Antibiotics versus placebo for prevention of postoperative infection after appendicectomy.

BACKGROUND: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes. OBJECTIVES: This review evaluated the use of antibiotics compared to placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes were described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. The efficacy of different antibiotic regimens were not evaluated. SEARCH STRATEGY: We searched The Cochrane Central Register of Controlled Trials (Cochrane Library 2005 issue 1); Pubmed ; EMBASE; and the Cochrane Colorectal Cancer Group Specialised Register (April 2005). In addition, we manually searched the reference lists of the primary identified trials. SELECTION CRITERIA: We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers. MAIN RESULTS: Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above, although the results were not significant. AUTHORS' CONCLUSIONS: Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy.

BACKGROUND: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes. OBJECTIVES: The objective of this review is to evaluate the use of antibiotics with placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes are described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. This review do not attempt to compare the effect of different regimens. That clinical question is addressed in another review undertaken by Bleuer 1999. SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register (Cochrane Library 2002 issue 4); Pubmed, Embase and the Cochrane Colorectal Cancer Group Specialised Register (Up to October 2002). In addition we manually searched the reference lists of the primary identified trials. SELECTION CRITERIA: We evaluated Randomised Controlled Trials (RCTs) and Controlled Clinical Trials (CCTs) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis, and undergoing appendectomy. Both studies on children and adults were reviewed. The outcome measures of the studies were: Wound infection, intra abdominal abscess, length of stay in hospital, and mortality. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed, recorded and cross-checked by two reviewers. MAIN RESULTS: Forty-five studies including 9576 patients were included in this review. The overall result is that the use of antibiotics is superior to placebo for preventing wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above although the results were not significant. REVIEWER'S CONCLUSIONS: Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration is given pre-, peri- or post-operatively, and could be considered for routine in emergency appendectomies.

Antibiotics versus placebo for prevention of postoperative infection after appendectomy.

BACKGROUND: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes. OBJECTIVES: The objective of this review is to compare the use of antibiotics with placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes are described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. This review do not attempt to compare the effect of different regimens, a clinical question that is addressed in another review undertaken by this Group (CCCG). SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register (Cochrane Library 2000 issue 4), Medline (January 1966 to September 2000), Embase and the Cochrane Colorectal Cancer Group specialised register (September 2000). In addition we manually searched the reference lists of the primary identified trials. SELECTION CRITERIA: Randomised Controlled Trials (RCT) and Controlled Clinical Trials (CCT) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis undergoing appendectomy were evaluated. Both studies on children and adults were reviewed. The outcome measures of the studies were either wound infection, intraabdominal abscess, length of stay in hospital or mortality. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed, recorded and cross-checked by to reviewers. MAIN RESULTS: Forty-four studies including 9298 patients were included in this review. The overall result is that use of antibiotics is superior to placebo for the outcome wound infection and intraabdominal abscess, with no apparant difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above although the results were not significant. REVIEWER'S CONCLUSIONS: Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration are given pre-, per- and post-operatively and could be considered for routine in emergency appendectomies.

Increased collagen deposition in an uncomplicated surgical wound compared to a minimal subcutaneous test wound.

Little information is currently available concerning the relationship between results obtained in humans from surgical test wounds and results from wound models. Therefore, to evaluate human wound healing parameters, tubings of expanded polytetrafluoroethylene were implanted in a subcutaneous test wound in the arm of 47 volunteers and 20 patients undergoing hernia repair. The surgical patients also had implants left in the surgical wound cavity. After 10 days the deposition of collagen in the tubings as expressed by hydroxyproline content was 30% higher in the surgical wound than in the test wound, p < 0.05. The amount of collagen deposited in the tubing within the surgical wound did not correlate with measurements in the test wound, whereas a significant correlation of proline levels was found between the two sites, p < 0.05. Deposition of proline and total protein in the model was equivalent. In both wound types age negatively correlated with levels of protein, but not collagen. The variability of the results was 40% lower in the subcutaneous test wound than in the surgical wound. There was no significant difference in hydroxyproline deposition between the volunteers and the patients undergoing hernia repair. In patients undergoing minor surgery without signs of compromised healing the expanded polytetrafluoroethylene test wound in the arm reflects the deposition of non-collagenous protein, but not collagen, within the surgical wound.

Antibiotics versus placebo for prevention of postoperative infection after appendicectomy.

BACKGROUND: Appendicitis is the most common cause of acute abdominal pain requiring surgical intervention. The cause of appendicitis is unclear and the mechanism of pathogenesis continues to be debated. Despite improved asepsis and surgical techniques, postoperative complications, such as wound infection and intraabdominal abscess, still account for a significant morbidity. Several studies implicate that postoperative infections are reduced by administration of antimicrobial regimes. OBJECTIVES: The objective of this review is to compare the use of antibiotics with placebo or no treatment in patients undergoing appendectomy. Will these patients benefit from antimicrobial prophylaxis? The outcomes are described according to the nature of the appendix, as either simple appendicitis (including the non-infectious stage) and complicated appendicitis. This review do not attempt to compare the effect of different regimens, a clinical question that is addressed in another review undertaken by this Group (CCCG). SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register (Cochrane Library 2000 issue 4), Medline (January 1966 to September 2000), Embase and the Cochrane Colorectal Cancer Group specialised register (September 2000). In addition we manually searched the reference lists of the primary identified trials. SELECTION CRITERIA: Randomised Controlled Trials (RCT) and Controlled Clinical Trials (CCT) in which any antibiotic regime were compared to placebo in patients suspected of having appendicitis undergoing appendectomy were evaluated. Both studies on children and adults were reviewed. The outcome measures of the studies were either wound infection, intraabdominal abscess, length of stay in hospital or mortality. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed, recorded and cross-checked by to reviewers. MAIN RESULTS: Forty-four studies including 9298 patients were included in this review. The overall result is that use of antibiotics is superior to placebo for the outcome wound infection and intraabdominal abscess, with no apparent difference in the nature of the removed appendix. Studies exclusively on children and studies examining topical application reported results in favour to the above although the results were not significant. REVIEWER'S CONCLUSIONS: Antibiotic prophylaxis is effective in the prevention of postoperative complications in appendectomised patients, whether the administration are given pre-, per- and post-operatively and could be considered for routine in emergency appendectomies.

Less collagen production in smokers.

BACKGROUND: An association between smoking and impaired wound healing has been reported in retrospective studies. The smoking status of a surgical patient may be confounded by social and medical parameters. We have evaluated the effect of smoking in a test wound in volunteers, with special reference to a reliable scientific match between smokers and nonsmokers. METHODS: In a prospective open study with blinded assessment, 19 smoking (20 cigarettes/day) and 18 nonsmoking healthy volunteers were matched with respect to baseline characteristics. The deposition of total protein and mature collagen (expressed as hydroxyproline) was assessed in an expanded polytetrafluoroethylene wound healing model implanted subcutaneously for 10 days. RESULTS: The nonsmokers had a 1.8 times higher median amount of hydroxyproline than the smokers (p < 0.01). The deposition of hydroxyproline was negatively correlated with the consumption of tobacco both before (r = -0.44; p < 0.01) and during the study (r = -0.48; p < 0.005). The impairment was specific for the production of collagenous proteins and not other proteins. CONCLUSIONS: The synthesis of subcutaneous collagen in smokers is specifically impeded, indicating an impaired wound-healing process. Because mature collagen is the main determinator of strength of an operative wound, the results support the view that patients should be advised to stop smoking before an operation.

The effect of hyperbaric oxygen on irradiated oral tissues: transmucosal oxygen tension measurements.

PURPOSE: This study measured the effect of hyperbaric oxygen (HBO) treatment on transmucosal oxygen tension in irradiated human oral mucosa. PATIENTS AND METHODS: Ten patients received 30 dives of HBO as part of their treatment for mandibular osteoradionecrosis. A noninvasive, nonheated oxygen electrode was used to measure the tissue surface transmucosal oxygen tension directly on the attached gingiva. Measurements were done before, during, and after HBO treatment. The normal level of gingival surface transmucosal oxygen tension was measured in five healthy volunteers. RESULTS: During HBO treatment, the transmucosal oxygen tension increased significantly after five dives of HBO (P < .05). After 30 dives, the increases were from a mean of 50% to a mean of 86% of the transmucosal oxygen tension of normal healthy gingiva. CONCLUSION: An increase in the transmucosal oxygen tension is based on neo-angiogenesis. Patients with subischemic tissues, such as the study population with postirradiation mucosal and osseous necrosis, therefore may benefit from treatment with HBO.

Reduced collagen accumulation after major surgery.

The preoperative and postoperative wound-healing capacity of 23 patients undergoing elective major abdominal, thoracic or urological surgery was tested objectively by the subcutaneous accumulation of hydroxyproline and proline in an expanded polytetrafluoroethylene (ePTFE) tube. Before scheduled surgery two ePTFE tubes were implanted for removal after 5 and 10 days. This was repeated for each patient immediately after surgery. After 10 days a higher amount of hydroxyproline was measured before than after operation (median 2.91 (range 0.37-14.45) versus 1.45 (range 0.26-6.94) micrograms/cm, P = 0.01)). This decline was significantly higher in the six patients who had a postoperative infection (median 3.02 (range -0.06 to 6.14) versus 0.36 (range -1.56 to 12.60) micrograms/cm, P = 0.02). This study shows that major surgery is associated with impairment of subcutaneous collagen accumulation in a test wound, suggesting diminished systemic wound-healing capacity in such patients.

Gentamicin concentrations in human subcutaneous tissue.

Wound infections frequently originate from the subcutaneous tissue. The effect of gentamicin in subcutaneous tissue has, however, normally been evaluated from concentrations in blood or wound fluid. The aim of the present study was to investigate the pharmacokinetic properties of gentamicin in human subcutaneous adipose tissue by a microdialysis technique. Seven healthy young volunteers each had four microdialysis probes placed in the fat (subcutaneous) layer of the abdominal skin. After the administration of a 240-mg gentamicin intravenous bolus, consecutive measurements of the drug concentrations in serum and subcutaneous interstitial fluid were obtained simultaneously for 6 h. The tissue gentamicin concentration peaked after 10 to 30 min. The peak concentration in the tissue was 6.7 +/- 2.0 mg.liter-1 (standard deviation), equivalent to 39.1% of the peak concentration in serum. The area under the concentration-versus-time curve for the first 6 h in the tissue was 1,281 +/- 390.0) mg.min liter-1, equivalent to 59.7% of the area under the concentration-versus-time curve in serum. It is concluded that the microdialysis technique can be used to make dynamic and quantitative measurements of the gentamicin concentration in human subcutaneous tissue. In this adipose tissue, the peak concentrations of gentamicin were approximately seven times the MIC for Pseudomonas aeruginosa and 33 times the MIC for Staphylococcus aureus after the administration of an intravenous bolus of 240 mg, indicating the presence of sufficient concentrations in the adipose tissue to be effective against common bacteria.

Letters.

LIMITATIONS OF DOPPLER ASSESSMENT TOPICAL USE OF GENTAMICIN.

The wound healing process in surgical patients evaluated by the expanded polytetrafluoroethylene and the polyvinyl alcohol sponge: a comparison with special reference to intrapatient variability.

The aim of this study was to compare two wound healing models in surgical patients with special reference to the intrapatient variability. Two pieces of expanded polytetrafluoroethylene tubing and one perforated silicone tube containing two polyvinyl alcohol sponges were subcutaneously inserted into 28 patients and were removed after 10 (9 to 11) days. The amount of hydroxy-l-proline in two segments of the same piece of expanded polytetrafluoroethylene tubing correlated significantly with each other. Similar results were found for proline. Proline content in each polyvinyl alcohol sponge correlated weakly with each other, whereas no correlation was found between hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same patient. In addition, no correlation was found between leucine in the two adjacent polyvinyl alcohol sponges or between the hydroxy-l-proline/leucine ratio in these same sponges. No concordance could be detected between the averages of hydroxy-l-proline content in the two segments of expanded polytetrafluoroethylene tubing and the hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same person, although an association between the averages of proline in the two pieces of expanded polytetrafluoroethylene tubing and proline content in the two polyvinyl alcohol sponges from the same individual was observed. The measurement error was greater for the polyvinyl alcohol sponges than for the expanded polytetrafluoroethylene tubing implants during the first 10 days after wounding. The expanded polytetrafluoroethylene tubing accumulated 2.5 times more hydroxy-l-proline per length unit than the polyvinyl alcohol sponge. We concluded that the expanded polytetrafluoroethylene implant rather than the polyvinyl alcohol implant is preferred for quantitation of subcutaneous collagen deposition in surgical patients because it accumulates more new tissue and has a lower variability.

[Methods for measurement of wound extent]. / Målemetoder til vurdering af sårstørrelse.

Healing is a biologically complicated process, which is difficult to measure objectively. Several products and pharmaceuticals have been applied to the treatment of both acute and chronic wounds. There are, however, only few well-documented studies of the effect and many recommendations are based on casuistries, undocumented studies or in vitro studies. One of the most prominent problems has been the lack of exact measurements. This article describes the available clinical measurement parameters and discusses their strengths and weaknesses. The following methods of measurement are described: Wound surface area (WSA), wound area (WA), and volume (VOL). A stratification of wounds before measuring is suggested depending on aetiology and form (volume or surface wounds). The most sensitive measure for assessment of wound healing is recommended. From a clinical point of view the transition from a volume to surface wound is not distinct, and therefore WA is recommended as the most relevant measurement during wound healing.

Evaluation of the wound healing potential in human beings from the subcutaneous insertion of expanded polytetrafluoroethylene tubes.

Subcutaneous insertion of expanded polytetrafluoroethylene tubes with local anesthesia constitutes a minimally invasive model permitting quantitative and qualitative studies of the wound healing potential in human beings. Light and electron microscopic examination of these implants in rats showed a normally appearing granulation tissue. The amount of hydroxyproline accumulated in the expanded polytetrafluoroethylene tubes may be assayed and converted to collagen content. In 28 surgical patients, the collagen content increased from 6.6 microg/cm (interquartile range: 5.1 to 9.9) after 5 days to 12.4 microg/cm (7.1 to 16.8) after 10 days (p < 0.05). The median ratio between the higher and lower collagen amount measured in two expanded polytetrafluoroethylene tubes inserted for an identical period within the same patient was 1.25 (1.10 to 1.81). This variability ratio was not related to the amount of collagen accumulated or the duration of implantation. There was a tendency for higher collagen amounts in the middle section than in the ends of the expanded polytetrafluoroethylene tubes, with a median ratio between the two sections equaling 1.12 (0.96 to 1.58); (p > 0.05). No infectious or hemorrhagic complications from the insertion occurred in any of the patients. Increments of collagen deposition with time may be easily assessed by this expanded polytetrafluoroethylene tube model, which is inexpensive and has high patient acceptance. Measurement variability was encountered, which has to be taken into account when designing clinical trials.