E. Andrew Ochroch

Preventing and Treating Pain after Thoracic Surgery

THE pain that accompanies thoracic surgery is notable for its intensity and duration. Acutely, moderate to severe levels of pain may not decrease substantially over the course of hospitalization and the first postoperative month. Chronically, pain can last for months to years, and even low levels of pain can decrease function. Other than pain syndromes associated with limb amputation, pain after thoracic surgery may be the most recognized pain syndrome associated with a specific surgery. Although used with increasing frequency, thoracoscopic approaches have not had the favorable impact on pain that many had anticipated. Given that the adverse effects of thoracic surgery on pulmonary function can be mitigated by effective perioperative analgesia, it is not surprising that thoracic surgeons have joined anesthesiologists in becoming strong advocates of analgesic interventions known to limit the pain accompanying thoracic surgery. Here, we review evidence-based strategies for preventing and treating this type of pain.

LONG-TERM PAIN AND ACTIVITY DURING RECOVERY FROM MAJOR THORACOTOMY USING THORACIC EPIDURAL ANALGESIA

Background Pain following thoracotomy can persist for years with an undetermined impact on quality of life. Factors hypothesized to modulate this painful experience include analgesic regimen, gender, and type of incision. Methods A total of 157 generally healthy patients of both genders scheduled for segmentectomy, lobectomy, or bilobectomy through a posterolateral or muscle-sparing incision were randomly assigned to receive thoracic epidural analgesia initiated prior to incision or at the time of rib approximation. Pain and activity scores were obtained 4, 8, 12, 24, 36, and 48 weeks after surgery. Results Overall, there were no differences in pain scores between the control and intervention groups during hospitalization (P ≥ 0.165) or after discharge (P ≥ 0.098). The number of patients reporting pain 1 yr following surgery (18 of 85; 21.2%) was not significantly different (P = 0.122) from the number reporting preoperative pain (15 of 120; 12.5%). During hospitalization, women reported greater pain than men (worst pain, P = 0.007; average pain, P = 0.016). Women experienced fewer supraventricular tachydysrhythmias (P = 0.013) and were thus discharged earlier (P = 0.002). After discharge women continued to report greater discomfort than men (P ≤ 0.016), but did not differ from men in their level of physical activity (P = 0.241). Conclusions Initiation of thoracic epidural analgesia prior to incision or the use of a muscle-sparing incision did not significantly impact pain or physical activity. Although women reported significantly greater pain during hospitalization and after discharge, they experienced fewer complications, were more likely to be discharged from the hospital sooner, and were just as active after discharge as men.

Assessment of laryngeal view: Percentage of glottic opening scorevs Cormack and Lehane grading

PurposeTo examine the intra- and inter-rater reliability of two methods that categorize laryngeal view during direct laryngoscopy, the Cormack-Lehane grading system and a new scale, the percentage of glottic opening (POGO) scale.MethodsSeven anesthesiologists from the University of Pennsylvania Health System viewed 25 identical pairs of slides of laryngeal views during direct laryngoscopy. Each anesthesiologist rated the 50 slides for both Cormack-Lehane grades and POGO scores. The latter CL replaces grades 1 and 2 C-L grades with a percentage of glottic opening: the POGO score. Inter and intra-physician reliability for the Cormack-Lehane grades were determined using the kappa statistic analysis, comparison of POGO scores was performed using the intraclass correlation coefficients (r1).ResultsThe POGO score had a better inter and intra-physician reliability than the Cormack-Lehane grading system. The intra-physician reliability for the POGO score was very good with an average interclass r1 value of 0,88. The inter-physician score was good with a r1 of 0.73. The Cormack-Lehane grading system had excellent intraphysician concordance (average kappa = 0.83.) but the inter-physician reliability was poor (kappa = 0.16.)ConclusionThe Cormack-Lehane grading system has very poor inter-physician reliability. The lack of interphysician reliability with Cormack-Lehane grading calls into question the results of previous studies in which different laryngoscopists used this method to assess laryngeal view. The POGO score appears to have good intra and inter-rater reliability. It has several theoretical advantages and may prove to be more useful for research studies in direct laryngoscopy.RésuméObjectifVérifier la fiabilité intra et interobservateur de deux méthodes de classification de la vue du larynx pendant la laryngoscopie directe: le système de cotation de Cormack-Lehane et une nouvelle échelle, le pourcentage d’ouverture glottique (POG).MéthodeSept anesthésiologistes de l’University of Pennsylvania Health System ont visionné 25 paires identiques de diapositives du larynx sous laryngoscopie directe. Chaque anesthésiologiste a coté les 50 diapositives selon les échelons Cormack-Lehane et les scores POG. Cette dernière échelle remplace les rangs 1 et 2 C-L par un pourcentage d’ouverture glottique: le score POG. La fiabilité inter et intraobservateur des rangs Cormack-Lehane a été déterminée par une analyse statistique kappa, la comparaison des scores POG a été réalisée en utilisant des coefficients de corrélation interclasses (r1).RésultatsLe POG a fourni une meilleure fiabilité inter et intraobservateur que le système de cotation Cormack-Lehane. La fiabilité intraobservateur du score POG a été très bonne, la valeur interclasse moyenne r1 étant de 0,88. Le score interobservateur a été bon selon un r1 de 0,73. Le système de Cormack-Lehane a donné une excellente concordance intraobservateur (kappa moyen = 0,83) mais la fiabilité interobservateur a été pauvre (kappa = 0,16).ConclusionLe système de cotation Cormack-Lehane a présenté une très pauvre fiabilité interobservateur. Cette lacune remet en question les résultats d’études antérieures où différents médecins ont utilisé la méthode pour évaluer la vue du larynx. Le score POG semble avoir une bonne fiabilité intra et interévaluateur. Il présente certains avantages théoriques et peut se révéler plus utile lors de recherches en laryngoscopie directe.

Continuous Positive Airway Pressure via the Boussignac System Immediately after Extubation Improves Lung Function in Morbidly Obese Patients with Obstructive Sleep Apnea Undergoing Laparoscopic Bariatric Surgery

Background:Morbidly obese patients are at elevated risk of perioperative pulmonary complications, including airway obstruction and atelectasis. Continuous positive airway pressure may improve postoperative lung mechanics and reduce postoperative complications in patients undergoing abdominal surgery. Methods:Forty morbidly obese patients with known obstructive sleep apnea undergoing laproscopic bariatric surgery with standardized anesthesia care were randomly assigned to receive continuous positive airway pressure via the Boussignac system immediately after extubation (Boussignac group) or supplemental oxygen (standard care group). All subjects had continuous positive airway pressure initiated 30 min after extubation in the postanesthesia care unit via identical noninvasive ventilators. The primary outcome was the relative reduction in forced vital capacity from baseline to 24 h after extubation. Results:Forty patients were enrolled into the study, 20 into each group. There were no significant differences in baseline characteristics between the groups. The intervention predicted less reduction in all measured lung functions: forced expiratory volume in 1 s (coefficient 0.37, SE 0.13, P = 0.003, CI 0.13–0.62), forced vital capacity (coefficient 0.39, SE 0.14, P = 0.006, CI 0.11–0.66), and peak expiratory flow rate (coefficient 0.82, SE 0.31, P = 0.008, CI 0.21–0.1.4). Conclusions:Administration of continuous positive airway pressure immediately after extubation maintains spirometric lung function at 24 h after laparoscopic bariatric surgery better than continuous positive airway pressure started in the postanesthesia care unit.

What is the role of NSAIDs in pre-emptive analgesia?

NSAIDs inhibit the cyclo-oxygenase enzymes, and decrease peripheral and central prostaglandin production. In addition to reducing the inflammation that accompanies tissue injury, decreasing prostaglandin production attenuates the response of the peripheral and central components of the nervous system to noxious stimuli. Such a reduction in the response to pain can reduce the peripheral and central sensitisation induced by noxious stimuli, and reduce the pain experienced in response to subsequent noxious stimuli. These properties would seem to make NSAIDs ideal drugs to use in a pre-emptive fashion, where analgesics are administered prior to a noxious stimulus, such as surgery, with the expectation that reduction in peripheral and central sensitisation will lead to a decrease of pain.However, the available perioperative trials of pre-emptive NSAID use have yielded modest or equivocal results, and these may be due, in part, to controversy associated with the definition of pre-emptive analgesia and how to conduct the corresponding clinical trials. Although NSAIDs may have a limited ability by themselves to induce a pre-emptive analgesic effect, the available trials suggest how the perioperative use of these drugs may be made more effective. It is expected that NSAIDs will play an increasing role in multimodal analgesia and pain relief in general.

Use of the intubating laryngeal mask airway by medical and nonmedical personnel.

The intubating laryngeal mask airway (ILMA) is a newly available device designed to allow for blind endotracheal intubation and treatment of patients with difficult airways. We studied the intubation success rates and speed with initial use of this device on an intubation manikin to determine whether this device might be easily used by trained and untrained personnel. Rapid and successful intubation with a device requiring limited or no training could have widespread implications for both health care providers and laypersons. The study consisted of 2 parts. In part 1, health care providers with intubation experience, health care providers without prior intubation experience, and nonmedical personnel were instructed to enter a room and intubate a manikin using the ILMA. A single page set of schematic directions was provided within the ILMA setup. The main outcomes were the intubation success rate and the time required for successful ventilation and intubation. In part 2, participants were retested after a standardized <60 second device demonstration. The 111 participants in the study included 44 emergency physicians (40%), 21 anesthesiologists (19%), and 46 other medical or nonmedical personnel (41%). On first attempted use of the device, and with no prior training, 59% of all participants successfully intubated the manikin. Attending and resident physicians had an 83% initial success rate. The median time to ventilation was 47 seconds, and the median time from ventilation until intubation was 29 seconds. Following the <60 second demonstration, 108 of 111 (97%) participants achieved success, with the median time to ventilation 18 seconds, and the median time from ventilation until intubation 17 seconds. All attending and resident physicians succeeded in intubation following the demonstration. Success rates on first attempt correlated with level of training, prior intubation experience, and prior LMA use (all P < .001). After a <60 second demonstration, medical and nonmedical personnel with and without prior intubation training can successfully use the ILMA to rapidly establish an airway in a manikin model. The ILMA should be further studied to determine if it may permit endotracheal intubation by first responders, paramedical personnel, and other medical staff with limited or no laryngoscopy skills.

Clinical and Demographic Characteristics of Patients With Chronic Pain After Major Thoracotomy

ObjectivesThe characteristics and etiology of long-term pain after major thoracotomy and methods for its prevention have yet to be established. MethodsOne hundred and twenty patients who had completed the hospital-based portion of a prior study to evaluate the efficacy of intraoperative epidural use during major thoracotomy, all of whom had received patient-controlled thoracic epidural analgesia until at least thoracostomy tube removal, and who were followed for 48 weeks after surgery provided data for this study. ResultsAlthough preoperative pain was associated with elevated pain levels during hospitalization and the first few months after discharge, there was no association with pain 48 weeks after surgery. Furthermore, pain during the first few postoperative days, although associated with pain during the first few postoperative months, was not associated with pain 48 weeks after surgery. However, for patients who reported pain 48 weeks after surgery, pain levels were elevated late in hospitalization after epidural catheter removal and pain after discharge did not decrease over time. During hospitalization, patients who would eventually report pain 48 weeks after surgery experienced a greater impact of pain and reported that analgesic therapy was less effective. DiscussionPostoperative pain that persists but eventually dissipates was a common finding whose intensity was associated with immediate preoperative and postoperative pain levels. In contrast, pain later on during hospitalization, its impact, and perceived analgesic effectiveness best identified those who would continue to report pain almost 1 year after surgery.

Sepsis-induced cholestasis, steatosis, hepatocellular injury, and impaired hepatocellular regeneration are enhanced in interleukin-6 -/- mice.

Objective:Hepatic dysfunction is an important but poorly understood component of sepsis. In severe sepsis, liver dysfunction is characterized by cholestasis, steatosis, hepatocellular injury, impaired regeneration, a decreased response to the cytokine interleukin-6, and high mortality. To determine whether loss of interleukin-6 activity caused hepatic dysfunction and mortality, we induced sepsis in wild-type (interleukin-6 +/+) and interleukin-6 knockout (interleukin-6 −/−) mice. We hypothesized that sepsis in interleukin-6 −/− mice would increase cholestasis, steatosis, hepatocellular injury, and mortality and impair hepatocyte regeneration. Design:Randomized prospective experimental study. Setting:University medical laboratory. Subjects:Male adolescent C57Bl6 interleukin-6 +/+ and interleukin-6 −/− mice. Interventions:Mild sepsis was induced using cecal ligation and single puncture (CLP). Severe, lethal sepsis was induced using cecal ligation and double puncture (2CLP). Some mice received recombinant human interleukin-6 at the time of CLP/2CLP. All animals were fluid resuscitated at the time of surgery and every 24 hrs thereafter. In survival cohorts, mortality at 16, 24, 48, and 72 hrs was recorded. In separate cohorts, surviving animals were killed at 24 and 48 hrs, and liver tissue was harvested. A separate cohort of mice received bromodeoxyuridine for detection of regeneration. Measurements and Main Results:2CLP was 100% fatal within the first 12 hrs in interleukin-6 −/− mice. Mortality from 2CLP in interleukin-6 +/+ mice before 24 hrs was nil but was 90% by 72 hrs. At 72 hrs, CLP was 40% fatal in interleukin-6 +/+ mice but 90% in interleukin-6 −/− mice. CLP induced cholestasis, steatosis, and hepatocellular injury in interleukin-6 −/−, but not interleukin-6 +/+, mice. Regeneration was absent following CLP in interleukin-6 −/− animals but occurred in interleukin-6 +/+ mice. Early administration of recombinant human interleukin-6 did not reverse abnormalities in interleukin-6 −/− mice. Conclusions:The absence of interleukin-6 is an important determinant of hepatic dysfunction and mortality in sepsis.

AIRWAY MANAGEMENT AND DIRECT LARYNGOSCOPY A Review and Update

Direct laryngoscopy is the direct visualization of the larynx while using a rigid laryngoscope to distract the structures of the upper airway. This article reviews the anatomy relevant to laryngoscopy and then presents a stepwise approach to the procedure. Alternative intubation techniques, positioning, laryngoscopy blades, and stylets are then covered. Pharmacologic adjuncts are discussed briefly as they relate to the difficult airway and incorporation into overall airway management.

Comparison between the analgesic efficacy of transversus abdominis plane (TAP) block and placebo in open retropubic radical prostatectomy: a prospective, randomized, double-blinded study

STUDY OBJECTIVE To compare the efficacy of ultrasound-guided tansversus abdominis plane (TAP) block with placebo for postoperative analgesia after retropubic radical prostatectomy (RRP). DESIGN Prospective, randomized, double-blinded study. SETTING Tertiary-care Veterans Affairs (VA) hospital. PATIENTS ASA physical status 1, 2, and 3 patients scheduled for RRP. INTERVENTIONS Patients were randomized to two groups: the TAP group and the control group. All patients underwent an ultrasound-guided TAP block procedure after induction of general anesthesia and received either local anesthetic (TAP group) or normal saline (control group). MEASUREMENTS Opioid use and verbal analog pain scores at 1, 6, 12, and 24 hours after surgery were recorded, as was the frequency of side effects. Times to ambulation and first oral intake also were recorded. MAIN RESULTS The TAP block group had lower pain scores and required less total opioid in the first 24 hours after surgery. Time to first oral intake and time to ambulation were similar between the two groups. CONCLUSION The TAP block has early benefits in postoperative analgesia after RRP.