Nausea & Vomiting Dr. Nawaf O. Al-Amri Emergency Medicine Resident Saudi Board Of Emergency Medicine
DefinitionsNausea : Vague , unpleasant sensation that precedesvomiting , it may happen alone , with retching or vomiting ,and shares the same pathway of vomiting but due lessstimulation of that .Retching : Rythmatic synchronized contractions of thediaphragm , abdominal and intercostal muscles against aclosed glottis causing the intra abdominal and decrease theintra thoracic pressure causing the gastric contents to go upthrough the esophagus .
DefinitionsRumination : Regurgitation of the ingested food thatsubsequently is re-swallowed or ejected , mainly found ininfants , children and mentally challenged adults .Regurgitation : Gentle expulsion of gastric contents withouthaving nausea or vomiting & without the involvement ofabdominal or diaphragmatic muscles , but instead is due tothe relaxation of the lower esophageal sphincter instead .
DefinitionsVomiting : Forceful expulsion of gastric contents thru the mouth.
Pathophysiology1- The vomiting center is located in the lateral reticularformation in the Medulla Oblongata , and receives impulsesfrom the following areas :A- Higher brain centers : responding to pain , sights , smells ,tastes and even feelings and emotionsB- GI system ( Mainly Stomach ) : through direct and indirectirritation of any part of the GI tract , mainly the stomachgoing via Vagus and Sympathetic routes and over to thevomiting center .
PathophysiologyC- Heart : Through Vagus and Sympathetic Route .D- Genitalia : Through Vagus and Sympathetic RouteE- Vestibular System : Mainly due to a primary infection ordisposition locally or due to motion sickness , firing to thelateral vestibular nucleus .F- Chemoreceptor Trigger Zone : Located in Area Posterma ,which is in the floor of the 4th ventricle , its between theblood brain barrier ( In & Out ) >> Responds exogenous andendogenous substances .
Pathophysiology2- All of the previous areas have receptors that “ whentriggered “ will send and afferent impulse to the vomitcenter :A- GI Tract : has serotonin receptors .B- CTZ : receives from within the Area Posterma which hasDopamine and Serotonin receptors , as well as outside thebody substances which are mostly : drugs , uremia ,radiation , chemotherapy , toxins ( B , V , F , P ) , hormones ,and peptides , opiates , and digitalis or aspirin Via Canaboid, Substance P & Hydroxytryptamine receptors .
PathophysiologyC- Vestibular Nucleus : Muscarinic & Histaminic Receptors .3- Now that we know the receptors and their physologicalzones and how they respond & where impulses go , we’lldiscuss the actual mechanics of vomiting :A- Afferent impulses due to any stress on any of the areaswill shoot and impulse going to the vomiting center >>which generates Efferent impulses either Mild causingNausea or Mild causing retching or Severe causing vomiting .
PathophysiologyB- Due to Mild impulses , the duodenal & jejunal muscleswill contract while the gastric tone decreases >> causingreflux of intestinal contents to the stomach along withtachycardia , hyper-salivation & repetitive swallowing ,Which now completes a ( Nausea Phase ) depending on thestrength of the stimulus .C- If impulses are moderate and had much time to act , thevomiting center starts to send impulses through the Phrenicnerve going to the ( Diaphragm ) , The Vagus nerve going tothe ( Esophagus , Stomach & Duodenum ) , The Spinalnerves going to the ( Abdominal & Intercostal Muscles ) .
PathophysiologyD- Due to all of the pervious impulses , a rythmaticsynchronized movement of contractions of the Diaphragm ,Abdominal & Intercostal muscles , And closure of the Glottis>> Which causes the intra-abdominal pressure to rise andthe intra-thoracic pressure to decrease , pushing contents upthe esophagus against the glottis ( The Retching Phase ) .E- When Severe & continuous prolonged impulses are athand >> Abdominal muscles contract & the Hiatal part of thediaphragm relaxes >> the pyloric part of the stomachcontracts While the Cardia & Fundus Parts Relax .
PathophysiologyF- This will cause relaxation of the upper and loweresophageal sphincters , which will then allow the gastriccontents that are under sever pressure to gush through theesophagus and out through the mouth , Thus reaching thelong waited ( Vomiting Phase ) .
Classifications- Primary Vs. Secondary :A- Primary : Usually due to a GI illness ( Obstruction OrGastroenteritis )B- Secondary : Due to either :1- Sever visceral pain .2- Sever Systemic illnesses ( MI , Sepsis , Shock ) .3- Specific conditions like : pregnancy “ Hormonal “ , RaisedICP “ CNS Mechanism “ , Toxins “ Homeostatic Reflex “ .Motion Sickness “ Neuroendocrine “ Or Chemo “ CTZ “ .
Classifications- Acute Vomiting : Occurs ( < or = 1 Week ) , Usuallyassociated with : obstruction , ischemic , toxic , metabolic ,infectious , neurological and post-operative reasons .- Chronic : Occurring for more than 1 Month , Usually due topartial obstruction , motility disorder , neurological chroniccondition , pregnancy or functional reasons .- Cyclic : Which has an onset of repetitive but interruptedcycles of high frequency vomiting , followed by anasymptomatic phase usually due to Viral Causes .- Recurrent .
Most Common Cause Of Nausea And Vomiting 1- Acute Gastroenteritis2- Systemic Febrile Illnesses . 3- Medications
Sequelae Of Vomiting-Aspiration :Vomiting in a patient with altered mental status , low ordepressed level of consciousness , or one that suffers fromextremely repetitive cycles will most likely have bad epiglotticcontrol or non for that matter , which in term will lead toaspiration of gastric contents whatever they are to therespiratory tract and lung causing aspiration pneumonia .The results of that will almost always be troubling especially ifthe contents were of chemical or highly irritating to therespiratory tract causing compromise to the Airway .
Sequelae Of Vomiting- Mallory Weiss Syndrome :Due to sever and repetitive retching and vomiting a partial tearof the mucosa and sub-mucosa in the stomach andgastroesophageal junction will form , which may lead to bleedingwhich most likely will be minimal and self limiting , but canproceed to a more catastrophic form .
Sequelae Of Vomiting- Boerhaaves Syndrome :Which Happens commonly due to repetitive , extreme prolongedbouts of retching and vomiting , causing a full tear of all thelayers of the esophagus , mainly and most commonly theposteriolatral lower part of the esophagus which is by itself aLethal medical emergency .
Sequelae Of Vomiting-Hypovolemia :due to a lot of vomiting , high water volume content and sodiumand chloride will be lost from the body , which will causecontraction of the extracellular fluid space leading to activationof the Renin – Angiotensin – Aldosterone system .
Sequelae Of Vomiting- Electrolyte Imbalance :Mainly Hypokalemia due to a very complex reflex due to volumedepletion which will cause Hyperaldosteronism , Leading toincreased re-absorption of Sodium & Increased Excretion of largeamounts of Potassium in the urine .
Sequelae Of Vomiting- Hypochloremic Metabolic Alkalosis :Although the acid base system in the body is well protective , itcan decompensate due to a group of stressors that will shift itfrom equilibrium to either Acid or Alkali Side .This is very evident in the setting of Continuous large amountvomiting for more than 3 Days Owing : ( Loss of H+ from HCL +Low Volume Concentration + Hypokalemia + Chloride Depletion +High Aldosteron + Shifting Of H+ from extra to intra cellular ) , AllGathering up to cause sever metabolic alkalosis due to extremehigh frequency vomiting .
History1- Duration : to define the type of vomiting and to give you a closepicture of what kind of sequelae might have this patient developed .2- Time + Onset / Offset : to define the type or the etiology causing it :A- Acute Onset : Gastroenteritis , Pancreatitis , Cholycystitis ,Appendicitis , Anaphylaxis , Medication Effect Or Toxicity .B- Morning : Raised ICP , Primary Tension or Migraine Headaches ,Pregnancy , Uremia , Alcoholism .C – 1 Hour After Eating : Gastric Outlet Obstruction Or Gastroparisis .D- 12 Hours After Eating : Gastric Or Intestinal Obstruction .
History3- Content Of The Vomit :- If Bilious >>> then Gastric outlet obstruction is out of the question ,cause the area between the stomach and duodenum is intact .- If Undigested Food >>> Achalasia Or Stricture- If Digested Food >>>> Might be due to toxins or anaphylaxis .- If Hematemisis >>> Suspect Upper GI Bleed with its causes .- If Fecal Mater Or Smells So >>>> Distal Bowel Obstruction , Fistula ,Bacteria Overgrowth due to long standing outlet obstruction .
History4- Associated Symptoms : Hyper-salivation, defecation, tachycardia, bradycardia, atrialfibrillation, and termination of ventricular tachyarrhythmias are associatedphenomena with nausea and vomiting. Chronic headaches with nausea and vomitingshould raise the index of suspicion for an intracranial lesion. Also, vomiting withoutpreceding nausea is typical of central nervous system pathology5- Past Medical & Surgical Hx : The past medical history will reveal the presence of anyGI disease or previous surgeries6- Social & Traveling Hx : The social history should include inquiries about alcohol orother substance abuse.7- Medications & Dietary Habits : Nutritional history is valuable in the consideration offailure to thrive in infancy thorough medication list, including over-the-counter drugs,should be included.
Special Considerations In Pediatric Group* Bulging Fontanel >>>> Meningitis .* Projectile Vomiting >>>> Pyloric Stenosis .* Unusual Odors >>>> Metabolic Or Toxicological Causes .* Visible Bowel Loops >>>> Obstruction .* Enlarged Parotid Gland + Loss Of Dental Enamel >>>> Bulimia* Mild Reflux & Rumination & Regurgitation might be normal in first few months of life .* First Week Vomiting >>> Obstructive , Inborn Error Of Metabolism , Serious Infection .* After 1 Week >>> Pyloric Stenosis , Feeding Problems .* First Month >>>> Infections , Metabolic Causes , Caw Milk , Failure To Thrive , SubduralHematoma in Abused Children .* Adolescents + Teenagers >>> Cyclic Vomiting , Food Poisoning , HSP , Pneumonia , DKA ,Anorexia Nervosa , Bulimia , Drug Abuse .
Tests- CBC : If Hb and HCT are High >>> Dehydration due to loss of dilutional effect .- Electrolytes : Hypochloremia , Hypokalemia .- BUN / Creatinine Ratio : If 20:1 >> Sever Dehydration .- Lipase : Pancreatitis >>> Dehydration- Urineanalysis : For UTI , Pregnancy Test , DKA , Hematouria , Stones , Sterile Pyoriain Appendicitis .- Culture , Sensitivity & Titers : To Rule In Or Out Infection ( B , V , F , P ) .- LFTs + Ammonia : Cholysystitis , Ascending Cholingitis , Liver Failure .- Chest & Abdominal X-Rays : Focus , Perforation , Obstruction .- CT & Angio : Ischemia & Infarction .- ECG : MI - TFT : Thyroid Disease - Drug Levels
Assessment & Management- Make sure you cover your : A-B-C-D-E- Try to limit and stop lethal & Critical causes likeBoerhaaves , GI Bleed , Mesenteric Ischemia ,Intracranial Bleed , Meningitis , DKA , MI & Sepsis .- Direct your therapy to the cause of nausea andvomiting while treating the effects of that process .
Assessment & Management1- Rehydration & Electrolyte Imbalance: If thepatient can take orally and tolerate it , Give ORS orAny rehydration fluids like Getorade , If cant take P.O>>>> I.V Aiming To Replenish Fluid Volume AndElectrolytes Loss .2- Nasogastric Tube : If the patient is persistentlyvomiting due to a GI bleed , Gastroparisis ,Pancreatitis , Or Bowel Obstruction .
Assessment & Management3- Pharmacological Treatment (( Very Important )) :A- Phenothiazine : (( Prochlorperazine , Droperidol, Promethazine ))- Have Dopamine Antagonistic Effect In CTZ .- Side Effects may include : Restlessness and Dystonia , Which can be treatedwith Diphenhydramine + Benztropine.B- Serotonin Antagonists : (( Ondansetron“ Zofran “ ))- Works Well In Area Posterma & The GI Tracts .- Best For Chemotherapy & Theophylline Or Acetaminophen Toxicity AdjunctTherapy .- Side Effects may include : Headaches & Constipation .
Assessment & ManagementC- Prokinetic Agents : (( Metoclopramide, Cisapride))- Works as An Antagonist to Dopamine + Cholinergic + Serotonin Receptors .- Cisapride Works On The GI Receptors Only Unlike Metoclopramide .- They Both Increase Gastric Motility & Emptying .- Side Effects may include : Restlessness , Lightheadedness & Dystonia .D – Antihistamines : (( Dimenhydrinate , Meclizine ))- Best used to prevent Motion Sickness & N&V Due To Vestibular Problems .- Side Effects may Include : Drowsiness , Dry Mouth , & Hypertension .
Assessment & ManagementE – Anticholinergics: (( Scopolamine & Hyoscine“ Bascopan “ ))- Which may be given as a supportive treatment to colicky pain inUncomplicated acute gastroenteritis & and is also effective inprophylaxis of Motion SicknessF- Benzodiazepines :- Which are effective in Nausea and vomiting due to anxiety disorder .G- Substance P Neurokinin 1 Antagonists : (( Aprepitant ))- Used an adjunct therapy to prophylaxis against post ChemotherapyN&V as well as Post-Operative .
Etiology Directed Treatment- Pregnancy Related N&V :* For Mild To Moderate >>> Rehydration P.O or I.V + Pyridoxine +Antihistamines + Prokinetic Agents + Ondansetron + Prochlorperazine.* For Severe >>> Admission , Fluids + Electrolytes , Corticosteroids .- Post Operative Related N&V : Due To Nitroxide & Propofol* Ondansetron , Metoclopramide, Droperidol.- Post Chemotherapy Related N&V : Acute ( 24 Hours ) Chronic ( > 1 Day )* Ondansetron + Aprepitant + Dexamethasone.
Nausea & Vomiting Dietary Steps- We cant expect all patients who had nausea and vomiting to resumetheir normal diet once vomiting stops , it should be in the followingsequence to grantee a relaxed gradual coming back to normal diet :Step 1 : Start With Water , Clear Fluids & Electrolyte ReplenishingDrinks , Keep In Mind That Citrus & Sweet Flavored Can Irritate GI .Step 2 : After Pt Has Tolerated Clear Fluids , Next Step Is Semi LiquidsLike Soups , Bare In Mind Though That They Should Be Low Fat HighCarbs .Step 3 : Tolerating The Above , Start On A Moderate Diet Of HighProtein And Low FatStep 4 : Patient Can Resume Normal Diet , If Above Are Tolerated .
DO NOT DISCHARGE IF1- There Is A Significant Underlying Disease .2- If The Diagnosis Or Cause Of Nausea & Vomiting Isn’t Clear .3- Poor , Relapse Or No Response To Treatment .4- Nausea & Vomiting Continues Or Becomes Even More Frequent .5- If The Patient Is Of The Extremes Of Age .6- If The Patient Is Un-Able To Follow Up In The Clinic .7- If The Patient Is Dependant Or Unable To Follow Instructions .8- If The Patient Still Cant Take Per Oral .
DISCHARGE IF1- There Is No Significant Underlying Disease .2- If The Cause Is Clear & Appears To Be No Serious .3- Good Or Full Response To Treatment .4- Nausea & Vomiting Becomes Less Or Stops .5- If The Patient Can Actually Take Clear Fluids Per Oral .6- If The Patient Has A Close Follow-Up In 24-48 Hours .7- If The Patient Understands The Instructions & Is Able To Abide ToThem And Is Self Dependant .
Take Home Message1- Understanding Pathophysiology Of N&V Is Important In Defining &Treating Lethal And Critical Causes .2- Not Every Etiology Responds To Just Antiemetic Therapy , Your GoalIs To Know How And Why And From Where Its Happening In Order ToHit The Right Receptor With Your Medication .3- Although Nausea & Vomiting Might Sound Easy And Less SeriousThan A lot Of Signs & Symptoms , Its Sequelae Can Sometimes BeCatastrophic .4- Abide To The ( A , B , C , D , E ) Protocol In Management .5- Treat The Causes As You Are Treating The Sequelae Of N & V