POCUS Exam Notes PDF

POCUS ----- What is POCUS? A qualitative cage-side diagnostic and monitoring tool, that uses sonography to answer simple binary questions. It is an enhancement of a physical exam What is the value of POCUS? Minimally invasive, patient-side, real-time, faster diagnostics, accuracy, aids decision ma...

POCUS ----- What is POCUS? A qualitative cage-side diagnostic and monitoring tool, that uses sonography to answer simple binary questions. It is an enhancement of a physical exam What is the value of POCUS? Minimally invasive, patient-side, real-time, faster diagnostics, accuracy, aids decision making, repeatable, radiation sparing Ultrasound probe mostly used in POCUS micro convex curvilinear Do we need to clip for performing POCUS? no, split the fur (unless really dense fur) What makes the image brighter or darker gain What makes the ultrasonographic window larger and deeper or smaller and more superficial depth/zoom What changes the resolution to higher or lower frequency Indications for POCUS Respiratory distress, emergency presentation, unstable patients, trauma, collapsed large dog, critically ill patients, recovery from anaesthesia The 5 views: subxiphoid, urinary bladder, left paralumbar, right paralumbar, umbilical All 5 can find free fluid- gather around liver, bladder, retroperitoneal space Subxiphoid view Diaphragm (bright white line), liver, gal bladder, caudal vena cava, pleural space, pericardium Caudal vena cava: how big it is shows hyper or hypovolaemic Urinary bladder view Urinary bladder, body wall (colon, uterus and prostate) Non-invasive urinary output measurements Bladder volume = height x length x width x 0.52 Left paralumbar view Spleen, left kidney, retroperitoneal space, body wall, intestines Right paralumbar view Liver, right kidney, retroperitoneal space, body wall, intestines Umbilical view Free fluid on the dependant side of the abdomen PLUS: pleural space and lung ultrasound Indications: Respiratory distress, emergency presentation, unstable patients, trauma, collapsed large dog, critically ill patients, recovery from anaesthesia Pleural line: indicates the interface between the soft tissue (fluid rich) of the wall and lung tissue (gas rich) 6 key structures in the healthy pleural space and lung: Bat sign, glide sign, curtain sign, A lines, B lines, lung pulse Bat sign: the characteristic appearance of the pleural line (which represents the parietal pleura) along with the adjacent ribs. The ribs resemble the wings of the bat, while the pleural line mimics the body of the bat Glide sign: shimmering of the pleural line indicates sliding of parietal and visceral pleura on each other with breathing Significance: its absence identifies pneumothorax at that spot Curtain sign: in the caudal border of the thorax, the pleural line will be "hidden" by the diaphragm moving back and forth with breathing and abdominal organs will be visible in the caudal half of the field Significance: landmark for the end of the lung field caudally, aids in identifying a pneumothorax\ A line: bright horizontal reverberation artefacts from the ultrasound bouncing off the pleural line, somewhat attenuate towards the distant field B line: bright vertical lines originating from the pleural line, reaching the distant ultrasonic field moving forward and backward with breathing Lung pulse: fine shimmering of the pleural line in sync with the cardiac pulse; seen in the region of the heart Significance: its presence rules out pneumothorax Pneumothorax: absence of glide signs, lung point, absence of B-lines and lung pulse, double or asynchronous curtain sign Pleural effusion looks like: black angular and triangular structures usually ventral transthoracic and subxiphoid views Shred signs and lung consolidation: portion of the non-aerated ling that looks like tissue (liver); originates from the pleural line. "Shred sign": partial consolidation bordering with aerated lung, irregular and bright contours POCUS videos notes ------------------ Depth -- how far into the tissue it penetrates Focal position -- focuses higher resolution on where it is e.g caudal vena cava want the focal position further down Frequency -- low means goes in deeper tissues but images are lower definition. Higher means higher definition Gain -- brighter or darker -- to do with the dampening etc of ultrasound probe Freeze and track back -- can see the last 10 seconds Gel vs alcohol Coupling agent Alcohol is main one, gel is messy! Sliding: sliding to the side (lateral) Sweeping: in one direction back and forth Rocking: tip stays in place, tail moves on the vertical plane Fanning: the tail of the probe moves on the horizontal plane, tip stays in place Rotating: moving clockwise or counterclockwise on its axis For ultrasound guided IV catheter- place proximal to the needle, see if going in, change the angle and slowly push in Oncology ======== Oncology Introduction --------------------- What is cancer: Cells that have lost the normal controls that balance cell death with cell proliferation The sooner you catch it, the better chance your treatment will help Steps to success -- what, where, when Describing the mass: fixed vs moveable, ulcerated vs non-ulcerated, size, subcut vs dermal vs intracavitary, soft vs hard How to identify the mass: fine needle aspirate or biopsy with histopathology **If it is important enough to take off, it is important enough to submit for histopathology** FNA: woodpecker or aspirate method -- evaluate if its cellular or acellular, which cells you are seeing and criteria of malignant FNA provides an origin Carcinoma: urothelial carcinomas, squamous cell carcinoma, mammary carcinoma, anal sac adenocarcinoma Sarcomas: osteosarcoma, fibrosarcoma, soft tissue sarcoma Round cell tumour: lymphoma, melanoma, mast cell tumour Benign Malignant Grading: Based on the appearance of cells. Done by histopathologists, higher grades are more aggressive (malignant) Staging Based on T, N, M - Size, regional lymph node involvement, distant metastasis Based on: physical exam, FNA, CBC/biochem/urinalysis, radiographs, US, echocardiogram, CT, MRI, bone marrow aspirate Stage with intention Carcinomas typically spread via lymphatics +/- lungs Sarcomas typically spread via blood Round cells can do either or both Lymph nodes: can normally feel submandibular, prescapular and popliteal When to stage: always unless it wont change what you would do Paraneoplastic syndromes: Alterations in bodily structure or function due to cancer that are not directly due to the physical effect of the primary or metastatic lesion which can be more damaging than the actual tumour Eg: cancer cachexia, gastric ulcers, hypercalcaemia, hypoglycaemia, hypertrophic osteopathy, monoclonal gammopathy Treatment options: surgery, radiation, chemotherapy Things to consider: Just because we can, doesn't mean we should Neoadjuvant -- before surgery treatment (to shrink tumor) Adjuvant -- after surgery treatment (to destroy residual microscopic disease) Palliative -- to improve quality of life without aiming to prolong lifespan Curative intent -- to prolong lifespan Surgery: the only treatment for cancer that will CURE a pet is surgery NEVER place a drain in a surgery field for cancer -- if you didn't get it all, you will spread the cells If you try to resect a scar from a previous incomplete surgery, you must assume the entire scarline is now full of cancer cells Radiation: High dose of radiation which kills cancer cells and shrinks tumours e.g xrays or protons Indicated for: Local disease or improving quality of life from local disease Need cells to be dividing Limited availability and costly set up Chemotherapy: Used for widespread disease or when other options aren't available due to location Needs cells to be actively dividing Because systemic, may get systemic side effects Stage-treat-recheck Rechecks depend on tumor biology and treatment choice A few months if radiation Complete response -- no evidence of tumor at this time Partial response -- tumor burden shrank by at least 30% Stable disease -- tumor less than 20% larger or shrank by less than 30% Progressive disease -- tumor is at least 20% larger or new lesions are noted When to change treatment: based on owner goals and where patients is in protocol Skin tumours and margins ------------------------ Dogs -- number 1 tumour 1/3 of all tumours Skin -- number 2 tumour, ¼ of all tumours Mesenchymal tumours are subcutaneous: e.g Fibrosarcoma, Lipoma, HSA, melanoma Epithelial tumours are true skin tumours. E.g SCC, BCT (basal cell), sebaceous gland tumour Round cell tumours: e.g lymphoma, MCT, plasmacytoma, histiocytoma, TVT The first and best chance to cure cancer is at the initial surgery Inappropriate surgery may make a curable cancer UNCURABLE Collection of samples for skin tumours Do an FNA in every case NEVER open formalin before cytological slides as degrade cells Aspiration: repeat 3-5 times, expel gently, smear gently, air dry and stain, need at least 2 sets of stains You can never tell from just looking at a tumour how bad it is Measure tumours, record location on a body map, allow comparison between visits Types of surgery: marginal Excision vs Wide Excision vs Compartmental Excision Capsules can be pseudocapsules which means tumour cells are on both sides -- you cannot tell just by palpating Degree of differentiation: Well- more normal, look more like the individual normal cells Poorly -- varied, unlike the normal tissue Incomplete margins: Want to avoid incomplete margins which aren't palpable to include these cells If you do it poorly, have a dirty scar which has tumour cells and needs another surgery En-bloc resection: a block of tissue at and least one fascial plane (nearly all the body there is the cutaneous trunci which acts as the deep margins) Surgery: mark margins, cut straight down, use scissors to cut (DON'T blunt dissect), remove the tissue and fascia Margins: Incomplete resection of ALL tumours is known to be associated with increased rates of recurrence and a poorer prognosis, Histological review of all resected tissues should be a routine aspect of all oncologic surgery [Squamous cell carcinomas] Cause: Exposure to sunlight, pyrimidine bases in the DNA molecule form dimers, leading to transcription errors during replication (& mutation...), immunosuppressive effect and potential imbalance in T cell function Behaviour: Locally invasive, don't usually metastasize Location: non-haired skin on cats Tx options: surgical, cryosurgery, radiotherapy, photodynamic therapy, chemotherapy Surgical resection: excellent long term control possible, immediate re-operation if dirty margins Radiotherapy: Indicated for poorly differentiated, incompletely excised or irresectable tumours Photodynamic therapy: superficial lesions only, inexpensive and well tolerated, topical administration, referral only Mast cell tumours: 2 main kinds of systems of describing: Grade 1-2-3 OR Low vs High Grading: determined on degree of granules tells how big a margin to cut and how likely the mass is to have spread. More granules better prognosis Markers of poor prognosis: Fixed, large, systemic signs of histamine, near prepuce Metastasis: Local lymph nodes then Liver/Spleen. To the lungs is rare Grade 1 (LOW ) Grade 2 (LOW) Grade 2 (HIGH) Grade 3 (HIGH) Grade 1 (low) and grade 2 (low) 0.5cm-1cm margin. Unlikely metastasis. No chemo Grade 2 (low and high) 2cm margin. 10% metastasis. May require chemo if LN positive Grade 3 (high) 3cm margin. % metastasis. Definitely requires chemo. Mammary gland tumours --------------------- **Canine mammary tumours** Most common tumour in females Under hormonal influence -- decreased incidence with spaying Signalment: median age: 10-11 years. Pure breed \> Mixed Histological types 50/50 split between benign and malignant Most to least common histological types - Epithelial/Mesenchymal/Mixed Carcinoma/sarcoma malignant, adeoma is benign **Cannot** predict the type of tumour through what it looks like Surgery: Complete resection will cause successful local management (except if it has already metastasised) -- dependant on clear margins Prognosis: 75% of patients with mammary neoplasia will survive their disease with successful surgery Prognostic features: presentation, clinical stage, surgical margins, tumour type and grade Stage I: No mets, tumour \5cm - median survival time 210-287 days Stage IV: Lymph nodes mets - median survival time 90-165 days Stage V: Distant mets - median survival time 224 days Inflammatory carcinoma Can be diagnosed with the eyes alone rough, open, weeping, serous discharge, hot, BAD Signalment: sexually intact older dogs Clinical Signs: hot, swollen, oedematous mammary chain +/- limbs anorectic, generalized weakness, weight loss Prognosis: Mean survival [25-60] days with palliative treatment [Surgery not recommended] How to get information to plan surgery: FNA, biopsy, staging, radiographs, ultrasound, blood, grading FNA: to rule out non-mammary disease (e.g. mast cell tumour, lipoma, etc), to confirm mammary neoplasia Biopsy: difficult to justify 'incisional' biopsy in most cases, excisional biopsy usually appropriate Metastasis: to regional LN is around 50%, can also be distant mets to lungs, spleen, liver, kidney, bone, distant lymph nodes Thoracic radiographs and abdominal ultrasound vs CT scan of thorax and abdomen Surgical planning: 66% of tumours occur in glands 4 or 5 25-61% of cases will have multiple masses Only 10% have malignant/benign combinations Surgical options: Nodulectomy- Cut around physical bit (bleeds) Local mastectomy- remove whole mammary gland Regional mastectomy- grouping mammary glands Unilateral mastectomy- One side Bilateral mastectomy - Both sides Predicting prognosis: influenced by tumour grade, type and size Size: \4cm are 42% benign Adjunctive therapy for high grade tumours: chemotherapy Influence of hormones: Binding of oestrogen to ER receptor stimulates cell division and growth, ER is present in normal mammary tissue and over-expressed in 90% of benign tumours, less expression in malignant tumours ER+ tumours tend to be less aggressive To spay or not to spey: Early OHE has profound effect on tumour incidence Survival times considered similar for spayed/unspayed dogs **Mammary tumours in cats** Third most common tumour Signalment: Siamese cats increased incidence, mean age of 10 years Aggressive pattern of growth, almost always malignant, locally aggressive and high rates of metastases Neutering has sparing effect Clinical examination -- aggressive growth and high rates of meta ALL tumours need to get staging prior to surgery -- thoracic radiographs, abdominal US and node aspiration Treatment: radical mastectomy and removal of enlarged LN, often do in 2 surgeries Prognosis for long term survival is poor Prognostic factors: lymph node status, tumour size and stage, high grade tumours, conservative surgery Chemotherapy ------------ Chemotherapy is a treatment, not a cure, for systemic neoplastic disease Chemotherapy non-specifically attacks actively dividing cells. Most work in the S phase (DNA replication) with some M (mitosis) Side effects of chemotherapy: due to normal body cells that are also actively dividing and therefore damaged by chemotherapy BAAG Alopecia Bone marrow: lowers number of neutrophils which can predispose to secondary issues Animals with \5mm or PRIMARY LESION (FCP, UAP, OCD) **Recommendations for controlling ED** Never breed affected individuals or their parents Never breed siblings of affected individuals Never breed offspring of affected individuals Avoid the use of second-degree relatives for breeding. The concept of only breeding dogs with [less than the median score] is more practical Elbow dysplasia clinical signs: lameness in puppies 4-12 months, pain on elbow extension and/or extension, pain on direct pressure, reduced ROM, elbow carried externally rotated, often sub-clinical Ununited Anconeal Process (UAP) Tx options: conservative (not great), UAP removal, ulnar osteotomy, lag screw fixation Removal: only if osteotomy/lag screw procedures declined and better if done young Proximal ulna osteoectomy Increased morbidity and [prolonged convalescence] over surgery to remove AP Indications: adolescents to remove restraining effect of short ulnar and allow fusion to occur Lag screw fixation: Not advised in long standing cases when UAP has remodelled or detached, giant breeds may be riskier Osteochondrosis - OCD Disorder of endochondral calcification of the hyaline cartilage Debris filled horizontal cleft along the tideline Clinical signs when a vertical cleft develops, probably due to trauma Genetic predisposition to rapid growth, males \>\> females, excess energy intake If diagnosed early, OCD should be treated surgically (arthroscopy) Fragmented coronoid process (FCP) Common esp Labradors and Rottweilers The lesion consists of fissures or fragmentation of the medial coronoid DX of exclusion Arthroscopy is the method of choice as it can be combined with therapy Proximal ulnar osteoectomy: Incongruity is thought to cause a step lesion between the articular surfaces of the lateral and medial coronoids and the proximal radius, Ulna ostectomy/osteotomy has been advocated to allow the ulnar to rotate into alignment Removal of the FCP alone may temporarily improve lameness but has not shown long-term benefit Treatment by arthrotomy +/- ulna osteotomy A medial muscle splitting arthrotomy (between pronator and flexor carpi ulnaris) is preferred Fragments are retrieved, or the fissured MCP is osteotomised The proximal -- "dynamic" ulna osteotomy +/- supported by an IM pin Osteotomy increases lameness (3 mths) short term pain, eventual gain Arthroscopy is helpful to determine prognosis **Moral of the story...** If juvenile lameness is ignored, radiographs are not taken (or not the correct views) or a definitive cause not pursued in the absence of radiographic findings; DJD can develop at a rapid pace. If such an animal is eventually referred for evaluation at a referral centre, it may already\\ be too late to intervene. Arthroscopy allows for treatment at the time of lesion confirmation. Capus, tarsus and feet ---------------------- [Carpal laxity syndrome ] Puppies 6-12 weeks, present with carpal hyperflexion associated with [tautness of the tendons of the flexor carpi ulnaris] muscle Radiographs show normal bone development Treatment: benign neglect - exercise of carpet for good footing. Soft sports support dressings for a few hours a day [Radial carpal bone luxation]: Treatment is open reduction, temporary radial to ulnar- carpal bone pin and prosthetic MCL [Radial carpal bone fractures] Boxers RCB have 3 centres of ossification, can be simple cranial slab, medial cleft or comminuted forms Tx: rigid fixation with compression -- lag screws Prognosis: guarded with respect to athletic function, simple slabs have best prognosis, sagittal fractures more challenging, comminuted fractures are guarded [Carpal hyperextension] Presentation: acute lameness with a history of working or falling, varies with injury from moderate with hyper-extension to non-weight bearing The carpus is normally supported by the short palmar ligaments and the dense **[palmar fibro-cartilage]** Dx: by manipulation and stress radiography to show what its like to standing Injuries may include fracture/luxation and collateral ligament injury (Valgus is medial collateral, varus is lateral collateral) [Antebrachiocarpal joint luxation ] Significant trauma causes complete disruption of the joint capsule and supporting ligaments, including the palmarcarpal fibrocartilage Primary repair is impossible, arthrodesis is required (fusion) and the joint never moves again [Collateral ligament repair]: primary repair of the ligament with locking loop sutures supported by a prosthesis through bone tunnels in the distal radius and radial carpal bone [Carpal arthrodesis (joint fusion) is indicated: ] intractable pain due to DJD irreparable intra-articular fracture Pan- vs partial carpal arthrodesis Partial carpal arthrodesis is indicated only when only the middle or carpometacarpal joints are affected -- beware of strain injuries to the support of the antebrachiocarpal joint Partial carpal arthrodesis may lead to later antebrachiocarpal joint OA and a poor result longer term Principals of arthrodesis 80% of the dogs treated by PCA returned to full or substantial work Post op complications are minimal and dogs are usually back to working normally OCD- shoulder is good, hocks is the WORST Malleolar: collateral ligament origin, these tear off, can luxate the joint Tarsus or hock OCD Most common locations: [Talar ridges], medial and lateral Large breed dogs present **lame** with **effusion** and **dec ROM** as pups Tx options: [surgical removal] of the flap and curettage / forage of the lesion (arthrotomy or arthroscopy) Prognosis for Hock OCD is generally **poor**. Worst for *large and deep* lesions. The joints deteriorate, ROM is lost and DJD ensues, dogs are lame and lameness worsens over time Can be crippling and may necessitate *arthrodesis*, *amputation* or *euthanasia* in very extreme cases. Talar fractures Treat as any articular fracture, must get really good anatomical fixation, require compression POOR prognosis Talo-cural luxation Rare without malleolar fractures, open reduction, temporary pins or ESF Collateral injury/malleolar fractures The ligaments can be torn or the malleolus avulsed, fractured Repair tears with screw/washer Repair avulsions with k-wire tension band Dx collateral injuries: manipulate the hock trying to displace it Numbered tarsal bone fractures Usually working dogs Many can be repaired by lag screw fixation and protect the repair with a cast/splint Intertersal instability Diagnosis by stance, palpation and stress radiographs Treatment is to arthrodese the joint with pin & tension band or plate Prognosis good as talo-crural joint is the most mobile and distal joints are mostly immobile Tarso-metatarsal instability Common injury to working dog, prognosis for working is very good Common calcanean tendon (= Achilles Mechanism) injuries Patient adopts a plantigrade stance Very disabling injury Diagnosis is by palpation -- thickened tendon and abnormal ability to flex the hock whilst maintaining stifle extension What makes up the Achillies mechanism? 5 muscles and 3 tendons -- superficial digital tendon, gastrocnemius tendon and common tendon Complete vs incomplete In a complete the superficial digital flexor tendon is also cut -- typical for [lacerations] In an incomplete the SDF is still intact but the GT and or CTs are torn Incomplete show flexion of the toes with a less plantigrade stance Repair: tendon much be accurately reapposed, locking loop or 3 loop-pully with non-absrobable suture, immobilisation needed to last 6 weeks Metacarpal/tarsal fractures Single or double bone fractures are usually treated **conservatively** in a none-walking cast or splint [Three of four] present a challenge. Internal fixation with miniplates is the most accurate and aids healing but complications can be greater than closed reduction and casting Shoulder -------- **Shoulder diseases** Developmental -- OCD, congenital luxation Traumatic -- Fractures, dislocations bicipital tenosynovitis Inflammatory -- IM arthritis Degenerative -- DJD (OA) Neoplastic **Shoulder OCD** Disorder of endochondral ossification leads to thickened cartilage which is unable to cope with biomechanical loading which results in fissures are flaps (osteochondritis dissecans) Young, rapidly growing dogs of the large and giant breeds, 2/3rds are male Good prognosis and the shoulder is a nice sloppy joint Clinical signs Forelimb lameness Palpation reveals pain during flexions and extension, can have effusion Dogs affected are usually 4-7 months of age Confirmed by radiography **Radiographs:** lateral shoulder, pull forward the leg and look for lesions on the caudal humeral head and joint mice The lesion appears as an area of increased radiolucency, ie black, because cartilage does not absorb xrays as much as bone Flap which comes off joint mouse **Treatment:** Surgical treatment to remove the flap and any joint mice (broken flap) is recommended Arthrotomy or arthroscopy **Principals of treatment:** Use the least invasive technique, gently remove the entire underrun flap and leave verticle edges, do not aggressively currette the lesion itself, Osteostyksis (microcracking) or forage (drilling small holes) to make bed bleed, clot is substrate for fibrocartilage **Trauma -- fractures:** Scapula/spine fractures are treated conservatively with rest or a Velpeau sling unless majorly displaced - plated Neck fractures are stabilised with cross pins or small plates Acromial fx's treated by tension band Glenoid fx's require anatomic reduction as they are intra-articular **Trauma -- supraglenoid tubercle avulsion** The origin of the biceps, fracture usually in skeletally immature large breed dogs Tx: referral case. Lag screw compression or tension band required **Luxation/ dislocation of the shoulder may be congenital or acquired (trauma)** Congenital seen in toy and small breeds, esp Poodles Variable degrees of lameness, in congenital cases may not be dramatic Palpable disparity between acromion and the greater tubercle +/- instability Treatment: poor outcome in congenital, conservative usually satisfactory, traumatic can be managed conservatively. Surgery reserved for repeat luxations and those with intra-articular fractures **Bicipital Tenosynovitis** Difficult to diagnose and treat Injury/inflammation of the tendon of origin of the *biceps brachii* and its *synovial sheath* Injury cannot heal due to constant motion, inflammation becomes chronic Clinical signs: chronic exercise induced lameness, shoulder muscle atrophy, clinical improvement with rest, acute pain on palpation, Positive biceps retraction test **Diagnosis**: contrast radiography (regular is usually normal). Arthroscopy is the method of choice **Treatment**: Conservative therapy is tried first see what makes it worse, remove these activities for 2-3 months Intra-articular methyl-prednisolone + rest, strict reduction of specific activity Surgery recommended for refractory cases, via arthroscopy or arthrotomy -- cut tendon of origin +/- tenodesis Tendonesis: severance of the tendon of origin and Reattachment to the proximal humerus below the intertubercular groove Medial Glenohumeral Ligament Laxity Deceased extension, increased abduction \> 30^0^ abduction angle (above 50 is pathologic) Diagnosis: Arthroscopy (see torn fibres) Treatment \< 45^0^ abduction -- Conservative - Hobbles or brace for 6 weeks, then rehabilitation Treatment 45-65^0^: imbrication/thermal capsulorrhaphy, do not decrease inflammation for 6 weeks postop, only hobbles/brace Treatment \> 65^0^: disruption of the ligament, joint capsule and subscapularis tendon