Surg Flashcards
Causes of mechanical bowel obstruction
extraluminal: adhesions, herniae, abscess, neoplasm, volvulus
intraluminal: faecolith, intussusception, gallstone ileus, meconium
mural: atresia, inflammatory bowel disease, diverticulosis, neoplasm
Psuedo obstruction of bowel
Pseudo-obstruction refers to the presentation of
symptoms and signs mimicking mechanical obstruction but with no obstructing
lesion. It is more common in elderly patients suffering from chronic medical conditions.
Treatment is conservative.
Spiking temperatures
abscess/collection formation
Repairing AAA
Elective surgical repair of aneurysm
is indicated with an aneurysm diameter greater than 5.5 cm. Operative options include replacement with a prosthetic graft or endovascular stent graft repair.
Mortality from aneurysm rupture without surgery
is 100 per cent; and even if the patient reaches the hospital surgical unit alive, overall mortality is very high (80–95%).
Signs and symptoms of carcinoma of the large bowel vary depending on site
Right-sided lesions in the caecum/ascending colon are associated with
weight loss and anaemia, whereas symptoms of change in bowel habit and bleeding
per rectum are more common in the sigmoid colon/rectum.
Pancreatic psudocyst
Usually located in the lesser sac adjacent to the pancreas.
Occur due to ductal leakage following inflammation of the pancreas (acute or chronic).
Present non-specifically with abdominal discomfort,
nausea, early satiety etc.
Complications of pancreatic pseudocyst include
infection (most common), obstruction (of common bile duct leading to jaundice)
and perforation.
Rarely erosion of nearby vessels cause pseudoaneurysm formation which can be fatal.
Most pseudocysts resolve spontaneously. CT shows a round/ovoid fluid-filled cavity encapsulated by a fibrous wall. A pseudocyst does not have a true epithelial lining.
Pancreatic pseudocysts can be treated
by drainage if it is felt that there is a high risk of complication
Managing rectal fissure
Initially medical with liberal use of stool softeners to break the cycle of pain. GTN/diltiazem ointment may be
applied topically to relax the sphincter. Surgical procedures include lateral internal sphincterotomy and controlled sphincter dilatation.
Abdominoperineal resection
Operation of choice for lower rectal tumours
where sphincter preservation is not possible. It involves the removal of the anus, rectum and part of the sigmoid colon, and the formation of a permanent
colostomy.
Indications for a Hartmann’s
Hartmann’s procedure involves excision of part of the left colon with end colostomy and closure or exteriorization of the distal remnant.
Relief of obstruction – for example in a patient presenting with obstruction secondary to sigmoid colon carcinoma. The malignancy with appropriate margins can be excised and a colostomy formed. The Hartmann’s procedure can be reversed at a later date.
Perforation of sigmoid colon. The patient presents as an emergency with a perforated sigmoid diverticulum/secondary to undiagnosed malignancy. A primary anastomosis is not possible with the degree of inflammation and peritonitis.
Refractory sigmoid volvulus. Occasionally sigmoid volvulus fails to resolve by conservative measures/passing of flatus tube etc., and emergency surgery is required. If primary anastomosis is deemed likely to fail, then a Hartmann’s procedure is performed in the first instance (can be reversed later depending on
the case).
Shoulder tip pain
Referred from peritiontic (eg diaphragm and
gallbladder). Acromion - diaphragm. Angle of scapula - gallbladder
Embryological origins of epigastic pain
Mainly foregut structures - stomach, duodenum, liver, gallbladder, spleen and pancreas. T8 T9
Embyrological origins of periumbilical pain
Midgut structures - small bowel, ascending colon, appendix. T10 T11
Embryological origins of suprapubic pain
Hindgut pain - colon, rectum, bladder, uterus, fallopian tubes, testicular. T12 L1
Body fluid breakdown
60% body weight H20, 40% intracellular, 20% extravellular (5% IV, 15% interstitial).
Intracellular ions - High K Low Na
Extracellular ions - Low K High Na (K is 98% IC)
Interstitial - V low protein
IV - High protein
Blood vs Colloids vs Crytalloids vs 5% dextrose
Blood - fills up IV space almost exclusively
Colloid - majority stays IV due to high high osmotic potential
Crystalloid - will distribute over entire extravascular compartment (4 times bigger than IV) so 1L hartmans only 250ml stays IV
5% dextrose - will distribute over both IC and EC compartments
Normal daily fluid losses
Urine 2000ml + 80-130mmol Na + 60mmol K
Faeces 300ml
Insensible (lungs and skin) 400ml
Total 2700
GIT causes of water and electrolyte imbalances
D&V, ileostomy, NG aspiration, fistulous losses, pyloric stenosis, pancreatic fistula
In paralytic ileus and bowel obstruction, several litres of fluid may become acutely sequestered in the gut contributing to hypovolaemia. Resolution of an ileus is marked by diuresis
Is potassium supplementation requires post surgery or trauma?
NO, potassium is released from damaged tissue, and can be further increased by transfusion. Supplementary potassium should not be needed in first 48h post
Effect of surgery on fluid balance
Activation of vasopressin, catecholamines, RAS and steroids result in oliguria and water retention.
Clinical examination - if euvolaemic, overhydration may dilute blood causing pulmonary oedema and provide a salt load the patient cannot excrete
Potassium is released from damaged tissue, and can be further increased by transfusion. Supplementary potassium should not be needed in first 48h post. Esp watch in RF where excess K cannot be excreted.
Preoperative fluid management in elective case
NBM and clear fluids up to 2-3h pre surgery unless gastric emptying is affected (DM, carcinoma of head of pancreas). Pre-op carbohydrate drinks (2-3h pre surg) reduce preoperative anxiety and postop N&V
Electrolyte contents of 0.9% saline (vs human plasma)
Osmolality: 308 (291) Na: 154 (135-145) K: Ca: Mg: Cl: 154 (94-111) Lactate: HCO3:
Electrolyte contents of Hartmann’s (vs human plasma)
Osmolality: 278 (291) Na: 131 (135-145) K: 5 (3.5-5) Ca: 2 (2.2-2.6) Mg: Cl: 111 (94-111) Lactate: 29 (1-2) HCO3:
Electrolyte contents of 5% albumin (vs human plasma)
Osmolality: 300 (291) Na: 150 (135-145) K: Ca: Mg: Cl: 150 (94-111) Lactate: HCO3:
Electrolyte contents of 4% dextrose + 0.18% saline (vs human plasma)
Osmolality: 283 (291) Na: 30 (135-145) K: Ca: Mg: Cl: 30 (94-111) Lactate: HCO3:
Sample fluid replacement of lost fluid in typical adult without co-morbidities and no fluid deficit
1.5-3L fluid + Na 50-100mmol + K 40-80mmol / 24h
3 x 1L fluids per 24h
0.4% dextrose + 0.18% saline + 20mmol K in each bag
or
Using hartmann’s Na/K/Cl/Lactate/Ca
Calculating fluid deficit
Clinically
<5% No clinical signs
5-10% Dry mucous membranes, loss of skin turgor, tachycardia and postural hypotension, low JV pressure
>15% circulatory collapse
So 70kg man with 10% - 10% x 60% x 70 = 4.2L
If state of fluid depletion is unclear, fluid challenge with 200ml bolus of colloid or balances crystalloid solution
Physiology of malnutrition
Depletion of glycogen stores leads to fat catabolism resulting in the primary energy source for the brain to be ketones. IC minerals Mg and PO4 become depleted. Insulin production is halted, and though initially protein is preserved muscle catabolism occurs (occurs earlier with sepsis and trauma). Impaired immune responces lead to infection and worse wound healing.
Anthropometric measurements of malnutrition
Triceps skin fold thickness (reflect fat stores)
Midarm muscle circumference (MAMC)
Hand grip strength (non dominant)
Principles of preoperative assessment (3 things to do)
- History and confirmation of initial indication for surgery still exists
- If the patient fit enough for the procedure?
- Are co-morbidities managed? (eg if HBA1c 100 probs best to postpone elective surgery)
Taking a pre-op history - PMHx
DM - medications. Can result in gastroparesis (gastric stasis) increasing aspiration risk despite fasting.
Resp - nature of disease, how far away from best is patient?
Cardio - what is exercise telerance? Stable/unstable
RA - associated with unstable C spine. XR needed
Rheumatic fever, cardiac heart disease, prosthesis - needs prophylactic Abx
SSD - prone to sickle cell crisis under GA and post op
Taking a pre-op history - PSHx
Nature - what has been done, indication, complications (DVT/PE, infection, MRSA, dehiscence)
Taking a pre-op hisotry - Anaesthetics
Difficult intubation Aspiration Rare (scoline apnoea - AD pseudocholinesterase deficiency results in prolonged paralysis with short acting muscle relaxants like suxamethonium; malignant hyperpyrexia - AD uncontrolled increase in muscle oxidative metabolism leads to difficult to control pyrexia)
Taking a pre-op history - Social
Alcohol and fags
Substance abuse - think hepatitis and HIV
Allergies - latex, anaesthetics, antimicrobials, iodine
Pre op management of DM
- Diet controlled - nil
- Oral hypoglycaemics/SC insulin - stop night before, commenced on glucose+insulin infusion.
Esp avoid long acting insulin which can cause intraoperative hypoglycaemia.
Diabetic - first on list
Pre op management of asthma
Peak flow, if possible avoid pollinating months when planning elective surgery
Pre op management of COPD
Consider regional anaesthesia, whether pt requires post op ventilation on ICU. Think epidural
Pre op management of CABG/Angioplasty
Assess cardiac function - ECG ± Echo
Consider local anaesthesia
Pre op management - oral anticoagulants
Eg Warfarin, Dibigatran, Apixaban Indication important Should be discontinued prior to surgery Eg. AV prosthesis generally safe to discontinue to a while but MV prothesis not If needed, switch to SC heparin
Pre op management - oral antiplatelets
Discuss with cardio regarding dual antiplatelet therapy
Should ideally be stopped 10 days prior to surgery
Pre op management - COCP
Increased risk of DVT/PE - stop 6 weeks before major surgery. POP safe. Counsel need to change to condoms.
Pre op management - Roids
Patients who are steroid dependant will require IV hydrocortisone to tide them over perioperative stress
Pre op management - Immunosupression
More prone to post op infection and absorbtion of immunosupressants may be affected
Pre op management - diuretics
Important to have normal K levels pre op
Pre op management - MOIs
Rarely used now, but interact with anaesthetic agents to cause hypotension
Pre op management - obstructive jaundice
These pts often have prolonged PTT and require vitK and either human prothrombin complex or FFP. Intraoperatively maintain diuresis with fluid replacement and mannitol as susceptible to AKI (HR syndrome)
ASA grades (mortality)
I - no cormobidities (<0.1%)
II - mind systemic disease does not limit activity (0.3%)
III - severe systemic disease, not incapacitating (2-4%)
IV - Incapacitating constantly life threatening disease (20-40%)
V - not expected to survive >24h with or without surgery (>50%)
Timetable for post op complications
<24 hours - LOCAL:haemorrhage, anatomical injury (eg ligation of ureter during pervic surgery) GENERAL asphyxia - aspiration of vomit, obstructed airway
24h-3weeks - LOCAL: paralytic ileus, infection (wound, peritonitis, pelvic, subphrenic), secondary haemorrhage, dehiscence (wound, anastamosis), obstruction due to fibrous adhesions. GENERAL pulmonary collapse, bronchopneumonia, embolus, retention, ATN, enterocolitis, bed sore
Late - LOCAL: obstruction due to fibrosis, incisional hernia, recurrance of lesion (malignancy). GENERAL: anaemia, vitamin deficiency, diarrhoea, OP,
Dumping Syndrome
A group of symptoms, including weakness, abdominal discomfort, and sometimes abnormally rapid bowel evacuation, occurring after meals in some patients who have undergone gastric surgery.
Type of surgery vs infection risk
Clean - eg hernia repair. No viscera opened, without inflammation, infection <1%
Clean contaminated - viscous opened with little or no spillage, infection <10%
Contaminated - obvious spillage, obvious inflammatory disease (eg gangrenous appendix), infection 15-20%
Dirty - eg gunshot, frank pus or gross soiling (eg bowel perforation). Infection 40%
Gas gangrene
Gas gangrene (also known as clostridial myonecrosis and myonecrosis) is a bacterial infection that produces gas in tissues in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria. It is a medical emergency. Especially likes poorly vascularized tissue eg amputation stump.
Prophylactic Abx in bowel and biliary surgery
Depends on what you want to cover. Good choice is 3rd gen cephalosporin with metronidazole to cover anaerobes. Fluconazole for candida may also be required.
Antibiotic associated enterocolitis
C. Diff is a grap positive spore forming bacteria.
Extensive enterocolitis causes diarrhoea and bowel will show mucosal inflammation with psudomembrane formation. Sigmoidoscopy shows red friable mucosa with whitish/yellow patches which may form psudomembranes.
Feaco-oral transmission associate with PPI use
Id of toxins A & B in stool diagnostic.
Complications of toxic megacolon and rapid dehydration
Good infection control with oral metronidazole 14 days
Notable MDR organisms
MRSA VISA VRSA ESBL (extended spectrum B lactamases) CRE (carbopenem resistant enterobacteriaceae) VRE (vancomycin resistant enterococci)
Basal atelectasis post op
Some degree of pulmonary collapse occurs after almost every abdominal or transthoracic procedure. Mucous is retained in bronchial tree, blocking smaller bronchi. The alveolar air is absorbed leading to collapse of the supplied lung segments. While normal, increased risk of infection
Post op pulmonary collapse
Some occurs normally (basal atelectasis)
Smokers, Chronic pulmonary diseas, chest wall disease increase risk
Anaesthetic drugs increase mucous secretion and depress ciliary action, while post op pain inhibits taking deep breaths and causes mucous retension
Occurs in first 48hours. Dyspnoea, tachypnoea, T, fruity cough, diminished breath sounds that side, basal dullness and air entry depresses with course crackles.
Prevention - postpone surgery until all infections cleared. Pre op breathing exercises and stop smoking
Post op encourage coughing (small dose opiates to limit pain but not high enough to affect coughing reflex) with breathing exercises. Abx if becomes infected.
Post op DVT
Virchows triad - flow (immobilization on operative table and post op in bed with depression of respiration), vessel wall (damage prompts thrombus formation, can be caused by pressure by matress on calf or direct at op), thrombotic tendency (intraoperative blood loss and platelet consumption leads to new platelets being formed, peaking at 10 days post op. Fibrinogen also rises)
Ascertain other risk factors, incl genetic (eg G20210A prothrombin mutation or fVL
Good prophylaxis (eg COCP), early mobilisation, intermittant calf comression during surgery, TED stockings and elevation, SC LMWH Wells Score
In established case - LMWH with conversion to warfarin in future
Post op PE
PE classically occur day 10 post op
Signs - tachyponeoa, pleuritic chest pain, raised JVP (reflecting right heart strain), cyanosis, pleural rub
CTPA, CXR, ECG (may show rhythm changes, right heart strain, S1Q3T3) ABG
Oxygen + LMWH ± Analgesia
Critical options include streptokinase (CI following surgery) or pulmonary embolectomy
Factors which impair wound healing
Uraemia, cachexia with protein deficiency, vitamin C deficiency, jaundice, obesity, steroids, DM
Managing wound dehiscence
Reassure with morphine and antiemetic
Cover contents with sterile guaze soaked with saline and prepare for operation.
Resuture under GA using nylon strong sutures passed through all layes of abdominal wall
Prognosis good unless underlying disease takes over
High risk for future incisional hernia
Signs of wound dehiscence
Abdomen usually day 10
Warning sign if pink fluid discharges through incision - represents serous effusion (always present in abdominal cavity after operation), tinged with blood and which seeps through the hole in wound. If this progresses, patient finds bowel or omentum through wall, usually after cough or strain.
Post op hypotension - management
In a surgical patient hypotension is hypovolaemia until proven otherwise. Resuscitate with a fluid challenge and monitor clinical response while sending bloods for FBC and clotting
Duct of Lushka
Duct of Luschka is used to refer to an accessory bile duct. They are small ducts that distinctly enter the gallbladder bed, or small tributaries of minor intrahepatic radicals of the right hepatic ductal system.
Common complication post laparoscopy
Umbilical port site bleed / haematoma
Steroid cover during surgery
Minor surgery - if less than 10mg/d no cover needed, if more than 10mg/d give 25mg preop IV hydrocortisone the return to normal steroid use post op
Intermediate surgery - 25mg IV hydrocortisone pre op, then every 8h for 24h until normal resumed
Major surgery - 50mg IV hydrocortisone preop then 50mg IV every 8h for 72h then resume normal
Manage: urgent surgery pt on warfarin with INR 3
Discontinue warfarin, vit K 2-3mg, monitor INR every 6-8h post op and have FFP, cryoprecipitate and XM blood ready to cover the surgery
Insulin sliding scale during surgery
Add 50 units of Actarapid to 0.9% saline to total volume 50ml (1ml = 1 unit). Calculated as 1 ml (unit) / h. Blood glucose should be measured hourly and scale adjusted.
BM > 16 - 6 ml/h BM 13-16 - 4ml/h BM 10-13 - 3 ml/h BM 7-10 - 2ml/h BM 5-7 - 1ml/h BM 4-5 - 0.5ml/h
Medical staff monitor every 2-4h to ensure glucose within 5-10mmol/L
This needs to be run with 5% dextrose with 20mmol/L KCl supplementation through the same cannula to avoid hypos if cannula blocks
Half live of IV insulin
2.5 minutes
Causes of post op cellulitis
Staph Aureus and Strep Pyogenes, if immunocompromised staph epidermidis
Initial first line fluid replacement for trauma ATLS
2L Hartmann’s
Typical daily requirements for adults (H2O, Na, K)
1-2.5L H2O
1mmol/kg Na
0.5-1mmol/kg K
Electrolytes in ileal fluid (important in high output ileostomies)
130 mmol/L Na
110 mmol/L Cl
10 mmol/L K
Post op fistula
Serious if involves alimentary canal or biliary/pancreatic adnexea following abdominal surgery. Escape of bowel / bile contents through drainage site. If in doubt methylene blue given orally.
Sample of fluid tested for creatinine (urinary), bile (biliary), amylase (pancreatic).
Injection of radio opaque dye at time of ct will visualise size and if distal obstruction.
Treating post op fistula
- Protect skin around fistula - edges covered by Stomadhesive (adheres to moist surfaces) or silicone barier cream. Consider colostomy appliance
- Replace loss of fluids, electrolytes, nutrients and vitamins
- Reduce sepsis - abx and pus drainage
On this conservative management fistula may heal but if in site of inflammatory disease (CD) or malignant in origin needs surgery.
Patient will likely be toxic and rapid catabolism occurs
Post op pyrexia
Mild pyrexia normal response to surgery.
Examine and exclude infection
Risks of Laparoscopic surgery
Cannula insertion - perforation of viscus, bladder, aorta
Insufflation - vagal stimulation causing profound bradycardia, CO2 retention, CO2 embolism
Surgery itself - bleeding, trauma
Port closure - inadequate closure leading to hernia
Risks of OGD
Oesophageal perforation, variceal bleeding
Risks of ERCP
perforative cholangitis, pancreatitis
Risks of Colonoscopy
perforation, esp if polypectomy or stenting of stricture
Commonest causative agent in cellulitis
Group A B haemolytic strep (eg pyogenes)
Why do abscesses cause swinging fever?
Initially abscess is hard, red and painful. Becomes soften and fluctuant and if not drained discharges into body cavity.
Abscess if established needs drainage
True vs False diverticulum
True - outpouching covered by all layers of the bowel wall (e.g. Meckel’s)
False - lacking normal muscle coat of the bowel
Causes of colonic diverticuli
Low fibre diet - disease of western civilisation
Structural abrnomalities - CTD incl Marfans and Ehler Danlos
Abnormal motility and increased intraluminal pressure.
Complications of diverticuli
Diverticulitis resulting in perforation into either peritioneum (peritonitis) or pericolic tissues (pericolic abscess)
Large bowel obstruction - muscular hypertrophy and inflammatory fibrosis
Haemorrhage - erosion of vessel within diverticular fundus.
Managing acute diverticulitis
Conservative - fluids, metronidazole + ciprofloxacin / penicillin + gentamycin
Pericolic abscess - percutaneous drainage
If stable, surgery may be avoided. If sepsis controlled, laparotomy and resection of diseased segment.
If emergency usually Hartmann’s
Managing chronic diverticular disease
Conservative - Milpar (lubricant laxative) plus high roughage diet including F&V, wholemeal bred, bran.
Angiodysplasia - investigating and treatment
Colonoscopy - GS, bright red submucosal lesions 0.5-1cm with small dilated vessels visible on close inspection. Visible on barium enema
Mesenteric angiogram - actively bleeding angiodysplasias will feature contrast bleeding into bowel.
Treatment - transfuse if severe, colonoscopic electrocoagulation or argon plasma coagulation may be curative. Resection (usually R hemi) may be required.
UC and colon cancer
5-12% op patients with colitis for 20years duration will develop malignant change. Annual / biannual colonoscopy with biopsies
Surgery for refractive severe UC
Usually total colectomy and rectum removal with either permanent ileostomy or ileoanal anastamosis with interposed pouch of ileum.
All patients will likely be on high dose steroids - IV hydrocortisone cover
Familial history in CRC
Baseline lifetime risk CRC - 1/50
1 FDR - 1/17
1FDR <45 - 1/10
Think FAP and HNPCC
FAP
FAP gene, AD, 0.5% all CRC, 25% de novo
Prophylactic total colectomy with ileoanal pouch befor 25 years olf
HNPCC
AR, 5% all CRC, MSH2 (60%) MLH1 (30% MMR genes
Tumours favour R colon,
Dukes classification CRC (+ 5 yr survival %)
A - confined to muscularis mucosae (90%)
B - extends through muscularis mucosae (65%)
C - local lymph nodes (30%)
D - mets (<30%)
- More likely today to use TNM classification
Red flag for CRC
Change in bowel habit
Mucous / Blood
Screening CRC
Faecal occult blood test (screening offered every 2 years to all 60-74 year olds)
Bowel scope screening - this additional one-off test is gradually being introduced in England. It is offered to men and women at the age of 55
Investigating suspected CRC
Faecal occult blood tests Sigmoidoscopy / Colonoscopy (biopsy is able to be taken as well) CT colonography (virtual colonoscopy) replaced barium enema (which used to show apple core appearance) CEA levels useful, but baseline important
CRC - principles of surgical treatment
Wide resection of mass together with regional lymph nodes. If bowel unobstructed, can be prepared beforehand and primary anastamosis possible. If obstructed (anastamosis CI) defunction distal bowel with colostomy or ileostomy for possible anastamosis at a later date.
Even palliatively best scenario is tumour removal to avoid obstruction. If not, try at least stenting
Chemotherapy in CRC
Adjuvant therapy in CRC includes 5-fluorouracil (5FU) and may reduce recurrance.
Survival prolonging treatments include 5FU + irinotecan, cetuximab (mAb against epidermal growth factor) and bevacizumab (mAb against VEGF)
Colostomy - what do think about when you see one?
Need to divert faeces to allow healing of more distal bowel anastamosis or fistula
Decompression of a dilated colon, prelude to resection of obstructing lesion
Removal of distal colon and rectum
Loop vs End vs Double barreled colostomy
Loop - colon bought to surface and antimesenteric border opened. Rod or similar device stops bowel from moving back inside. Temporary measure to divert faeces and rest distal bowel. Easy to reverse and better blood supply to bowel
End - permanent. May be used in a patient undergoing total rectal excision or following perforated diverticular disease where primary anastamosis not viable.
Double barrelled (Paul Mikulicz) - proximal and distal ends both out, kind of like loop but divided fully. Rarely used as distal segment often too short.
Complications of colostomy formation
Retraction - real (due to tension) or apparent (necrosis of terminal bowel)
Stenosis - due to ischaemia or poor apposition of colonic mucosae
Paracolostomy hernia - peritoneal contents herniate through adbsominal wall defect made to hold stoma
Prolapse
Lateral space bowel obstruction
Then there are complications arising from poor fitting appliances or poorly made stomas
Managing a new colostomy
In the first few weeks faecal discharge is semi liquid but this gradually reverts to normal solid stools
Appliances are both wind and waterproof
Most patients find they pass one stool a day despite no sphincter (morning shits are the norm)
Large amounts of v&g can cause diarrhoea and flatus
AXR - small bowel obstruction
Ladder pattern of dilated loops
Central position
Striations - vena conniventes, which pass completely across width of distended loop
AXR - large bowel obstruction
Bowel tends to lie peripherally, haustrations of taenia coli, not extending the whole width of bowel
Coffee bean sign if sigmoid volvulus
CT with oral gastrograffin contrast to image further
Preop management of acute bowel obstruction
NG tube + aspiration to decompress bowel and reduce aspiration risk
IV fluids - these pts will sequested huge amounts of fluid in the gut. Hartman’s or Saline with K
Ab
Operating principles of bowel obstruction
Determine viabilility of bowel:
Loss of peristalsis
Loss of normal sheen
Colour (green/black is non viable, purple may recover)
Loss of arterial pulsation in supplying mesentery
If extensive areas are doubtful reopen 48h (remember Mr Tsohazis case) to reassess
Small bowel can be excised at will, as due to excellent blood supply and cleanliness easy to anastamose.
Large bowel obstruction treated by primary ileocolic anastamosis if lesion proximal to spleinc flexure. Left sided lesions managed with excision, and temporary colostomy with mucus fistula (if distal end will not reach surface fo Hartman’s)
Closed loop obstruction
Specific form of mechanical bowel obstruction. Combination of distal complete obstruction + competent ileocaecal valve preventing reflux. Highly distended caecum at risk of perforation.
Adhesion obstruction
Adhesions account for 3/4 of all SB obstructions. Initially conservative with IV fluids and NG suction.
If strangulation, perforation or failure to respond urgent laparotomy
Sigmoid volvulus
Think elderly, constipated patients. M>W 4:1. 2% of intestinal obstructions in UK. More common in other parts of world.
Loop of sigmoid colon usually anticlockwise from 1/2 to 3 turns
Treating sigmoid volvulus
Long soft rectal tube passed through sigmoid colon - usually untwists and early volvulus - accompanied by huuge amounts of flatus and liquid shit.
If this fails, laparotomy to untwist followed by tube decompression. If gangrene, excise and both open ends brought to surface (Paul-Mikulewicz procedure) as a double barelled colostomy, subsequently closed
Mesenteric oclusion
++++ AF
Mural thrombus 2* to MI
Vegetation on valve
Paradoxical embolus from DVT (which crossed to other side via patent foramen ovale)
Atherosclerosis - usually preceding Hx of “angina”, pain after meals as gut struggles to process with limited blood supply
Rigler’s sign
Radiograph - gas on both sides of the bowel wall
