Predictors of Post-operative Pain and Opioid Consumption in Patients Undergoing Liver Surgery

BACKGROUND

Post-operative pain management is a critical component of perioperative care. Patients at risk of poorly controlled post-operative pain may benefit from early measures to optimize pain management. We sought to identify risk factors for post-operative pain and opioid consumption in patients undergoing liver resection.

METHODS

This is a multi-institutional prospective nested cohort study of patients undergoing open liver resection. Opioid consumption and pain scores were collected following surgery. To estimate the effects of patient factors on opioid consumption (oral morphine equivalents-OME) and on pain scores (NRS-11), we used generalized linear models and multivariable linear regression model, respectively.

RESULTS

One hundred and fifty-three patients who underwent open liver resection between 2013 and 2016 were included in the study. The mean patient age was 62.2 years, and 43.3% were female. Younger patients were significantly more likely to use more opioids in the early post-operative period (16.7 OME/10 years, p < 0.001). Patient factors that were significantly associated with increased NRS-11 pain scores also included younger patient age (difference in pain score of 0.3/10 years with cough and 0.2/10 years at rest, p < 0.01 for both) as well as a history of analgesic use (difference in pain score of 0.9 with cough and 0.6 at rest, p < 0.01 and p = 0.07, respectively).

CONCLUSION

Younger patients and those with a history of analgesic use are more likely to report higher post-operative pain and require higher doses of opioids. Early identification of these patients, and measures to better manage their pain, may contribute to optimal perioperative care.

A polymorphism in the regulatory region of the CC-chemokine receptor 5 gene influences perinatal transmission of human immunodeficiency virus type 1 to African-American infants

There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Delta32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5' regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We genotyped 1,442 infants (1,235 uninfected and 207 HIV-1 infected) for five CCR5 and CCR2 polymorphisms: CCR5-59353-T/C, CCR5-59356-C/T CCR5-59402-A/G, CCR5-Delta32, and CCR2-64I. The clinical significance of each genotype was assessed by measuring whether it influenced the rate of perinatal HIV-1 transmission among 667 AZT-untreated mother-infant pairs (554 uninfected and 113 HIV-1 infected). We found that the mutant CCR5-59356-T allele is relatively common in African-Americans (20.6% allele frequency among 552 infants) and rare in Caucasians and Hispanics (3.4 and 5.6% of 174 and 458 infants, respectively; P < 0.001). There were 38 infants homozygous for CCR5-59356-T, of whom 35 were African-Americans. Among the African-American infants in the AZT-untreated group, there was a highly significant increase in HIV-1 transmission to infants with two mutant CCR5-59356-T alleles (47.6% of 21), compared to those with no or one mutant allele (13.4 to 14.1% of 187 and 71, respectively; P < 0.001). The increased relative risk was 5.9 (95% confidence interval, 2.3 to 15.3; P < 0.001). The frequency of the CCR5-59356-T mutation varies between population groups in the United States, a low frequency occurring in Caucasians and a higher frequency occurring in African-Americans. Homozygosity for CCR5-59356-T is strongly associated with an increased rate of perinatal HIV-1 transmission.

Interphase cytogenetic analysis of erbB2 and topoII alpha co-amplification in invasive breast cancer and polysomy of chromosome 17 in ductal carcinoma in situ

Breast cancer is a genetically complex disease. Fluorescence in situ hybridisation can be used to analyse the genetics of breast-cancer progression in interphase cytogenetics. We have analysed the histological distribution of erbB2 and topoll alpha co-amplification in paraffin sections of invasive breast cancer and show that the co-amplified loci share the same histological distribution in the tumour and have a similar nuclear distribution within individual nuclei. Regions of the tumours without amplification are easily recognized and tumours with erbB2 and topoll alpha co-amplification can be distinguished from those with erbB2 amplification alone. In addition, FISH was used to show polysomy of chromosome 17 in non-invasive ductal carcinoma in situ of the breast and erbB2 amplification in both the invasive and non-invasive components of a breast cancer biopsy. This report of an interphase cytogenetic analysis of non-invasive breast carcinoma in situ demonstrates the usefulness of FISH for the genetic study of breast cancer progression.

The recruitment of mast cells, exclusively of the mucosal phenotype, into granulomatous lesions caused by the pentastomid parasite Porocephalus crotali: recruitment is irrespective of site

Adults of the porocephalid pentastomid Porocephalus crotali infect the lung of rattlesnake definitive hosts and larvae develop in rat intermediate hosts. In the latter, nymphs encyst within a variety of tissue sites (commonly abdominal fat bodies and lungs) and each becomes the focus of an eosinophilic granuloma. From an early stage in infections, granulomas become increasingly infiltrated by mast cells which, using conventional histology and paired immunofluorescence against mast cell proteases, appear to be exclusively of the mucosal phenotype. Mucosal mast cells are concentrated along the dorsal region of the parasite and in a plug of tissue containing degenerating cuticles within independent granulomas, which is located between its head and tail. ELISAs against the rat mast cell proteases I and II (RMCP I and II), extracted from abdominal fat, lung, spleen, liver and kidney granulomas at various intervals post-infection, reveal a substantially elevated concentration of RMCP II in all lesions. In fat, concentrations increase up to about 100 days post-infection, at which time moulting ceases and inflammatory responses subside. RMCP II was scarcely detectable in matched control tissues. Unlike infections with certain nematode parasites, where enteric mucosal mast cells secrete RMCP II systemically, concentrations of RMCP II in the serum of infected rats were significantly reduced when compared with age-matched uninfected controls. These results confirm that P. crotali can selectively recruit mucosal mast cells to a variety of tissue sites, most of which are non-mucosal. Possible mechanisms are discussed.