Jane L. Hall

Prevention of respiratory complications after abdominal surgery: a randomised clinical trial.

Abstract Objective: To evaluate the prevention of respiratory complications after abdominal surgery by a comparison of a global policy of incentive spirometry with a regimen consisting of deep breathing exercises for low risk patients and incentive spirometry plus physiotherapy for high risk patients. Design: Stratified randomised trial. Setting: General surgical service of an urban teaching hospital. Patients: 456 patients undergoing abdominal surgery. Patients less than 60 years of age with an American Society of Anesthesia classification of 1 were considered to be at low risk. Outcome measures: Respiratory complications were defined as clinical features consistent with collapse or consolidation, a temperature above 38°C, plus either confirmatory chest radiology or positive results on sputum microbiology. We also recorded the time that staff devoted to prophylactic respiratory therapy. Results: There was good baseline equivalence between the groups. The incidence of respiratory complications was 15% (35/231) for patients in the incentive spirometry group and 12% (28/225) for patients in the mixed therapy group (P=0.40; 95% confidence interval -3.6% to 9.0%). It required similar amounts of staff time to provide incentive spirometry and deep breathing exercises for low risk patients. The inclusion of physiotherapy for high risk patients, however, resulted in the utilisation of an extra 30 minutes of staff time per patient. Conclusions: When the use of resources is taken into account, the most efficient regimen of prophylaxis against respiratory complications after abdominal surgery is deep breathing exercises for low risk patients and incentive spirometry for high risk patients. Key messages Key messages Most postoperative respiratory complications were due to atelectasis: less than 1% of the patients developed pneumonia An American Society of Anesthesia classification >1 and an age >/=60 years is a simple way of defining patients at high risk of respiratory complications and other adverse events after abdominal surgery A regimen consisting of deep breathing exercises (low risk patients) and incentive spirometry (high risk patients) is an efficient way of providing prophylaxis against respiratory complications after abdominal surgery

Methodologic standards in surgical trials.

BACKGROUND Concerns have been raised that flaws in the design and analysis of trials will hinder the interpretation of their relevance to clinical practice. The objective of this study was to review the nature and methodologic standards of surgical trails published in 10 prestigious journals between January 1988 and December 1994. METHODS We evaluated the demography and methodologic standards of 364 trials. Each article was independently scrutinized by two assessors with documentation of the interassessor variation. RESULTS Less than 50% of the trials made comment about an unbiased assessment of outcome, gave an adequate description of the randomization technique, or provided a prospective estimate of the sample size. Economic factors were declared in 6.5% of the trials. Only 2% of the trials attempted to measure the effect of an intervention on the quality of life patients. CONCLUSIONS Readers should be cautious when interpreting the results of surgical trials.

Duration of antimicrobial prophylaxis in vascular surgery

BACKGROUND This randomized clinical trial compares the incidence of wound infection after vascular surgery in patients who received prophylaxis using the same antibiotic as either a single-dose or a multiple-dose regimen (until the lines/drain tubes were removed, but not for more than 5 days). METHODS Each of the 302 patients who entered the study received ticarcillin 3.0 g/clavulanate 0.1 g (Timentin) intravenously immediately after the induction of anesthesia. Patients randomized to the multiple-dose group received an average of 14.3 doses (range 9 to 20). RESULTS The incidence of wound infections was 18% (28 of 153) for patients in the single-dose group and 10% (15 of 149) for patients in the multiple-dose group (P = 0.04; relative risk estimate = 2.00, 95% confidence interval = -1.02 to 3.92). CONCLUSIONS A multiple-dose antibiotic regimen, rather than single-dose therapy, provides optimal prophylaxis against wound infection for patients undergoing vascular surgery.

Antibiotic prophylaxis in cardiac operations

This clinical trial, which was composed of 1,031 adults undergoing cardiac operations, compared the efficacy of a single dose of 1 g of ceftriaxone with a 48-our regimen consisting of flucloxacillin and gentamicin. There was no significant difference (p = 0.89) in the overall incidence of major infections: 30 of 515 patients (5.8%; 95% confidence interval, 5.4% to 6.2%) taking ceftriaxone and 29 of 516 patients (5.6%; 95% confidence interval, 5.2% to 6.0%) taking flucloxacillin and gentamicin. Subgroup analyses, with a lower statistical power, failed to show a significant difference between patients who received ceftriaxone and those who received flucloxacillin/gentamicin: major sternal wound infections arose in 2.7% of the patients taking ceftriaxone versus 1.6% in those on the 48-hour regimen (p = 0.20) and major limb wound infections arose in 4.2% and 5.4%, respectively (p = 0.44). Single-dose prophylaxis was associated with fewer intravenous administrations (864 doses versus 9,570 doses) and cost less (A

Respiratory insufficiency after abdominal surgery

17,248 versus A

Surgery on trial: An account of clinical trials evaluating operations

78,510). Although the regimen that included gentamicin was associated with the greatest biochemical impairment of renal function, the overall toxicity for both groups was low. We conclude that a single dose of ceftriaxone provided cost-efficient prophylaxis for adults undergoing cardiac operations when compared with a 48-hour regimen of gentamicin and flucloxacillin. The general principle revealed by our data is that the short-term administration of an appropriate antibiotic regimen represents optimal prophylaxis for patients undergoing cardiac procedures.

The measurement of wound infection after breast surgery.

Abstract The objective of this study was to define the relationship between respiratory insufficiency (RI) and various putative risk factors for patients undergoing abdominal surgery. A review of 1332 adults undergoing abdominal surgery was undertaken. Information was collected in a unbiased, prospective and uniform manner with regard to baseline characteristics, perioperative events and adverse outcomes after surgery. Respiratory insufficiency was defined as either: a PO2 < 60 mm Hg, the performance of a tracheotomy, or endotracheal intubation for more than 24 h. The incidence of RI was 3% (40/1332). A logistic regression analysis only identified an American Society of Anesthesia (ASA) classification > 2 (P < 0.001) and the presence of chronic bronchitis (P= < 0.05) as significant risk factors. In addition, 33% (8/24) of the patients who developed postoperative intraperitoneal sepsis and 30% (14/47) of the patients who underwent a reoperation developed RI. It was concluded that patients with a significant systemic disease (ASA > 2), as well as patients with chronic bronchitis, should be the recipients of intense efforts to prevent pulmonary complications after abdominal surgery.

Baseline comparisons in surgical trials

BACKGROUND The objective of this study was to review published clinical trials to determine the level of compliance with issues relevant to operations. METHODS We evaluated 10 methodologic criteria in 186 trials that were published in 10 prestigious journals between January 1986 and December 1995. RESULTS One quarter of the trials failed to provide a clear account of the operative technique, 34% of the trials did not adequately detail the adverse events that occurred after operation, and 40% of the trials neglected to declare the nature and success of the follow-up of patients after the operation. Only 35% of the trials indicated that there was an attempt to standardize either the surgical procedure or perioperative care. In addition, less than 20% of the trials declared a method for assessing compliance with the surgical protocol or commented on the use of resources during the perioperative period. CONCLUSIONS Greater attention needs to be paid to the specific issues that arise when operations are evaluated in clinical trials.

Assessing wound morbidity after breast surgery using telephone interviews and postal questionnaires

Abstract:  Infection in breast wounds often occurs in the form of cellulitis, but the conventional criteria for wound infection are the presence of either pus or a serous discharge containing pathogens. Wound scoring systems may offer a more quantitative and clinically relevant approach when evaluating the morbidity caused by infection in wounds. The aim of this study was to develop a wound scoring system for patients undergoing breast surgery. The components of previously described wound scoring systems were measured in 218 women undergoing nonreconstructive breast surgery. Using conventional criteria, the incidence of wound infection was 5.5% (12/218). However, 22% of the patients exhibited at least one sign of wound infection, and 11% of the patients received antibiotics for cellulitis without any other indication of a wound infection. The validity of the wound scoring system was supported by its strong content validity, the presence of construct validity as evidenced by concordance with the conventional criteria (p < 0.001), and criterion validity in the form of an association between the presence of a seroma and a positive wound score (p < 0.001). It was also noted that 27% of the patients with an appreciable wound score (more than 40 points) had cellulitis but did not satisfy the conventional criteria for a wound infection. In conclusion, it is advisable to use a wound scoring system that includes cellulitis when evaluating patients who have undergone breast surgery. 

A Multivariate Analysis of the Risk of Pulmonary Complications After Laparotomy

Introduction:  Baseline measurements are an essential component of clinical trials. They should establish that the groups involved are clinically equivalent so that any observed differences can be attributed to the intervention under evaluation. The objective of this study was to review the use of baseline comparisons in surgical trials.