Effects of Intra-operative Cardiopulmonary Variability On Post-operative Pulmonary Complications in Major Non-cardiac Surgery: A Retrospective Cohort Study

Intraoperative cardiopulmonary variables are well-known predictors of postoperative pulmonary complications (PPC), traditionally quantified by median values over the duration of surgery. However, it is unknown whether cardiopulmonary instability, or wider intra-operative variability of the same metrics, is distinctly associated with PPC risk and severity. We leveraged a retrospective cohort of adults (n = 1202) undergoing major non-cardiothoracic surgery. We used multivariable logistic regression to evaluate the association of two outcomes (1)moderate-or-severe PPC and (2)any PPC with two sets of exposure variables- (a)variability of cardiopulmonary metrics (inter-quartile range, IQR) and (b)median intraoperative cardiopulmonary metrics. We compared predictive ability (receiver operating curve analysis, ROC) and parsimony (information criteria) of three models evaluating different aspects of the intra-operative cardiopulmonary metrics: Median-based: Median cardiopulmonary metrics alone, Variability-based: IQR of cardiopulmonary metrics alone, and Combined: Medians and IQR. Models controlled for peri-operative/surgical factors, demographics, and comorbidities. PPC occurred in 400(33%) of patients, and 91(8%) experienced moderate-or-severe PPC. Variability in multiple intra-operative cardiopulmonary metrics was independently associated with risk of moderate-or-severe, but not any, PPC. For moderate-or-severe PPC, the best-fit predictive model was the Variability-based model by both information criteria and ROC analysis (area under the curve, AUCVariability-based = 0.74 vs AUCMedian-based = 0.65, p = 0.0015; AUCVariability-based = 0.74 vs AUCCombined = 0.68, p = 0.012). For any PPC, the Median-based model yielded the best fit by information criteria. Predictive accuracy was marginally but not significantly higher for the Combined model (AUCCombined = 0.661) than for the Median-based (AUCMedian-based = 0.657, p = 0.60) or Variability-based (AUCVariability-based = 0.649, p = 0.29) models. Variability of cardiopulmonary metrics, distinct from median intra-operative values, is an important predictor of moderate-or-severe PPC.

Postoperative pulmonary complications with adjuvant regional anesthesia versus general anesthesia alone: a sub-analysis of the Perioperative Research Network study

BACKGROUND

Adjuvant regional anesthesia is often selected for patients or procedures with high risk of pulmonary complications after general anesthesia. The benefit of adjuvant regional anesthesia to reduce postoperative pulmonary complications remains uncertain. In a prospective observational multicenter study, patients scheduled for non-cardiothoracic surgery with at least one postoperative pulmonary complication surprisingly received adjuvant regional anesthesia more frequently than those with no complications. We hypothesized that, after adjusting for surgical and patient complexity variables, the incidence of postoperative pulmonary complications would not be associated with adjuvant regional anesthesia.

METHODS

We performed a secondary analysis of a prospective observational multicenter study including 1202 American Society of Anesthesiologists physical status 3 patients undergoing non-cardiothoracic surgery. Patients were classified as receiving either adjuvant regional anesthesia or general anesthesia alone. Predefined pulmonary complications within the first seven postoperative days were prospectively identified. Groups were compared using bivariable and multivariable hierarchical logistic regression analyses for the outcome of at least one postoperative pulmonary complication.

RESULTS

Adjuvant regional anesthesia was performed in 266 (22.1%) patients and not performed in 936 (77.9%). The incidence of postoperative pulmonary complications was greater in patients receiving adjuvant regional anesthesia (42.1%) than in patients without it (30.9%) (site adjusted p = 0.007), but this association was not confirmed after adjusting for covariates (adjusted OR 1.37; 95% CI, 0.83-2.25; p = 0.165).

CONCLUSION

After adjusting for surgical and patient complexity, adjuvant regional anesthesia versus general anesthesia alone was not associated with a greater incidence of postoperative pulmonary complications in this multicenter cohort of non-cardiothoracic surgery patients.

Detection of Natural Infection by Leishmania sp. in Bats (Chiroptera, Mammalia) that Inhabit the City of Corrientes, Argentina

Leishmaniasis is a zoonotic disease of importance in Argentina. It is important to be acquainted with its possible natural hosts and reservoirs. Bats have several reservoir attributes, which means they could fulfill these roles. The aim of this work was to investigate the presence of Leishmania sp. in bats that inhabit the city of Corrientes. Bats were captured and identified. From the captured specimens, spleen samples were taken and Leishmania sp. detection techniques were applied, including both optical microscopy and PCR. It was possible to capture 95 bat specimens belonging to 10 species. Using cytological preparations, a prevalence of 1.29% was detected and using PCR a prevalence of 32% was found. Our results confirm the presence of natural infection by Leishmania sp. in bats of the city of Corrientes which reveals the possibility of these animal species fulfilling a reservoir role for this disease.

Postoperative Pulmonary Complications, Early Mortality, and Hospital Stay Following Noncardiothoracic Surgery: A Multicenter Study by the Perioperative Research Network Investigators

Importance

Postoperative pulmonary complications (PPCs), a leading cause of poor surgical outcomes, are heterogeneous in their pathophysiology, severity, and reporting accuracy.

Objective

To prospectively study clinical and radiological PPCs and respiratory insufficiency therapies in a high-risk surgical population.

Design, Setting, and Participants

We performed a multicenter prospective observational study in 7 US academic institutions. American Society of Anesthesiologists physical status 3 patients who presented for noncardiothoracic surgery requiring 2 hours or more of general anesthesia with mechanical ventilation from May to November 2014 were included in the study. We hypothesized that PPCs, even mild, would be associated with early postoperative mortality and use of hospital resources. We analyzed their association with modifiable perioperative variables.

Exposure

Noncardiothoracic surgery.

Main Outcomes and Measures

Predefined PPCs occurring within the first 7 postoperative days were prospectively identified. We used bivariable and logistic regression analyses to study the association of PPCs with ventilatory and other perioperative variables.

Results

This study included 1202 patients who underwent predominantly abdominal, orthopedic, and neurological procedures. The mean (SD) age of patients was 62.1 (13.8) years, and 636 (52.9%) were men. At least 1 PPC occurred in 401 patients (33.4%), mainly the need for prolonged oxygen therapy by nasal cannula (n = 235; 19.6%) and atelectasis (n = 206; 17.1%). Patients with 1 or more PPCs, even mild, had significantly increased early postoperative mortality, intensive care unit (ICU) admission, and ICU/hospital length of stay. Significant PPC risk factors included nonmodifiable (emergency [yes vs no]: odds ratio [OR], 4.47, 95% CI, 1.59-12.56; surgical site [abdominal/pelvic vs nonabdominal/pelvic]: OR, 2.54, 95% CI, 1.67-3.89; and age [in years]: OR, 1.03, 95% CI, 1.02-1.05) and potentially modifiable (colloid administration [yes vs no]: OR, 1.75, 95% CI, 1.03-2.97; preoperative oxygenation: OR, 0.86, 95% CI, 0.80-0.93; blood loss [in milliliters]: OR, 1.17, 95% CI, 1.05-1.30; anesthesia duration [in minutes]: OR, 1.14, 95% CI, 1.05-1.24; and tidal volume [in milliliters per kilogram of predicted body weight]: OR, 1.12, 95% CI, 1.01-1.24) factors.

Conclusions and Relevance

Postoperative pulmonary complications are common in patients with American Society of Anesthesiologists physical status 3, despite current protective ventilation practices. Even mild PPCs are associated with increased early postoperative mortality, ICU admission, and length of stay (ICU and hospital). Mild frequent PPCs (eg, atelectasis and prolonged oxygen therapy need) deserve increased attention and intervention for improving perioperative outcomes.

Phylogenetic classification and clinical aspects of a new putative Deltapapillomavirus associated with skin lesions in cattle

Bovine papillomaviruses (BPVs) are recognized as causal agents of benign and malignant tumors in cattle. Thirteen types of BPVs have already been described and classified into 3 distinct genera. Divergences in the nucleotide sequence of the L1 gene are used to identify new viral types through the employment of PCR assays with degenerated primers. In the present study, a method for identifying BPVs based on PCR-RFLP and DNA sequencing allowed the identification of a new putative Deltapapillomavirus, designated JN/3SP (JQ280500.1). The analysis of the L1 gene showed that this strain was most closely related to the BPVs -1, -2, -13 , and OaPV1 (71-73% genetic similarity). In this study, we describe the detection of this new putative Deltapapillomavirus type and verify its phylogenetic position within the genus.

Macrophage inflammatory protein-1beta (MIP-1beta) produced endogenously in brain during E. coli fever in rats

Macrophage inflammatory protein-1 (MIP-1) evokes an intense fever, independent of a prostaglandin mechanism, and is now thought to play an important role in the defence response to bacterial pyrogens. The purpose of this study was 2-fold: (i) to determine whether the potent doublet of this cytokine, MIP-1beta, is actually produced in the brain in response to a pyrogenic dose of a lipopolysaccharide of Escherichia coli and (ii) to determine the anatomical site of synthesis of this cytokine in the brain. Following the intense fever produced by intraperitoneal administration of lipopolysaccharide in the unrestrained rat, MIP-1beta immunoreactivity was identified post mortem in two regions of the brain implicated in fever: the organum vasculosum laminae terminalis (OVLT) and the anterior hypothalamic, preoptic area (AH/POA). Microinjection of goat anti-mouse MIP-1beta antibody (anti-MIP-1beta) directly int the AH/POA markedly suppressed fever in rats in response to lipopolysaccharide. Further anti-MIP-1beta administered 180 min after the injection of lipopolysaccharide acted as an antipyretic and reversed the fever induced by the endotoxin. anti-MIP-1beta or control immunoglobulin G antibody microinjected into the hypothalamus immediately before the intraperitoneal injection of the control saline did not alter the temperature of the rats. Taken together, the present results demonstrate that MIP-1beta is produced in the brain in response to a bacterial endotoxin. These observations, in the light of earlier data on fever induced by MIP-1beta, further support the hypothesis that endogenously synthesized MIP-1beta acts as an intermediary factor in the evocation of fever by acting on the thermosensitive cells of the brain.

GABAergic and cholinergic mediation in the antinociceptive action of homotaurine

1. The role of GABAergic and cholinergic mechanisms in the antinociceptive effect of homotaurine (22.25-111.24 mg/kg i.p.) in chemical (acetic acid) and thermal (tail flick, tail immersion) tests has been studied by means of the interaction with baclofen and anticholinergic drugs. 2. Baclofen (2 mg/kg p.o.) and scopolamine sulfate (2.5 mg/kg i.p.) potentiate the antinociceptive effect of the amino acid in the chemical test. 3. Bicuculline (1 mg/kg i.p.) pretreatment does not modify the antinociceptive effect of homotaurine in the tail immersion and tail flick tests. 4. Scopolamine sulfate and methylnitrate (1 mg/kg i.p.) antagonise the effect of homotaurine (111.24 mg/kg i.p.) in the tail flick test. 5. The above results imply that peripheral GABAB and central cholinergic mechanisms play a role in the antinociceptive effect of homotaurine.

Removal of instrument signature from mariner 9 television images of Mars

The Mariner 9 spacecraft was inserted into orbit around Mars in November 1971. The two vidicon camera systems returned over 7300 digital images during orbital operations. The high volume of returned data and the scientific objectives of the Television Experiment made development of automated digital techniques for the removal of camera system-induced distortions from each returned image necessary. This paper describes the algorithms used to remove geometric and photometric distortions from the returned imagery. Enhancement processing of the final photographic products is also described.