Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Use of core biopsy in diagnosing cervical lymphadenopathy: a viable alternative to surgical excisional biopsy of lymph nodes?

OBJECTIVES Lymphoma often presents with a neck mass and while fine-needle aspiration cytology may be suggestive, tissue biopsy is required for reliable diagnosis and classification of a lymphoma that is sufficient to deliver the correct treatment for the patient. Traditionally, excisional biopsy of a lymph node has been the standard method of tissue sampling, providing ample tissue for assessment. However, this requires theatre time, and preceding fine-needle aspiration cytology, which may incur a delay. With careful use of tissue, coupled with advances in immunohistochemical and molecular investigative techniques, core biopsy provides a possible alternative to traditional fine-needle aspiration and excisional biopsy. In this study, we aimed to determine the efficacy of diagnosing neck masses. METHOD A retrospective analysis was performed of patients being investigated for a neck mass who were undergoing ultrasound-guided core biopsies of cervical lymph nodes over a 17-month period. The final histology report was scrutinised to assess whether adequate tissue was obtained to allow for full tissue diagnosis. RESULTS Over the 17-month period analysed, 70 patients with cervical lymphadenopathy underwent core biopsy. Of these, 63 (90%) were diagnostic for either lymphoma or other pathology and did not require further tissue sampling. Overall, 19 patients were diagnosed with lymphoma, of which only 1 required further biopsy due to inconclusive initial core biopsy. CONCLUSIONS Current guidelines for investigating lymphomas require that excisional biopsy be performed to obtain ample tissue to allow full nodal architecture assessment and ancillary investigation to reach an accurate histological classification. Within our head and neck multidisciplinary team, however, it is considered that results from core biopsies can be obtained in a more timely fashion and with histological accuracy equal to those of open biopsy. The results obtained demonstrate that core biopsy is an effective tool for investigation. We believe this should be the first-line investigation of choice, as it reduces the need for patients to undergo surgery, is more cost effective and offers a faster diagnosis.

Improved Knowledge, Attitudes, and Behaviors After Implementation of TeamSTEPPS Training in an Academic Emergency Department: A Pilot Report

TeamSTEPPS is a validated, formal patient safety curriculum created by the Agency for Healthcare Research and Quality (AHRQ) for the development of high-functioning multidisciplinary teams. TeamSTEPPS was implemented in an academic emergency department (ED), including all ED hospital staff as well as physicians and residents. It was hypothesized that extensive interprofessional education combined with implementation of specific tools would increase knowledge of TeamSTEPPS principles, attitudes, and behaviors. The TeamSTEPPS knowledge test and the AHRQ Hospital Survey attitude test were administered at 0, 45, and 90 days after training. Behaviors were evaluated using an observation tool that was developed to document huddle occurrence. Knowledge and attitudes significantly improved 45 days from baseline (P < .05) and were sustained by day 90. In this pilot study, the implementation of TeamSTEPPS training in a multidisciplinary team in an academic ED led to increased knowledge and improved communication attitudes. Adoption of a specific behavior, the huddle, also was observed.

Laryngopyocoele presenting with acute airway obstruction

A 66-year-old woman was transferred to the emergency department with a left-sided neck lump and fever. She was stridulous with reduced consciousness level and required immediate intubation to protect her airway. CT imaging showed a fluid-filled and air-filled lesion in the left side of the neck; the diagnosis was later confirmed as an infected laryngocoele. She underwent ultrasound guided drainage of the lesion with successful reduction of the neck lump. Following elective tracheostomy she was weaned from ventilation. Subsequent direct endoscopy and biopsy showed no evidence of malignancy or other lesion. She was discharged with permanent tracheostomy to be sustained until definitive surgical resection of the laryngocoele.

Effect of weather on medical patient volume at Kansas Speedway mass gatherings

INTRODUCTION

Provision for the safety and health care of persons attending mass-gathering events presents unique challenges to organizers. This study was designed to determine the factors that contribute to patients seeking medical care during these events.

METHODS

We performed a retrospective review of patient care records for visits that occurred during race weekends at the Kansas Speedway from April 2007 to October 2010. Data were collected regarding the overall gathering size of each event to calculate the number of patient encounters per 10,000 attendees. Patients' final disposition was determined to calculate the transfer-to-hospital rate per 10,000 attendees. Weather data, including temperature, humidity, and precipitation, were documented for each event. Negative binomial regression was used to test the relationship between weather factors and the rate of patient encounters.

RESULTS

Twenty-two event days over 6 race weekends were evaluated, with a total of 1305 patients (58% male; mean age: 37 years), a mean patient encounter rate of 13 per 10,000 attendees, and a mean transfer-to-hospital rate of 0.24 per 10,000 attendees. Our regression model demonstrated that each 0.55°C (1°F) increase in daily mean temperature was associated with a 4% increase in the rate of total complaints (P = .03) and a 6% increase in major trauma presentations (P = .019). Major trauma events were 2.4 times more frequent at ambient temperatures >17.2°C (63°F) (P = .03). Each inch of precipitation was associated with a 61% decrease in total patient volume (P = .05).

CONCLUSION

Weather factors significantly and predictably affect the use of medical services at the Kansas Speedway. Such data regarding mass-gathering events can be used for resource planning.

In vivo assessment of hydrocephalus shunt

OBJECTIVES

Over a 3-year period, we have performed 312 tests in 197 shunted patients. The data have been analyzed retrospectively to: (1) investigate the parameters describing CSF dynamics that correlate with shunt under-drainage and (2) estimate accuracy of this method.

METHODS

Constant rate infusion tests into shunt prechamber were performed.

RESULTS

In 161 of the 312 infusion tests, results indicated under-draining shunts. Patients in the under-draining group had higher baseline and plateau CSF pressures, higher resistance to CSF outflow and higher levels of baseline pulse amplitude waveform. During the test, a significantly greater vasogenic waves and lower compensatory reserve was noticed in patients with blocked shunts. In 21 patients with suggestion of shunt blockage and who subsequently underwent operative revision of the shunt, reports of intraoperative shunt patency were available. Shunt blockage was confirmed intra-operatively during surgery in 19 cases.

CONCLUSIONS

In vivo shunt testing is easy, safe and clinically useful, aiding decision in difficult clinical situations, where shunt malfunction is suspected but not certain. It also has satisfactory positive predictive power.

Comparison of once- and twice-daily clarithromycin in the treatment of adults with severe acute lower respiratory tract infections

BACKGROUND

Although the modified-release (MR) formulation of clarithromycin has demonstrated bioequivalence to the immediate-release (IR) formulation and thus can be prescribed for lower respiratory tract infections (LRTIs), a MEDLINE search from 1995 through 1998 and information on file with the manufacturer indicate that no data are available on the effectiveness of this new formulation in the treatment of severe LRTIs such as community-acquired pneumonia.

OBJECTIVE

This study was designed to compare clinical success rates (percentage of patients with clinical cure or improvement) with once- and twice-daily regimens of clarithromycin in the treatment of patients with severe, acute LRTIs requiring oral antibiotic therapy.

METHODS

In this multicenter, investigator-blinded, randomized, parallel-group study, adult patients with clinical evidence suggesting severe, acute LRTI were recruited from 22 general practices in the United Kingdom. Patients were randomly allocated to receive either clarithromycin 500 mg BID (IR tablets) or clarithromycin 1 g OD (two 500-mg MR tablets) for 7 to 14 days. The outcome measures were resolution of or improvement in clinical signs and symptoms (including resolution of cough), unscheduled visits for the same symptom, days to resumption of normal activities, and improvements in quality of life (assessed using the EQ-5D version of the EuroQoL questionnaire). Clinical, microbiologic, and serologic assessments were performed before, during, and after treatment. Efficacy and safety data were analyzed on an intent-to-treat basis.

RESULTS

One hundred sixty men (n = 83) and women (n = 77) between the ages of 19 and 88 years took part in the study, 78 receiving clarithromycin 500 mg BID and 82 receiving clarithromycin 1 g OD. At 4 weeks after the start of treatment, the high clinical success rates were comparable between groups: 84.6% with clarithromycin 500 mg BID and 90.2% with clarithromycin 1 g OD. No significant differences in outcome measures were noted between the 2 regimens. Both treatments were well tolerated, with taste disturbance being the most commonly reported adverse event (10.6% vs 6.1% with clarithromycin 500 mg BID and 1 g OD, respectively).

CONCLUSIONS

The 2 clarithromycin regimens were equally efficacious and well tolerated in the treatment of severe, acute LRTIs. However, caution should be exercised in applying these results to the general population, because the study excluded certain categories of patients who would normally be treated. In addition, the small sample size may have obscured clinically significant differences between the 2 regimens.

Effects of esmolol on patients with left ventricular dysfunction

This study examined the effect of esmolol, an ultrashort-acting beta-receptor blocker, in 10 patients with severe left ventricular dysfunction. Simultaneous hemodynamic and radionuclide angiographic measurements were obtained at incremental doses of esmolol (2, 4, 8, 12 and 16 mg/min). At a dose of 4 mg/min, esmolol produced beats blockade: a decrease in heart rate from 91 +/- 4 to 83 +/- 4 beats/min (p less than 0.05) (mean +/- SEM) and a decrease in systolic aortic pressure from 133 +/- 5 to 128 +/- 5 mm Hg (p less than 0.05). At the maximal dose, the heart rate decreased to 79 +/- 3 beats/min (p less than 0.05) and biventricular function was depressed; the left ventricular ejection fraction decreased from 27 +/- 2 to 21 +/- 2% (p less than 0.05) and the right ventricular ejection fraction decreased from 38 +/- 2 to 29 +/- 2% (p less than 0.05). These changes were accompanied by increases in left ventricular end-diastolic volume (p less than 0.05), left ventricular end-systolic volume (p less than 0.05) and pulmonary artery wedge pressure (p less than 0.05), as well as a decrease in cardiac output (p less than 0.05). The hemodynamic abnormalities (which showed considerable interindividual variability) returned to near baseline levels 10 to 30 minutes after infusion was stopped. Thus, esmolol can be administered to patients with severe left ventricular dysfunction. The beneficial effect (beta-adrenergic blockade) is usually achieved with small doses without clinically important hemodynamic changes. At larger doses, however, significant changes in biventricular function may be observed.

Efficacy and safety of esmolol vs propranolol in the treatment of supraventricular tachyarrhythmias: a multicenter double-blind clinical trial

The efficacy and safety of intravenous esmolol infusion was compared to that of intravenous propranolol injection in patients with supraventricular tachyarrhythmias (SVT) in a multicenter double-blind parallel study. A total of 127 patients were randomized to either the esmolol (n = 64) or propranolol (n = 63) group. Therapeutic response was achieved in 72% of esmolol and 69% of propranolol patients (p = NS). The average dose of esmolol in responders was 115 +/- 11 micrograms/kg/min. Therapeutic response was sustained in the 4-hour maintenance period in 67% of esmolol and 58% of propranolol patients (p = NS). Rate of conversion to normal sinus rhythm was similar in the two treatment groups. After discontinuation, rapid recovery from beta blockade (decrease in heart rate reduction) was observed in esmolol patients (within 10 minutes) compared to propranolol patients (no change in heart rate up to 4.3 hours). The principal adverse effect was hypotension, reported in 23 esmolol (asymptomatic in 19) and four propranolol (asymptomatic in three) patients. In the majority of esmolol patients, hypotension resolved quickly (within 30 minutes) after esmolol was discontinued. It was concluded that esmolol was comparable in efficacy and safety to propranolol in the treatment of patients with SVT. Unlike propranolol, because of the short half-life of esmolol, rapid control of beta blockade is possible with esmolol in clinical conditions when required.

Chitin biosynthesis during Blastocladiella zoospore germination: evidence that the hexosamine biosynthetic pathway is post-translationally activated during cell differentiation

De novo construction of a chitinous cell wall accompanies Blastocladiella emersonii zoospore germination. At least an order of magnitude increase in total hexosamine occurs during germination. This increase is into polymer (chitin) and occurs on schedule in the presence of cycloheximide. Uridine-5'-diphospho-N-acetylglucosamine (UDPGlcNAc), both the end product of hexosamine biosynthesis and a substrate for chitin biosynthesis, is a potent inhibitor of the activity of the first pathway-specific enzyme of hexosamine biosynthesis in zoospore extracts. Certain uridine nucleotides, not perceptibly influencing the activity of the first enzyme per se, counteract the inhibitory effects of UDPGlcNAc. The concentration of UDPGlcNAc in the zoospore is sufficient to act as an inhibitor of the enzyme, but the amount of UDPGlcNAc is sufficient, by over an order of magnitude, to account for the chitin synthesized during germination. Both the production of UDPGlcNAc and its utilization for chitin synthesis appear to be post-translationally regulated in zoospores and during zoospore germination.