Unique strategy using a standard double lumen tube during one lung ventilation for successful intraoperative airway management in patients with a giant bulla on the ventilated side: case series

Giant lung bullae are usually seen in patients with severe chronic obstructive pulmonary disease. Over time, air trapping leads to severe dyspnea and CO₂ accumulation. In severe cases, overinflation and rupture of the bulla can cause secondary life-threatening tension pneumothorax. Since positive pressure ventilation exerts deleterious effects on the bulla, general anesthesia is always challenging in patients with giant bullae. We encountered remarkable intraoperative hypercapnia and decreased tidal volume in a 58-year-old male patient with bilateral bullae who underwent right upper bullectomy, due to overinflation of a bulla located in the upper lobe of the ventilated side. Through this experience, to avoid further overinflation, we devised an original, unique and simple airway management strategy using a standard double lumen tube (DLT), which only requires slightly deeper advancement of the DLT to achieve selective lobar blockade during one lung ventilation (OLV). Following the first case, we used this strategy in a 48-year-old male patient who underwent left giant bullectomy, resulting in successful airway management without overinflation during OLV. We recommend our strategy as an option for successful intraoperative airway management during OLV in select bullectomy patients with bilateral giant bullae.

Inhibition of endothelin A receptor by a novel, selective receptor antagonist enhances morphine-induced analgesia: Possible functional interaction of dimerized endothelin A and μ-opioid receptors

BACKGROUND

The misuse of opioids has led to an epidemic in recent times. The endothelin A receptor (ETAR) has recently attracted attention as a novel therapeutic target to enhance opioid analgesia. We hypothesized that endothelin A receptors may affect pain mechanisms by heterodimerization with μ opioid receptors. We examined the mechanisms of ETAR-mediated pain and the potential therapeutic effects of an ETAR antagonist, Compound-E, as an agent for analgesia.

METHODS

Real-time in vitro effect of Compound-E on morphine response was assessed in HEK293 cells expressing both endothelin A and μ opioid receptors through CellKey™ and cADDis cAMP assays. Endothelin A/μ opioid receptor dimerization was assessed by immunoprecipitation and live cell imaging. The in vivo effect of Compound-E was evaluated using a morphine analgesia mouse model that observed escape response behavior, body temperature, and locomotor activity.

RESULTS

In CellKey™ and cAMP assays, pretreatment of cells with endothelin-1 attenuated morphine-induced responses. These responses were improved by Compound-E, but not by BQ-123 nor by bosentan, an ETAR and endothelin B receptor antagonist. Dimerization of ETARs and μ opioid receptors was confirmed by Western blot and total internal reflection fluorescence microscopy in live cells. In vivo, Compound-E potentiated and prolonged the analgesic effects of morphine, enhanced hypothermia, and increased locomotor activity compared to morphine alone.

CONCLUSION

The results suggest that attenuation by endothelin-1 of morphine analgesia may be caused by dimerization of Endothelin A/μ opioid receptors. The novel ETAR antagonist Compound-E could be an effective adjunct to reduce opioid use.

Cerebral oxygen saturation (rSO2) during cardiopulmonary bypass (CPB) measured using the INVOS oximeter closely correlates with baseline rSO2

Baseline cerebral regional saturation (rSO₂) measured using the INVOS 5100C (Medtronic, MN, USA) varies widely among patients with cardiac and/or renal diseases. To identify significant correlates of baseline rSO₂ and to investigate intraoperative rSO₂ changes, we conducted a retrospective study in 494 patients undergoing on-pump cardiovascular surgery. Correlations between preoperative blood laboratory test variables and baseline rSO₂ before anesthesia were examined. Intraoperative rSO₂ changes were analyzed. Of all the variables examined, log-transformed B-type natriuretic peptide (BNP) most significantly and negatively correlated with baseline rSO₂ (r = - 0.652, p < 0.0001). Intraoperatively, rSO₂ showed the lowest value during cardiopulmonary bypass (CPB) (median rSO₂: 56.2% during CPB vs. 63.9% at baseline, p < 0.0001). Although rSO₂ during CPB correlated positively with hemoglobin concentration and oxygen delivery during CPB (r = 0.192, p < 0.0001; and r = 0.172, p = 0.0001, respectively), it correlated much more closely with baseline rSO₂ (r = - 0.589, p < 0.0001). Thus, patients showing low baseline rSO₂ primarily associated with preoperatively high BNP continued to show low rSO₂ even during CPB independent of hemodynamics artificially controlled by CPB. Our findings suggest that low baseline rSO₂ in patients with high BNP due to cardiac and/or renal diseases is more likely to result from tissue edema causing alterations in optical pathlength and thus in calculated rSO₂ values, not readily modifiable with CPB, rather than actual cerebral hemodynamic alterations readily modifiable with CPB. These may partly explain why the INVOS oximeter is a trend monitor requiring baseline measures.

Genome-wide association study identifies candidate loci associated with chronic pain and postherpetic neuralgia

BACKGROUND

Human twin studies and other studies have indicated that chronic pain has heritability that ranges from 30% to 70%. We aimed to identify potential genetic variants that contribute to the susceptibility to chronic pain and efficacy of administered drugs. We conducted genome-wide association studies (GWASs) using whole-genome genotyping arrays with more than 700,000 markers in 191 chronic pain patients and a subgroup of 89 patients with postherpetic neuralgia (PHN) in addition to 282 healthy control subjects in several genetic models, followed by additional gene-based and gene-set analyses of the same phenotypes. We also performed a GWAS for the efficacy of drugs for the treatment of pain.

RESULTS

Although none of the single-nucleotide polymorphisms (SNPs) were found to be genome-wide significantly associated with chronic pain (p ≥ 1.858 × 10^-7), the GWAS of PHN patients revealed that the rs4773840 SNP within the ABCC4 gene region was significantly associated with PHN in the trend model (nominal p = 1.638 × 10^-7). In the additional gene-based analysis, one gene, PRKCQ, was significantly associated with chronic pain in the trend model (adjusted p = 0.03722). In the gene-set analysis, several gene sets were significantly associated with chronic pain and PHN. No SNPs were significantly associated with the efficacy of any of types of drugs in any of the genetic models.

CONCLUSIONS

These results suggest that the PRKCQ gene and rs4773840 SNP within the ABCC4 gene region may be related to the susceptibility to chronic pain conditions and PHN, respectively.

Effects of rs958804 and rs7858836 single-nucleotide polymorphisms of the ASTN2 gene on pain-related phenotypes in patients who underwent laparoscopic colectomy and mandibular sagittal split ramus osteotomy

Background

Opioids are widely used as effective analgesics, but opioid sensitivity varies widely among individuals. The underlying genetic and nongenetic factors are not fully understood. Based on the results of our previous genome‐wide association study, we investigated the effects of single nucleotide polymorphisms (SNPs) of the astrotactin 2 (ASTN2) gene on pain‐related phenotypes in surgical patients.

Methods

We investigated the effects of two SNPs, rs958804 T/C and rs7858836 C/T, of the ASTN2 gene on eight and seven pain‐related phenotypes in 350 patients who underwent laparoscopic colectomy (LAC) and 358 patients who underwent mandibular sagittal split ramus osteotomy (SSRO), respectively. In both surgical groups, intravenous fentanyl patient‐controlled analgesia (PCA) was used for postoperative analgesia, and 24‐hour postoperative PCA fentanyl use was the primary endpoint.

Results

The association analyses among the two SNPs and pain‐related traits showed that 24‐hour fentanyl use was significantly associated with the two SNP genotypes in both surgical groups. The Mann‐Whitney test showed that 24‐hour fentanyl use was lower in patients with the C allele than in patients with the TT genotype of the rs958804 T/C SNP (P = .0019 and .0200 in LAC and SSRO patients, respectively), and it was lower in patients with the T allele than in patients with the CC genotype of the rs7858836 C/T SNP (P = .0017 and .0098 in LAC and SSRO patients, respectively).

Conclusion

The two SNPs of the ASTN2 gene were consistently associated with fentanyl requirements after two different types of surgery. These findings may contribute to personalized pain control.

We investigated the effects of two SNPs, rs958804 T/C and rs7858836 C/T, which are located in the same LD block of the ASTN2 gene, on pain‐related phenotypes in two groups of patients who underwent laparoscopic colectomy and mandibular sagittal split ramus osteotomy. We found that these SNPs consistently reduced fentanyl requirements for postoperative analgesia, possibly by enhancing the analgesic effect of fentanyl.

Postoperative analgesia in patients undergoing robot-assisted thoracic surgery: a comparison between thoracic epidural analgesia and intercostal nerve block combined with intravenous patient-controlled analgesia

BACKGROUND

Recently, robot-assisted thoracic surgery (RATS) is increasingly applied to lung or mediastinal tumor surgery. However, appropriate methods of postoperative analgesia for RATS have not been studied.

METHODS

Patients who underwent RATS at a single university hospital between January, 2017 and March, 2018 were studied retrospectively. Patients were anesthetized with either general anesthesia alone or combined general and thoracic epidural anesthesia. Accordingly, postoperative analgesia was managed with either intravenous patient-controlled analgesia (PCA) with fentanyl or thoracic epidural analgesia (TEA) with morphine and levobupivacaine. Patients were thus divided into 2 groups (PCA and TEA) according to methods of postoperative analgesia, and analgesic efficacies were compared between the groups with regard to pain scores evaluated on a 11-point numerical rating scale (NRS) at 0, 3, 6, 12, 18, 24, and 48 h postoperatively, rescue analgesic requirements within 24 h, side effects of anesthesia and analgesia, including respiratory depression, hypotension, nausea, pruritus, and urinary retention, time to ambulation after surgery, and hospital stay after surgery.

RESULTS

Data from 107 patients (76 in Group PCA and 31 in Group TEA) were analyzed. NRS pain scores at 6, 18, and 48 h were significantly less or tended to be less in Group TEA than in Group PCA (1.8±2.0 vs. 2.6±1.8, P=0.045; 1.7±1.5 vs. 2.4±1.8, P=0.047; and 1.9±1.4 vs. 2.5±1.6, P=0.063, respectively). The number of patients who required rescue analgesics within 24 h was significantly less in Group TEA than in Group PCA [4/31 (12%) vs. 32/76 (42%), P=0.004]. The other parameters were not significantly different between the groups.

CONCLUSIONS

Compared with PCA, TEA provided better analgesia after RATS in terms of less pain scores, less rescue analgesic requirements, and similar side effect profiles. TEA with a hydrophilic opioid and local anesthetic seemed an appropriate method of postoperative analgesia in patients undergoing RATS.

Morphologic changes in hepatitis virus-related liver cirrhosis: Relationship to hemodynamics of portal vein on dynamic contrast-enhanced CT

INTRODUCTION

The morphologic changes in the compensated stage of liver cirrhosis (cLC) are not diffuse atrophic changes. With cLC lobar or segmental changes combined with atrophy of the right lobe and medial segment together with hypertrophy of the caudate lobe and lateral segment are commonly seen. The purpose of this study was to evaluate the morphologic changes in hepatitis virus-related liver cirrhosis in relationship to haemodynamics of the portal vein on dynamic contrast-enhanced computed tomography (DCE-CT) METHODS: This study included 72 patients, 46 with hepatitis virus-related cirrhosis and 26 with a normally functioning liver, who underwent DCE-CT. In cirrhosis patients, the morphologic change index (MCI) of the liver was calculated and categorised into two groups, high-MCI (MCI ≥ 0.4) (n = 21) and low-MCI (MCI < 0.4) (n = 25). Cross-sectional areas of the main, right and left portal veins and the intra-portal distribution from splenic venous flow were evaluated for their relationships with the MCI and compared among three groups (normal-control, low MCI and high MCI).

RESULTS

There was a significant difference in the cross-sectional area of the left portal vein between the high-MCI group and the low-MCI group (p = 0.013) and the control group (p = 0.008). A significant correlation was identified between the cross-sectional area of the left portal vein and the MCI (r = 0.508, p < 0.001).

CONCLUSION

Cross-sectional area of the left portal vein may be a factor related to morphologic changes in hepatitis virus-related liver cirrhosis and could be a possible index of the left portal venous flow volume.

IMPLICATIONS FOR PRACTICE

This study may be useful for predicting the degree of hepatic morphologic changes and the condition of cirrhosis in association with regional hepatic morphologic changes.

Specific airway management for SVC replacement during giant anterior mediastinal tumor resection

Background

Giant anterior mediastinal tumor (GAMT) resection is a challenging procedure, for which anesthesiologist might take to need special precautions.

Case presentation

A 48-year-old male patient had been scheduled to undergo GAMT resection and superior vena cava (SVC) replacement. The tumor spread surrounding SVC and left main bronchus (LMB), resulting in small volume of his left lung. A soft left-sided double lumen tube (DLT) was selected to keep the patency of LMB during left one lung ventilation (OLV) against the tumor weight. Semi-awake intubation with spontaneous breathing was selected for DLT insertion to avoid lower airway occlusion. During left OLV after right open thoracotomy, his SPO₂ decreased below to 90%. We performed selective right upper lobe bronchial blockade using the combination of DLT and bronchial blocker. The surgery was successfully completed with this strategy.

Conclusions

Although such cases are rare, they are informative for anesthesiologists, providing optional strategies.

The dynamic collapse of the trachea during anesthesia for a pediatric patient with a large anterior mediastinal mass: A case report

Anesthesia for patient with large anterior mediastinal mass might induce life-threatening complication. Maintaining the spontaneous breathing throughout the procedure and finding rescue position are the cornerstones of anesthetic management.

Intercostal misplacement of a thoracic epidural catheter discovered during lung cancer surgery: a case report

BACKGROUND

Blind epidural catheter placement can lead to inadvertent misplacement. We present a case of intercostal misplacement of a thoracic epidural catheter.

CASE PRESENTATION

A 67-year-old male underwent left lung cancer surgery via thoracotomy with epidural analgesia via the Th 5-6 intervertebral space, although with some difficulty. We detected dermatomal cold sensory loss around Th five min after initial administration of local anesthetics through the catheter before general anesthesia induction. However, the epidural catheter was intraoperatively found below the fifth rib, running along the course of the intercostal nerve. The catheter was successfully withdrawn via his back, and we postoperatively performed paravertebral block under ultrasound guidance. He did not complain of complications at discharge.

CONCLUSIONS

Detailed bilateral assessment of sensory loss after initial local anesthetic administration might have facilitated preoperative detection of the misplacement. In cases requiring multiple catheter insertion attempts, switching to another analgesic method should be considered.

Ventilation failure after lateral jackknife positioning for robot-assisted lung cancer surgery in a patient after lingula-sparing left upper lobectomy

BACKGROUND

Ventilation failure commonly occurs when a standard left-sided double-lumen tube is used in patients after left upper lobectomy having remarkable angulation of the left main bronchus. We present a female without remarkable angulation, in whom ventilation failure occurred after lateral jackknife positioning.

CASE PRESENTATION

A 73-year-old female after lingula-sparing left upper lobectomy without remarkable angulation was scheduled for robot-assisted right upper lobectomy. Ventilation failure with a standard left-sided double-lumen tube occurred when she was placed not in the lateral position but in the lateral jackknife position required for robotic surgery. After replacement by the Silbroncho® left-sided double-lumen tube, adequate one-lung ventilation became possible.

CONCLUSIONS

Ventilation failure with a standard tube may occur more easily when patients with bronchial angulation are placed in the lateral jackknife than lateral position due to posture-induced exacerbations of bronchial angulation. The Silbroncho® tube seems useful in such situations.

Association between the rs7583431 single nucleotide polymorphism close to the activating transcription factor 2 gene and the analgesic effect of fentanyl in the cold pain test

Background

Activating transcription factor 2 (ATF2) is a member of the leucine zipper family of DNA binding proteins and is widely distributed in tissues. Several recent studies have demonstrated that this protein is involved in mechanisms that are related to pain and inflammation. However, unclear is whether polymorphisms of the ATF2 gene, which encodes the human ATF2 protein, influence pain or analgesic sensitivity. This study examined associations between the analgesic effect of fentanyl in the cold pressor‐induced pain test and polymorphisms in the ATF2 gene in 355 Japanese subjects.

Results

In this study, 33 single nucleotide polymorphisms (SNPs) were selected, and a total of 2 linkage disequilibrium blocks with 6 Tag SNPs (rs1153702, rs7583431, rs2302663, rs3845744, rs268214, and rs1982235) were observed in the region within and around the ATF2 gene. We further analyzed associations between these Tag SNPs and clinical data. Even after multiple testing with Bonferroni adjustments, an increase in the analgesic effect of fentanyl in the cold pressor‐induced pain test was significantly associated with a greater number of the A allele of the rs7583431 SNP (linear regression, P = .001).

Conclusions

The present findings may contribute to adequate pain relief in individual patients. Although more research on the genetic factors that influence opioid sensitivity is needed, analgesic requirements may be predicted by analyzing ATF2SNPs, together with other polymorphisms of genes that are reportedly associated with opioid sensitivity, such as CREB1,OPRM1, and GIRK2.

In this study, 33 single nucleotide polymorphisms (SNPs) were selected, and a total of 2 linkage disequilibrium blocks with 6 Tag SNPs (rs1153702, rs7583431, rs2302663, rs3845744, rs268214, and rs1982235) were observed in the region within and around the ATF2 gene. We further analyzed associations between these Tag SNPs and clinical data. Even after multiple testing with Bonferroni adjustments, an increase in the analgesic effect of fentanyl in the cold pressor‐induced pain test was significantly associated with a greater number of the A allele of the rs7583431 SNP (linear regression, P = .001).

Genome-wide scan identifies candidate loci related to remifentanil requirements during laparoscopic-assisted colectomy

AIM

 Opioids are widely used as effective analgesics, but opioid sensitivity is well known to vary widely among individuals. We explored the genetic factors that contribute to individual differences in intraoperative opioid sensitivity by performing a genome-wide association study.

PATIENTS & METHODS

We conducted a multistage genome-wide association study in subjects who underwent laparoscopic-assisted colectomy.

RESULTS

A nonsynonymous SNP, rs199670311, within the TMEM8A gene region and intronic SNPs, including rs4839603, within the SLC9A9 gene region were significantly associated with intraoperative opioid requirements (p = 3.409 × 10^-8 in the dominant model for rs199670311; p = 4.162 × 10^-6 and p = 4.229 × 10^-6 in the additive and recessive models, respectively, for rs4839603). The A and T alleles of the rs199670311 and rs4839603 SNPs, respectively, were associated with lower opioid sensitivity in patients.

CONCLUSION

Our findings provide valuable information for personalized pain treatment during laparoscopic-assisted colectomy.

Effect of attention bias modification on brain function and anxiety in patients with irritable bowel syndrome: A preliminary electroencephalogram and psycho-behavioral study

BACKGROUND

Gastrointestinal symptoms of irritable bowel syndrome (IBS) show a reciprocal relationship with anxiety. In this intervention-based study, we investigated the utility of attention bias modification (ABM) therapy in patients with IBS. We hypothesized that IBS-related electroencephalographic abnormalities would be normalized after ABM therapy.

METHODS

Seventeen patients with IBS and 13 healthy subjects completed five ABM intervention sessions over a 2-month period. Each session included 128 ABM trials, resulting in a total of 640 trials across the intervention period. For each trial, subjects viewed a pair of facial expression images and were instructed to indicate the position of the neutral face as quickly and accurately as possible by pressing one of two buttons on a button box. Electroencephalography data (alpha and beta power percentages) were collected during the 1st and 5th sessions.

KEY RESULTS

Generalized estimating equations of relative alpha power revealed a significant effect of period was identified at O2 (P=.036). Paired t tests revealed that ABM significantly increased relative alpha power at O2 in patients with IBS. Generalized estimating equation of relative beta power revealed a significant effect of the group × period interaction was identified at Pz (P=.035). Paired t tests revealed that ABM significantly decreased relative beta power at Pz in patients with IBS.

CONCLUSIONS & INFERENCES

Attention bias modification may normalize brain function related to attention and anxiety in patients with IBS.

Brain natriuretic peptide (BNP) may play a major role in risk stratification based on cerebral oxygen saturation by near-infrared spectroscopy in patients undergoing major cardiovascular surgery

Purpose

A previous study reported that low baseline cerebral oxygen saturation (ScO₂) (≤50%) measured with near-infrared spectroscopy was predictive of poor clinical outcomes after cardiac surgery. However, such findings have not been reconfirmed by others. We conducted the current study to evaluate whether the previous findings would be reproducible, and to explore mechanisms underlying the ScO₂-based outcome prediction.

Methods

We retrospectively investigated 573 consecutive patients, aged 20 to 91 (mean ± standard deviation, 67.1 ± 12.8) years, who underwent major cardiovascular surgery. Preanesthetic baseline ScO₂, lowest intraoperative ScO₂, various clinical variables, and hospital mortality were examined.

Results

Bivariate regression analyses revealed that baseline ScO₂ correlated significantly with plasma brain natriuretic peptide concentration (BNP), hemoglobin concentration (Hgb), estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction (LVEF) (p < 0.0001 for each). Baseline ScO₂ correlated with BNP in an exponential manner, and BNP was the most significant factor influencing ScO₂. Logistic regression analyses revealed that baseline and lowest intraoperative ScO₂ values, but not relative ScO₂ decrements, were significantly associated with hospital mortality (p < 0.05), independent of the EuroSCORE (p < 0.01). Receiver operating curve analysis of ScO₂ values and hospital mortality revealed an area under the curve (AUC) of 0.715 (p < 0.01) and a cutoff value of ≤50.5% for the baseline and ScO₂, and an AUC of 0.718 (p < 0.05) and a cutoff value of ≤35% for the lowest intraoperative ScO₂. Low baseline ScO₂ (≤50%) was associated with increases in intubation time, intensive care unit stay, hospital stay, and hospital mortality.

Conclusion

Baseline ScO₂ was reflective of severity of systemic comorbidities and was predictive of clinical outcomes after major cardiovascular surgery. ScO₂ correlated most significantly with BNP in an exponential manner, suggesting that BNP plays a major role in the ScO₂-based outcome prediction.

In vitro rumen fermentation characteristics and microbes of thin tail sheep given sweet potato (Ipomoea batatas L) biomass

<p class="abstrak2">Sweet potato plant is produced in Indonesia in large quantities. Sweet potato leaves and stems can be used as a source of protein and the tuber can be used as an energy source. This study was aimed to analyze the effect of feeding of sweet potato biomass on the rumen fermentation characteristics, digestibility of dry matter and organic matter as well as rumen microbial population of thin tail sheep. This study used a randomized block design by applying four feed treatments, i.e., T0 (100% Napier grass), T1 (70% of Napier grass + 30% concentrate), T2 (50% of Napier grass + 50% sweet potato leaves), and T3 (70% sweet potato leaves + 30% sweet potato tuber) with three replicates. Rumen fluid samples were taken with stomach tube method using a vacuum pump.  Results showed that the T3 diet has higher (P&lt;0.05) digestibility of dry matter and organic matter, concentration of NH₃ and VFA, and rumen bacterial population than those of T0 and T1diets but similar to that of T2 diet. Rumen pH and protozoa population was not different among the treatments. It can be concluded that the use of sweet potato biomass can improve the quality of rumen fermentation of sheep.</p>

[Successful One-lung Ventilation with a Right-sided Double-lumen Tube in a Patient with a Right Upper Tracheal Bronchus, who Underwent Left Pneumonectomy for Left Hilar Lung Cancer]

A 60-year-old male patient with left hilar lung cancer was scheduled to undergo left pneumonectomy or left sleeve lower lobectomy. Preoperative computer tomographic and bronchoscopic examinations revealed that the bronchus (B1) to the right apical segment (S1) was a tracheal bronchus (TB) originating from the trachea approximately 10 mm above the carina. Because the left main bronchus was to be dissected, a right-sided double-lumen tube (DLT) was selected to completely protect the right lung from spillage of secretions or cancer cells from the left lung. The right-sided DLT was placed so as to fit its lateral opening of the bronchial lumen to normal upper branches (B2, B3), while sacrificing ventilation of S1 with an abnormal branch (B1). However, one-lung ventilation (OLV) of the right lung could not be achieved, since a gas leakage from the opened tracheal lumen occurred, most probably due to intra-lobar micro-airway communications between S1 and S2/S3. The DLT was withdrawn until the blue bronchial cuff occluded the orifice of the TB (B1). Although the upper half of the blue bronchial cuff appeared above the tracheal carina, OLV through the two bronchial lumen openings could be achieved due to a specific, slanted doughnut shape of the blue bronchial cuff and the location of the abnormal branch (B1) approximate to the carina. Left pneumonectomy using successful OLV was completed safely without hypoxemia or hypercapnea. Our experience indicates that management of OLV for patients with a thoracheal bronchus needs special considerations of the exact location of the TB and intra-lobar micro-airway communications, in addition to types of scheduled surgical procedures.

Genome-wide association study identifies candidate loci associated with postoperative fentanyl requirements after laparoscopic-assisted colectomy

AIMS

Opioids are widely used as effective analgesics, but opioid sensitivity is well known to vary widely among individuals and the underlying genetic factors are not fully understood, thus hampering efficient pain treatment. We explored the genetic factors that contribute to individual differences in opioid sensitivity by performing a genome-wide association study.

METHODS

We conducted a multistage genome-wide association study in subjects who underwent laparoscopic-assisted colectomy (LAC).

RESULTS

A nonsynonymous SNP in the LAMB3 gene region, rs2076222, was strongly associated with postoperative opioid requirements. The C allele of this best-candidate SNP was associated with lower opioid sensitivity and/or higher pain sensitivity in the patient subjects.

CONCLUSION

Our findings provide valuable information for personalized pain treatment after LAC, in which the C allele of the rs2076222 SNP is associated with lower opioid sensitivity and requires more opioid analgesic after LAC.

Associations between the orexin (hypocretin) receptor 2 gene polymorphism Val308Ile and nicotine dependence in genome-wide and subsequent association studies

Background

Many genetic and environmental factors are involved in the etiology of nicotine dependence. Although several candidate gene variations have been reported by candidate gene studies or genome-wide association studies (GWASs) to be associated with smoking behavior and the vulnerability to nicotine dependence, such studies have been mostly conducted with subjects with European ancestry. However, genetic factors have rarely been investigated for the Japanese population as GWASs. To elucidate genetic factors involved in nicotine dependence in Japanese, the present study comprehensively explored genetic contributors to nicotine dependence by using whole-genome genotyping arrays with more than 200,000 markers in Japanese subjects.

Results

The subjects for the GWAS and replication study were 148 and 374 patients, respectively. A two-stage GWAS was conducted using the Fagerström Test for Nicotine Dependence (FTND), Tobacco Dependence Screener (TDS), and number of cigarettes smoked per day (CPD) as indices of nicotine dependence. For the additional association analyses, patients who underwent major abdominal surgery, patients with methamphetamine dependence/psychosis, and healthy subjects with schizotypal personality trait data were recruited. Autopsy specimens with various diseases were also evaluated. After the study of associations between more than 200,000 marker single-nucleotide polymorphisms (SNPs) and the FTND, TDS, and CPD, the nonsynonymous rs2653349 SNP (located on the gene that encodes orexin [hypocretin] receptor 2) was selected as the most notable SNP associated with FTND, with a p value of 0.0005921 in the two-stage GWAS. This possible association was replicated for the remaining 374 samples. This SNP was also associated with postoperative pain, the initiation of methamphetamine use, schizotypal personality traits, and susceptibility to goiter.

Conclusions

Although the p value did not reach a conventional genome-wide level of significance in our two-stage GWAS, we obtained significant results in the subsequent analyses that suggest that the rs2653349 SNP (Val308Ile) could be a genetic factor that is related to nicotine dependence and possibly pain, schizotypal personality traits, and goiter in the Japanese population.

Electronic supplementary material

The online version of this article (doi:10.1186/s13041-015-0142-x) contains supplementary material, which is available to authorized users.