Serotonin Syndrome

Serotonin Syndrome from Sun YaiCheng

The Serotonin Syndrome
N Engl J Med 2005;352:1112-20.

Clinical triad of the serotonin syndrome:

1. Mental-status changes
   

   agitation and delirium

2. Autonomic hyperactivity
   

   tachycardia, mydriasis, diaphoresis, the presence of bowel sounds and diarrhea

3. Neuromuscular abnormalities
   

   Hyperreflexia, inducible clonus, myoclonus, ocular clonus, spontaneous clonus, peripheral hypertonicity, and shivering

Diagnosis

• The presence of tremor, clonus, or akathisia without additional EPS should consider the diagnosis. 

• Physical examination should include a focused assessment of DTR, clonus, and muscle rigidity, in addition to an evaluation of the size and reactivity of the pupils, the dryness of the oral mucosa, the intensity of bowel sounds, skin color, and the presence or absence of diaphoresis.

Hunter Serotonin Toxicity Criteria
QJM 2003;96:635-42

Differential Diagnosis

Condition	Serotonin syndrome	Anticholinergic “toxidrome”	NMS	Malignant hyperthermia
Medication History	Proserotonergic drug	Anticholinergic agent	Dopamine antagonist	Inhalational anesthesia
Onset	<12 hr	<12 hr	1–3 days	30 min to 24 hr
Vital Signs	Hypertension, tachycardia, tachypnea, Hyperthermia (>41.1°C)	Hypertension (mild), tachycardia, tachypnea, hyperthermia (typically < 38.8°C)	Hypertension, tachycardia, tachypnea, hyperthermia (>41.1°C)	Hypertension, tachycardia, tachypnea, hyperthermia (can be as high as (46.0°C)
Pupils	Mydriasis	Mydriasis	Normal	Normal
Mucosa	Sialorrhea	Dry	Sialorrhea	Normal
Skin	Diaphoresis	Erythema, hot and dry	Pallor, diaphoresis	Mottled, diaphoresis
Bowel Sounds	Hyperactive	Decreased or absent	Normal or decreased	Decreased
Neuromuscular Tone	Increased, predominantly in lower extremities	Normal	“Lead-pipe” rigidity present in all muscle groups	Rigor mortis–like rigidity
Reflexes	Hyperreflexia, clonus	Normal	Bradyreflexia	Hyporeflexia
Mental Status	Agitation, coma	Agitated delirium	Stupor, alert Mutism, coma	Agitation

Management

1. Removal of the precipitating drugs 

2. Provision of supportive care 

3. Control of agitation

Control of agitation with benzodiazepines is essential in the management of the serotonin syndrome, regardless of its severity. 

Physical restraints are ill-advised and may contribute to mortality by enforcing isometric muscle contractions that are associated with severe lactic acidosis and hyperthermia.

4. Administration of 5-HT2a antagonists

Cyproheptadine

Initial dose: po 12 mg and then 2 mg q2h if symptoms continue
Maintenance dose: po 8 mg q6h

Olanzapine, sublingual 10 mg

Chlorpromazine, intramuscular 50-100 mg

5. Control of autonomic instability

Hypotension should be treated with low doses of direct-acting sympathomimetic amines (e.g., norepinephrine, phenylephrine, and epinephrine).

Hypertension and tachycardia should be treated with short-acting agents such as nitroprusside and esmolol.

6. Control of hyperthermia

In severely ill patients with hyperthermia (temperature >41.1°C), immediate paralysis should be induced with non-depolarizing agents such as vecuronium, followed by orotracheal intubation and ventilation.

There is no role for antipyretic agents in the management of the serotonin syndrome.

相關文章：SSRI & Serotonin Syndrome (中文 prezi 版)

Acute Coronary Syndromes

Acute Coronary Syndromes on Prezi

Acute Coronary Syndromes 2010 AHA Guidelines for CPR and ECC  Circulation. 2010;122:S787-S817 ACC/AHA 2009 Guidelines for STEMI and PCI Circulation. 2009;120;2271-2306 ACC/AHA 2007 Guidelines for UA/NSTEMI Circulation. 2007;116;e148-e304

TIMI Risk Score

• Age ≥ 65 years
• At least 3 risk factors for CAD (family history of CAD, hypertension, hypercholesterolemia, diabetes, or current smoker)
• Prior coronary stenosis of ≥ 50%
• ST-segment deviation on ECG
• At least 2 anginal events in prior 24 hours
• Use of aspirin in prior 7 days
• Elevated serum cardiac biomarkers

PCI Following ROSC After Cardiac Arrest

• Patients with OHCA due to VF in the setting of STEMI or new LBBB, emergent angiography with prompt recanalization of the infarct-related artery is recommended (Class I, LOE B).
• PPCI after ROSC in subjects with arrest of presumed ischemic cardiac etiology may be reasonable, even in the absence of a clearly defined STEMI (Class IIb, LOE B).
• Appropriate treatment of ACS or STEMI, including PCI or fibrinolysis, should be initiated regardless of coma (Class I, LOE B)

Management of Arrhythmias

• Primary VF accounts for the majority of early deaths during AMI. The incidence of primary VF is highest during the first 4 hours after onset of symptoms.
• Prophylactic antiarrhythmics are not recommended for patients with suspected ACS or MI in the prehospital or ED (Class III, LOE A).
• Routine IV administration of beta-blockers to patients without hemodynamic or electric contraindications is associated with a reduced incidence of primary VF (Class IIb, LOE C).
• Low serum potassium has been associated with ventricular arrhythmias. It is prudent clinical practice to maintain serum potassium >4 mEq/L (Class IIB, LOE A).

Blunt Carotid & Vertebral Vascular Injuries

Screening for and Treatment of Blunt Cerebrovascular Injuries from Sun YaiCheng

Western Trauma Association Critical Decisions in Trauma:
Screening for and Treatment of Blunt Cerebrovascular Injuries
J Trauma. Volume 67(6), December 2009, pp 1150-1153


Signs/Symptoms of BCVI

• Arterial hemorrhage from neck, mouth, nose

• Large or expanding cervical hematoma

• Cervical bruit in a patient younger than 50 years

• Focal or lateralizing neurologic deficit, including hemiparesis, TIA, Horner’s syndrome, oculosympathetic paresis, or VBI

• Evidence of cerebral infarction on CT or MRI

• Neurologic deficit that is incongruous with CT

  
Risk Factors for BCVI

• An injury mechanism compatible with severe cervical hyper-extension with rotation or hyper-flexion

• Lefort II or III midface fractures

• Basilar skull fracture involving the carotid canal

• Closed head injury consistent with DAI with GCS <6

• Cervical vertebral body or transverse foramen fracture, subluxation, or ligamentous injury at any level, or any fracture at the level of C1–C3

• Near-hanging resulting in cerebral anoxia

• Seat belt or other clothesline-type injury with significant cervical pain, swelling, or AMS

Diagnosis and Management of Blunt Carotid and Vertebral Vascular Injuries 

Neck Trauma

頸部創傷的評估和處置 from Sun YaiCheng

頸部創傷的評估和處置 機 轉

1. 頸部頓挫傷
2. 頸部穿刺傷
3. 窒息和上吊

Zones of the neck

Blunt Carotid & Vertebral Vascular Injuries (BCVI)

Early recognition and treatment of blunt carotid and vertebral vascular injuries may reduce the risk of stroke.

Suggested criteria for screening include:

1. C1–3 fracture

2. C -spine fracture with subluxation 

3. Fractures involving the foramun transversarium

頸部穿刺傷之處置

重要觀念

• 頸部創傷最主要之立即死因是血管損傷。
• 頸部創傷最主要之延遲死因是食道損傷。此種傷害並不常見，症狀不明確，容易延誤診斷造成高死亡率。
• 頸圈可能造成呼吸道外部壓迫，並且可能阻礙頸部之系列評估(例如擴散中之血腫)。
• 若無禁忌症，儘可能由有經驗者儘快做氣管內插管。

96年 急診醫學科專科醫師甄審考題

25歲男性業務員騎機車過馬路時，不慎和對方來車相撞，119送他到醫院時，發現他下巴中間有凹陷，臉部和口腔都在流血，右側脖子腫脹，血壓80/50 mmHg、心跳120/min、呼吸32/min，下列何種醫囑要先執行？

（A）臉部和口腔壓迫止血 （B）下巴固定 （C）輸林格氏液 2000ml （D）口咽氣管插管 （E）環甲軟骨切開術 （cricothyroidotomy）

相關文章：窒息和上吊 (Near Hanging & Strangulation)

Near Hanging & Strangulation

窒息和上吊 from Sun YaiCheng
 

1. 處決性（完全性）絞刑
   Judicial (complete) hanging 
傷者墜落距離超過自己身高 
2. 非處決性（非完全性）上吊 或  自殺性和意外性上吊
   Non-judicial (in-complete) hanging or suicidal and sccident hanging
   傷者墜落距離小於自己身高
3. 徒手窒息或絞扼窒息
   Manual Strangulation or ligature strangulation

機轉

1. 脊髓或腦幹損傷
2. 頸部結構機械性壓迫
3. 心臟停止

處決性絞刑    傷者常死於高位頸椎骨折造成脊髓斷裂

非處決性上吊  一般不會造成頸椎骨折

Hangman's Fracture 

Mechanism: extension
Stability: unstable
Fracture lines extending through the pedicles of C2 are well visualized
Retropharyngeal soft tissue swelling is apparent

Tardieu’s Spot
在絞扼上方之結膜、黏膜，皮膚造成點狀出血點

院內死亡主要原因
肺部併發症（吸入性肺炎、肺水腫、急性呼吸窘迫症）