Special Considerations in the Postoperative Care of the Cancer Patient





According to the National Cancer Institute, an estimated 1.7 million new cases of cancer were diagnosed in the United States in 2018, and more than 600,000 people died from the disease. In fact, cancer is the leading cause of death in the United States. Cancer mortality is higher among men than women, and when comparing groups based on race/ethnicity and sex, cancer mortality is highest in African American men and the lowest in Asian/Pacific Islander women. There are an estimated 15.5 million cancer survivors in the United States, with this number expected to increase to 20.3 million by 2026.


Because of the significant impact of cancer, there have been new advances in both diagnostic and therapeutic tools for cancer treatment that have allowed the number of patients living with cancer to increase. Intensive chemotherapy regimens and the use of new and more targeted therapeutic drugs have resulted in higher cancer cure rates. In addition, there are new, innovative clinical trials for treatments that may also prolong overall survival. Last, there are a number of drugs and surgical therapies that not only improve quality of life for patients but also extend overall survival. Although these treatments may increase the number of patients living with cancer, they also may lead to severe morbidity and mortality that increase the costs of cancer care. National expenditure for cancer care in the United States in 2017 was $147.3 billion, and in future years costs are likely to increase as the population ages and cancer prevalence increases. Costs are also likely to increase as new and often more expensive treatments are adopted as standards of care. ,


Most cancer patients will have at least one surgical procedure during the continuum of their cancer care. In patients with solid tumor malignancies, more than 75% of those patients will undergo a surgical procedure for cure, and almost 90% will have surgery for other reasons that include diagnostic or palliative procedures, brachytherapy, or surgery unrelated to cancer. The increasing age of patients with cancer, the increasing number of comorbid conditions, and the complexity of cancer care before surgery often affect their perioperative course. Routine perioperative considerations in cancer patients do not differ from those in healthy patients. However, there are special considerations in the perioperative setting that should be considered in cancer patients who undergo surgical resection. These perioperative factors can influence postoperative outcomes. These factors include but are not limited to nutritional status, functional status of the patient, the complex issue of wound healing, and the effects of neoadjuvant and adjuvant therapies. In addition, postoperative factors, including postsurgical pain control and venothromboembolism prophylaxis, are also factors that need to be considered. In this chapter, we will specifically focus on unique considerations in postoperative care in the cancer patient.


Nutrition


Nutritional status is an important factor in cancer treatment and can greatly influence postoperative outcomes. Evolving evidence continues to demonstrate a relationship between nutritional status and various clinical outcomes, including quality of life, the ability to tolerate cancer treatment, and overall survival. Weight loss, which often occurs during the diagnosis and treatment of cancer, has been identified as a significant indicator of malnutrition and can portend a poor prognosis in postsurgical cancer patients. Specifically, malnutrition has been associated with poor performance status, increased frailty, and increased postoperative morbidity. Weight loss alone has been associated with lower tolerance of chemotherapy resulting in shorter duration of treatment in patients with nonmetastatic breast cancer. This correlates to higher recurrence and lower overall survival rates in this patient population.


The stress of surgery increases protein utilization and creates a catabolic state. This can lead to the onset of protein calorie malnutrition that has been associated with delayed wound healing, postoperative pulmonary complications, increased incidence of anastomotic leak, and increased risk of postoperative wound infection. All of the consequences of cancer-associated malnutrition can lead to prolonged hospital length of stay, need for rehabilitation, and increased cost of care.


Perioperative cancer-related malnutrition is related to poor outcomes; therefore it is important to identify nutritional problems early. Historically, serum proteins, such as albumin and prealbumin, have been widely used to determine patients’ nutritional status. However, in the oncologic setting, several nutritional screening tools have been validated and allow for early recognition of cancer patients at nutritional risk who are likely to benefit from dietary support. These tools include the Nutritional Risk Screening 2002 (NRS 2002), the Malnutrition Universal Screening Tool (MUST), the Malnutrition Screening Tool (MST), and the Mini Nutritional Assessment (MNA). Most of these screening tools evaluate clinical and anthropometric data, including height, current and ideal weight, weight loss, rate of weight loss, and body mass index (BMI). Other information, including current treatment regimens, planned nutritional intake, and gastrointestinal disorders, are also frequently assessed.


Preoperative patients at nutritional risk should be promptly identified and referred for comprehensive nutritional assessment prior to surgery. Nutritional intervention should be initiated if malnutrition is present at the time of preoperative evaluation or when nutritional intake is expected to be adequate for more than 7–10 days. For better postoperative outcomes, malnourished patients undergoing elective surgery should receive nutritional support for 10–14 days prior to surgery, even if surgery must be delayed. This nutritional support should be in the form of enteral nutrition, except in patients with poor swallowing function or parenteral nutrition in patients with compromised gastrointestinal (GI) function. ,


Functional Status


For cancer patients, preoperative functional status greatly influences postoperative clinical outcomes. Functional status is a multidimensional concept defined as a patient-oriented health outcome that contains aspects of individual daily functioning, including physical, psychologic, and social factors. One measure of functional status is the Eastern Cooperative Oncology Group (ECOG) Performance Status, a score ranging from 0 (“fully active”) through 3 (“capable of only limited self-care”) to 5 (“dead”). The other scale often used is the Karnofsky scale. This scale ranges from 10 (moribund) to 100 (no limitations). An alternative measure of a patient’s general health is the American Society of Anesthesiologists (ASA) score. This measure of physical status ranges from 1 for a normal healthy patient to 5 for a moribund patient who is not expected to survive surgery.


The postoperative period is associated with a 20%–40% reduction in functional and physiologic capacity. In a study evaluating patients who underwent oncologic abdominal surgery postoperative pulmonary complications, specifically pneumonia, unplanned intubations and respiratory failure occurred most frequently in patients who underwent esophagectomy, with advanced ASA class and with partial and totally dependent functional status. These results underlie the importance of functional status on postoperative outcomes. It is essential in achieving and maintaining functional independence, a common prerequisite for hospital discharge and the ability to independently function.


Prehabilitation


Since we know that functional status can have a big impact on postoperative outcomes, determining methods to improve functional status before surgery is essential to improve postoperative recovery. Prehabilitation has been defined as a strength-training program to increase functional capacity in preparation for stressful events such as a surgical procedure. Prehabilitation was first documented in 1946 in the military, where physical medicine specialists trained men of “poor physique” who needed physical development or restoration. These military recruits were provided with nutrition, physical training, and education to help with the improvement of the patient’s physical status. , In the past 20 years, most of the literature surrounding prehabilitation focuses on joint replacement and cardiac patients demonstrating improved functional status, decreased complications, and improved length of stay in various studies. ,


Prehabilitation in cancer patients is an emerging field. It has become more common to treat solid tumor cancers (e.g., breast, gynecologic, pancreas, colorectal, and genitourinary) with neoadjuvant chemotherapy or radiation, or both, prior to surgical resection. Because of the risk of deconditioning and subsequent functional decline while receiving neoadjuvant treatment, the preoperative period is the prime time to intervene with a mobility program and structured exercise to circumvent and prevent some of the sequelae of treatment and improve postoperative outcomes. Patients who do not receive prehabilitation have a risk for slower recovery of functional capacity after surgery as demonstrated in Fig. 37.1 .




Fig. 37.1


Cancer continuum and prehabilitation.


Wound Healing


Postsurgical wound healing in cancer patients is a complex process that can be influenced by myelosuppression; malignancy; and treatment-related immunosuppression, including steroids, neoadjuvant and adjuvant chemotherapy, and radiation. Normal wound healing requires an orderly progression of complex processes that result in restoration of the anatomic and functional integrity of tissues. This process involves a series of sequential and overlapping cellular activities, driven by growth factors and cytokines that promote the migration and recruitment of specific cells to the site of the tissue injury. Normal wound healing involves major cell types, including polymorphonuclear leukocytes (PMN), platelets, macrophages, keratinocytes, and fibroblasts.


Table 37.1 provides a summary of the phases of wound healing: inflammation, proliferation, and maturation. The inflammatory phase lasts 4–6 days from surgery and is characterized by the cellular inflammatory processes. The proliferative phase lasts from 4–14 days after injury. Cytokines and growth factors secreted by platelets and macrophages from the inflammatory phase drive angiogenesis, fibroplasia, collagen synthesis, granulation tissue formation, and reepithelization. Maturation occurs from 8 days to 1 year postsurgery, and the focus is on collagen deposition and remodeling. At 1 year, the tensile strength of skin and fascial wounds is 80%–85% of unwounded tissue, essentially never attaining the same tensile strength as prior to surgery. Along the same lines, GI wounds attain appropriately 65% of wounded tensile strength at 1 year.



Table 37.1

Phases of Wound Healing
























































































Phase of Wound Healing Days Post Wound Healing Major Cell Types Major Growth Factors Wound Healing Processes
Inflammatory phase 4–6 days Platelets Transforming growth factor β (TGF-β) Homeostasis
b-Fibroblast growth factor (bFGF), Wound epithelization
Macrophages Epidermal growth factor receptor
(EGFR)
T lymphocytes Interleukin (IL)-2 (IL-2) Tissue debridement
Polymorphonuclear leukocytes (PMNs) IL-1 Infection prevention
Proliferation 4–14 days Platelets IL-1 Angiogenesis
Macrophages IL-6 Granulation tissue formation
Keratinocytes Tumor necrosis factor-α (TNF-α) Collagen synthesis
Transforming growth factor α (TGF-α), Organized collagen deposition
Fibroblasts Vascular endothelial growth factor
(VEGF)
Maturation 8 days to 1 year Platelets Fibroblast growth factor (bFGF) Increased wound tensile strength
Macrophages Epidermal growth factor (EGF)
Keratinocytes


Treatment of cancer patients often involves multiple modalities, all of which impact their ability to heal wounds. Within the spectrum of cancer treatment, surgery is often employed for curative purposes by eradication or tumor debulking in anticipation of further treatment. The timing of surgical intervention in relation to radio- or chemotherapy is fundamentally important in recovery and wound healing.


Adjuvant Therapy


Radiation Therapy


Radiation therapy is based on the ability of target tissues to absorb energy and can cause damage to vital structures, including cellular DNA. Wound healing complications are worsened by radiation exposure to skin, connective tissue, and underlying vasculature. Clinically, prior radiation exposure has been demonstrated to increase the incidence of flap failures, fistulas, wound necrosis, delayed or prolonged healing, and infection. , Of note, wound healing is most affected by ionizing radiation when surgery is performed 6 months or more after radiation therapy. During the intervening period, the irradiated tissue becomes hypoxic, and fibroblasts become dysfunctional, which can lead to increased wound-healing complications. Consequently, the timing of surgery in reference to proposed radiotherapy can have a significant impact on the outcome of wounds.


Fewer wound complications have been demonstrated when radiation is given in the postoperative setting. Because acute radiation exposure delays wound healing due to effects on the skin, connective tissue, and vasculature, it is logical to conclude that the effects on healing wounds can be minimized if the majority of wound healing has occurred prior to radiation treatment. Treatments should be initiated within 6 to 8 weeks postoperatively, as the benefits of radiotherapy may decrease if treatments are delayed further.


Chemotherapy


Chemotherapy, alone or as a part of treatment regimen with surgery and radiation, is a fundamental treatment of cancer. Chemotherapy specifically targets proliferating cells by interfering with specific components of the cell cycle. Although chemotherapeutic agents preferentially target rapidly dividing cells, any tissue can be affected by these treatments. Macrophages and fibroblasts involved in wound healing are just as susceptible to these effects as cancer cells. Consequently, the timing of surgical intervention as well as the specific agents prescribed should be considered in wound healing in cancer patients.


Typically, chemotherapy is delayed by 2 weeks postsurgery, and the optimal timing of perioperative treatment using various antineoplastic agents remains unknown. Individual cytotoxic agent classes and the potential adverse effects on wound healing are discussed in Table 37.2 .


Jun 26, 2022 | Posted by in ANESTHESIA | Comments Off on Special Considerations in the Postoperative Care of the Cancer Patient
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