Open Abdomen Part 2

Fig A- uploaded by Georg F. Weber

The role of IRA B cells in sepsis. During peritoneal infection, Escherichia coli LPS activates innate-like B1a B cells' TLR-4 receptors. After migrating to lymphoid organs, B1a B cells mature into the newly identified IRA B cells. IRA B cells protect against microbial sepsis. 

https://www.researchgate.net/figure/The-role-of-IRA-B-cells-in-sepsis-During-peritoneal-infection-Escherichia-coli-LPS_fig1_257753782

Evidence for open abdomen

Two randomised controlled trials (RCTs) compared open abdomen with closed abdomen in the management of patients with peritoneal sepsis (Robledo et al 2007, van Ruler et al 2007). In one trial, 40 adult patients with severe secondary peritonitis were randomised to receive open abdomen or closed abdomen after intra-peritoneal lavage (Robledo et al 2007). The mortality in patients with open abdomen was 55% compared to 30% in closed abdomen. However, this difference was not statistically significant, nor was there a statistically significant difference in the morbidity (Robledo et al 2007).

In the other trial, 232 adult patients with severe secondary sepsis were randomised to planned relaparotomy (open abdomen with relaparotomy performed every 36-48 hours until the abdomen was clear of sepsis) versus relaparotomy if clinically indicated (closed abdomen with relaparotomy performed only if there was clinical deterioration or lack of clinical improvement with a likely intra-abdominal cause) (van Ruler et al 2007).

After a follow-up period of 12 months, 36% of participants who underwent planned relaparotomy died compared to 29% of participants who underwent relaparotomy if clinically indicated. However, this difference was not statistically significant (van Ruler et al 2007). There were no significant differences in overall complications or the requirement for readmissions between the two groups (van Ruler et al 2007). About 42% of the people in the relaparotomy if clinically indicated group required relaparotomies; the overall number of relaparotomies was fewer in this group. The median length of intensive therapy unit stay (7 vs 11 days, P = 0.001) and hospital stay (27 vs 35 days, P = 0.008) was significantly shorter for people who underwent relaparotomy if clinically indicated, compared to those who received planned relaparotomy (van Ruler et al 2007). Therefore, the use of resources by the relaparotomy if required group was significantly less compared with that for the planned relaparotomy group (van Ruler et al 2007).

There is no evidence to support the use of routine open abdomen management in patients with severe peritonitis.

There have been no RCTs comparing open abdomen with closed abdomen in other settings, including trauma, in which management using open abdomen is used. Therefore, it is not known whether open abdomen is better than closed abdomen in these settings.

Classification of open abdomen

While there are reasons for managing patients with open abdomen (Box 1), the supporting evidence base is not robust. There are several techniques for managing patients with open abdomen. The type of treatment that the patient receives may depend on the reasons for performing open abdomen (Björck et al 2009). There is no universally accepted way of classifying open abdomen. Open abdomen can be classified as follows, based on a consensus meeting in 2009 (Figure 2) (Björck et al 2009):

Figure 2. Classification of open abdomen

• Grade 1A: Clean open abdomen without adherence between bowel and abdominal wall, or fixity (retraction of the abdominal wall).
• Grade 1B: Contaminated open abdomen without adherence or fixity.
• Grade 2A: Clean open abdomen developing adherence or fixity.
• Grade 2B: Contaminated open abdomen developing adherence or fixity.
• Grade 3: Open abdomen complicated by fistula formation.
• Grade 4: Frozen open abdomen with adherent or fixed bowel; unable to close surgically; with or without fistula.

In patients with a frozen abdomen, an adherent or fixed bowel makes it difficult to access the abdominal viscera during abdominal surgery. Classifying the severity of open abdomen will allow comparison of results obtained after different types of treatment of open abdomen. This is the case irrespective of whether treatment differs according to the grade of open abdomen. Determining the grade of open abdomen may also allow selection of the most appropriate treatment for a specific patient.

Management of open abdomen

The management of patients with open abdomen is challenging, and requires a multidisciplinary approach. In contrast to the usual situation where the continuity of the abdominal wall is restored, in open abdomen it is not restored. Patients undergo repeat operations every few days until the condition that precipitated open abdomen is resolved and abdomen closure can be achieved.

Goal of the treatment

The main treatment goals of open abdomen are (Burlew et al 2011, Kafka-Ritsch et al 2012, Kreis et al 2013, Bruhin et al 2014, Fortelny et al 2014):

• To control the source of infection, by a thorough peritoneal lavage and closure of the perforation, or diversion of faeces to the exterior by a stoma.
• To protect the bowel from damage.
• To minimise the adhesions between the bowel and abdominal wall.
• To enable nursing care.
• To allow permanent closure of the wound by bringing the fascial edges together.

Some of these goals are met by temporary abdominal closure. Several techniques are listed in Box 2. The method used for managing open abdomen may vary according to the reason for and severity of open abdomen. For example, in the initial stages of open abdomen, when there is no retraction of fascia, negative pressure wound therapy alone may be sufficient. However, if the indication for open abdomen persists beyond 24 to 72 hours, negative pressure wound therapy may have to be combined with a method to prevent retraction of fascia (Kreis et al 2013).

Box 2. Temporary abdominal closure techniques

Negative pressure wound therapy

• Vacuum pack (self-made).
• Commercial systems.
• May be combined with retention sutured sequential fascial closure or mesh.

Dynamic retention sutures

• May be combined with negative pressure wound therapy.

Wittmann patch (artificial burr)

• May be combined with negative pressure wound therapy.

Bogota bag

• May be combined with negative pressure wound therapy.

Mesh

• May be combined with negative pressure wound therapy.

Zipper

Complete time out activity 3

Bringing the fascial edges together to allow permanent closure of the abdomen is one of the treatment goals in the management of open abdomen. Identify which of the techniques in Box 2 prevent the retraction of the fascia.

Achieving temporary abdominal closure

Different techniques for temporary abdominal closure may be compared in terms of their short and long-term outcomes. Important short-term outcomes that should be used to compare the safety and effectiveness of the different treatments include (Figure 4):

Long-term outcomes that may be used to compare the safety and effectiveness of the different treatments include (Figure 5):

Evidence for temporary closure

There are a few studies of sufficient quality to allow treatments to be directly compared. A systematic review identified that studies did not report the case mix (the number of patients who belonged to the different grades of open abdomen) and did not stratify their results according to the grade of open abdomen (Bruhin et al 2014). Only randomisation allows a true comparison of different treatments and avoids selection bias, regardless of whether the results are stratified by grade of severity.

In non-randomised studies, one cannot be sure whether the differences in the treatment results are because of the treatment used or because of the differences in the types of people who received the treatment. Various methods have been used to adjust for the differences in the type of people who receive the treatment, for example, using matched controls, regression analysis and propensity matched scoring. However, differences resulting from factors other than the treatment that the patient receives remain a problem in non-randomised studies.

Table 1. Results from randomised controlled trials comparing different treatments in the management of open abdomen

Reference	Population, and treatments compared (Number of participants)	Outcomes	Comment
Bee et al (2008)	Adult patients in a trauma centre requiring management with open abdomen; they underwent damage control laparotomy, had massive visceral oedema, or required planned re-exploration. Treatments were negative pressure wound therapy (NPWT) (31) versus mesh (20).	Short-term mortality: 8/31 (26%) NPWT versus 5/20 (25%) mesh. Fistula: 6/31 (19%) NPWT versus 2/20 (10%) mesh. Fascial closure: 9/31 (29%) NPWT versus 5/20 (25%) mesh. Intra-abdominal abscess: 12/31 (39%) NPWT versus 9/20 (45%) mesh.	NPWT was combined with mesh if abdominal closure could not be achieved in 9 days. Three participants were excluded who died within 7 days from the results of fistula, fascial closure, and intra-abdominal abscesses. Such exclusions can bias the results and so these patients were included for calculating the percentages.
Pliakos et al (2010)	Adults requiring open abdomen. Treatments were retention sutured sequential fascial closure (RSSFC) + NPWT (27) versus NPWT (26).	Short-term mortality: 6/27 (22%) RSSFC + NPWT versus 5/26 (19%) NPWT. Fistula: not reported. Fascial closure: 14/15 (93%) RSSFC + NPWT versus 6/15 (40%) NPWT*. Length of hospital stay: 12 days (15 patients) RSSFC + NPWT versus 18 days (15 patients) NPWT*.	Trial participants who were dead before abdominal closure, had<15cm abdominal gap, and had a high morbidity score at first change of device were excluded. As a result, only 30 of 53 randomised participants were included in the analysis. This may cause biased results. All participants were included in calculating the proportion who died. For all other outcomes, only 15 participants were included in each group.
Rencüzoğulları et al (2015)	Patients with abdominal compartment syndrome following trauma or surgery. Treatments were NPWT (20) versus Bogota bag (20).	Short-term mortality: 5/20 (25%) NPWT versus 7/20 (35%) Bogota bag. Fistula: 2/20 (10%) NPWT versus 1/20 (5%) Bogota bag. Fascial closure: not reported. Renal failure: 4/20 (20%) NPWT versus 5/20 (25%) Bogota bag. Sepsis: 2/20 (10%) NPWT versus 4/20 (20%) Bogota bag. Pneumonia: 3/20 (15%) NPWT versus 3/20 (15%) Bogota bag. Myocardial infarction: 1/20 (5%) NPWT versus 0/20 (0%) Bogota bag. Pulmonary emboli: 0/20 (0%) NPWT versus 1/20 (5%) Bogota bag.
*Statistically significant (P<0.05)

There has been no systematic review of RCTs on the different methods of managing open abdomen. There have been three RCTs comparing different treatments in the management of open abdomen. The population, treatments compared, and outcomes reported in these RCTs are listed in Table 1. These trials were all small and were not powered to measure clinically significant differences in the important outcomes – that is the sample size was small and the risk of false negative errors was high.

In such a situation, treatments cannot be considered equivalent on the basis of the lack of statistical significance (for example, the P-value not being less than 0.05) because of the high risk of false negative errors. In the single study that showed statistically significant results (Pliakos et al 2010), a significant proportion of participants were excluded from the analysis, making the results unreliable. Moreover, several important patient outcomes were not reported in these trials. None of the studies reported long-term follow up of participants. Therefore, there is no evidence for any differences in clinical outcomes between the treatments compared from the RCTs.

Table 2. Results from the most recent systematic review

Temporary abdominal closure method	Number of participants (number of studies)	Mortality	Fistula	Fascial closure
Negative pressure wound therapy	1,627 (32)	30%	15%	52%
Negative pressure wound therapy with fascial traction	463 (6)	22%	6%	73%
Dynamic retention sutures	77 (5)	11%	12%	74%
Wittmann patch	128 (1)	19%	2%	93%
Bogota bag	363 (6)	27%	10%	47%
Mesh	583 (8)	34%	17%	34%
Zipper	124 (5)	39%	34%	34%
Loose packing	42 (2)	40%	74%	Not available
Skin only closure	No studies	Not available	Not available	Not available
(Atema et al 2015)

Evidence was sought from non-randomised studies, in the absence of evidence from RCTs. There have been several systematic reviews on different methods of management of open abdomen (Boele van Hensbroek et al 2009, Quyn et al 2012, Navsaria et al 2013, Bruhin et al 2014, Atema et al2015). The results from the most recent of these systematic reviews (Atema et al 2015) are shown in Table 2. This systematic review only included patients who underwent open abdomen management for non-trauma causes and reported on 4,358 patients from 74 studies (Atema et al 2015). The most common method of management reported was negative pressure wound therapy (2,090 patients), and loose packing was the least common method of management reported (42 patients). Skin only closure was not reported in any study.

While Table 2 indicates the frequency of different methods of management of open abdomen, no conclusions can be drawn on the comparative benefits and harms of different methods, because of the different types of patients included in the different studies. However, it is clear from the systematic review that management of open abdomen has a high mortality and morbidity rate.

Complete time out activity 5

• Reflect on how the different techniques used in the management of open abdomen might affect the day-to-day nursing care of the patient.
• Consider how the different techniques used in the management of open abdomen might affect the mobility of the patient? Discuss your deliberations with a colleague.

Learning Points

1. Important short-term outcomes that should be used to compare the safety and effectiveness of the different treatments include: mortality, development of fistulas, other complications, fascial closure, intra-abdominal infection in patients requiring open abdomen management for reasons other than abdominal sepsis, health-related quality of life, length of hospital stay, return to normal activity, return to work, and resource use.
2. Long-term outcomes that may be used to compare the safety and effectiveness of the different treatments include: mortality, health-related quality of life, intestinal obstruction requiring hospital admissions and/or surgical treatment for division of adhesions, ventral hernias requiring surgery, and number of working days lost.

Nursing care

The method of managing open abdomen chosen is likely to have a significant effect on the way that the patient is managed on a day-to-day basis. The abdominal organs are not protected by the abdominal wall in most types of open abdomen management, with the possible exception of mesh repair. Therefore, extreme care should be taken when moving these patients for the purposes of personal hygiene and/or prevention of pressure ulcers. The main issues that nurses should consider when caring for a patient with open abdomen are listed in Box 3.

Box 3. Nursing care of the patient with open abdomen

• Use extreme care when moving patients for the purposes of personal hygiene and/or prevention of pressure ulcers.
• Change wound dressings frequently in response to more frequent soiling of dressings.
• Take care during dressing changes to ensure that the attachments of the bags or mesh, or the suction tube of negative pressure wound therapy are not disturbed.
• Avoid prone positioning as much as possible.
• Monitor fluid balance and nutrition.

Wound dressings are likely to be soiled more frequently in patients with open abdomen than in patients managed with a closed abdomen. Additional care should be taken during these dressing changes to ensure that the attachments of the bags or mesh, or the suction tube of negative pressure wound therapy are not disturbed. The use of suction tubes with negative pressure wound therapy may impair the mobility of the patient.

Patients with open abdomen have an increased sensible fluid loss. The haemodynamic parameters such as pulse rate and blood pressure (and central venous pressure if the patient has a central venous catheter) should be monitored, along with urinary output, to ensure that the hydration of the patient is adequate. Electrolytes should be monitored in the form of blood tests, repeated on a daily basis, or more frequently, if indicated by the patient’s condition. Usually, patients with open abdomen are not allowed to eat; nutrition should be maintained by enteral or parenteral nutrition.

The use of prone positioning in the management of critical care patients is controversial (Kopterides et al 2009). Open abdomen is a relative contraindication for prone positioning of the patient because of the pressure on the abdominal organs during the prone position of a patient who lacks the support of the abdominal wall.

The National Institute for Health and Care Excellence (2013) supported the use of negative pressure wound therapy in the UK; this was on the basis of a literature review. There was no cost-effectiveness analysis to support the use of negative pressure wound therapy for management of open abdomen and their conclusions appear to ignore the bias in the studies resulting from the lack of blinding and post-randomisation drop-outs.

Complete time out activity 6

The main patient outcomes reported in studies on open abdomen were short-term mortality, fistula, abdominal infections, fascial closure and hospital stay. Discuss with your colleagues whether other outcomes should be assessed in such studies. Are there any differences in the outcomes considered as important by different healthcare professionals?

Learning Points

1. The abdominal organs are not protected by the abdominal wall in most types of open abdomen management, with the possible exception of mesh repair, therefore extreme care should be taken when moving these patients for the purposes of personal hygiene and/or prevention of pressure ulcers.
2. Additional care should be taken during dressing changes to ensure that the attachments of the bags or mesh, or the suction tube of negative pressure wound therapy are not disturbed.
3. Patients with open abdomen have an increased sensible fluid loss. The haemodynamic parameters such as pulse rate and blood pressure should be monitored, along with urinary output, to ensure that the hydration of the patient is adequate.

Conclusions

• There is no robust evidence that open abdomen is better than closed abdomen for managing abdominal sepsis and trauma.
• Negative pressure wound therapy appears to be a popular method of management of open abdomen. However, there is no evidence to suggest that it is better than other methods of management of open abdomen. Furthermore, there is no evidence of differences in clinical results between the other methods of management of open abdomen.
• Well-designed RCTs, which include short and long-term patient outcomes, are required to develop an evidence base for practice.
• Nurses caring for patients with open abdomen should be aware of the necessity for care during moving and handling and during dressing changes as well as the importance of monitoring fluid balance and nutrition in these patients.

Acronyms

NHS: National Health Service

NICE: National Institute for Health and Care Excellence

NPWT: negative pressure wound therapy

RCT: randomised controlled trial

RSSFC: retention sutured sequential fascial closure

Glossary

Anastomotic leak: the most significant complication after colorectal surgery, especially after anterior resection. It is a major cause of post-operative mortality and morbidity.

Gastroschisis: a congential defect where the abdominal wall is not completely closed.

Intra-abdominal haemorrhage: bleeding into the peritoneal cavity.

Ischaemia: an inadequate blood supply to an organ or part of the body, especially the cardiac muscles. The condition is often marked by pain and organ dysfunction. Causes of ischaemia include arterial embolism, atherosclerosis, thrombosis and vasoconstriction.

Laparotomy: a surgical incision into the peritoneal cavity to gain access to the abdomen.

Necrotising enterocolitis: an acute inflammatory bowel disorder that occurs primarily in pre-term or low-birth weight neonates, typically within the first two weeks of life.

Pancreatitis: an inflammation of the pancreas.

Perforation: a hole or opening made through the entire thickness of a membrane or other tissue or material.

Ventral hernia: where a loop of bowel protrudes through the abdominal muscles.

Wound dehiscence: the rupture of a wound along a surgical incision.

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1. Open abdomen is a relative contraindication for prone positioning of the patient because of the pressure on the abdominal organs during the prone position of a patient who lacks the support of the abdominal wall.