Peritoneal Surgery

Jeffrey A. Norton MD¹

Harry A. Oberhelman MD, FACS¹

Martin S. Angst MD²

¹SURGEONS

²ANESTHESIOLOGIST

EXPLORATORY OR STAGING LAPAROTOMY

SURGICAL CONSIDERATIONS

Description: Exploratory laparotomy is indicated primarily in patients suffering abdominal trauma or other acute abdominal catastrophes. It is important that a thorough and systematic intraabdominal examination be carried out to prevent missing significant injuries (e.g., ruptured duodenum or transected pancreas). Any active bleeding should be controlled prior to a systematic examination. Other indications for laparotomy include certain patients with fever of undetermined origin or those in whom a specific diagnosis cannot be made, or for staging of selected patients with Hodgkin’s disease. A staging laparotomy (Fig. 7.9-1) consists of splenectomy, wedge and needle biopsies of both lobes of the liver, and biopsies of the periaortic, celiac, mesenteric, and portahepatic lymph nodes. In young women, suturing (pexing) the ovaries in the midline protects them from radiation. Indications for staging in Hodgkin’s disease and lymphomas vary from institution to institution, but PET /CT scans have limited their use.

Basically, the procedure begins with a midline abdominal incision; then the abdomen is explored, and both needle and wedge biopsies of the liver may be performed. The spleen may be removed by incising the lateral peritoneal attachment and delivering the spleen into the wound. The short gastric vessels are cut and ligated and the splenic vessels exposed. These are cut individually and ligated, and the spleen is removed. Paraaortic nodes are exposed through a left paraaortic incision in the retroperitoneum and removed for biopsy. Lymph channels are clipped to prevent lymphatic leakage. The nodes dissected extend to the inferior margin of the duodenum. It may be necessary to cross the aorta and biopsy any enlarged nodes on the right side. More recently, laparoscopy is being performed for staging of certain intraabdominal malignancies (e.g., pancreatic and gastric cancer); however, its use has decreased with improved multiphasic CT scans.

Usual preop diagnosis: Abdominal trauma; Hodgkin’s disease or other lymphomas

Figure 7.9-1. Staging laparotomy. (Reproduced with permission from Scott-Conner CEH, Dawson DL: Operative Anatomy, 2nd edition. Lippincott Williams & Wilkins, Philadelphia: 2003.)

▪ SUMMARY OF PROCEDURES

	Staging Laparotomy	Exploratory Laparotomy
Position	Supine	⇚
Incision	Midline abdominal	⇚ or transverse
Special instrumentation	Abdominal retractor	⇚
Unique considerations	Ovarian pexy	Careful monitoring of VS in trauma patients
Antibiotics	Cefoxitin 1-2 g iv	Cefazolin iv 1-2 g
VTE prophylaxis	Heparin 5000 units sq	⇚
Surgical time	1.5-2 h	Variable, 1-2 H&Plus;
Closing considerations	Splenic bed hemostasis	Hemostasis
EBL	100-200 mL	Variable, 200-500 mL
Postop care	± NG decompression; PACU → ward	ICU for trauma patients
Mortality	< 1%	2-5%
Morbidity	Prolonged ileus: 10-15% Pulmonary complications: 5-10% Wound infection: 2-3% Small bowel obstruction: 1% Intraperitoneal bleeding: < 1%	⇚ Atelectasis: 5-10% Wound infection: 5-10% Hemorrhage: 1-3% Pneumonia: < 1%
Pain score	6-8	6-8

ANESTHETIC CONSIDERATIONS

(Procedures covered: exploratory/staging laparotomy that is not trauma-related; splenectomy)

PREOPERATIVE

Typically, nongynecologic patients presenting for staging laparotomy (which may include splenectomy) have Hodgkin’s disease, or other lymphomatous or cancerous disorders. Apart from the primary disease, these patients are often in reasonably good health and will not have had radiation or chemotherapy before the staging laparotomy. Patients presenting for splenectomy may be divided into two less healthy groups: (a) trauma patients (whose management is described in Trauma Surgery, p. 751) and (b) a more complex group with myeloproliferative disorders
and other varieties of hypersplenism. The periop management of these two groups is more complicated. The latter group may have received chemotherapy and/or radiation therapy, which may affect a variety of organ systems. It is incumbent on the anesthesiologist to be aware of the periop implications of these adjunctive treatments. The actual extent of a staging or exploratory laparotomy can vary substantially. A good understanding of the surgeon’s plan and its inherent risks (e.g., removing tumor in close proximity to a major blood vessel) is crucial for providing adequate anesthesia care.

Respiratory	Patients who have splenomegaly may have a degree of left lower lobe atelectasis and compromised ventilation 2° intraabdominal pathology: ↓ FRC → ↑ A-a gradient + ↓ PaO₂. This should be evaluated by physical exam. Some may have been treated with chemotherapeutic agents (e.g., bleomycin at a total dose > 200 mg/m²) that cause pulmonary pathology including fibrosis. Toxic drug effects are potentiated by smoking, XRT, and high FiO₂. Tests: CXR, PFTs, and ABG as clinically indicated
Cardiovascular	Patients with systemic disease requiring splenectomy may be chronically ill and have ↓ cardiovascular reserve. Patients who have received certain chemotherapeutic agents (e.g., doxorubicin at a dose > 550 mg/m²) may suffer from cardiotoxic side effects that can be worsened by XRT. Manifestations include CHF and dysrhythmias. Tests: ECG, ECHO, and stress test as clinically indicated
Neurological	Patients may have neurological deficits from receiving certain chemotherapeutic agents (e.g., peripheral neuropathies caused by vinblastine and cisplatin or CNS pathology caused by 5-fluorouracil and mithramycin). Evidence of neurologic dysfunction should be documented in the preop evaluation.
Hematologic	Patients are likely to present with splenomegaly 2° hematologic disease (e.g., Hodgkin’s disease, non-Hodgkin’s lymphoma, chronic leukemia, myeloid metaplasia, thrombotic thrombocytopenic purpura, idiopathic autoimmune hemolytic anemia, and sickle cell disease). Cytopenia is very common. Preop replacement of platelets should be considered in patients with severe thrombocytopenia. However, the effectiveness of preop platelet replacement may be limited in patients with hypersplenism because transfused platelets are mostly sequestrated by the spleen. Myelosuppression should be anticipated in all patients receiving active chemotherapy. Tests: CBC
Hepatic	Some chemotherapeutic agents (e.g., methotrexate and mithramycin) may be hepatotoxic. Evaluation of LFTs should be considered in patients at risk. Tests: LFTs including INR
Renal	Some chemotherapeutic drugs (e.g., methotrexate and cisplatin) are nephrotoxic, and patients may present with impaired renal function. Tests: BUN, creatinine and electrolytes
Laboratory	Other tests as indicated from H&P
Premedication	Consider midazolam 1-2 mg iv. In patients with suspected gastrointestinal stasis the use of full-stomach precautions should be considered (see p. B-5) to minimize the risk of pulmonary aspiration. A supplemental intravenous steroid dose (e.g., 25-100 mg hydrocortisone) should be considered in patients receiving preop corticosteroids as part of their chemotherapeutic regimen.

INTRAOPERATIVE

Anesthetic technique: GETA ± epidural for postop analgesia. If postop epidural analgesia is planned, placement of catheter prior to anesthetic induction is helpful to establish correct placement in the epidural space (accomplished by injecting 1-2% lidocaine (50-100 mg) via the epidural catheter to elicit a segmental block). The use of epidural anesthetic techniques for postoperative pain control in patients undergoing major, nonvascular abdominal surgery has been shown to provide superior pain control compared with IV-PCA. However, adequate pain control can be achieved with the use of IV-PCA.

Induction	Standard induction (see p. B-2) except in patients at risk for pulmonary aspiration, who require a rapid-sequence induction (see p. B-5).
Maintenance	Standard maintenance (see p. B-3). High inspired O₂ concentrations (> 30%) may aggravate chemotherapy-induced (e.g., bleomycin) lung injuries. Combined epidural/GA: The epidural catheter ideally is placed at a level corresponding to the surgical site (generally low to mid-thoracic). This allows the use of both lipophilic and hydrophilic drugs at the lowest possible dose, adds flexibility to the anesthesiologist’s choice of agents, and minimizes the likelihood of side effects. A continuous infusion (after an initial bolus dose) is the preferred mode of administering epidural local anesthetics because satisfactory analgesia can be achieved with less fluctuations in BP. Lower concentrations of bupivacaine (0.125-0.25%) can be infused to provide supplemental analgesia, whereas higher concentrations (0.5%) may improve surgical conditions (complete sensory and motor block). The infusion rate is contingent on the desired segmental spread, but often ranges between 5 and 10 mL/h. Lipophilic opiods (e.g., fentanyl) can effectively be given by continuous infusion. Longeracting hydrophilic opioids (e.g., hydromorphone 0.4 mg or morphine 2 mg for an epidural placement at the lower to mid-thoracic spine) can be injected as a bolus along with the initial bolus dose of a local anesthetic. However, hydrophilic opioids tend to spread rostrally within the intrathecal space and may cause sedation and respiratory depression if dosed too aggressively. Vulnerable patients include the elderly, patients with obstructive airway disease, and patients suffering from obesity. The use of epidural local anesthetics is associated with sympatholysis, and ↓ BP has to be anticipated. Critical ↓ BP is treated with fluids iv and/or vasopressors (e.g., ephedrine 5-10 mg iv). In patients undergoing a surgical procedure with a significant risk for major bleeding, it is prudent to delay administration of epidural local anesthetics until the critical part of surgery has been completed. Systemic sedatives (e.g., opiates and benzodiazepines) should be minimized as they increase the likelihood of postop respiratory depression. Low-dose ketamine: If the placement of an epidural catheter is not an option, the use of a low-dose ketamine iv infusion may be considered as an adjuvant analgesic regimen (e.g., 0.5 mg/kg bolus before surgical incision, followed by an infusion of 0.2 mg/kg/h that is stopped 30 min before the end of surgery). Low-dose ketamine provides opioid-sparing effects (30-50%), reduces postop pain, decreases the incidence of opioid-mediated side effects, reduces wound hyperalgesia, and may decrease the development of chronic pain after surgery. Escalating ketamine doses beyond 30 mg/d is not associated with increased opioid-sparing effects. The risk for the occurrence of psychomimetic side effects appears to be low in patients undergoing general anesthesia. Gabapentin/pregabalin: Single-dose administration of 600-1200 mg gabapentin or 150-300 mg pregabalin before surgery should be considered in patients not eligible for an epidural anesthetic technique. Gabapentin and pregabalin provide opioid-sparing effects (30-50%), reduce postop pain, somewhat lower the incidence of opioid-mediated side effects, and may decrease the development of chronic pain after surgery. Gabapentin and pregabalin can cause postop sedation. However, available data suggest that pronounced sedation only occurs in a small fraction of patients (e.g., frail and elderly). Nonsteroidal anti-inflammatory drugs and acetaminophen: Perioperative administration of nonselective NSAIDs, COX-2-selective NSAIDs and acetaminophen is associated with moderate opioid-sparing effects. Overall, NSAIDs seem to be somewhat more effective than acetaminophen, and only NSAIDs have conclusively been shown to reduce opioid-mediated side effects. Whether aggressive dosing with iv acetaminophen (1 g q 6 h) will provide additional benefits has not been established. Potential benefits of adding NSAIDs need to be balanced against the risk of drug-related side effects including bleeding and renal failure.
Emergence	Most patients can be extubated at the end of surgery. Patients undergoing extensive surgery with major fluid shifts may require prolonged intubation until cardiovascular stability and sufficient reduction of soft-tissue edema (compromised airway) is achieved.
Blood and fluid requirements	IV: 14-16 ga × 1-2 Anticipate large fluid loss IV: 14-16 ga × 1-2 Warm fluids T&C or T&S	Potential for major blood loss. In patients with difficult iv access, postinduction placement of additional access is prudent. In splenectomy patients with hypersplenism, Plt transfusion is best given after ligation of the splenic vessel (avoid sequestration). Intraoperative fluid therapy should be titrated to a patient’s particular needs (adequate peripheral perfusion, urine output > 0.5 mL/kg/h, no base deficit). Overly generous intraoperative fluid administration may be associated with postoperative morbidity (e.g., delayed recovery of bowl function) and extended hospital stay.
Monitoring	Standard monitors (see p. B-1). UO ± Arterial line ± CVP (large volume shifts, need for vaso-active drugs, postop care) ± TEE (assessment of volume status)	Others as indicated by patient’s status. To prevent hypothermia during long operations, use warming blanket(s), consider heated humidifier and warming room temperature. Place an arterial line in patients with hemodynamic instability or those at risk for significant intraop bleeding. Availability of a rapid infusion device for delivery of IV fluids at body temperature should be considered in patients at risk for large blood loss. Consider CVP for guiding fluid management, particularly in patients with concomitant cardiovascular disease.
Positioning	[check mark] and pad pressure points [check mark] eyes
Complications	Unexpected bleeding	Plt transfusion may be necessary.

POSTOPERATIVE

Complications

Bleeding

Atelectasis (usually left lower lobe)

PONV (see p. B-6)

VTE (see p. B-8)

Patient should be recovered in ICU or hospital ward that is accustomed to treating side effects of epidural local anesthetics and opiates (e.g., arterial hypotension, respiratory depression, breakthrough pain, nausea, pruritus).

Pain management

Epidural analgesia PCA (see p. C-3).

Postop pain control with an epidural rather than a PCA regimen is superior in patients undergoing major abdominal surgery. In high-risk patients with pulmonary impairment an epidural regimen may reduce the incidence of respiratory failure. The use of epidural (or systemic) local anesthetic can speed up bowel recovery and reduce hospital length of stay. The improvement of other major clinical outcomes (e.g., cardiovascular) has not yet been demonstrated convincingly in patients undergoing nonvascular abdominal surgery.

Tests

CXR, if CVP placed perioperatively CBC