How should medical therapy support patients with generalized peritonitis from diverticular perforation before and after surgery?
Considerations
A key component of the first-line management of the septic patient with peritonitis is the administration of intravenous antimicrobial therapy, before and after surgery. Antimicrobial therapy plays a pivotal role in the management of intra-abdominal infections, preventing multiple organ dysfunction caused by the ongoing peritoneal triggers. Indeed, an insufficient or otherwise inadequate antimicrobial regimen is one of the variables more strongly associated with unfavorable outcomes in critically ill patients [
86].
Broad-spectrum antimicrobial therapy, including coverage against anaerobic microorganisms, is needed [
87]. The empirically designed antimicrobial regimen (be it single or combined) is based on the underlying severity of infection, the pathogens presumed to be involved, and the risk factors indicative of major resistance patterns. Subsequent modification of the initial regimen may be possible later, on the basis of culture results (if available) and the patient’s clinical status. Indeed, the pathophysiological changes occurring during sepsis as well as the patient’s immunological status may significantly affect drug disposition in critically ill patients [
88].
It has not yet been established which antimicrobial regimen is the best. A Cochrane systematic review [
89] included 40 studies with 5094 patients and compared 16 different antibiotic regimens. All antibiotics showed equivocal comparability in terms of clinical success. As a consequence, no specific recommendations can be made for first-line treatment. Other factors such as local guidelines and preferences, ease of administration, costs and availability must, therefore, be taken into consideration when deciding on the antibiotic regimen. The most widely recommended dosing regimens (and their modifications according to renal function) are discussed in detail in the WSES position paper [
90].
The spread of antimicrobial resistance is one of the leading public health problems worldwide and has been accelerated by the overuse and misuse of antimicrobial drugs [
91]. According to guidelines, the diagnostic algorithm for a range of bacterial infections comprises a measurement of serum procalcitonin to identify sepsis [
92] and to guide antimicrobial therapy [
93].
Poorly controlled acute postoperative pain is associated with increased morbidity, functional and quality-of-life impairment, delayed recovery time, prolonged duration of analgesic drug use, and higher healthcare costs.
Conventional opioids remain the standard of care for the management of acute postoperative pain; however, the risk of opioid-related adverse events can limit optimal dosing, leading to poor pain control. To this end, multimodal analgesia should be applied [
94] to improve analgesic effect, to reduce the doses of any single agent, and to minimize risks of untoward effects [
95,
96].
Intravenous patient-controlled analgesia (PCA) is recommended over healthcare provider-initiated intermittent bolus dosing of opioids since current evidence shows greater effectiveness and patient satisfaction. Intravenous boluses of opioids might be considered during the first several hours after surgery for faster pain relief and analgesic titration [
97]. Paracetamol, pro-paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended as components of multimodal analgesia. A systematic review found that paracetamol and COX-2 selective and non-selective agents, added to PCA, significantly reduced morphine consumption [
97].
Alarmingly, 4 recent meta-analyses [
98‐
101] found that NSAID use is significantly associated with a higher risk of anastomotic leakage. This effect seems to be molecule-specific (diclofenac is associated with the highest risk) [
101] and class-specific (being non-significant with COX-2 selective agents) [
100,
101]. Furthermore, the risk varies with the duration of the treatment, and it is higher after 3 or more days of NSAID treatment than after 1 or 2 days only [
102]. Although the balance of benefit versus risk (analgesic effect/risk of anastomotic disruption) may be acceptable in elective surgery, perioperative NSAIDs (especially given for more than 48 h) in emergent colorectal surgery should be evaluated carefully and on an individual basis, taking into account the presence of risk factors for anastomotic leakage (i.e. advanced age, malnutrition, severe comorbidities, intraoperative difficulties and complications).
Amongst regional anesthetic techniques, epidural analgesia remains the golden standard for postoperative pain control in patients undergoing open abdominal surgery [
102,
103], allowing for a faster recovery of gastrointestinal transit and reducing the length of hospital stay [
104].
POI has a multifactorial etiology and can deeply affect the patient’s recovery, lengthening hospital stay and increasing costs [
105,
106]. The incidence of POI after colorectal surgery ranges from 15 to 19% [
107,
108] and 60% of patients have a severe clinical presentation [
82]. Intraoperative blood loss, administration of any intravenous opioids in the first 48 h, postoperative epidural analgesia and non-compliance with intraoperative fluid management protocols are predictors of POI [
109].
Although many different options (nasogastric tube, fluid restriction, colloid versus crystalloid combinations, early feeding, prokinetics) are available, management of POI is still a matter of debate, albeit rapidly evolving [
110].
Chewing gum as a form of sham feeding is an inexpensive and well-tolerated means of promoting gastrointestinal motility following major abdominal surgery. A recent meta-analysis [
111] found that the incidence of POI is significantly reduced in patients using chewing gum.
Till now the use of prokinetics in the treatment of POI has been disappointing even if prucalopride, a highly selective 5-HT4-receptor agonist, can shorten POI and improve recovery time, as well as reduce intestinal inflammation [
110].
A meta-analysis [
112], evaluating both the efficacy and safety of the currently available drugs for prevention of POI, concluded that, despite study inconsistency (due to heterogeneity of endpoints) and lack of head-to-head studies, there is enough evidence to recommend the use of alvimopan, a peripherally-acting mu-opioid receptor antagonists (PAMORA) in major gastrointestinal surgery. Two further meta-analyses [
113,
114] confirmed that- after
open abdominal surgery this PAMORA can accelerate recovery of gastrointestinal function, shorten the length of hospital stay, and reduce POI-related morbidity without compromising opioid analgesia, resulting in a cost-saving approach [
115].