Sodium Nitroprusside Toxicity

Sodium Nitroprusside Toxicity: Mechanism of Action: After parenteral injection, sodium nitroprusside enters red blood cells, where it receives an electron from the iron (Fe⁺²) of oxyhemoglobin. This non-enzymatic electron transfer results in unstable nitroprusside radical and methemoglobin (Hb Fe⁺³). The former moiety spontaneously decomposes into five cyanide ions and...

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Carcinoid Crisis

Carcinoid Crisis Definition: -Carcinoid crisis is the most serious and life-threatening complication of carcinoid syndrome and is generally found in people who already have carcinoid syndrome. -Carcinoid crisis occurs when all of the symptoms of carcinoid syndrome come at the same time.  Causes: ➧ Spontaneous  ➧ Precipitating factors:  -Stress,...

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Drugs Avoided in Patients with Renal Failure

Drugs Avoided in Patients with Renal Failure ➧ The excretion of water-soluble drugs and their active metabolites will be impaired. For drugs that are renally excreted the half-life increases slowly with deteriorating renal function until severe nephron loss at which point the half-life increases sharply with further reductions in renal function. Dialysis can only...

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Drugs affecting IOP

Drugs affecting IOP ➧ Normal intraocular pressure (IOP) is between (10 - 20 mmHg). The average value of IOP is 15.5 mmHg with fluctuations of about 2.75 mmHg. ➧ IOP also varies with other factors such as heart rate, respiration, fluid intake, systemic medication, and topical drugs. ➧ Intraocular vascular tone is predominantly affected by CO₂; hypocarbia decreases...

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Drugs with Rebound Phenomenon

Drugs with Rebound Phenomenon ➧ The rebound effect, or rebound phenomenon, is the tendency of some medications, in sudden discontinuation, to cause a return of the symptoms it relieved, to a degree stronger than they were before treatment first began. Medications with a known rebound effect can be withdrawn gradually, or, in conjunction with another medication that...

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Accidental Total Spinal Anesthesia

Accidental Total Spinal Anesthesia Definition: ➧ A syndrome of the central neurological blockade.  ➧ It occurs when a volume of local anesthetic (LA) solution, intended for epidural anesthesia, enters the subarachnoid space and ascends to the cervical region. Causes:  a) After a known dural tap:  ➧ Accidental total spinal analgesia may occur...

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Failed Spinal Anesthesia

Failed Spinal Anesthesia Introduction: ➧ Spinal (intrathecal) anesthesia is one of the most reliable regional block methods: the needle insertion technique is relatively straightforward, with cerebrospinal fluid (CSF) providing both a clear endpoint of successful needle placement and a medium for carriage of local anesthetic (LA) within subarachnoid space. However, the...

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Management of Failed Spinal Anesthesia

Management of Failed Spinal Anesthesia ➧ Failure of a spinal anesthetic is an event of significant concern for both patient and anesthetist when it is immediately apparent, but it can have serious consequences (clinical and medico-legal) if the problem only becomes evident once surgery has started. ➧ This can be a source of pain, anxiety, and psychological...

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Needle Misplacement during Caudal block

Needle Misplacement during Caudal block Sites of Misplacement: A-SubperiostealB-False decoy hiatusC-posterior sacral ligamentD-Anterior sacral wallE-BoneF-Lateral foramen...

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