Randomized clinical trial of a simple pulmonary recruitment manoeuvre to reduce pain after laparoscopy

Pulmonary recruitment maneuver reduces the intensity of post-laparoscopic shoulder pain: a systematic review and meta-analysis

BACKGROUND

Post-laparoscopic shoulder pain (PLSP) is a common complication following laparoscopic surgeries. This meta-analysis aimed to investigate whether pulmonary recruitment maneuver (PRM) was beneficial to alleviated shoulder pain after laparoscopic procedures.

METHODS

We reviewed existing literature in the electronic database from the date of inception to January 31, 2022. The relevant RCTs were independently selected by two authors, after which data extraction, assessment of the risk of bias, and comparison of results.

RESULTS

This meta-analysis included 14 studies involving 1504 patients, among which 607 patients were offered pulmonary recruitment maneuver (PRM) alone or in combination with intraperitoneal saline instillation (IPSI), while 573 patients were treated with passive abdominal compression. The administration of PRM significantly decreased the post-laparoscopic shoulder pain score at 12 h (MD (95%CI) - 1.12(-1.57, - 0.66), n = 801, P < 0.001, I² = 88%); 24 h (MD (95%CI) - 1.45(-1.74, - 1.16), n = 1180, P < 0.001, I² = 78%) and at 48 h (MD (95%CI) - 0.97(-1.57, - 0.36), n = 780, P < 0.001, I² = 85%). We observed high heterogeneity in the study and analyzed the sensitivity but failed to identify the cause of the heterogeneity, which may have resulted from the different methodologies and clinical factors in the included studies.

CONCLUSION

This systematic review and meta-analysis indicate that PRM can reduce the intensity of PLSP. More studies may be needed to explore the usefulness of PRM in more laparoscopic operations besides gynecological surgeries and determine the optimal pressure of PRM or its appropriate combination with other measures. The results of this meta-analysis should be interpreted with caution owing to the high heterogeneity between the analyzed studies.

Intraoperative Respiratory and Hemodynamic Strategies for Reducing Nausea, Vomiting, and Pain after Surgery: Systematic Review and Meta-Analysis

BACKGROUND

Despite improved medical treatment strategies, post-operative pain, nausea, and vomiting remain major challenges. This systematic review investigated the relationship between perioperative respiratory and hemodynamic interventions and postoperative pain, nausea, and vomiting.

METHODS

PubMed and Embase were searched on March 8, 2021 for randomized clinical trials investigating the effect of perioperative respiratory or hemodynamic interventions in adults undergoing non-cardiac surgery. Investigators reviewed trials for relevance, extracted data, and assessed risk of bias. Meta-analyses were performed when feasible. GRADE was used to assess the certainty in the evidence.

RESULTS

This review included 65 original trials; of these 48% had pain, nausea and/or vomiting as the primary focus. No reduction of postoperative pain was found in meta-analyses when comparing recruitment maneuvers with no recruitment, high (80%) to low (30%) fraction of oxygen, low (5-7 ml/kg) to high (9-12 ml/kg) tidal volume, or goal-directed hemodynamic therapy to standard care. In the meta-analysis comparing recruitment maneuvers with no recruitment maneuvers, patients undergoing laparoscopic gynecological surgery had less shoulder pain 24 hours postoperatively (mean difference in the numeric rating scale from 0 to 10: -1.1, 95% CI: -1.7, -0.5). In meta-analyses, comparing high to low fraction of inspired oxygen and goal-directed hemodynamic therapy to standard care in patients undergoing abdominal surgery, the risk of postoperative nausea and vomiting was reduced (odds ratio: 0.45, 95% CI: 0.24, 0.87 and 0.48, 95% CI: 0.27, 0.85). The certainty in the evidence was mostly very low to low. The results should be considered exploratory given the lack of pre-specified hypotheses and corresponding risk of Type 1 errors.

CONCLUSION

There is limited evidence regarding the impact of intraoperative respiratory and hemodynamic interventions on postoperative pain or nausea and vomiting. More definitive trials are needed to guide clinical care within this area. This article is protected by copyright. All rights reserved.

Pulmonary Recruitment Maneuver Reduces Shoulder Pain and Nausea After Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Background

Pain and nausea are common after laparoscopic surgery. This prospective, randomized, controlled trial aimed to investigate postoperative pain and as a secondary endpoint nausea, when performing a ventilator-piloted Pulmonary Recruitment Maneuvre (PRM) at the end of laparoscopic cholecystectomy.

Method

Patients having elective laparoscopic cholecystectomy were randomized to either ordinary exsufflation or ventilator-piloted PRM, to evacuate intra-abdominal carbon dioxide (CO₂) before abdominal closure. A questionnaire with numeric rating scales (NRS) was utilized to evaluate pain and nausea at five occasions during 48 h following surgery. Analgesic and antiemetic treatment was also analyzed.

Results

147 patients were analyzed, 76 receiving PRM and 71 controls. Overall pain was well controlled, with no significant difference between the groups regarding incidence (P=0.149) nor intensity (P=0.739). Incidence of shoulder pain was lower in the PRM group during the 48 postoperative hours, 44.7% versus 63.4% (P=0.023). The number needed to treat (NNT) to reduce shoulder pain was 6 (95% Confidence Interval, CI, 2.9–35.5) for the 48-h period. Incidence of nausea was lower in the PRM group during the 48-h period, 51.3% versus 70.4% (P=0.018). NNT was 6 (95% CI 2.9–27.4) for the 48-h period. Nausea intensity was lower in the PRM group during the 48 h (P=0.025). Fewer in the PRM population required antiemetics, 25.0% versus 42.3% (P=0.027).

Conclusion

A ventilator-piloted PRM at the end of laparoscopic cholecystectomy reduced incidence of shoulder pain, and incidence and intensity of nausea. Clinical trial registrationwww.clinicaltrials.gov. Identifier: NCT03026543.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-021-06262-6.

Postoperative analgesic efficacy of the pulmonary recruitment manoeuvre compared to intraperitoneal hydrocortisone in laparoscopic gynaecological surgeries

Background and Aims

Laparoscopic surgeries are becoming attractive because of early recovery. Adequate postoperative pain relief may be a major concern. Several methods have been used to relieve laparoscopic postoperative pain.

Methodology

This prospective, randomised, controlled study was conducted during the period between February and June 2019. Patients were assigned into three groups. Patients in the hydrocortisone group received intraperitoneal 100mg hydrocortisone in 150 ml normal saline together with the routine method to remove carbondioxide (CO2). For patients in the pulmonary recruitment group, CO₂ was exsufflated by pulmonary recruitment manoeuvre together with the routine method to remove CO₂. In the control group CO₂ was removed by applying gentle abdominal pressure allowing passive exsufflation through the port site.

Results

A total of 57 patients were included in the study. There was no statistically significant difference between the three groups as regards demographic characteristics. There was a statistically significant difference in the 24 h postoperative analgesic consumption (primary outcome) in the hydrocortisone and pulmonary recruitment groups in comparison to the control group:P value <0.001. Also, time to first request for analgesia was significantly longer and the visual analogue scale (VAS) score was significantly lower in the hydrocortisone and pulmonary recruitment groups compared to the control group:P value <0.001.

Conclusion

Intraperitoneal hydrocortisone and pulmonary recruitment manoeuvre could both effectively reduce pain after gynaecological laparoscopic surgeries, however, intraperitoneal hydrocortisone might give a longer pain-free time.

Significance of umbilical trocar size and intra-abdominal pressure on postoperative pain after transabdominal preperitoneal repair for inguinal hernia

INTRODUCTION

Laparoscopic inguinal hernia repair is reported to be associated with lower postoperative pain than open repair. However, in the actual clinical setting, some patients experience relatively severe pain. This study aimed to elucidate surgical factors that affect pain after transabdominal preperitoneal (TAPP) repair.

METHODS

We evaluated 199 patients who underwent elective TAPP for inguinal hernia from 2014 to 2019 in Heisei Memorial Hospital. The umbilical trocar size was changed from 12 to 5 mm from October 2017. The pneumoperitoneum intra-abdominal pressure was changed from 10 to 8 mmHg from 2019. Postoperative pain scores and analgesics were compared between patients who were grouped according to trocar size and intra-abdominal pressure, as well as 80 patients who received open repair.

RESULTS

Patients with a 12 mm trocar had significantly higher pain than open repair patients (P < .0001). Patients with a 5 mm umbilical trocar and 8 mm Hg intra-abdominal pressure had significantly lower pain than a 12 mm trocar (P = .025) and did not significantly differ with pain after open repair. Analgesic use significantly decreased in patients using a 5 mm trocar than 12 mm (P = .002).

CONCLUSION

Umbilical trocar size and pneumoperitoneum intra-abdominal pressure were significantly associated with post-TAPP pain. Using a 5 mm umbilical trocar and 8 mm Hg intra-abdominal pressure achieved pain levels as comparatively low as open repair.

Pulmonary recruitment can reduce residual pneumoperitoneum and shoulder pain in conventional laparoscopic procedures: results of a randomized controlled trial

BACKGROUND

This study is aimed to evaluate the pulmonary recruitment maneuver as a means to effectively reduce residual pneumoperitoneum and postoperative shoulder pain in patients undergoing conventional laparoscopic procedures and compare it to the instillation of intraperitoneal anesthetics.

METHODS

Patients undergoing laparoscopic cholecystectomy, appendectomy or hernioplasty were randomized into two groups: pulmonary recruitment maneuver (PRM) and intraperitoneal anesthetic instillation (IAI). Six hours after surgery patients were asked to fill out a visual analog scale to identify shoulder pain and a chest X-ray was taken. Groups were analyzed for incidence of residual pneumoperitoneum and shoulder pain as well as for volume of residual subdiaphragmatic gas and intensity of pain.

RESULTS

A total of 84 patients (42 per group) were included in the study. Patients in the PRM group had a lower incidence of subdiaphragmatic gas present in the chest X-ray (29% vs 55%) p = 0.01 and less volume of residual pneumoperitoneum (mean difference -.31(95%CI -7.36, 0.72), p = 0.02). They also were half as likely to present shoulder pain (24% vs 50%) p = 0.01 and showed less pain intensity than those in the IAI group (mean difference -2.04(95%CI - 3.25, - 0.84), p = 0.000). The risk of presenting shoulder pain when residual pneumoperitoneum was present showed an RR = 11.1, p = 0.0001 in the PRM group and an RR = 8.3, p = 0.000 in the IAI group. The volume of subdiaphragmatic gas was positively correlated with the intensity of shoulder pain (r = 0.54, p = 0.000).

CONCLUSIONS

The pulmonary recruitment maneuver is effective in reducing the incidence and volume of residual pneumoperitoneum, as well as the incidence and intensity of shoulder pain in patients undergoing conventional laparoscopic procedures.

Effect of the pulmonary recruitment maneuver on pain after laparoscopic gynecological oncologic surgery: a prospective randomized trial

OBJECTIVE

To evaluate the effectiveness of the pulmonary recruitment maneuver (PRM) at the end of the operation to decrease laparoscopy-induced abdominal or shoulder pain after gynecological oncologic surgery.

METHODS

In total, 113 women undergoing laparoscopic surgery for malignant or premalignant gynecological lesions were assigned randomly to two groups: the PRM group (the patient was placed in the Trendelenburg position (30°) and the PRM, consisting of two manual pulmonary inflations to a maximum pressure of 40 cmH₂O) (n=54) and the control group (n=52). Postoperative shoulder and abdominal pain was assessed 12, 24, and 48 hours later using a visual analog scale (0-10). In addition, the incidence of post-discharge nausea and vomiting was recorded until 48 hours after discharge.

RESULTS

Postoperative shoulder pain at 12 and 24 hours was significantly less severe in the PRM group (2.2±0.5 and 2.0±0.4) than in the control group (4.0±0.5 and 3.9±0.4; both p<0.001). The PRM significantly reduced the severity of upper abdominal pain at 12 and 24 h compared with the control group (3.1±0.4 and 2.9±0.4 vs. 5.9±0.5 and 4.9±0.5; both p<0.001). The analgesic requirement during the postoperative period was similar in the two groups (control group, 78.8%; PRM group, 75.9%; p=0.719).

CONCLUSION

The PRM effectively and safely reduced postoperative shoulder and upper abdominal pain levels in patients undergoing laparoscopic gynecological oncologic surgery. Trial registry at ClinicalTrials.gov, NCT01940042.

Multi-Modal Analgesic Technique for Pain Control in Patients Undergoing Diagnostic Gynecological Laparoscopy: Randomized Controlled Clinical Trial

BACKGROUND:

Advancement in minimally invasive laparoscopic surgeries make it one of the best choices for both the surgeon and the patient. The anesthesiologist had to improve the techniques used to control post-operative pain.

AIM:

In this study, we hyposethized that multi-modal analgesic technique which is a combination of two simple techniques (intraperitoneal lidocaine and pulmonary recruitment) allow better result than using only one of them.

PATIENTS AND METHOD:

This randomised controlled, double-blind study was conducted in Kasr-Alainy hospital, faculty of medicine, Cairo University, Egypt from September 2017 till February 2018. Fifty female patients, scheduled for diagnostic gynecologic laparoscopy were included in the study. Patients were randomly allocated using random computer allocation with numbered closed opaque envelopes into four study group. GM (n = 12): Patients received pulmonary recruitment maneuver and intra-peritoneal Lidocaine, GL (n = 13): Patients received intra-peritoneal Lidocaine, GP (n = 13): Patients received Pulmonary Recruitment Maneuver, GC (n = 12): Patients received passive exsufflation through the port site. In the ward, patients were asked to fulfil a questionnaire about pain severity using (VAS) at 1, 3, 6-hour post-operative both the patients and the anesthesiologist that assess the (VAS) were blind of the patient group

RESULTS:

Regarding pain score between groups VAS 1 (the primary outcome) was lowest in GM {4.5 (3-5)} in comparison with other groups (P value = 0.015), while VAS 3 & VAS 6 wasn’t statistically significant between groups. Regarding Time of first rescue analgesia; GM {3 (1.75-4)} showed the longest time in between groups (P-value = 0.042). As regard nausea and vomiting; there was no statistically significant difference in in-between groups.

CONCLUSION:

Application of Multi-modal analgesic technique allows better analgesia for a longer duration than the use of the sole technique for control of abdominal pain in patients undergoing diagnostic gynaecological laparoscopy.

Interventions to reduce shoulder pain following gynaecological laparoscopic procedures

BACKGROUND

Laparoscopy is a common procedure used to diagnose and treat various gynaecological conditions. Shoulder-tip pain (STP) as a result of the laparoscopy occurs in up to 80% of women, with potential for significant morbidity, delayed discharge and readmission. Interventions at the time of gynaecological laparoscopy have been developed in an attempt to reduce the incidence and severity of STP.

OBJECTIVES

To determine the effectiveness and safety of methods for reducing the incidence and severity of shoulder-tip pain (STP) following gynaecological laparoscopy.

SEARCH METHODS

We searched the following databases: Cochrane Gynaecology and Fertility (CGF) Specialised Register, the Cochrane Central Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO and CINAHL from inception to 8 August 2018. We also searched the reference lists of relevant articles and registers of ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of interventions used during or immediately after gynaecological laparoscopy to reduce the incidence or severity of STP.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcomes: incidence or severity of STP and adverse events of the interventions; secondary outcomes: analgesia usage, delay in discharge, readmission rates, quality-of-life scores and healthcare costs.

MAIN RESULTS

We included 32 studies (3284 women). Laparoscopic procedures in these studies varied from diagnostic procedures to complex operations. The quality of the evidence ranged from very low to moderate. The main limitations were risk of bias, imprecision and inconsistency.Specific technique versus "standard" technique for releasing the pneumoperitoneumUse of a specific technique of releasing the pneumoperitoneum (pulmonary recruitment manoeuvre, extended assisted ventilation or actively aspirating intra-abdominal gas) reduced the severity of STP at 24 hours (standardised mean difference (SMD) -0.66, 95% confidence interval (CI) -0.82 to -0.50; 5 RCTs; 670 participants; I² = 0%, low-quality evidence) and reduced analgesia usage (SMD -0.53, 95% CI -0.70 to -0.35; 4 RCTs; 570 participants; I² = 91%, low-quality evidence). There appeared to be little or no difference in the incidence of STP at 24 hours (odds ratio (OR) 0.87, 95% CI 0.41 to 1.82; 1 RCT; 118 participants; low-quality evidence).No adverse events occurred in the only study assessing this outcome.Fluid instillation versus no fluid instillationFluid instillation is probably associated with a reduction in STP incidence (OR 0.38, 95% CI 0.22 to 0.66; 2 RCTs; 220 participants; I² = 0%, moderate-quality evidence) and severity (mean difference (MD) (0 to 10 visual analogue scale (VAS) scale) -2.27, 95% CI -3.06 to -1.48; 2 RCTs; 220 participants; I² = 29%, moderate-quality evidence) at 24 hours, and may reduce analgesia usage (MD -12.02, 95% CI -23.97 to -0.06; 2 RCTs; 205 participants, low-quality evidence).No study measured adverse events.Intraperitoneal drain versus no intraperitoneal drainUsing an intraperitoneal drain may reduce the incidence of STP at 24 hours (OR 0.30, 95% CI 0.20 to 0.46; 3 RCTs; 417 participants; I² = 90%, low-quality evidence) and may reduce analgesia use within 48 hours post-operatively (SMD -1.84, 95% CI -2.14 to -1.54; 2 RCTs; 253 participants; I² = 90%). We are uncertain whether it reduces the severity of STP at 24 hours, as the evidence was very low quality (MD (0 to 10 VAS scale) -1.85, 95% CI -2.15 to -1.55; 3 RCTs; 320 participants; I² = 70%).No study measured adverse events.Subdiaphragmatic intraperitoneal local anaesthetic versus control (no fluid instillation, normal saline or Ringer's lactate)There is probably little or no difference between the groups in incidence of STP (OR 0.72, 95% CI 0.42 to 1.23; 4 RCTs; 336 participants; I² = 0%; moderate-quality evidence) and there may be no difference in STP severity (MD -1.13, 95% CI -2.52 to 0.26; 1 RCT; 50 participants; low-quality evidence), both measured at 24 hours. However, the intervention may reduce post-operative analgesia use (SMD-0.57, 95% CI -0.94 to -0.21; 2 RCTs; 129 participants; I² = 51%, low-quality evidence).No adverse events occurred in any study.Local anaesthetic into peritoneal cavity (not subdiaphragmatic) versus normal salineLocal anaesthetic into the peritoneal cavity may reduce the incidence of STP at 4 to 8 hours post-operatively (OR 0.23, 95% CI 0.06 to 0.93; 2 RCTs; 157 participants; I² = 56%; low-quality evidence). Our other outcomes of interest were not assessed.Warmed, or warmed and humidified CO₂ versus unwarmed and unhumidified CO₂There may be no difference between these interventions in incidence of STP at 24 to 48 hours (OR 0.81 95% CI 0.45 to 1.49; 2 RCTs; 194 participants; I² = 12%; low-quality evidence) or in analgesia usage within 48 hours (MD -4.97 mg morphine, 95% CI -11.25 to 1.31; 1 RCT; 95 participants; low-quality evidence); there is probably little or no difference in STP severity at 24 hours (MD (0 to 10 VAS scale) 0.11, 95% CI -0.75 to 0.97; 2 RCTs; 157 participants; I² = 50%; moderate-quality evidence).No study measured adverse events.Gasless laparoscopy versus CO₂ insufflationGasless laparoscopy may be associated with increased severity of STP within 72 hours post-operatively when compared with standard treatment (MD 3.8 (0 to 30 VAS scale), 95% CI 0.76 to 6.84; 1 RCT; 54 participants, low-quality evidence), and there may be no difference in the risk of adverse events (OR 2.56, 95% CI 0.25 to 26.28; 1 RCT; 54 participants; low-quality evidence).No study measured the incidence of STP.

AUTHORS' CONCLUSIONS

There is low to moderate-quality evidence that the following interventions are associated with a reduction in the incidence or severity, or both, of STP, or a reduction in analgesia requirements for women undergoing gynaecological laparoscopy: a specific technique for releasing the pneumoperitoneum; intraperitoneal fluid instillation; an intraperitoneal drain; and local anaesthetic applied to the peritoneal cavity (not subdiaphragmatic).There is low to moderate-quality evidence that subdiaphragmatic intraperitoneal local anaesthetic and warmed and humidified insufflating gas may not make a difference to the incidence or severity of STP.There is low-quality evidence that gasless laparoscopy may increase the severity of STP, compared with standard treatment.Few studies reported data on adverse events. Some potentially useful interventions have not been studied by RCTs of gynaecological laparoscopy.

Perioperative factors that contribute to postoperative pain and/or nausea and vomiting in ambulatory laparoscopic surgery

INTRODUCTION

Both postoperative pain and postoperative nausea and vomiting are major factors that determine the time and quality of recovery in laparoscopic surgery.

OBJECTIVE

To determine the perioperative factors that contribute to the appearance of postoperative pain and postoperative nausea and vomiting in outpatient laparoscopic surgery.

MATERIAL AND METHODS

A prospective study was conducted on a cohort of 297 patients undergoing laparoscopic ambulatory surgery. A record was made of preoperative factors (usual medication, anaesthetic risk, etc.), intraoperative (surgical and anaesthetic times, drugs, CO₂ pressure, etc.), and postoperative factors (major and minor complications, recovery times, etc.). As dependent variables, the postoperative symptoms considered were, nausea, vomiting, and/or postoperative pain.

RESULTS

Considering as a combined variable the occurrence of níusea, vomiting or moderate/severe pain (4 or more points on a visual analogue scale), one or more of these symptoms occurred in 58.7% of the patients (95% CI: 52.8-64.4). Using a logistic regression, the variables associated with the appearance of symptoms were: female gender (OR: 3.4), waiting time over 45minutes prior to surgery (OR: 4.9) and no anti-emetic prophylaxis (OR: 12.2).

CONCLUSIONS

In patients undergoing ambulatory laparoscopic surgery, one in 4had postoperative nausea and vomiting, and approximately half of moderate-intensity pain before discharge. Considering the overall the occurrence of pain and/or postoperative níusea and vomiting, these symptoms affect more than half of the patients being operated on, and are more frequent in women and in those who have to wait to access the operating room.

The Intensity of Postlaparoscopic Shoulder Pain Is Positively Correlated with the Amount of Residual Pneumoperitoneum

STUDY OBJECTIVE

Residual carbon dioxide, which is inevitably retained in the abdominal cavity after laparoscopy, plays an important role in inducing postlaparoscopic shoulder pain (PLSP). The aim of this study was to determine the relationship between the volume of a residual pneumoperitoneum and the intensity of PLSP.

DESIGN

A prospective cohort study (Canadian Task Force classification II-2).

SETTING

A university hospital.

PATIENTS

A total of 203 patients undergoing laparoscopy for nonmalignant gynecologic diseases.

INTERVENTIONS

Gynecologic laparoscopy.

MAIN OUTCOME MEASURES

The volume of the residual pneumoperitoneum was measured by performing chest radiography 24 hours after surgery. The pneumoperitoneum was graded as high volume (defined as ≥the median volume of the pneumoperitoneum) and low volume (defined as <the median volume). Perioperative data including PLSP intensity scores were collected.

RESULTS

The median volume of the residual pneumoperitoneum was 17.0 mL (0.5-133.8 mL). The intensity of PLSP was significantly higher in the high-volume group compared with the low-volume group (p < .001). A lower volume of the pneumoperitoneum was associated with less analgesic requirement (p = .032), a shorter hospitalization period (p = .007), and higher satisfaction from the surgery (p = .005). The residual gas volume and PLSP score exhibited a positive correlation that was statistically significant (r = 0.735, p < .001).

CONCLUSION

The volume of the residual pneumoperitoneum was positively correlated with the intensity of shoulder pain after laparoscopy. Therefore, surgeons should release as much gas as possible from the peritoneal cavity at the end of laparoscopy.

Insufflation with humidified and heated carbon dioxide in short-term laparoscopy: a double-blinded randomized controlled trial

Background. We tested the hypothesis that warm-humidified carbon dioxide (CO₂) insufflation would reduce postoperative pain and morphine requirement compared to cold-dry CO₂ insufflation. Methods. A double-blinded, randomized, controlled trial was conducted to compare warm, humidified CO₂ and cold-dry CO₂. Patients with benign uterine diseases were randomized to either treatment (n = 48) or control (n = 49) group during laparoscopically assisted vaginal hysterectomy. Primary endpoints of the study were rest pain, movement pain, shoulder-tip pain, and cough pain at 2, 4, 6, 24, and 48 hours postoperatively, measured by visual analogue scale. Secondary outcomes were morphine consumption, rejected boli, temperature change, recovery room stay, and length of hospital stay. Results. There were no significant differences in all baseline characteristics. Shoulder-tip pain at 6 h postoperatively was significantly reduced in the intervention group. Pain at rest, movement pain, and cough pain did not differ. Total morphine consumption and rejected boli at 24 h postoperatively were significantly higher in the control group. Temperature change, recovery room stay, and length of hospital were similar. Conclusions. Warm, humidified insufflation gas significantly reduces postoperative shoulder-tip pain as well as morphine demand. This trial is registered with Clinical Trial Registration Number   DRKS00003853 (German Clinical Trials Register (DRKS)).

[Diagnostics and therapy of chronic pain following hernia operation]

The frequency of chronic pain after hernia repair is currently much higher than the recurrence rate. For inguinal hernias it has been shown that mesh-based techniques are comparable to mesh-free techniques concerning chronic pain. Risk factors could be clearly identified for inguinal hernia repair and include open repair, meshes with small pores, mesh fixation with sutures or tacks, pre-existing pain and severe pain during the early postoperative period. The last two risk factors are also important for incisional hernias. For laparoscopic incisional hernia repair, the width (> 10 cm) of the gap seems to correlate with chronic pain. The diagnostic measures are restricted to the identification of a segmental problem in terms of nerve entrapment which can be blocked by local anesthesia or definite neurectomy. In some cases of chronic pain after inguinal hernia repair removal of the mesh will be advisable. After incisional hernia repair a segmental involvement is rarely seen. Localized pain may be induced by stay sutures which can be removed. Mesh removal is, however, a complex procedure especially after open repair resulting in hernia recurrence and therefore represents a salvage technique. The prophylaxis of chronic pain is therefore of utmost importance as is the identification of patients at risk which is now possible. These patients for example with inguinal hernias should be treated laparoscopically with an adequate technique including meshes with big pores and without fixation or fixation with glue only.