Decompressive laparotomy for abdominal compartment syndrome.

BACKGROUND: The effect of decompressive laparotomy on outcomes in patients with abdominal compartment syndrome has been poorly investigated. The aim of this prospective cohort study was to describe the effect of decompressive laparotomy for abdominal compartment syndrome on organ function and outcomes. METHODS: This was a prospective cohort study in adult patients who underwent decompressive laparotomy for abdominal compartment syndrome. The primary endpoints were 28-day and 1-year all-cause mortality. Changes in intra-abdominal pressure (IAP) and organ function, and laparotomy-related morbidity were secondary endpoints. RESULTS: Thirty-three patients were included in the study (20 men). Twenty-seven patients were surgical admissions treated for abdominal conditions. The median (i.q.r.) Acute Physiology And Chronic Health Evaluation (APACHE) II score was 26 (20-32). Median IAP was 23 (21-27) mmHg before decompressive laparotomy, decreasing to 12 (9-15), 13 (8-17), 12 (9-15) and 12 (9-14) mmHg after 2, 6, 24 and 72 h. Decompressive laparotomy significantly improved oxygenation and urinary output. Survivors showed improvement in organ function scores, but non-survivors did not. Fourteen complications related to the procedure developed in eight of the 33 patients. The abdomen could be closed primarily in 18 patients. The overall 28-day mortality rate was 36 per cent (12 of 33), which increased to 55 per cent (18 patients) at 1 year. Non-survivors were no different from survivors, except that they tended to be older and on mechanical ventilation. CONCLUSION: Decompressive laparotomy reduced IAP and had an immediate effect on organ function. It should be considered in patients with abdominal compartment syndrome.

Intra-abdominal hypertension and the abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome

PURPOSE: To update the World Society of the Abdominal Compartment Syndrome (WSACS) consensus definitions and management statements relating to intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS). METHODS: We conducted systematic or structured reviews to identify relevant studies relating to IAH or ACS. Updated consensus definitions and management statements were then derived using a modified Delphi method and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines, respectively. Quality of evidence was graded from high (A) to very low (D) and management statements from strong RECOMMENDATIONS (desirable effects clearly outweigh potential undesirable ones) to weaker SUGGESTIONS (potential risks and benefits of the intervention are less clear). RESULTS: In addition to reviewing the consensus definitions proposed in 2006, the WSACS defined the open abdomen, lateralization of the abdominal musculature, polycompartment syndrome, and abdominal compliance, and proposed an open abdomen classification system. RECOMMENDATIONS included intra-abdominal pressure (IAP) measurement, avoidance of sustained IAH, protocolized IAP monitoring and management, decompressive laparotomy for overt ACS, and negative pressure wound therapy and efforts to achieve same-hospital-stay fascial closure among patients with an open abdomen. SUGGESTIONS included use of medical therapies and percutaneous catheter drainage for treatment of IAH/ACS, considering the association between body position and IAP, attempts to avoid a positive fluid balance after initial patient resuscitation, use of enhanced ratios of plasma to red blood cells and prophylactic open abdominal strategies, and avoidance of routine early biologic mesh use among patients with open abdominal wounds. NO RECOMMENDATIONS were possible regarding monitoring of abdominal perfusion pressure or the use of diuretics, renal replacement therapies, albumin, or acute component-parts separation. CONCLUSION: Although IAH and ACS are common and frequently associated with poor outcomes, the overall quality of evidence available to guide development of RECOMMENDATIONS was generally low. Appropriately designed intervention trials are urgently needed for patients with IAH and ACS.

Cytotoxic and genotoxic effects of extracellular generated singlet oxygen in human lymphocytes in vitro.

The induction of sister-chromatid exchanges (SCE) together with the proliferation rate index (PRI) were studied in human lymphocytes in vitro after treatment with singlet oxygen. When produced outside the cells, singlet oxygen can increase the duration of the cellular cycle as measured by an enhancement of the differences between the proliferation rate indexes of the control and the treated cells. A dose-dependent increase in the SCE rate per chromosome was also detected after contact between the singlet oxygen and lymphocytes.

Singlet oxygen-induced mutations in M13 lacZ phage DNA.

The mutagenic consequences of damages to M13 mp19 RF DNA produced by singlet oxygen have been determined in a forward mutational system capable of detecting all classes of mutagenic events. When the damaged M13 mp19 RF DNA is used to transfect competent E. coli JM105 cells, a 16.6-fold increase in mutation frequency is observed at 5% survivors when measured as a loss of alpha-complementation. The enhanced mutagenicity is largely due to single-nucleotide substitutions, frameshift events and double-mutations. The single-nucleotide substitutions occur in the regulatory and in the structural part of the lacZ gene under the predominant form of a G:C to T:A transversion. The spectrum of mutations detected among the M13 lacZ phages surviving the singlet oxygen treatment is totally different from those appearing spontaneously. SOS induction mediated through u.v.-irradiation of bacteria leads to an increase of the mutation frequency in the M13 surviving to the singlet oxygen treatment. The mutation spectrum in this case is a mixture between those observed with the spontaneous mutants and the mutants induced by singlet oxygen. Lesions introduced in the M13 mp19 RF DNA can be partly repaired by the enzymatic machinery of the bacteria. It turns out that excision-repair and SOS repair are probably involved in the removal of these lesions by singlet oxygen.

Singlet oxygen mutagenicity induced in the lac operon.

We have studied the specificity of singlet oxygen (1O2) mutagenesis in single-stranded DNA phage by analysing 1O2-induced mutations in the lac insert of the M13 mp 19 hybrid phage. 107 lac mutants were analysed showing mainly single-base substitutions with a total of 93% and 7% of 40-50 base deletion mutations. Most of the substitutions are G----T and C----A transversions with respectively 27 and 54% of the mutations. The replicative form of the M13 mp 19 DNA (RFDNA) was used as substrate for the 1O2 reactions, there are then two types of progeny phages DNA's. As guanine residues are the targets of the oxidation, it appears that both types of transversions are provided by one type of lesion: the guanine oxidised by 1O2 is read like a thymine by E. coli DNA polymerase-I.

Mutagenesis of the lac promoter region in M13 mp10 phage DNA by 4'-hydroxymethyl-4,5',8-trimethylpsoralen.

Double-stranded M13 phage DNA (M13 mp10 replicative form) was photoreacted with 4'-hydroxymethyl-4,5',8-trimethylpsoralen, using light of wavelength greater than 320 nm or greater than 390 nm to generate predominantly crosslinks or monoadducts, respectively. The damaged DNAs were scored for inactivation and mutagenesis after transfection into Escherichia coli. The appearance of light-blue or colorless plaques on indicator medium showed that mutation had occurred in the lac insert of the viral DNA. A comparison of the consequences of the two phototreatments with psoralen supports the idea that crosslinks are both more lethal and more mutagenic than monoadducts. Numerous mutant clones partially or totally deficient in beta-galactosidase were plaque-purified and amplified. The viral DNA of each clone was sequenced by the dideoxy chain-terminating procedure. All of the observed base-pair changes were mapped to the lac promoter region and consisted of 3 transition, 14 transversion, and 6 single base-pair frame-shift mutations. The predominant mutation was a T.A----G.C transversion.