Principles of perioperative care





Learning outcomes


After studying this chapter you should be able to:


Knowledge criteria





  • List the principles of infection control



  • Describe the appropriate use of blood and blood products



  • Discuss the general pathological principles of postoperative care



  • Describe the principles of fluid–electrolyte balance and wound healing



Clinical competencies





  • Plan perioperative care for a patient undergoing the common gynaecological procedures



  • Recognize normal postoperative course



  • Interpret relevant postoperative investigations



  • Recognize symptoms and signs of common postoperative complications



  • Initiate a management plan for common/serious postoperative complications





Preoperative care


Patient counselling and consent (see also Appendix C )


Selection of the appropriate procedure for the appropriate patient should include detailed counselling and informed consent. The patient should be informed about the proposed procedure and its risks and benefits, adverse events and other procedures that may become necessary, length of hospital stay, anaesthesia, recovery, tissue examination, storage and disposal, use of multimedia in records, teaching, and alternative therapies available, including no treatment. If there are any procedures that the patient would specifically not wish to be performed, this needs to be documented.


Risks should ideally be presented as a frequency or percentage and estimated according to individual risk factors. Consent should be obtained by someone who is capable of performing the procedure or has experience of the procedure and confirmed by the operating or supervising surgeon.


Preoperative assessment


Clinical history and examination


Preoperative screening of medical conditions or risk factors should be followed by clinical examination including cardiovascular and respiratory examination to evaluate fitness for anaesthesia.


Investigations


Preoperative blood investigations include full blood count; urea and electrolytes for screening for renal disease in patients with hypertension, diabetes and in women on diuretics; liver function tests for patients with a history of alcohol abuse or liver disease; group and screen prior to procedures with risk of bleeding and cross match if heavy bleeding is anticipated or antibodies are present. The availability of a cell saver should be considered if significant bleeding is anticipated.


Blood glucose tests and HbA1C are indicated to screen for diabetes and assess diabetic control. Routine coagulation screening is not necessary unless the patient has a known bleeding disorder, or has been on medication that causes anticoagulation. A chest X-ray is indicated for patients with chest disease. A pregnancy test should be undertaken in all women of reproductive age. An electrocardiogram is mandatory preoperatively in patients with cardiac disease, hypertension and advanced age.


Medications


Aspirin should be discontinued 7–10 days before surgery as it inhibits platelet cyclooxygenase irreversibly, so platelet aggregation studies can be abnormal for up to 10 days. Non-steroid anti-inflammatory drugs (NSAIDs) cause inhibition of cyclooxygenase, which is reversible.


Clopidogrel bisulfate, an oral antiplatelet agent, causes a dose-dependent inhibition of platelet aggregation and takes about 5 days after discontinuation for bleeding time to return to normal. Patients on oral anticoagulants need to be converted to low-molecular weight heparin (LMWH). Management of these patients should be undertaken by a multidisciplinary team involving haematologists.


Women with risk factors for venous thromboembolism (VTE) should receive LMWH thromboprophylaxis. The combined oral contraceptive pill should be stopped 4–6 weeks prior to major surgery to minimize the risk of VTE and alternative contraception should be offered. The progesterone-only pill is not known to increase the risk of VTE. Although hormone replacement therapy is a risk factor for postoperative VTE, this risk is small and it is not necessary to stop prior to surgery. On the day of surgery, patients should be advised which of their medications they should take.


Preoperative preparation


Management of anaemia


Iron deficiency anaemia should be treated with iron therapy before surgery. Recombinant erythropoietin (Epo) can be used to increase haemoglobin concentrations. To be effective, iron stores must be adequate and iron should be given before or concurrently with Epo. When significant blood loss is anticipated in women who will not accept blood products, Epo may be used to increase the hemoglobin concentration preoperatively.


Gonadotropin-releasing hormone agonists may be used preoperatively to stop abnormal uterine bleeding and increase hemoglobin concentrations.


Autologous blood donation avoids the risks of human immunodeficiency virus (HIV) or hepatitis infection and transfusion reactions.


Antibiotic prophylaxis


Antibiotic prophylaxis should be administered intravenously before the start of the procedure. In prolonged procedures or where the estimated blood loss is excessive, additional doses should be administered. Co-amoxiclav or cephalosporins with metronidazole are the commonly used antibiotics. For patients with known hypersensitivity, alternative broad-spectrum agents include combinations of clindamycin with gentamicin, ciprofloxacin, or aztreonam, metronidazole with gentamicin, or metronidazole with ciprofloxacin. In patients with known history of MRSA infection or colonization, addition of vancomycin is recommended. Preoperative screening is recommended in women at risk for sexually transmitted infections and antibiotic cover for Chlamydia with doxycycline or azithromycin should be given.


Skin preparation with an antiseptic and a sterile technique reduce the risks of infection. Minor procedures do not require antibiotic prophylaxis.


Management of diabetes


Good glucose control in the perioperative period is important for the prevention of diabetic ketoacidosis and healing and infectious complications. Oral hypoglycaemics should be stopped on the day of surgery and replaced by an insulin sliding scale, except for minor procedures in a well-controlled patient. Type I diabetics should have a sliding scale commenced on the day of surgery.




Intraoperative complications


Regional and general anaesthesia


Complications related to regional and general anaesthesia include fluid overload, electrolyte disturbances and gas embolization.


Local anaesthesia


Serious adverse reactions are uncommon, but they are secondary to inadvertent intravascular injection, excessive dose, and delayed clearance. Central nervous system side effects include mouth tingling, tremor, dizziness, blurred vision, seizures, respiratory depression and apnoea. Cardiovascular side effects are those of myocardial depression (bradycardia and cardiovascular collapse).


The adverse events associated with injectable local anaesthetic agents are reduced by attention to total dosage and avoidance of inadvertent intravascular administration.


Topical agents can also be associated with adverse events, secondary to systemic absorption.


Complications secondary to patient positioning


Acute compartment syndrome


Compartment syndrome in the legs may occur due to lithotomy position when the pressure in the muscle of an osteofascial compartment is increased, causing ischaemia followed by reperfusion, capillary leakage from the ischaemic tissue, and further increase in tissue oedema resulting in neuromuscular compromise and rhabdomyolysis. Leg holders, pneumatic compression stockings, high body mass index and prolonged surgical time are risk factors. Decompression techniques and early physiotherapy may reduce long-term sequelae.


Neurological injury


Injury to motor nerves arising from the lumbosacral plexus (femoral, obturator and sciatic nerves) and the sensory nerves (iliohypogastric, ilioinguinal, genitofemoral, pudendal, femoral, sciatic and lateral femoral cutaneous nerves) can occur with lithotomy position and prolonged operative time.


Femoral neuropathy may occur secondary to excessive hip flexion, abduction and external hip rotation, which contribute to nerve compression. The sciatic and peroneal nerves are fixed at the sciatic notch and neck of the fibula respectively. Flexion of the hip with a straight knee, and excessive external rotation of the thighs cause stretch at these points. The sciatic nerve can be traumatized with excessive hip flexion. The common peroneal nerve is also susceptible to compression injury.


Ideal lithotomy positioning requires moderate flexion of the knee and hip, with limited abduction and external rotation. The surgeons and assistants should avoid leaning on the thigh of the patient.


Haemorrhage


Intraoperative haemorrhage is blood loss of more than 1000 mL or blood loss that requires blood transfusion. Massive haemorrhage is defined as acute loss of more than 25 % of the patient’s blood volume or a loss that requires a lifesaving intervention.


A loss of 30–40 % of the patient’s blood volume may result in cardiovascular instability. More than 40 % blood loss is life threatening. Severe hemorrhage can lead to multiple organ failure and death unless resuscitation takes place within an hour.


The first step is pressure applied to the bleeding area. In laparoscopic surgery, pressure can be applied with an atraumatic laparoscopic grasper. In large vessel bleeding, a laparotomy is usually required.


Diathermy, suturing, or surgical clips can be used to control small vessel bleeding. Vessels should be separated from surrounding structures before ligation, to avoid inadvertent injury.


If initial attempts to arrest bleeding fail, bilateral internal iliac artery ligation should be considered, but only performed by surgeons experienced with this procedure.


Topical haemostatic agents for control of diffuse, low-volume venous bleeding include Gelfoam ® /thrombin (Pfizer), an absorbable gelatin matrix, Surgicel ® (Ethicon), made of oxidized regenerated cellulose, FloSeal ® (Baxter), a haemostatic agent made from human plasma and constituted by mixing gelatin and thrombin and Tisseel ® (Baxter), a mixture of thrombin and highly concentrated human fibrinogen.


The patient’s haemodynamic status should be continuously monitored. Fluid replacement and transfusion of blood and blood products should be considered. Assistance of a second senior gynaecologist and anaesthetist, additional nursing and theatre staff and an additional surgeon with expertise in vascular surgery may be necessary. Blood should be cross matched. Haemoglobin, platelet count, PT and aPTT should be checked. If the PT and aPTT exceed 1.5 times the control value, fresh frozen plasma should also be given. The ratio of red blood cells (RBCs) to fresh frozen plasma should be <2 : 1, as studies on trauma suggest that ratios of 1–1.5 : 1 are associated with reduced mortality. If fibrinogen is low, cryoprecipitate should be given and a haematologist involved.


Platelet transfusion is indicated if the platelet count is less than 50 000/mL. Acid–base balance and plasma calcium and potassium levels should be monitored.


A systolic blood pressure <70 mmHg, acidosis, and hypothermia inhibit clotting enzymes and increase the risk of coagulopathy. Large volumes of fluids and transfusion of packed RBCs dilute the clotting factors and platelets and predispose to coagulopathy. Component therapy is used when there is clinical evidence of coagulopathy or microvascular diffuse bleeding.


If other measures fail to control bleeding, a pressure pack may be left in the pelvis for 48 to 72 hours. A pelvic drain will enable monitoring of continued bleeding. An indwelling urinary catheter allows urine output monitoring.


Ureteric and bladder injury


The incidence of ureteric and bladder injury during major gynecologic surgery is 2–6 per 1000 cases and 3–12 per 1000 cases, respectively.


Risk factors for bladder injury include endometriosis, infection, bladder over distension and adhesions. In cases with adhesions, it is important to use sharp dissection of the bladder during a hysterectomy, as blunt dissection may result in injury. During laparoscopic surgery, the bladder should be empty to avoid injury with the trocars. Lateral rather than suprapubic trocar insertion will reduce the risk of bladder injury. Bladder thermal injury may be delayed, and clinically manifest several days postoperatively.


Small defects less than 1 cm heal spontaneously and do not need to be repaired. A larger injury is closed in two layers using a running absorbable suture. The integrity of the bladder can be assessed by filling the bladder with indigo carmine or methylene blue dye. Ureteric patency is assessed using indigo carmine intravenously to demonstrate dye efflux from both ureters or by ureteric stenting. An indwelling catheter should be inserted for 7–14 days.


Ureteric trauma may be caused by transection, crush injury, devascularization or thermal injury. If ureteric injury is suspected, patency can be evaluated by intraoperative cystoscopy with dye or ureteric stenting. If there is doubt an urologist should be consulted and in case of confirmed injury an end-to-end anastomosis or reimplantation, can be undertaken.


Cystoscopy should be performed intraoperatively where possible after all prolapse or incontinence surgery to rule out bladder or ureteric injury. In undiagnosed ureteric injuries, patients present with symptoms of abdominal pain, fever, haematuria, flank pain, and peritonitis.


Gastrointestinal injury


Gastrointestinal (GI) injury during gynecologic surgery occurs in between 0.05 % and 0.33 % of cases. Intraoperative GI injury has a mortality rate as high as 3.6 %. Injury may occur during Veress needle or trocars insertion, adhesiolysis, tissue dissection, devascularization and electrosurgery. Previous abdominal surgery increases the risk of adhesions. In these cases, laparoscopy should be undertaken using an open (Hassan) technique or entry through the left upper quadrant (Palmer’s point).


If an injury is suspected, the bowel should be examined and a surgeon’s opinion should be sought if in doubt. Unrecognized injuries present 2–4 days postoperatively with nausea, vomiting, abdominal pain and fever.


Veress needle injuries do not usually need to be repaired in the absence of bleeding or a tear. For punctures of the large intestine without tearing, meticulous irrigation of the peritoneal cavity and antibiotic treatment is important, as the large intestine contents have a high bacterial load. Intestinal injury should be repaired in two layers. In extended lacerations, a segmental resection is recommended. Thermal injuries require wide resection due to the risk of tissue necrosis, which may take days to manifest clinically.


Injury to the rectosigmoid colon may be detected by proctosigmoidoscopy.


A diverting colostomy is indicated in extensive colon injuries or injuries involving the mesentery.


Gastric perforation during laparoscopy may occur in cases with prior upper abdominal surgery and an inadvertently gas distended stomach following induction of anaesthesia. Small Veress needle punctures with no bleeding can be treated by irrigation. Larger defects such as trocar injuries require repair in two layers by a surgeon experienced in gastric surgery. The abdominal cavity should be irrigated to remove any gastric contents. Nasogastric suction usually is maintained postoperatively until normal bowel function returns.

Only gold members can continue reading. Log In or Register to continue

Mar 2, 2019 | Posted by in OBSTETRICS | Comments Off on Principles of perioperative care
Premium Wordpress Themes by UFO Themes