1_a_01_001-011.indd

One of the primary roles of Emergency Medical Ser-vices is to provide emergency care for life-threatening medical events. This section reviews clinical and system considerations in the EMS care of these time-critical conditions.
Altered Mental Status/Altered Level of Consciousness INTRODUCTION
patient as possible from the scene. Because the patient often cannot provide an adequate history, fi eld person- The patient presenting to the out-of-hospital care pro- nel may seek additional information from alternate vider with an altered level of consciousness (ALOC, sources, such as bystanders, family, and the physical also referred to as altered mental status or AMS) is one surroundings. Important questions may include the of the most common encounters in EMS. Many of the patient’s baseline health, the rapidity of the onset of conditions causing ALOC have the potential to cause the symptoms, and any complaints voiced or signs ex- signifi cant morbidity and mortality. It is essential that hibited by the patient. One particularly useful question proper care be initiated in the fi eld, often before the is whether or not the patient ever had a complete loss diagnosis is completed. In most instances, this treat- ment should be instituted in conjunction with attempts EMS personnel should search common locations to determine the underlying cause. In addition, the such as bathrooms, medicine cabinets, bedrooms, out-of-hospital care of these patients must address nightstands, and kitchens for clues about underlying possible complications such as cervical spine injury illnesses or possible ingestion. A medical alert bracelet and aspiration. The challenges are to rapidly identify or necklace should be sought. Other household mem- and treat potentially reversible problems in the fi eld bers exhibiting similar complaints or the presence of sick or deceased pets may point to carbon monoxide (CO) exposure.
If a drug overdose or poisoning is suspected, EMS EVALUATION
personnel should gather further pertinent information, including the route of exposure, the type of substance The differential diagnosis for the patient with an involved, and the time and amount of exposure. In the ALOC is extremely long and complex. Although the majority of cases, overdoses will occur by ingestion. If ultimate treatment for many of these causes falls out- the exact amount of exposure or ingestion is not known, side the scope of practice of the prehospital care pro- personnel should try to establish the maximum possible vider, EMS personnel should focus on conditions that quantity. Personnel should also note any actions taken may be effectively treated in the fi eld. A simple and by the patient or bystanders, including the administra- useful mnemonic for the potential causes of ALOC is tion of any “antidotes.” Empty pill containers, liquor bottles, syringes, and other drug paraphernalia can Once scene safety is assured, EMS personnel of greatly aid later treatment decisions, and if possible, all levels should provide BLS interventions. Once the should be brought to the emergency department.
ABCs are adequately addressed, additional history, Another important route of ingestion, especially in physical examination, and fi eld fi ndings may prove teenagers and young adults, is “huffi ng” or “sniffi ng.” useful in developing an appropriate treatment plan.
Huffi ng is the use of any chemical vapor to As the situation permits, EMS personnel should achieve an ALOC.1 Sniffi ng is specifi cally huff- systematically obtain as much information about the ing volatile gases for a similar effect. The data from Mnemonic for Causes of Altered Level
Glasgow Coma Scale. A Score of Less than
of Consciousness
9 Indicates Severe Neurological Impairment.
Infection: meningitis, encephalitis, brain the 2000 Monitoring the Future Study show that inhalants rank fourth behind alcohol, cigarettes, and marijuana in the abused substances list. Adults tend to huff nitrates more than other substances pri- marily for the effect of enhancing sexual experience. With any inhalant there is a risk of sudden sniffi ng death caused by an irregular heart rhythm leading to heart failure. Suffocation, asphyxiation, and aspira- that paramedics can give GCS scores that correlate tion are also risks inherent to this form of substance well with those of emergency physicians.2 The directed and focused secondary survey can With respect to the physical examination, the fi rst aid in determining the origins for the ALOC.
task is to determine the degree of the ALOC. Unfor-tunately, a variety of inexact terms are commonly HEENT: The head should be examined for any
used to describe ALOC. Descriptive terms such as obvious outward signs of trauma, such as stuporous, comatose, semicomatose, obtunded, con- scalp and facial lacerations, abrasions, and fused, and delirious are poorly defi ned and may lead contusions. The pupils should be observed to different interpretations by bystanders, providers, for symmetry and light reactivity. If they are and direct medical oversight (DMO) physicians. In dilated bilaterally this may indicate cerebral general, it is best for the level of consciousness to be hypoxia or barbiturate overdose, whereas described on the basis of the response that the patient pinpoint pupils often suggest an opioid over- makes to a given stimulus. Field providers can use the dose. Unequal pupils may be found in normal variants, but they could also indicate impend-ing herniation from trauma or a spontane- A ϭ the patient is alert.
ous intracranial hemorrhage. Any odor on V ϭ the patient responds only to loud verbal
the patient’s breath (acetone, bitter almonds, ethanol, or volatile agent) should be noted. P ϭ the patient responds only to painful stimuli.
U ϭ the patient is unconscious.
which may indicate seizure activity, or swell- EMS personnel may also use the Glasgow Coma ing, indicating anaphylactic shock, which is Scale (GCS; Table 1.2). A study done with paramed- an unlikely cause for ALOC unless there is ics scoring videotaped patients with ALOC confi rmed NECK: Any upper airway stridor should be
Noninvasive transcutaneous glucose measurement documented, and plans to care for a partially may soon be available for fi eld use.
or soon-to-be obstructed airway must take precedence.
CHEST: The respiratory rate, pattern, and depth
MANAGEMENT
should be noted. Again, any outward signs of trauma should be identifi ed.
The focus of a care protocol for the patient with ABDOMEN: A pulsatile mass in a patient with
ALOC is to identify and treat reversible conditions. In addition, the provider must use general support- dominal aortic aneurysm. In these situations ive measures to protect the patient from harm due to the EMS crew may consider transporting the the loss of protective refl exes (such as the gag refl ex). patient to a medical facility capable of caring Appropriate BLS measures, such as spine immobili- zation and basic airway management, should be insti- NEUROLOGIC: In addition to pupillary fi nd-
tuted before any attempt is made to gather a complete ings, any focal neurologic signs suggesting history or perform a detailed physical examination.
stroke or increased intracranial pressure, such as extremity fl accidity, should be noted and recorded as a baseline for possible progres-sion. Altered speech patterns may also be The fi rst priority is to assess and maintain an adequate elicited with the aid of bystanders. EMS airway. If the patient is apneic or hypoventilating, personnel should screen for stroke using an respirations should be assisted by bag-valve-mask established stroke scale; for example, the (BVM) or endotracheal intubation. In the patient with Cincinnati Prehospital Stroke Scale (CPSS), adequate respirations, a nasal or oropharyngeal airway the Los Angeles Prehospital Stroke Screen with non-rebreather mask oxygen may be appropriate. If the patient lacks a gag refl ex, intubation is probably warranted. Should the patient become agitated, it may SKIN: The skin may be used to determine
be more prudent to use supportive airway measures in- temperature (increased in infection or heat stead. If no contraindication exists, the lateral decubi- illness, decreased in exposure, dehydration, or tus position may be advantageous for many patients.
alcohol or barbiturate overdose); rashes (infection or allergic reaction); track marks Vital Signs
(possible narcotic overdose); or signs of previ-ous suicide attempt (healed wrist scars).
Once the airway is secured, the next step is to moni-tor and frequently reassess the patient’s pulse, blood The measurement of serum glucose level in the pressure (BP), pulse oximetry, and cardiac rhythm. fi eld is traditionally accomplished through the use Although not a standard part of EMS assessment, of reagent test strips (Chemstrip, Dextrostix). How- identifi cation of a fever or hypothermia may prove ever, several studies question the accuracy of these helpful in determining the etiology for the ALOC. A devices, with small but signifi cant numbers of false- common serious mistake is the failure to recognize positives and false-negatives.6–10 Problems may oc- cur with the interpretation of the color change by prehospital personnel. Old test strips, strips stored in unsealed containers, or those exposed to temperature Glucose Evaluation and
extremes may yield inaccurate readings.11,12 Devices Administration
that measure glucose, giving a digital readout of the serum glucose level from a single drop of the patient’s The next order in most protocols calls for the establish- blood, are currently in widespread prehospital use ment of IV access while concurrently drawing blood and do not require interpretation of results. The dis- samples. The blood obtained may then be tested for a advantage of the digital units is the need for frequent serum glucose level, with exogenous glucose adminis- calibration, which can be costly and time consuming. tration based on the result. Although the level at which CHAPTER 1 Altered Mental Status/Altered Level of Consciousness 5 glucose is given to the patient may vary from system to administration protocol (0.4 mg intramuscularly or system, most use a level of greater or equal to 80 mg/dl intravenously), which may reverse the life-threaten- when accompanied by appropriate signs and symptoms ing respiratory depression of opiate overdose but not of hypoglycemia. This method of testing is generally the full effects of the drug without precipitating the preferable to the blind administration of exogenous glu- violent “emergence” from opioid sedation that occa- cose to all patients with an ALOC. Studies have shown sionally accompanies full and rapid reversal. Some that only 25% of those patients with ALOC are hypo- authors have argued for a more selective use of nal- glycemic. The common assumption that an ampule of oxone, limiting the drug to patients with a respiratory dextrose 50% in water (D50W) “won’t hurt anyone” has rate less than 12 breaths/min, miosis, and circum- come under attack; exogenous glucose may result in stantial evidence of opioid abuse—not just ALOC. skin necrosis (after inadvertent extravasation or subcu- However, these criteria have not been prospectively taneous infi ltration); variable elevations in the serum studied. There have been several case reports of side glucose level, hyperosmolality, and hyperkalemia (in effects, such as hypertension, pulmonary edema, and certain diabetic patients with hyporeninemic hypoal- dysrhythmia production after use of naloxone, but dosteronism); and potentially a poorer neurological these cases involved patients receiving opioid anes- outcome in patients with focal or global cerebral or thesia, not patients with acute opioid exposures.29–32 myocardial ischemia.13–20 It is this last point that is of There is no currently available method to test for opi- the most concern. Although the exact mechanism re- oids in the fi eld. This step may be initiated earlier in mains undefi ned, it may be due to an increase in acido- the sequence if, based on the environmental or physi- sis secondary to the delivery of glucose; this effect may cal fi ndings, suspicion of opioid overdose is high.
be most pronounced in areas of poor blood fl ow.21,22 Failure to give an appropriate amount of an opi- This acidosis may then impede cellular recovery once oid antagonist is a potential pitfall. The synthetic and normal blood fl ow is restored. Although not all studies semisynthetic opioids may require large doses of have supported this hypothesis,23 the current consensus naloxone for reversal. However, rapid administration is that the administration of exogenous glucose may be of larger doses of opioid antagonists may precipitate a rapid and agitated return of consciousness. Many After administration of glucose to the hypoglyce- EMS systems thus employ titration of serial smaller mic patient, an improvement in mental status is usu- ally seen within 5 minutes. The average increase in In cases in which opioid overdose is suspected, serum glucose level following one ampule of D50W is ventilation can be supported with a BVM while wait- approximately 150 mg/dl.25–27 In cases of prolonged ing for the onset of naloxone. Naloxone given intrave- hypoglycemia, the patient may not respond to D50W.
nously can be expected to work within 2 minutes and EMS personnel may have diffi culty establishing only takes another minute or so if given intramuscu- IV access in patients with hypoglycemia. In these cas- larly.26 Intranasal (IN) naloxone has been shown to be es the use of intramuscular (IM) glucagon has been effective in the prehospital setting, although there may shown to be safe and effective.27 A minority of pa- be a delayed effect in comparison with IM adminis- tients without glycogen stores will not respond well to tration.33–35 IN naloxone may provide a way for BLS glucagon. The mean time to response to glucagon is personnel to deliver a potentially life-saving medicine approximately 6 to 9 minutes, with an increase in glu- to those suffering from opioid overdose.36 cose level of 100 mg/dl.25 Because of the risk of aspi- In all cases, it is extremely important that the ration, EMS personnel must exercise care when using prehospital care provider observe and record any re- oral glucose solutions in patients with ALOC.25 sponse by the patient to the administered medication. This will greatly aid the emergency department per- Naloxone
The next step in the standard protocol is to admin-ister an opiate antagonist. Naloxone is the current TREATMENT CHALLENGES
opiate antagonist of choice for the prehospital set-ting. Naloxone is generally safe, with very few seri- There is probably no patient category that can be more ous side effects, the most common being precipitation challenging than those presenting with ALOC. The of withdrawal.28 Some experts advocate a low dose large differential diagnosis, combined with the lack of direct pertinent information due to the inability of CONTROVERSIES
the patient to give a history, contribute to signifi cant potential for error.
Refusals of Care after Treatment for
The fi rst potential problem with these patients is that they could be misplaced in the ALOC proto- Hypoglycemia or Opiate Overdose
col. The various forms of shock all may present with Many hypoglycemic patients who have improvement ALOC, yet must be treated completely differently.
in mental status with fi eld treatment will refuse fur- For example, hypoxia or hypercapnia may cause ther medical care and transport. This practice has or worsen agitation or ALOC. Aspiration is a signifi - been shown to be generally safe if certain criteria are cant airway complication in these patients.
met.37,38 The proposed criteria for safe treatment and The next problematic group is patients who are diagnosed as being “just drunk.” EMS person-nel may erroneously focus on the presumption of • History of insulin-dependent diabetes mellitus.
alcohol intoxication without considering other po- • Pretreatment blood glucose level less tential conditions. The alcoholic is also prone to myriad medical problems, including liver disease, • Posttreatment blood glucose level greater than diabetes, hypoglycemia, and electrolyte imbalances (Table 1.3). Patients with alcoholic (or other) liver • Return of normal mental status within disease may present with hypoglycemia due to in- adequate glycogen stores. In addition, their clouded • Ability to tolerate food and/or liquid by mouth.
mentation may cause or result from insulin misuse. • Absence of complicating factors (chest pain, Other complications of alcohol, such as hypother- arrhythmias, dyspnea, seizures, alcohol intoxica- mia, aspiration, and encephalopathy, should also be tion, chronic renal failure requiring dialysis, or Trauma, particularly of the head and neck, is al- It is important for the provider (and DMO phy- ways a possibility in ALOC. EMS personnel should sician, when local protocols mandate DMO in these be aware of the increased risk of subdural hematoma situations) to also identify whether the patient is on a in elderly patients and chronic alcoholics. It is tempt- long-acting oral hypoglycemic agent. Despite any im- ing to assume that patients with seizures have an mediate improvement, all of these patients should be underlying seizure disorder. However, seizures may transported to the emergency department for further be caused by hypoxia, hypoglycemia, trauma, intra- evaluation and probable hospital admission due to the cranial hemorrhage, stroke, and drug overdoses. The prolonged half-life of their medications and high like- patient who has had a seizure is also more prone to If a treated hypoglycemic patient refuses trans- port, reliable bystanders such as coworkers or family members must chaperone and take responsibility for the patient. These patients may develop the recur-rence of hypoglycemia; reliable witnesses must be immediately available to summon EMS care. Where possible, the prehospital care provider or a reliable Possible Causes of ALOC in Alcoholics
family member should contact the patient’s primary care physician to arrange for follow-up evaluation.
A similar controversy may arise in narcotic over- dose patients successfully treated with naloxone. These individuals may feel well and wish to refuse transport to the emergency department. Because of the short half-life of naloxone, these patients may later develop the recurrence of symptoms, including coma.
Experience in systems that have been fully re- versing opioid overdose and allowing transport refus-als would suggest the actual risk of resedation is quite CHAPTER 1 Altered Mental Status/Altered Level of Consciousness 7 small.39,40 A long-acting (4 to 6 hour) opioid antago- in suspected tricyclic antidepressant overdose). Many nist, nalmefene, shows promise but has not received systems, however, treat ALOC entirely on “standing orders,” with physician contact an option.
Use of Flumazenil
PROTOCOLS
Flumazenil is a benzodiazepine antagonist that may be used to reverse signifi cant obtundation in selected The BLS protocols for patients with ALOC should patients with isolated acute overdoses of benzodiaze- focus on the evaluation and treatment of airway and pines. However, the use of fl umazenil in patients who breathing problems, while assuring cervical spine sta- have also ingested seizure-inducing medications (e.g., bilization when indicated. For the patient who is alert tricyclic antidepressants) or in those chronically pre- and able to take oral glucose, this treatment could be scribed benzodiazepines may result in seizures.41,42 considered within the basic provider’s scope of prac- These seizures may be refractory to benzodiazepine tice, depending on the state or regional protocols. treatment because of blockade of the benzodiazepine In the future, BLS protocols may include the use of receptor; death from fl umazenil-induced seizures strategies such as IN naloxone for suspected opioid have been reported.41 Due to these considerations and because benzodiazepine toxicity is generally man- Under standing orders, advanced providers may aged well with supportive care alone, most medical usually provide D50W to known diabetics with hypo- directors and medical toxicologists do not advocate glycemia and naloxone to suspected narcotic over- the use of fl umazenil in the fi eld.41,42 doses. However, if EMS personnel are unsure of the cause or suspect a polypharmaceutical overdose, then they should consult the DMO physician. The EMS Contacting a Medical Oversight
crew should strongly consider physician consultation Physician
for patients who wake up and refuse further treatment and transport.
A fi nal point of contention to be addressed is when the DMO physician should be contacted. This in large part is determined by the individual system depend- ing on the assessment abilities of the paramedics, number of calls handled by DMO, patient popula- EMS personnel and the DMO physician must always tion, preference of EMS medical director, and state approach the prehospital management of the patient regulations. Generally, it is recommended that the with ALOC in a systematic fashion and with a great physician should be contacted after glucose determi- deal of care. Treatment must be accomplished simul- nation is made and/or naloxone administered. This taneously with maneuvers designed to protect and enables the physician to individualize treatment (as in evaluate the patient. Attention must be given to sup- supplemental doses of naloxone or D50W) or to alter porting the patient’s vital functions and to reversing the normal mode of therapy (e.g., sodium bicarbonate those disorders that can be treated in the fi eld.
He smells strongly of alcohol. There isn’t anybody around to give us any history. His vital signs are as “Medic Base, this is Medic One. We are inbound with follows: BP 110 over palp, pulse 120, and respirations an approximately 35-year-old male found by police 12. The patient is currently asleep and snoring. We lying in the street. We arrived to fi nd this guy ob- are unable to obtain a further physical examination tunded and disheveled. He is a known street person. because his coat and clothes stink of urine, feces, and vomit. The police have requested we bring him into there is no response to the initial D50W, naloxone the emergency department for medical clearance for should be considered because mixed drug overdose jail. We have a 20-minute estimated time of arrival and just wanted to notify you and wonder if you have The medicolegal aspects of the “clearance for jail” topic and problems with releasing any patient with an ALOC to the police are important and How Would You Proceed?
fraught with potential hazardous consequences.
This is a common type of case and presents diffi cul-ties for a number of reasons. One of the distasteful aspects of the job that is performed by the prehospi-tal care provider is dealing with this sort of patient. “University Hospital, this is Medic Five. We are in- The majority of these cases will turn out to be just bound with a 26-year-old female found by her moth- drunk, but occasionally there will be an alternative er unconscious in her bed. Apparently the family had reason or reasons for the patient’s ALOC. Sound been trying to get hold of her all day and went over medical evaluation and treatment should apply in this evening. She apparently has taken an unknown quantity of the following medications: valium, The patient’s airway is of primary concern. The S-I-N-E-Q-U-A-N, and has obvious EtOH on board. report of snoring should alert the physician to a There are empty pill bottles by her bedside, dated potential problem with airway patency. An oral air- 3 days ago. Family states she has been depressed way should be inserted to check for a gag refl ex and lately. Vital signs are as follows: BP 120/palp, pulse keep the airway open. A decision to intubate may 130 and weak, respirations 18. Patient does not be at least partially based on the patient’s response respond well to verbal stimuli but arouses to pain. to this maneuver. In addition, all ALOC patients We have her on O2 and are preparing to start an IV, should be placed on oxygen, preferably high fl ow check a blood sugar, and will treat that appropri- (10 to 15 L/min) via a non-rebreather mask. This ately. Do you have any further orders?” patient should also be immobilized. This tenet ap-plies to most just drunk patients but particularly to How Would You Proceed?
those found lying in the street because this street The prehospital care providers have failed to dem- person could easily have been a victim of trauma.
onstrate the patency and function of the airway. An The vital signs obtained are a good start, but oral airway may be inserted to check for a gag refl ex, a focused secondary survey should be performed. and based on this, along with further information The patient should be carefully checked for signs of obtained by patient examination, intubation may trauma, particularly about the head and neck. The be warranted. The drugs involved in this case have pupils should be observed for both confi guration the potential to cause respiratory compromise. If and response to light. The lungs must be examined the medics fi nd the patient does not require intuba- and auscultated to help determine the adequacy of tion, they may be reminded to keep a close eye on ventilation and the abdomen inspected for rigidity this patient’s airway and breathing pattern while en and other signs of an acute abdomen. The extremi- ties may give clues as far as symmetry of movement A glucose level check and administration of and possible track marks. If the situation permits, naloxone are generally appropriate, and an IV line the patient should be undressed. The wet clothes is a good precaution because these patients can may be causing the patient to become hypothermic (no one is sure how long he was down), and a good A fi nal point is that the physician may individu- physical examination is important. It will also make alize treatment according to the situation. The cur- rent treatment of choice for a tricyclic overdose, and Once the IV line is established, a serum glucose one that could be instituted in the fi eld, is intrave- level should be checked. As previously stated, the nous sodium bicarbonate. This agent should only possible alcoholic population is prone to hypogly- be used after consultation with the physician. The cemia due to decreased glycogen storage ability in importance of being able to modify the treatment the alcoholic liver. This holds true even if the patient of the prehospital patient in a DMO consulting ba- is not diabetic. If the patient is not hypoglycemic, or sis cannot be overemphasized, particularly when the CHAPTER 1 Altered Mental Status/Altered Level of Consciousness 9 ingested medication is not one that EMS personnel withheld, though given naloxone’s safety profi le, it would not be an error to administer it empirically. The scenario suggests an intracranial catastrophe, and the patient should have her airway supported as necessary and be transported to a center that has “Medic Base, this is Medic 14 with Rescue 2. We are neurosurgical capabilities, if possible. As with all pa- downtown in the boardroom of a large company tients with ALOC, careful monitoring and support seeing the vice president, who is a 42-year-old fe- male complaining of a severe headache all morning. An important question is whether to treat the While she was giving a presentation she suddenly elevated BP. In general, in response to intracranial lost consciousness. She now responds to deep pain hemorrhage and stroke the body raises BP to help by withdrawing her arms to her chest. Her vital signs maintain cerebral perfusion. Current paradigms of are a BP 220/108, pulse of 92, and a respiratory stroke care advocate extremely slow and cautious rate of 24. Do you have any further orders?” lowering of BP using titratable IV agents.43 Although EMS personnel may rush to treat the elevated BP, it How Would You Proceed?
is probably best to defer hypertension treatment to This patient should have an IV line established and have her glucose checked. Because there is no rea-son to suspect an opioid overdose, naloxone can be REFERENCES
1. National Drug Intelligence Center, US Department of
8. Jones JL, Ray VG, Gough JE, Garrison HG, Whitley TW. Justice. Intelligence Brief: Huffi ng. The Abuse of Inhalants. Determination of prehospital blood glucose: a prospective, November 2001 ed.; 2001. Document # 2002-J0403-001.
controlled study. J Emerg Med 1992; 10(6): 679–682.
2. Menegazzi JJ, Davis EA, Sucov AN, Paris PM. Reliability 9. Lavery RF, Allegra JR, Cody RP, Zacharias D, Schreck DM. of the Glasgow Coma Scale when used by emergency phy- A prospective evaluation of glucose reagent teststrips in sicians and paramedics. J Trauma 1993; 34(1): 46–48.
the prehospital setting. Am J Emerg Med 1991; 9(4): 3. Kothari RU, Pancioli A, Liu T, Brott T, Broderick J. Cincin- nati Prehospital Stroke Scale: reproducibility and validity. 10. Maisels MJ, Lee CA. Chemstrip glucose test strips: correla- Ann Emerg Med 1999; 33(4): 373–378.
tion with true glucose values less than 80 mg/dl. Crit Care 4. Bray JE, Martin J, Cooper G, Barger B, Bernard S, Bladin C. Paramedic identifi cation of stroke: community validation 11. Crist D, Murray B, Jones J. Performance and storage of of the Melbourne ambulance stroke screen. Cerebrovasc blood glucose reagent strips (abstract). Prehosp Disast Med 5. Kidwell CS, Starkman S, Eckstein M, Weems K, Saver JL. 12. Herr RD, Metz R, Richards M. Chemstrip reliability de- Identifying stroke in the fi eld. Prospective validation of the clines with ambulance storage. Prehosp Disast Med 1989; Los Angeles prehospital stroke screen (LAPSS). Stroke 13. Adler PM. Serum glucose changes after administration of 6. Chernow B, Diaz M, Cruess D, et al. Bedside blood glucose 50% dextrose solution: pre- and in-hospital calculations. determinations in critical care medicine: a comparative Am J Emerg Med 1986; 4(6): 504–506.
analysis of two techniques. Crit Care Med 1982; 10(7): 14. D’Alecy LG, Lundy EF, Barton KJ, Zelenock GB. Dextrose containing intravenous fl uid impairs outcome and increases 7. Hogya PT, Yealy DM, Paris PM. The rapid pre-hospital death after eight minutes of cardiac arrest and resuscitation estimation of blood glucose using Chemstrip bG. Prehosp in dogs. Surgery 1986; 100(3): 505–511.
15. de Courten-Myers G, Myers RE, Schoolfi eld L. Hypergly- A prospective clinical study. J Toxicol Clin Toxicol 1996; cemia enlarges infarct size in cerebrovascular occlusion in cats. Stroke 1988; 19(5): 623–630.
31. Pallasch TJ, Gill CJ. Naloxone-associated morbidity and 16. Goldfarb S, Cox M, Singer I, Goldberg M. Acute hyperka- mortality. Oral Surg Oral Med Oral Pathol 1981; 52(6): lemia induced by hyperglycemia: hormonal mechanisms. Ann Intern Med 1976; 84(4): 426–432.
32. Prough DS, Roy R, Bumgarner J, Shannon G. Acute pul- 17. Longstreth WT Jr, Diehr P, Inui TS. Prediction of awaken- monary edema in healthy teenagers following conservative ing after out-of-hospital cardiac arrest. N Engl J Med 9 doses of intravenous naloxone. Anesthesiology 1984; 60(5): 18. Longstreth WT Jr, Inui TS. High blood glucose level on 33. Ashton H, Hassan Z. Best evidence topic report. Intranasal hospital admission and poor neurological recovery after naloxone in suspected opioid overdose. Emerg Med J 2006; cardiac arrest. Ann Neurol 1984; 15(1): 59–63.
19. Pulsinelli WA, Levy DE, Sigsbee B, Scherer P, Plum F. 34. Barton ED, Colwell CB, Wolfe T, et al. Effi cacy of intra- Increased damage after ischemic stroke in patients with hy- nasal naloxone as a needleless alternative for treatment of perglycemia with or without established diabetes mellitus. opioid overdose in the prehospital setting. J Emerg Med 20. Siemkowicz E. Hyperglycemia in the reperfusion period 35. Kelly AM, Kerr D, Dietze P, Patrick I, Walker T, Koutsogiannis hampers recovery from cerebral ischemia. Acta Neurol Z. Randomised trial of intranasal versus intramuscular nalox- one in prehospital treatment for suspected opioid overdose. 21. Marsh WR, Anderson RE, Sundt TM Jr. Effect of hyper- glycemia on brain pH levels in areas of focal incomplete 36. Belz D, Lieb J, Rea T, Eisenberg MS. Naloxone use in a cerebral ischemia in monkeys. J Neurosurg 1986; 65(5): tiered-response emergency medical services system. Pre- hosp Emerg Care 2006; 10(4): 468–471.
22. Rehncrona S. Brain acidosis. Ann Emerg Med 1985; 14(8): 37. Anderson S, Hogskilde PD, Wetterslev J, Bredgaard M, Moller JT, Dahl JB. Appropriateness of leaving emergency 23. Matchar DB, Divine GW, Heyman A, Feussner JR. The in- medical service treated hypoglycemic patients at home: a fl uence of hyperglycemia on outcome of cerebral infarction. retrospective study. Acta Anaesthesiol Scand 2002; 46(4): Ann Intern Med 1992; 117(6): 449–456.
24. Browning RG, Olson DW, Stueven HA, Mateer JR. 50% 38. Thompson R, Wolford R. Development and evaluation of dextrose: antidote or toxin? Ann Emerg Med 1990; 19(6): criteria allowing paramedics to treat and release patients presenting with hypoglycemia: a retrospective study. Pre-hosp Disast Med 1991; 6: 309–313.
25. Collier A, Steedman DJ, Patrick AW, et al. Comparison of intravenous glucagon and dextrose in treatment of severe 39. Paris PM. Personal Communication. City of Pittsburgh hypoglycemia in an accident and emergency department. Diabetes Care 1987; 10(6): 712–715.
40. Vilke GM, Sloane C, Smith AM, Chan TC. Assessment for 26. Davis EA, Menegazzi JJ, Sucov AN. Safety and effective- deaths in out-of-hospital heroin overdose patients treated ness of nalmefene vs. naloxone in opioid and mixed drug with naloxone who refuse transport. Acad Emerg Med overdose in the prehospital care setting. [Abstract] Prehosp 41. Haverkos GP, DiSalvo RP, Imhoff TE. Fatal seizures after 27. Vukmir RB, Paris PM, Yealy DM. Glucagon: prehospital fl umazenil administration in a patient with mixed overdose. therapy for hypoglycemia. Ann Emerg Med 1991; 20(4): Ann Pharmacother 1994; 28(12): 1347–1349.
42. Weinbroum AA, Flaishon R, Sorkine P, Szold O, Rudick 28. Hoffman JR, Schriger DL, Votey SR, Luo JS. The empiric V. A risk-benefi t assessment of fl umazenil in the manage- use of hypertonic dextrose in patients with altered mental ment of benzodiazepine overdose. Drug Saf 1997; 17(3): status: a reappraisal. Ann Emerg Med 1992; 21(1): 20–24.
29. Azar I, Turndorf H. Severe hypertension and multiple atrial 43. Pancioli AM. Hypertension management in neurologic premature contractions following naloxone administration. emergencies. Ann Emerg Med 2008; 51(3 Suppl): Anesth Analg 1979; 58(6): 524–525.
30. Osterwalder JJ. Naloxone—for intoxications with intrave- nous heroin and heroin mixtures—harmless or hazardous? CHAPTER 1 Altered Mental Status/Altered Level of Consciousness 11

Source: http://www.sinaiem.org/files/ems/Clinical%20Prehospital%20Medicine%20-%20Altered%20Mental%20Status.pdf