Article, Emergency Medicine

Serial monitoring of sedation scores in benzodiazepine overdose

Unlabelled imagesedation scores in “>Case Report

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American Journal of Emergency Medicine

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Serial monitoring of sedation scores in benzodiazepine overdose?

Abstract

Benzodiazepines are widely used for many diseases, and benzo- diazepine overdose is globally increasing in proportion to its prescriptions. Although most benzodiazepine overdoses are known to be safe and nonfatal without coingestions, morbidity or mortality after benzodiazepine overdose is closely related with the duration of unconsciousness or depth of compromised airway. Proper use of flumazenil, a potent antidote of benzodiazepine, seems to accelerate the recovery from the toxicity after benzodiazepine overdose. However, as the case we present demonstrates, careful attention and repetitive evaluations before and after use of flumazenil may be needed in benzodiazepine overdose because resedation occurs in approximately 30% of total flumazenil-treated cases, which suggests that the risk of aspiration or incidental death after administrating flumazenil might be significant without careful monitoring.

Benzodiazepines are frequently prescribed for many diseases and are also most commonly involved in drug overdose suicide attempts [1]. Since the introduction of flumazenil as a potent Benzodiazepine antagonist in 1981, many studies examining its safety and efficacy have been conducted [2-6]. Flumazenil can potentially reverse the depressed level of consciousness and consequent respiratory depres- sion after a benzodiazepine overdose [3,6]. Resedation occurs in approximately 30% of total flumazenil-treated cases, which suggests that the risk of aspiration or incidental death after administrating flumazenil might be significant without careful monitoring [6]. Therefore, we suggest that repetitive evaluations conducted before and after the use of flumazenil may be needed in cases of benzodiazepine overdose.

A 67-year-old woman came to our emergency department by a

119 ambulance; she was unconscious after a suicide attempt by clonazepam overdose. The patient’s daughter found her face down in her room, unconscious, 19 hours after clonazepam ingestion. The patient had a history of diabetes mellitus for more than 10 years and had depression and insomnia for 4 years. Her recent daily medications were glimepiride, 2 mg; phloroglucinol, 240 mg; and clonazepam (Rivotril, 0.5 mg/T; Roche, Seoul, Korea), 0.5 mg. Approximately 15 mg of clonazepam was the only ingested drug, estimated by the number of missing packets. On arrival, the patient was comatose with a Glasgow Coma Scale of 4 eye opening, verbal response, motor response (E2V1M1). Her vital signs were as follows: blood pressure, 120/50 mm Hg; pulse, 77 beats per minute; respiration, 14 breaths per minute; body temperature, 36.4?C; and SaPO2, 94%. The physical examination produced a grunting sound, a sore on the coccyx, and bilateral bullae on the nondependent portion of the foot (Fig. A). Arterial blood gas analysis showed the following: pH, 7.447; PCO2, 37.0 mm Hg;

? Source(s) of support in the form of equipment, drug, and grants: None.

PO2, 69.0 mm Hg; and HCO3-, 28.9 mmol/L. The chest x-ray showed focal segmental atelectasis on the left medial lower lung field. laboratory examinations showed the following: white blood cell count, 6700 x 109/L; hemoglobin level, 12.6 g/dL; platelet count, 157000 x 109/L; international normalized ratio, 1.08; fasting Blood sugar (FBS), 118 mg/dL; serum urea nitrogen, 10.9 mg/dL; serum creatinine, 0.96 mg/dL; aspartate aminotransferase, 24 IU/L; alanine aminotransferase, 21 IU/L; sodium, 142 mEq/L; potassium, 3.8 mEq/L; chloride, 102 mEq/L; and creatine kinase (CPK), 523 U/L. The electrocardiogram showed sinus tachycardia with a QRS duration of 96 milliseconds and a QTc interval of 423 milliseconds. Her initial Ramsay sedation scale (RSS) and Richmond Agitation-Sedation Scale (RASS) scores were 5 and -4, respectively. After injection of the first bolus of flumazenil, her RSS and RASS scores changed to 3 and -2, respectively, which were maintained for 40 minutes and then changed to 5 and -3, respectively. After the second bolus of flumazenil, the target RSS and RASS scores were reached and transiently maintained at 2 and 0, respectively, for 50 minutes. After the second resedation, flumazenil was continuously infused at a rate of 0.5 mg per hour. After 10 hours of continuous flumazenil infusion, the patient became alert and was not resedated (Fig. B). The next morning, she felt slightly dizzy and could not recall the events of the previous day. On the third day of her hospital stay, the patient was discharged after psychiatric interviews.

After a suicide attempt by clonazepam overdose, our patient showed mild hypoxia and atelectasis due to the decreased level of consciousness and subsequent suppression of respiratory control, bullous skin lesions on both feet, mild CPK elevation due to immobilization, and anterograde amnesia. Despite the absence of any evidence of coingestion, whether our patient’s results originated from an isolated clonazepam overdose was uncertain because a large portion of the observed morbidity and mortality after benzodiazepine overdose is related to the synergistic effects of coingested drugs [3,6]. As observed in our patient, bullous skin lesions, also known as “Coma blisters,” have been reported after several cases of central nervous system depressant poisoning [7]. Interestingly, our patient showed well-demarcated and large bullae on both feet (Fig. A). In addition, our patient showed anterograde amnesia, which is a frequent finding after suicide attempts by benzodiazepine overdose but is not necessarily associated with memory impairment [8]. Our patient came to our hospital unconscious 19.5 hours after her overdose, due to delayed detection. In this situation, gastric decontamination and activated charcoal would be ineffective and thus was not indicated; these treatments might even be harmful without airway protection. Fig. B shows the changes in the RSS and RASS scores of our patient. Before flumazenil administration, we examined the patient’s airway and assessed the presence of contraindications for flumazenil administration, such as a history of seizures or seizure risk. Next, we briefly evaluated the RSSs and RASSs using, in order, a loud voice, a light glabellar tap, and physical stimuli [9]. The RSSs and RASSs were repetitively evaluated before and after flumazenil

0735-6757/(C) 2014

image of Fig

Fig. This figure illustrates bilateral bullae on the both feet (A) and sedation scores (B) observed in the unconscious patient who came to our hospital after clonazepam overdose.

FMZA, flumazenil.

administration. In conclusion, we successfully managed the coma- tose patient after clonazepam overdose using sedation score-based applications of flumazenil.

Yeon Young Kyong, MD Jeng Tak Park, MD Kyoung Ho Choi, PhD?

Department of Emergency Medicine, Uijeongbu St Marys Hospital College of Medicine, The Catholic University of Korea, Uijeongbu, Korea

?Corresponding author. Department of Emergency Medicine Uijeongbu St Mary’s Hospital, College of Medicine

The Catholic University of Korea. Gumoh-dong 65-1, Uijeongbu-si

Gyeonggi-do, 480-130, Republic of Korea Tel.: +82 31 820 3027×3948; fax: +82 31 847 9945

E-mail address: [email protected] http://dx.doi.org/10.1016/j.ajem.2014.04.004

References

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