Ankur S. Narain, Fady Y. Hijji, Benjamin Khechen, Brittany E. Haws, Philip K. Louie, Daniel D. Bohl, and Kern Singh

25.1 Gastrointestinal Complications

25.1.1 Postoperative Nausea and Vomiting

• Background and etiology:

– Incidence rates approach 20 to 30% of patients undergoing spinal procedures.

– Risk factors include the following:

∘ Patient factors: female gender, history of motion sickness or postoperative nausea and vomiting (PONV), nonsmokers, younger age.

∘ Surgical factors: extended duration of anesthesia.

∘ Pharmacologic factors: postoperative opioids.

• Management:

– Prevention:

∘ Avoid general anesthesia and volatile anesthetics if possible.

∘ Limit opioid use.

∘ Promote adequate hydration.

– Treatment:

∘ Antiemetics.

▪ 5-HT3 receptor antagonists, neurokinin 1 (Nk-1) receptor antagonists, corticosteroids, butyrophenones, antihistamines, anticholinergics, phenothiazines.

▪ Use of dopamine and serotonin antagonist medication is associated with QT prolongation; monitoring of echocardiogram (ECG) for QT interval and presence of arrhythmias is recommended.

25.1.2 Dysphagia

• Background and etiology:

– Incidence rate approaching 71% following cervical procedures; most common in the first postoperative week.

– Risk factors include the following:

∘ Patient factors: female gender, older age.

∘ Surgical factors: multilevel procedures, revision procedures, procedures involving lower cervical levels (C4–C6).

– Etiology is multifactorial and may involve manipulation of esophageal tissue during surgery, hardware displacement, esophageal perforation, retropharyngeal abscesses, or neural injury.

– Reflexive coughing.

– Difficulty swallowing food or drink with leakage.

– Risk for aspiration and possible pneumonia.

• Clinical evaluation:

– Bedside swallowing test.

– Speech/language pathology consultation.

• Radiographic evaluation:

– Cervical radiographs: to evaluate for structural etiologies.

– Videofluoroscopic/modified barium swallow study: allows for evaluation of the pharynx and esophagus:

∘ Soft-tissue swelling with displacement of the esophagus is the most common finding.

∘ Can additionally evaluate for hardware failure.

• Management:

– Prevention:

∘ Avoidance of prolonged operative time.

∘ Intermittent relaxation of self-retaining retractors and partial deflation of the endotracheal cuff once retractors are in place.

∘ Instrumentation modifications (anchored spacer, smaller cervical plates).

– Treatment:

∘ Nothing by mouth (NPO) or restricted dietary status:

▪ Consider nasogastric (NG) or percutaneous endoscopic gastrostomy (PEG) tube placement if severe dysfunction with aspiration risk and nutritional deficits is present.

∘ Behavioral modifications: postural changes, swallowing maneuvers.

25.1.3 Postoperative Ileus

• Background and etiology:

– Incidence rate of 3.5% after elective spinal procedures (most common after anterior lumbar and lateral retroperitoneal procedures).

– Risk factors include the following:

∘ Patient factors: older age, male gender, previous opioid use, history of gastroesophageal reflux disease (GERD), history of abdominal surgery.

∘ Surgical factors: anterior or lateral surgical approaches.

– Etiology involves failure of peristalsis due to a pathologic response by the gastrointestinal (GI) tract to surgical manipulation and tissue trauma:

∘ Underlying sepsis and electrolyte abnormalities (hypokalemia, hyponatremia, and hypomagnesemia) may worsen ileus.

• Presentation:

– Pain, nausea, vomiting, abdominal distention, inability to pass flatus or stool.

• Radiographic evaluation:

– Abdominal radiographs:

∘ Identify possible bowel distention or transition points indicative of mechanical obstruction.

∘ Evaluate for mechanical obstruction or bowel injury.

• Management:

– Prevention:

∘ Limit bowel manipulation.

∘ Minimize narcotic consumption.

– Treatment:

∘ Place patient NPO for bowel rest.

∘ Administer intravenous (IV) fluids for electrolyte correction.

∘ Laxatives and slow diet advancement as tolerated.

∘ For patients with vomiting and distention, a nasogastric tube may provide symptomatic relief; however, there is no conclusive evidence that nasogastric tubes facilitate resolution of ileus.

25.2 Pulmonary and Respiratory Complications

25.2.1 Airway Compromise and Reintubation

• Background and etiology:

– Incidence approaching 6.1% of patients undergoing cervical spine surgery.

– Risk factors include the following:

∘ Patient factors: morbid obesity, obstructive sleep apnea, history of pulmonary disease, low preoperative hematocrit, high serum creatinine.

∘ Surgical factors: exposures involving more than three vertebral bodies, blood loss greater than 300 mL, exposures of C2–C4, operative time greater than 5 hours, anteroposterior approach.

– Etiologies include laryngopharynx and prevertebral soft-tissue edema, hematoma, cerebrospinal fluid (CSF) leaks, or hardware dislodgement.

∘ Presentation after 12 hours postoperatively is associated with airway edema.

∘ Delayed presentation after 72 hours postoperatively is associated with hematoma, CSF leaks, hardware failure.

• Presentation:

– Dyspnea, dysphonia.

– Can progress to stridor, cyanosis.

– Increased risk of aspiration.

• Clinical evaluation:

– Arterial blood gases demonstrate hypercarbia and hypoxia.

• Radiographic evaluation:

– Plain radiographs and CT scan:

∘ Lateral views often demonstrate prevertebral soft-tissue swelling.

• Management:

– Prevention:

∘ In high-risk patients, consider delayed extubation with postoperative intensive care unit (ICU) admission.

∘ Emergent intubation is required if there is evidence of airway compromise.

25.2.2 Pneumonia

• Background and etiology:

– Incidence ranges from 0.45 to 1.05% depending on surgical location.

– Risk factors include the following:

∘ Cervical procedures: Older age, chronic obstructive pulmonary disease (COPD), increased operative time, dependent functional status.

∘ Lumbar procedures: COPD, diabetes, increased number of operative levels, steroid use.

– Etiology is multifactorial:

∘ Endotracheal intubation can lead to mini-aspirations.

∘ Postoperative atelectasis reduces air movement.

∘ Postoperative dysphagia poses an additional aspiration risk.

• Presentation:

– Fever, dyspnea, productive cough often presenting postoperative day 3 (POD3) or later.

– Associated with higher rates of sepsis, mortality, and readmission.

• Clinical evaluation:

– White blood cells (WBCs).

– Sputum culture.

• Radiographic evaluation:

– Chest radiography: pattern of infiltrate can help determine etiology:

∘ Lobar infiltrates are associated with bacterial sources.

∘ Diffuse, interstitial infiltrates are associated with viral sources.

∘ Infiltrates in dependent areas are associated with aspiration:

▪ If patients are upright: inferior lung segments.

▪ If patients are supine: posterior lung segments.

– CT scan: allows for detailed evaluation:

▪ Detection of complications such as pleural effusions or abscess formation.

• Management:

– Prevention:

∘ Elevation of head of bed to 30 degrees and sitting up for all meals to prevent aspiration.

∘ Oral hygiene.

∘ Pulmonary rehabilitation with incentive spirometry to prevent atelectasis.

∘ Adequate analgesia.

∘ Supervised ambulation.

– Treatment:

∘ Antibiotics.