JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Vardi, A. Articles by Ziv, A. Search for Related Content PubMed PubMed Citation Articles by Vardi, A. Articles by Ziv, A. Related Collections Resuscitation Critical Care

---

ECONOMICS, EDUCATION, AND HEALTH SYSTEMS RESEARCH

Intraosseous Vascular Access in the Treatment of Chemical Warfare Casualties Assessed by Advanced Simulation: Proposed Alteration of Treatment Protocol

Amir Vardi, MD^*,, Haim Berkenstadt, MD^*,, Inbal Levin, PCCRN^*,, Ariel Bentencur, MD^*,, and Amitai Ziv, MD^*

*The Israel Center for Medical Simulation, Sheba Medical Center, Tel-Hashomer, Israel; and Departments of Pediatric Critical Care, Anesthesiology and Intensive Care, and Emergency Medicine, the Chaim Sheba Medical Center, Tel-Hashomer, Israel (affiliated with the Tel-Aviv University, Sackler School of Medicine, Tel-Aviv, Israel

Address correspondence and reprint requests to Amir Vardi, MD, Department of Pediatric Critical Care, Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, Israel 52621. Address e-mail to avardi{at}post.tau.ac.il

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Current treatment protocols for chemical warfare casualties assume no IV access during the early treatment stages. Time constraints in mass casualty scenarios, impaired manual dexterity of medical personnel wearing protective gear, and victims’ complex clinical presentations render standard IV access techniques impractical. A newly developed spring-driven, trigger-operated intraosseous infusion device may offer an effective solution. Sophisticated simulators were developed and used to mimic scenarios of chemical warfare casualties for assessing the feasibility of intraosseous infusion delivery. We evaluated the clinical performance of medical teams in full protective gear. The success rate in intraosseous insertion, time to completion of treatment goals, and outcome were measured in a simulated setting. Medical teams from major hospitals in Israel, designated for emergency response in a real chemical warfare mass casualty scenario, were trained in a simulated setting. All 94 participating physicians were supplied with conventional treatment modalities: only the 64 study group physicians received intraosseous devices. The simulated survival rate was 73.4% for the study group and 3.3% for the controls (P < 0.001). Treatment goals were achieved within 3.5 min (range, 1–9 min) in the study group and within >10 min for controls (P < 0.001), and the complication rate for intraosseous use was 13.8%. Personnel satisfaction with the intraosseous device was unanimous and high. New-generation intraosseous infusions have great potential value in the early treatment stages of chemical warfare casualties.

IMPLICATIONS: In a chemical warfare mass casualty scenario, the protective gear worn by medical personnel, the time constraints, and the casualties’ medical condition impose limitations on the establishment of IV access during early treatment of the victims. A spring-driven, trigger-operated intraosseous infusion delivery system may offer an effective solution.

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
Exposure to volatile nerve agents may cause the development over minutes of toxic symptoms related to excessive cholinergic discharge, eventually leading to death from respiratory failure (1). The survival of casualties may depend on the efficiency and promptness of medical assistance involving the use of specific antidotal treatment and supportive respiratory and hemodynamic measures (2).

The initial treatment of nerve agent casualties involves the protection of medical teams from exposure to the volatile nerve agents by use of full protective gear. The physical limitations of medical performance induced by the protective gear (3), combined with the chaotic nature of the expected mass casualty scenario, render intravascular access impractical at this stage of treatment.

On the basis of the early need for antidotal treatment, current protocols for the medical treatment of chemical warfare casualties assume the use of automatic IM antidote delivery without IV access during the early stages of treatment. This mode of antidotal treatment might be less effective in severe casualties, because of delayed absorption of medications, and in babies, in whom the dose of medication needs to be titrated to body weight (3). Venous access for antidotal treatment and fluid resuscitation mainly of combined toxicological and conventional injuries might, however, be problematic, even in the later stages of medical treatment, and alternatives such as an intraosseous (IO) line would appear to be of great benefit.

Until recently, IO lines could be used only in pediatric patients. The manual insertion of IO needles in adults (and even older children) was often unsuccessful because the needles tend to bend or slip off the surface of the harder adult bone (4,5). The development of spring-driven, trigger-operated devices for the insertion of the IO needle has made this technique suitable for both pediatric and adult patients, as previously described in studies that were not related to the chemical warfare casualty situation and in which the participants did not wear protective clothing (5–8). After insertion, the IO needle provides access to the noncollapsible marrow venous plexus and serves as a rapid, safe, and reliable route for the administration of medications and fluids during resuscitation (9–12). Moreover, IO infusion achieves peripheral-to-central circulation transit times comparable to those achieved by the IV route (13,14).

The aim of this study was to assess the value of applying a spring-driven, trigger-operated IO device in the treatment of chemical warfare casualties in patients of all ages. These evaluations were performed by means of advanced medical simulation technology.

	Methods

Top Abstract Introduction Methods Results Discussion References

 
The study was performed during a training project for national medical preparedness for the possibility of a chemical warfare mass casualty scenario. The training involved 550 participants—medical doctors and nurses from 9 major hospitals—over twelve 1-day sessions. Ninety-four of the participants (31 anesthesiologists, 23 pediatricians, 21 surgeons, and 19 internists) taking care of severely injured chemical warfare participants were assigned to give the initial treatment with (study group) or without (control group) the ability to use IO access for drug administration. To achieve similarity in training conditions and avoid confusion among participants in each of the 5 training days, randomization to the control and study groups was performed according to days and not according to individual participants. Randomization of the study terms assigned physicians trained during the first 3 training days to serve as the study group. Physicians trained during the next 2 consecutive training days served as the control group (Table 1). Pediatricians were assigned to treat infants and children, and other participants treated adult casualties.

Three scenarios were created with the assistance of medical experts in the treatment of chemical warfare casualties from the Israeli Defense Force Medical Corps and were based on information from reported casualties (15). The expected medical treatment for all the simulated casualties included 1) the achievement of airway and ventilation management by orotracheal intubation, 2) antidotal treatment with automatic autoinjectors (in the control group) and automatic autoinjectors or the IO device (in the study group), and 3) treatment of convulsions with benzodiazepines administered either IM or IO (Figs. 1 and 2). Any patient in whom a definitive airway was not established within 10 min was defined as not surviving. To accomplish these objectives, the participants had to overcome a preprogrammed "difficult airway management" scenario complicated by convulsions and copious airway secretions in infants and children or by trismus and laryngospasm in adults. The clinical response was related to the method of drug delivery: IM drug delivery induced a delayed response (16,17) in comparison with IO delivery (13,14).

View larger version (144K): [in this window] [in a new window]   Figure 1. A physician in full protective gear, placing the intraosseous needle into a mannequin simulating a severe combined chemical and conventional warfare casualty.

View larger version (147K): [in this window] [in a new window]   Figure 2. Two physicians in full protective gear ventilating a combined chemical and conventional warfare casualty through an endotracheal tube after intraosseous drug administration.

The Megacode Kid CPR-7500 (Medical Plastics Laboratory, Inc., Gatesville, TX) is a full-body mannequin reproduction of a 6-yr-old boy which is designed for the simulation and practice of a complete range of patient-care procedures. This mannequin also enables IM injections, venipuncture, IO access, and endotracheal intubations. The ALS baby trainer (Laerdal Medical AS) is a 3-mo-old, 5-kg baby simulator designed to provide airway management, vascular access, IO access, and endotracheal intubations.

Modifications were made to the adult simulators to enable the use of IO needles. A round hole was cut in the tibial plateau of the mannequin’s leg. A small reservoir was fitted into this hole and covered with an artificial bonelike material (Sawbones; Pacific Research Laboratories, Vashon, WA) and silicone rubber "skin." Alterations were also made to simulate seizure activity in the adult, pediatric, and infant simulators, and simulation of vomiting was added to some of the adult simulations.

The Bone Injection Gun (BIG) (WaisMed Ltd., Caesarea, Israel) is a spring-driven, trigger-operated device (Fig. 3). An adult and a pediatric version were used. Each participant underwent training in the proper use of the device. All simulations on the mannequins were performed in a specially designed environment that included simulated smoke, the sounds of sirens, and flashing emergency lights.

View larger version (156K): [in this window] [in a new window]   Figure 3. The Bone Intraosseous Gun—a spring-driven trigger-operated intraosseous injection device.

Team satisfaction with the addition of the BIG was assessed by questionnaires. The participants were asked their opinion of whether the device was simple and safe to use, whether they thought it had an important role in the chemical warfare scenario, and whether it should be incorporated into the medical-preparedness process.

The ² test was used for testing the correlation between alphanumeric variables. The variables included comparing the composition of the study and control groups with regard to physician specialty and the types of casualties and comparing the rates of survival within the study and control groups with regard to physician specialty and types of casualties. We used the Mann-Whitney U-test for two independent samples for comparing the duration of treatment between the study and control groups. In the study group, we used Student’s t-test for comparing two independent variables with nonequal variance for comparing the means of duration of administering treatment between anesthesiologists and other physicians.

	Results

Top Abstract Introduction Methods Results Discussion References

 
The similarity in the fields of specialty training of the study and control groups was statistically confirmed (² = 1.05; df = 3; P = 0.79), as was the similarity of age groups of the casualties (² = 1.20; df = 2; P = 0.55) (Table 1). The survival rate, defined as a definitive airway established within 10 min from the beginning of treatment, was more frequent in the study group in comparison with the control group (73.4% of casualties versus 3.3%, respectively; ² = 37.42; df = 1; P < 0.001) (Table 2).

In the study group, a Student’s t-test for comparing 2 independent variables with nonequal variance confirmed that the duration of treatment by anesthesiologists was significantly shorter than by physicians of other specialty fields (t = 8.24; df = 58.54; P < 0.001). The mean duration of treatment was 111 s (SD, 30 s) for the anesthesiologists and 248 s (SD, 100 s) for the others.

No association was found between the specialty of the physician (pediatrics, anesthesiology, surgery, and internal medicine) and patient survival (² = 1.71; df = 3; P = 0.64). This was also true when the study and control groups were studied separately, insofar as most physicians could not save the casualties, regardless of their training expertise, in the control group (² = 1.88; df = 3; P = 0.59), whereas most casualties survived in the study group regardless of the physicians’ skills and training background (² = 3.76; df = 3; P = 0.29).

No association was found between the age of the casualty and the outcome (² = 0.54; df = 2; P = 0.76) in the control group: most of the casualties did not survive whatever their age. In the study group, however, 100% of the neonates, 87.5% of the pediatric casualties, and 64.3% of the adult casualties survived (² = 7.29; df = 2; P = 0.03).

Sixty-four of the 72 attempts of IO insertion performed by 64 physicians were successful, yielding a success rate of 89%. All simulated casualties had a device inserted within three attempts.

Complications during use of the IO gun included displacement of the IO needle (in 3 of 72 attempts) and misplacement of the IO needle (in 5 of 72 attempts). Inappropriate handling of the BIG, i.e., holding the device with the needle tip pointing toward the hand of the caregiver, rather than the casualty’s bone, was prevented by the instructors of the simulated setting, when it almost occurred twice in 72 attempts of BIG insertion.

All participants expressed great satisfaction with the addition of the IO needle to conventional treatment modalities, and all 64 study group physicians agreed that the device should be incorporated into the arsenal of modalities for the early stages of treatment of chemical warfare casualties. Eleven of them believed that further instruction and experience with the BIG device were warranted.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
Simulation-based medical training of medical teams in the treatment of chemical warfare casualties demonstrated a significantly increased survival rate when a spring-driven trigger-operated IO infusion device was used compared with the conventional treatment of giving medication by using automatic or regular injectors.

Our results demonstrated that the survival rate increased from 3.3% to 73.4% and that the treatment time decreased from a mean longer than 10 minutes to 3 minutes in casualties whose caretakers used the BIG compared with controls who were treated conventionally. These results indicate a potentially valuable contribution of the BIG to the treatment of casualties of chemical warfare.

Previous studies had demonstrated that medical performance while treating nerve gas casualties in full protective gear may be influenced by physiological or psychological variables (18). These variables include increased respiratory effort and restricted visual field induced by the gas mask, interference with manual dexterity by the chemical protective gloves (19), and excessive heat load induced by the multilayered over garment (20). Moreover, it was demonstrated that emergency medical technicians’ speed of performance was affected by physical protection; the effect of gloves on manual dexterity was described as a major limiting factor (21). Hendler et al. (22) evaluated the ability of anesthesiologists wearing full protective gear to manage airways in mannequins. The time needed for orotracheal intubation was prolonged from 47.3 ± 6 seconds without to 69.2 ± 7 seconds with full protective gear, and repeated training did not improve performance.

In this study, anesthesiologists in the study group completed their treatment much faster than other specialist physicians (t = 6.025; P < 0.001). This finding might be worth considering in assigning physicians to treat casualties in this setup.

The IO device used in this study was the BIG, which is spring driven. Hand-driven devices, such as the threaded-needle SurFast (Cook Critical Care, Bloomington, IN) and the straight-needle Jamshidi needle (Baxter Healthcare Corp., Deerfield, IL) models may take longer to insert and have a greater reported failure rate (8). These differences might be more pronounced in the chemical warfare mass casualty scenario, in which the user is wearing protective gear. Another commercially available spring-driven device is the First Access for Shock and Trauma (Pyng Medical Corp., Richmond, BC, Canada). This device, however, was rated lower by emergency teams in a previous study (8). The need for applying a patch to the skin over the casualty’s sternum as part of the insertion technique is less suited for the chemical warfare mass casualty scenario when casualties have moist skin. The mean placement time of the BIG was 21 seconds (SD, 18 seconds) in our study and 70 seconds (SD, 33 seconds) in a previous report (8). This difference may be explained by the element of urgency in our simulated scenario.

Our overall failure rate of the IO device or its use was 10 (13.8%) of 72 attempts compared with 2 (6%) of 31 insertions in a previous report (8). The complications encountered in the use of an IO included its displacement or misplacement. The 4% IO misplacement rate is disturbing because the correct position was actually marked on the simulated adult leg. A possible explanation for the misplacement rate, the displacement rate, and the near-miss accidents of inappropriate handling of the BIG might be the effect of the full protective gear used while performing the procedure. Previous studies that measured failure and complication rates of the use of this IO device did not consider its use under the extreme conditions of full chemical protective clothing and masks. There were 29 cases of failure of intubation in the 30 casualties of the control group in whom drugs could not be administered IV. No intubation failure occurred in the 64 casualties of the study group in whom drugs were administered IO.

IM injection of midazolam resulted in a lapse of more than five minutes before any clinical response to the drug in both the study and the control groups. This time frame has been described by others and is expected to be even longer under conditions of shock and decreased peripheral perfusion (16,17).

Long-term complications could not be estimated in this simulation-based study, but they have been reported by others in <1% of patients after IO infusion (23,24). They included tibial fractures (25), lower-extremity compartment syndrome or severe extravasation of drugs (26,27), and osteomyelitis (20,28). Some of these complications could be avoided by heightened awareness. Local effects of IO infusions on the bone marrow and on bone growth have been shown to be minimal both in animal (29,30) and in human (31) studies.

Advanced medical simulation is routinely used to expose medical teams to critical and relatively rare events in the field, operating room, emergency department, or critical care department, and it was used in this study to simulate an unfamiliar situation. The scenarios developed for this study were designed with the aid of experts in toxicology, trauma care, critical care, and anesthesiology. Unlike conventional medical scenarios, however, which are based on broad clinical experience, the medical information on nerve gas intoxication is limited, and most information stems from a few reports in the medical literature and data from a terrorist attack in Japan (15). These features limit the ability to predict the clinical dynamics of various scenarios for the purposes of simulation.

In addition, the inevitable psychological stress and its effect on the performance of the medical teams during real nonconventional warfare will probably far exceed the level of stress they might experience during simulated training, and the negative repercussions on their performance will probably reflect this likelihood.

Another limitation is that outcome is difficult to interpret in a simulated setting such as the one we describe. The scenario designer programmed the outcome of "certain death" for casualties who received no intervention and guaranteed favorable outcome when the required steps were taken by the caretaker. This, of course, is unrealistic. The scenarios were, however, reviewed by experts in chemical warfare medicine and were approved by them as possible and probable, and the participants were instructed to approach them as authentic.

The aim of this study was to evaluate the use of a spring-driven, trigger-operated device for the insertion of an IO needle in the emergency treatment of severe chemical warfare casualties by medical teams wearing full protective gear. Advanced medical simulations of casualties of all ages were used for the evaluation. Our finding showed that the IO gun could play an important role in the immediate treatment of severe chemical warfare casualties. We propose a change in treatment protocol when the device is available in this setting and suggest considering the incorporation of similar devices as part of the standard equipment in the emergency treatment of mass casualties of chemical warfare.

	Acknowledgments

 
We thank Esther Eshkol for editorial assistance.

	Footnotes

 
The Bone Injection Guns (WaisMed Ltd., Caesarea, Israel) were supplied free of charge.

	References

Top Abstract Introduction Methods Results Discussion References

 

1. Sidell FR, Takafuji ET, Franz DR. Medical aspects of chemical and biological warfare. In: Zajtchuk R, Bellamy MC, eds. Textbook of military medicine. Office of the Surgeon General, Department of the Army, 1997: 144–57.
2. Sidell FR, Takafuji ET, Franz DR. Medical aspects of chemical and biological warfare. In: Zajtchuk R, Bellamy MC, eds. Textbook of military medicine. Office of the Surgeon General, Department of the Army, 1997: 326–36.
3. Marrs TC, Maynard RL, Sidell FR. Treatment and prophylaxis of organophosphate nerve agent poisoning. In: Marrs TC, Maynard RL, Sidell FR, eds. Chemical warfare agents: toxicology and treatment. Chichester, UK: John Wiley & Sons, 2000: 101–13.
4. Glaeser P, Losek J, Nelson D, et al. Pediatric intraosseous infusions: impact on vascular access time. Am J Emerg Med 1988; 6: 330–2.[ISI][Medline]
5. Guy J, Haley K, Zuspan SJ. Use of intraosseous infusion in the pediatric trauma patient. J Pediatr Surg 1993; 28: 158–61.[ISI][Medline]
6. Glaeser PW, Hellmich TR, Szewczuga D, et al. Five-year experience in prehospital intraosseous infusion in children and adults. Ann Emerg Med 1993; 22: 1119–24.[ISI][Medline]
7. Waisman M, Waisman D. Bone marrow infusion in adults. J Trauma 1997; 42: 288–93.[ISI][Medline]
8. Calkins MD, Fitzgerald G, Bentley TB, et al. Intraosseous infusion devices: a comparison for potential use in special operations. J Trauma 2000; 48: 1068–74.[ISI][Medline]
9. Fiser D. Intraosseous infusion. N Engl J Med 1990; 322: 1579–81.[ISI][Medline]
10. Banerjee S, Singhi SC, Singh S, Singh M. The intraosseous route is a suitable alternative to intravenous route for fluid resuscitation in severely dehydrated children. Indian Pediatr 1994; 31: 1511–20.[Medline]
11. Berg R. Emergency infusion of catecholamines into bone marrow. Am J Dis Child 1984; 138: 810–1.[Abstract]
12. Andropoulos DB, Soifer SJ, Schrieber MD. Plasma epinephrine concentrations after intraosseous and central venous injection during cardiopulmonary resuscitation in the lamb. J Pediatr 1990; 116: 312–5.[ISI][Medline]
13. Cameron JL, Fontanarosa PB, Passalaqua AM. A comparative study of peripheral to central circulation delivery times between intraosseous and intravenous injection using a radionuclide technique in normovolemic and hypovolemic canines. J Emerg Med 1989; 7: 123–7.[Medline]
14. Orlowski JP, Porembka DT, Gallagher JM, et al. Comparison study of intraosseous, central intravenous, and peripheral intravenous infusions of emergency drugs. Am J Dis Child 1990; 144: 112–7.[Abstract]
15. Okumura T, Takasu N, Ishimatsu S. Report on 640 victims of the Tokyo subway sarin attack. Ann Emerg Med 1996; 28: 129–35.[ISI][Medline]
16. Chamberlain JM, Altieri MA, Futterman C, et al. A prospective, randomized study comparing intramuscular midazolam with intravenous diazepam for the treatment of seizures in children. Pediatr Emerg Care 1997; 13: 92–4.[ISI][Medline]
17. Hung OR, Dyck JB, Varvel J, et al. Comparative absorption kinetics of intramuscular midazolam and diazepam. Can J Anaesth 1996; 43: 450–5.
18. Smoiander J, Louhevaara V, Korhonen O. Physiological strains in work with gas protective clothing at low ambient temperatures. Am Ind Hyg Assoc J 1985; 47: 720–3.
19. King JM, Frelin AJ. Impact of the chemical protective ensemble on the performance of basic medical tasks. Mil Med 1984; 149: 496–501.[ISI][Medline]
20. Fine BJ, Kobrick JL. Effect of heat and chemical protective clothing on cognitive performance. Aviat Space Environ Med 1987; 58: 149–52.[Medline]
21. Arad M, Berkenstadt H, Zehlinger J, et al. The effects of continuous operation in a chemical protective ensemble on the performance of medical tasks in trauma management. J Trauma 1998; 35: 800–4.
22. Hendler I, Nahtomi O, Segal E, et al. The effect of full protective gear on intubation performance by hospital medical personnel. Mil Med 2000; 165: 272–4.[ISI][Medline]
23. Heinild S, Sodergaard T, Tudvad F. Bone marrow infusions in childhood: experiences from 1000 infusions. J Pediatr 1974; 30: 400–12.
24. Rosetti VA, Thompson BM, Miller J, et al. Intraosseous infusion: an alternative route of pediatric intravascular access. Ann Emerg Med 1985; 14: 885–8.[ISI][Medline]
25. La Fleche FR, Slepin MJ, Vargas J, Milzman DP. Iatrogenic bilateral tibial fractures after intraosseous infusion attempts in a 3 month old infant. Ann Emerg Med 1989; 18: 1099–101.[ISI][Medline]
26. Vidal R, Kissoon N, Gayle M. Compartment syndrome following intraosseous infusion. Pediatrics 1993; 91: 1201–2.[Abstract/Free Full Text]
27. Simmons CM, Johnson NE, Perkin RM, van Stralen D. Intraosseous extravasation complication reports. Ann Emerg Med 1994; 23: 363–6.[ISI][Medline]
28. Rosovsky M, FitzPatrick M, Goldfarb CR, Finestone H. Bilateral osteomyelitis due to intraosseous infusion: case report and review of the English-language literature. Pediatr Radiol 1994; 24: 72–3.[ISI][Medline]
29. Pollack CV Jr, Pender ES, Woodall BN, et al. Long-term local effects of intraosseous infusion on tibial bone marrow in the weanling pig model. Am J Emerg Med 1992; 10: 27–31.[ISI][Medline]
30. Brickman KR, Rega P, Schoolfield L, et al. Investigation of bone developmental and histopathologic changes from intraosseous infusion. Ann Emerg Med 1996; 28: 430–5.[ISI][Medline]
31. Fiser RT, Walker WM, Seibert JJ, et al. Tibial length following intraosseous infusion: a prospective, radiographic analysis. Pediatr Emerg Care 1997; 13: 186–8.[ISI][Medline]

This article has been cited by other articles:

				K. A. Candiotti, A. Kamat, P. Barach, F. Nhuch, D. Lubarsky, and D. J. Birnbach Emergency Preparedness for Biological and Chemical Incidents: A Survey of Anesthesiology Residency Programs in the United States Anesth. Analg., October 1, 2005; 101(4): 1135 - 1140. [Abstract] [Full Text] [PDF]

				Adult Intraosseous Device Aids Terrorism Response Journal Watch Emergency Medicine, July 28, 2004; 2004(728): 10 - 10. [Full Text]

				G. H. Sigurdsson Anesthesiologists Should Be Familiar with the Management of Victims of Terrorist Attacks Anesth. Analg., June 1, 2004; 98(6): 1743 - 1745. [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Vardi, A. Articles by Ziv, A. Search for Related Content PubMed PubMed Citation Articles by Vardi, A. Articles by Ziv, A. Related Collections Resuscitation Critical Care

Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999