The accessory nerve is tested by asking the patient to shrug the shoulders (trapezius muscles) and turn the head (sternomastoid muscles) against your hand. Palpate the patient's sternocleidomastoid muscles and feel for tension as the patient attempts to turn his/her head. (DO NOT ATTEMPT IN THOSE WITH POTENTIAL CERVICAL INJURIES!!!) . XII: Hypoglossal Nerve The twelfth cranial nerve supplies efferent motor fibers to the muscles of the tongue. To test the hypoglossal nerve, have the patient stick out their tongue and move it side to side and with gloved hand or 4X4 check strength. If there is unilateral weakness, the protruded tongue will deviate towards the side of the weakness (i.e CVA) Further testing includes moving the tongue right to left against resistance or you cna have the patient say "la, la, la." Now, this all seems complexed, but again with practice, practice, practice.. one can perform all this in under a minute. The results will amaze you ! Especially in those with potential CVA, ICP and TBI Good luck and practice ! R/r 911

Whoa your Highness ! Maybe, your not aware that the "Golden Hour" is a myth!..just like responses should be in < than 8 minutes! Another traditional hand me down medical myth from one generation to another that has no scientific basis! The "hour" has been researched do death and can not be proven I highly suggest you read Dr. Bledsoe's article in this months JEMS ..."The first peak of deaths occurs within minutes of the event. Approximately 50% of trauma deaths are in this group The second peak occurs in the first few hours after injury. The third peak accounts for 20% of trauma deaths. It occurs within a few days after injury, with death often resulting sepsis and end organ failure"... As well EMS does very little in treatment and decrease in outcomes. Narrative quote mine: Bledsoe,B.: "Have We Set the Bar Too High?";JEMS 116 Please, if one wants to refer to being a "Shock" specialist, then one needs to really understand shock physiology and the expectations and treatment as well outcomes. Look beyond the "paramedic manual" and read some true studies of trauma. I suggest: Lerner, ED. Moscati,R: "The Golden Hour Scientific Fact or Medical Urban Legend? " Academic Emergency Medicine 8(7):758-760,201 Trunkey,DD: "Trauma", Scientific American 249:28-35, 1983 We need to come to reality folks, so much of what we do and think is CRAP! It has never been challenged scientifically and we are finding out a lot is a bunch of B.S. ! Many of what we presume is just ideas (good intentions or for research grant money) that was pushed through and immediately was accepted, because we in EMS are undereducated to challenge such. What a shame to our system. profession and more so to our patients! R/r 911

Since I have been a Paramedic over 3/4 of my life, it is hard to reflect what EMS has taught me since I don't remember much before EMS. Some things I do know about EMS is that you may love EMS, but EMS will never love you. This saying, you may pour your heart out to the profession, but never expect anything in return. The moment you are gone.. you are forgotten. I had planned all my life to be a Dr. in a ambulance, before the invention of Paramedics, so when Johnny & Roy came onto the scene, I knew my calling. I though I would only do it for about 2-5 yrs, then go into the ministry. Well, 30 years later here I am! I was a very naive kid, that was fortunately blessed from dysfunctional situations and world experiences.. At first I thought that was bad, now I see how lucky I was. EMS has taught me how to "size up" people. I feel I am about 95% right on my opinions about who, how people are. It taught me over years that my "calling" was to be there when the poop hits the fan.. as they say someone has to do it. Ironically, the more crap, the worse the patient gets, the calmer and more focused I become. This is why I become stressed in clinic settings.. and loose insight from mundane illnesses. I have learned that people over all try to be good, but cannot be trusted. Everyone has a "self" mode and will protect themselves over anyone else. There are those few that make the sacrifice and they are usually are labeled "caregivers" and work in the emergency or medical field. As well, they usually have a high divorce rate and never really "succeed" according to the worlds standards. It has taught me God has a sense of humor. Look at other people...and the platypus. That he is really in control and we are just performing. That is why it is hard for me to see atheism in this profession. So many times, I have seen those that are not supposed to survive a crash only later to die in a few minutes from another mishap, or the witnessed 44 year old witnessed arrest not die and the 98 year old with a history of multiple cardiac, diabetes, and HTN respond to delay care after the first medication. Again.. we are really not in charge of anything or producing the real outcome.. just instruments to be used. The down side is I see people entering this profession taking everything for granted for those that fought hard with blood and tears to increase education and professional levels. That EMT's want the easiest way out... no matter what it might sacrifice to the patient. EMT's (over all ) like to brag, but don't want to back anything up with academia and research. I do predict that there will be a split in EMS in the future. Those with education and those that was trained (similar to LPN vs. RN) and this will be interesting. R/r 911

Cushing and shock would represent the opposite signs. (shock < BP, > pulse: Cushing >BP , <pulse) I do agree kids crash faster and the reason being they do not present the ability to talk and give information about their LOC etc.. that is why it is essential that we recognize the m.o.i. and a detailed pediatric neuro assessment. As well, I have seen more prominence in projectile vomiting with children over adults in number. Remember that the child's head in proportion of body mass is much larger and cause of this have more head injuries. (Bobble head theory) Watch a child fall, they usually will strike the head reason due to the weight in proportion of the rest of the body. Now, in theory place this in a projectile situation such as non-restrained MVC. My suggestion is on real MVC with children non-restrained treat aggressive for potential head injuries until ruled out.. i.e suction near-by, IV lifeline in place. It is much easier to perform if things are in place then when the sh*t hits the fan..! R/r 911

I highly recommend that everyone read Dr. Bryan Bledsoe's : "Are We Setting the Bar Too High" ; in this month's JEMS. Describing so much of our treatment and ideas are set off ....."myths and common rules of this is how we always done method",,,,,, So much of what we do and perform has never been proven to be correct. Some of this includes such thought of major standards such as the .. the common 8 minute response time and the controversial mythical "Golden Hour" hoax (which has been proven to be false).But, we continue to endorse such B.S. because that is what has been handed down, now for generations. There are many treatment regimes that need to be evaluated and studied. This is just not for EMS but in all of medicine as well. That is why scientific studies are so important, but those studies have to be performed under stringent criteria. R/r 911

Good points Azcep.. I have seen a few TBI with Cushing's Triad, and as of yet, never seen but one survive. That because emergency burr hole was able to be performed and ICP monitoring was established. Like Azcep described there are many misunderstandings and confusion of the reflex. As he described and some others CVA can cause this as well. The amount of pressure, and degree of ICP pushing upon the pons of the brain stem, and amount of bleeding occurring. This is why it is so essential we become more educated in advance neuro assessments than the PEARL bull sh*t , that is being taught..Which means nothing! Once we start educating EMT's on neuro assessments such cranial nerves, nystgmus, and brain perfusion and cerebral resuscitation. So many are still performing hyperventillation and witholding fluids.. R/r 911

Let's keep it simple BP= C.O. X HR X T.P R. Which in cardiac arrest you have ONLY have the compression perfusion, you have NO true cardiac heart rate again for except the compression from an outside source and peripheral resistance is greatly depressed because of lack of muscle tone except from medication(s). So reality the pressure one would obtain is not really the patients pressure, rather only perfusion pressure of outside source. The same as if the patient was on a bypass machine. Circulation pressure, not the true patients pressure. If one wants to remove all doubt of having knowledge of resuscitation measures; just take a peripheral blood pressure in a cardiac arrest. Again, because one is only getting a pressure from the compressions (or perfusion) being performed at the time. For one to get an a true accurate blood pressure from the compressions to measure coronary artery pressure an arterial line would have to be placed in and measure a true and accurate pressure of coronary circulation and cerebral perfusion. Which coronary pressure should be at 40 torr and slightly higher for cerebral perfusion. The same philosophy for shock therapy, and the debate over raising pressure more would cause more detrimental problems. If one does not have high enough pressure for cerebral perfusion, in ethical debate, what good are we doing, producing a brain damaged patient ? I doubt you will see intraarterial lines even considered, unless one was already in place prior to arrest state. Costs, plus having to have damn good blow flow to cannulate the line. Why? Theoretical thinking is great, not always practical. As more and more studies are revealing once the patient is in cardiac arrest state one needs to determine how much resuscitation measure should even be performed. Since results of cardiac arrest is dismissal to say the least (in hospital < 15% ). Emphasis should be placed on pre-cardiac arrest phase. R/r 911

Yes, poor perfusion and conscious V-fib can occur (hence cough CPR).. I too had one that once was telling me .. please.... don't ...... do ........ . that!.... Yes, it is weird, but needed to be done. R/r 911

Yes, most areas judges can expunge a driving record offense if demonstrated a reason or vaidity to .. R/r911

I would miss too many days if I attended all the funerals of the patients I cared for. ( Man, that sounded bad ! :shock: ) Personally, I have never attended any unless I personally know them. I draw the line between empathy and sympathy. Nothing against those that want to attend, just my personal decision of not mixing professional life and personal life. I know of many nurses that have attended those that died, especially of those that cared for them a long or multiple times. Many times, we in EMS and nursing see patients far longer and more often than family members. R/r 911

I guess Rick Kendrick no longer makes the KED, it is now KEOD (Kendricks other Extrication Device) which to the eye looks very similar to the KED.. here is a link with the instructions. It too describes optional groin straps, then it contradicts itself that one should criss cross unless groin or pelvic injuries..? http://www.epandr.com/downloads/images/KODE2.pdf As well, has anyone used the traction splint for arms?.. I have never seen or heard of such.. R/r 911

At one time, the manufacture recommended the "same side" with potential indications of a pelvis fracture. I personally prefer the same side method, as one I usually suspect pelvic fxr.s in high speed MVC's with lower extremities, and it appears more adventitious in ease and speed to apply as well. R/r 911

That would be okay if the "normal " patient weighed only 150 pounds, but many patients weigh over 300 to 500 pounds, so one would have to be able to lift 200 pounds or more. Anything, that would promote back injury prevention would be great. Not lifting repetitiously and asking for assistance prevents back injuries, which is the number one on the job injury in EMS. R/r 911

It all depends upon the situation. I don't mind, if they ask or I will tell them, that they will be in my prayers. If they act if they want further intervention, I will ask if they would like prayer. As a Christian, it does not bother me and in fact actually makes feel honored, that they would allow me into their emotional and personal space. Unfortunately, EMS does not even address patient's spirituality aspect. Please, do not confuse spirituality and religion, or denomination as being the same. Again, another one of our poor aspects and lack of understanding of patient care. Spirituality and even beliefs maybe just as important as anything emotional and physical to a patient. Although, we may not be with the patient very long, or the event may not present an opportunity, we should recognize the emotional needs of our patients. This might be even informing staff to notify Chaplain services, to see that it is covered. (Ironically, I had to write a thesis on this) Less than 20% of admissions into hospital lack addressing patients' spirituality, which 80% of patient's believe is essential in their healing process. I don't believe that we have to "preach" and definitely not stop the treatment processes, but to address their needs would not be hard. This can be done quickly and diplomatically by addressing their request.. If it is a severe case, I will inform them, I usually tell them ..."I am already saying a prayer, while I take care of you" (which is the truth).. This usually satisfies their needs at the time, and allows me to continue with my treatment. R/r 911