ACCF联合颈前路减压zero-p椎间植骨融合内固定术治疗多节段脊髓型颈椎病

目的探讨颈前路椎体次全切除减压融合术(ACCF)联合颈前路减压zero-p椎间植骨融合内固定术治疗多节段脊髓型颈椎病的临床疗效。方法回顾性分析自2016-05—2017-07采用ACCF联合颈前路减压zero-p椎间植骨融合内固定术治疗的30例多节段脊髓型颈椎病,比较术前、术后1周及末次随访时JOA评分、颈椎Cobb角、椎间隙高度。结果30例均顺利完成手术并获得完整随访,随访时间平均21.6个月,切口均一期愈合,植骨均骨性愈合,无内固定松动、移位、断裂、伤口感染、声音嘶哑及神经功能加重等并发症。术后1例出现脑脊液漏,2例出现吞咽不适,非手术治疗后均治愈。术后1周与末次随访时JOA评分、颈椎Cobb角、椎间隙高度较术前均明显改善,差异有统计学意义(P<0.05)。末次随访时根据JOA评分改善率评定综合疗效:优12例,良14例,可4例。结论ACCF联合颈前路减压zerop椎间植骨融合内固定术治疗多节段脊髓型颈椎病安全可靠,能够有效地恢复椎间隙高度和颈椎生理曲度。     

颈前路椎体次全切除联合椎间隙减压融合内固定术治疗多节段颈椎病

【摘要】 目的：探讨颈前路椎体次全切除联合椎间隙减压融合内固定术治疗多节段颈椎病的疗效。方法：回顾性分析2002年3月～2012年1月采用颈前路椎体次全切除联合椎间隙减压融合内固定术治疗的32例多节段颈椎病患者资料,男20例,女12例;年龄48～76岁,平均52.32±5.73岁。脊髓型颈椎病26例,脊髓型合并神经根型颈椎病6例。病变累及3个节段29例,累及4个节段3例。术前JOA评分为8.07±1.82（5~11）分,颈前柱高度为67.29±2.63（61.98～73.01）mm,颈椎曲度C值为2.86±2.63[（-3.14）～8.42]。均行颈前路混合减压融合内固定术,其中脊髓主要受压节段采用椎体次全切除减压,脊髓次要受压节段行椎间隙减压。观察手术并发症情况及术后1周、6个月、12个月时JOA评分、颈前柱高度与颈椎曲度C值的恢复情况。结果：手术时间90～160min,平均105min;术中出血量100～350ml,平均200ml。术后1例出现饮水呛咳,术后2周恢复正常;2例出现声音嘶哑,经对症处理均于术后1个月内恢复正常。随访12～24个月,平均14.0±3.1个月。术后6～12个月均获骨性愈合,末次随访时无假关节形成和内固定松动或断裂。术后1周、6个月、12个月时颈前柱高度、颈椎曲度C值及JOA评分均较术前明显提高（P<0.05）。术后12个月JOA评分改善率为（68.38±11.07）%,按改善率评定手术疗效,优11例,良17例,好转4例。结论：颈前路椎体次全切除联合椎间隙减压融合内固定术是治疗多节段颈椎病一种安全、有效的方法。     

零切迹颈椎前路椎间融合固定系统治疗颈椎病及无骨折脱位颈脊髓损伤

目的：探讨零切迹颈椎前路椎间融合固定系统（简称 Zero-P 系统）治疗颈椎病及无骨折脱位颈脊髓损伤患者的临床疗效。方法对行颈椎前路手术的14例颈椎病患者（16节段）和5例无骨折脱位颈脊髓损伤患者（5节段）采用 Zero-P 系统进行减压固定。观察手术时间、术中出血量、术后早期并发症;颈椎病患者采用 JOA 评分评价疗效。结果手术时间为55～120（75±16）min;术中出血量为50～450（150±85）ml。术后11例出现吞咽困难,2～5 d 基本恢复,未出现其他早期并发症。患者均获随访,时间3个月～3年6个月,末次随访时14例颈椎病患者 JOA 评分改善率为72．7％,其中优9例,良3例,中2例;5例颈脊髓损伤患者Frankel 分级均为 E 级。影像学资料提示术后椎间融合良好,未出现临近节段椎间盘退变。结论仅需处理椎间盘的颈椎前路手术采用 Zero-P 系统进行减压固定,可以取得早期良好的临床疗效,但应注意患者的选择。     

前路三节段椎间盘切除减压治疗颈椎病的近期疗效分析

目的 分析颈前路三节段椎间盘切除减压术治疗颈椎病的临床与影像学结果.方法 2002年10月至2007年1月,对23例颈椎病患者行颈前路连续三节段椎间盘切除减压、自体髂骨植骨、钢板内固定术,男15例,女8例;年龄32～66岁,平均51.4岁.通过分析术前及随访时JOA评分,观察其改善率,并记录术后颈部症状及Odom分级.测量术前、术后1周及末次随访时颈椎侧位X线片,观察颈椎融合节段曲度(Cobb角).在末次随访时,观察融合节段的融合情况以及邻近节段退变情况.结果 随访时间11～48个月,平均19.8个月.20例脊髓型颈椎病患者术前JOA评分(11.1±1.0)分,术后3个月(14.6±1.0)分,两者比较差异有统计学意义,平均改善率62%.3例神经根型颈椎病患者末次随访时,2例症状全部消失,1例左侧三角肌肌力由术前2级恢复至4级.术后Odom分级:优15例,良4例,一般4例.术后17.4%(4/23)的患者颈部仍有症状.植骨融合率100%.术前Cobb角为3.7°,术后1周为10.8°,末次随访为10.4°.未观察到邻近节段病变.无神经系统及与内固定物相关的并发症.结论 颈前路三节段椎间盘切除减压、自体髂骨植骨融合、钢板内固定术可以获得很高的植骨融合率.     

颈前路减压植骨融合Zero-P钢板与传统钢板内固定治疗单节段颈椎病的疗效比较

目的比较颈前路减压植骨融合Zero-P钢板与传统钢板内固定治疗单节段颈椎病的临床疗效。方法回顾性分析自2010-01—2013-04行颈前路减压植骨融合内固定术治疗的51例单节段颈椎病,24例术中采用Zero-P钢板(观察组),27例术中采用传统钢板与椎间融合器(对照组)。比较2组术后疼痛VAS评分(神经根型颈椎病)、JOA评分(脊髓型颈椎病)、NDI指数、颈椎Cobb角、吞咽困难Bazaz等级、植骨融合Eck等级、邻近节段退变发生率。结果 51例均获得随访,观察组随访(81.0±4.4)个月,对照组随访(79.0±3.4)个月。观察组术后1、6个月吞咽困难Bazaz分级优于对照组,差异有统计学意义(P <0.05);但2组术后12个月吞咽困难Bazaz分级差异无统计学意义(P>0.05)。2组术后邻近节段退变发生率、术后12个月植骨融合Eck分级差异无统计学意义(P>0.05)。观察组与对照组术后1个月、12个月及末次随访时JOA评分、疼痛VAS评分、NDI指数、颈椎Cobb角比较差异无统计学意义(P>0.05)。结论颈前路减压植骨融合内固定治疗单节段颈椎病术中应用Zero-P钢板在减轻患者术后早期吞咽困难症状方面较传统颈前路钢板固定具有优势,但这两种手术方式在维持颈椎生理曲度、缓解临床症状、植骨愈合、邻近节段退变发生率方面并无明显差异。     

颈前路分节段减压植骨融合术治疗多节段颈椎病

目的：评价颈椎前路分节段减压植骨融合术治疗多节段颈椎病的有效性和安全性.方法：自2006年6月至2013年6月,采用颈前路保留中部椎体、分节段减压、植骨融合、钛板螺钉内固定术治疗连续4个节段病变的颈椎病患者24例,其中男15例,女9例;年龄47～75岁,平均57.9岁.分别于术前、术后1周和末次随访时行标准正侧位X片观察融合、植入物移位、相邻节段病变、融合节段Cobb角的变化.采用JOA评分对神经功能恢复情况进行评价.结果：手术均顺利完成,术后2例患者出现声音嘶哑,对症处理后逐步好转.19例患者获得随访,平均随访3.9年（3.1～5.3年）.随访患者平均植骨融合时间为4.5个月（3～7个月）;末次随访时无螺钉松动、移位等发生;9例患者钛网不同程度下沉,其中4例下沉＞3 mm;4例相邻节段退变.融合节段Cobb角由术前的（5.76±4.16）°提高到术后1周的（10.40±2.94）o（P＜0.01）;末次随访时下降到（8.57±2.82）o,与术前比较差异有统计学意义（P＜0.01）;JOA评分末次随访时（14.6±1.1）与术前（8.2±1.9）比较差异有统计学意义（P＜0.01）.结论：颈椎前路分节段减压植骨融合术治疗多节段颈椎病,具有临床可操作性,在彻底减压的同时,在恢复颈椎曲度和神经功能状态方面具有一定优势.     

前路椎间隙减压融合与后路单开门椎管扩大成形术治疗多节段脊髓型颈椎病的疗效比较

目的比较颈前路椎间隙减压植骨融合内固定与后路单开门椎管扩大成形术治疗多节段脊髓型颈椎病的临床疗效。方法回顾性分析自2013-01—2015-12诊治的112例累及4节段(C3~7)的脊髓型颈椎病,49例采用颈前路椎间隙减压植骨融合内固定术治疗(前路组),63例采用后路单开门椎管扩大成形术治疗(后路组)。比较2组手术时间、术中出血量、术后引流量、住院时间,术后1周、术后3个月、末次随访时椎间高度、颈椎生理曲度C值、JOA评分。结果 112例均获得随访,随访时间平均24.3(18~28)个月。前路组在手术时间、术中出血量、术后引流量、住院时间,以及术后椎间高度、颈椎生理曲度C值、JOA评分方面均优于后路组,差异有统计学意义(P 0.05)。前路组所有患者随访期间均获得骨性融合。结论与颈后路单开门椎管扩大成形术相比,颈前路椎间隙减压植骨融合内固定术治疗多节段脊髓型颈椎病能更有效增加病变节段椎间高度,恢复颈椎生理曲度,改善术后脊髓神经功能,而且手术创伤更小。     

颈前路Zero-P系统与传统钛板联合cage系统治疗多节段颈椎病的病例对照研究

目的:探讨颈前路零切迹椎间植骨融合内固定系统(zero-profile intervertebral fusion system,Zero-P)和颈前路减压植骨融合内固定术(conventional cage-plate intervertebral fusion system,CCP)应用于颈椎病多节段(≥2个节段)减压融合内固定的近期临床疗效。方法:选取2012年10月至2017年10月因颈椎病行颈椎前路多节段减压融合术的42例作为研究对象。其中Zero-P组21例,CCP组21例。分别记录两组手术一般状况及围术期参数,颈部手术前后VAS、JOA评分及吞咽困难发生率。测量患者在术后1周、1个月及末次随访时的椎前软组织厚度。同时测量融合节段脊柱功能单位Cobb角,观察颈椎整体曲度的改变情况。于术后1周,1、3、12个月追踪临床疗效并复查颈椎正侧位X线片,评价内固定效果。结果:两组患者年龄、性别、病程、手术节段、平均随访时间及住院日组间差异无统计学意义(P0.05)。手术切口长度、术中出血量、手术时间、术后引流量Zero-P组分别为(4.37±0.72)cm、(50.9±7.98)ml、(84.4±8.18)min、(76.2±10.13)ml,CCP组分别为(6.50±0.71)cm、(108.6±9.25)ml、(118.6±8.55)min、(130.1±9.42)ml,两组比较差异有统计学意义(P0.05)。末次随访时VAS评分及JOA改善率两组间差异无统计学意义(P0.05),颈椎整体生理曲度两组间差异无统计学意义(P0.05)。术后1周、1个月及末次随访椎前软组织厚度Zero-P组分别为(11.6±1.9)、(9.8±1.4)、(9.5±1.6)mm,CCP组分别为(12.5±2.6)、(11.1±2.4)、(11.0±1.9)mm,两组间各随访时间点椎前软组织厚度差异有统计学意义(P0.05)。至末次随访时,Zero-P组无一例诉吞咽困难,CCP组有3例发生吞咽困难,两组间差异有统计学意义(P0.05)。结论:在颈椎病多节段减压融合中,不论是传统CCP系统还是新型的Zero-P系统均为有效治疗手段,但Zero-P系统具有手术切口小、手术时间短、术中出血少、操作方便的优点,且术后椎前软组织肿胀恢复佳,术后发生吞咽困难的可能性更低。     

Zero-P椎间融合术在治疗颈前路融合术后相邻节段退变性疾病中的应用

目的探讨采用Zero—P椎间融合术治疗颈前路减压融合内固定术后相邻节段退变性疾病的疗效。方法对16例颈前路减压融合内固定术后发生相邻节段退变性疾病的患者采用Zero-P行颈前路椎间融合术,比较患者手术前后日本骨科学会（Japanese Orthopaedic Association,JOA）评分,观察患者术后吞咽困难发生情况及椎间融合情况。结果患者术后JOA砰分较术前提高,差异有统计学意义（P〈0．05）,未发生吞咽困难,所有患者均获得牢固融合。结论采用Zero—P椎间融合术治疗颈前路融合术后相邻节段退变性疾病中短期疗效较好。     

颈前路融合术椎间撑开高度与邻近节段退变的相关性研究

目的探讨颈前路单节段融合术椎间撑开高度与邻近节段早期退变的相关性。方法回顾性分析2008年1月至2013年4月粤北人民医院采用颈椎前路单节段椎间盘摘除植骨融合术(ACDF)治疗的44例颈椎病患者的临床资料。依据融合节段手术前后椎间隙高度变化进行分组:A组(12例):椎间撑开高度≤2 mm;B组(16例):椎间撑开高度2~4 mm;C组(16例):椎间撑开高度4 mm。分别测量各组术前、术后1周及末次随访颈椎融合节段Cobb角和日本骨科学会(JOA)评分,计算术前、末次随访R值及R'值,观察末次随访邻近节段骨质增生及颈部轴性症状(AS)发生情况。结果术后1周及末次随访时各组颈椎融合节段Cobb角和JOA评分均较术前有明显改善(P0.05),末次随访时R值和R'值明显低于术前(P0.05)。比较术后1周及末次随访时3组间颈椎融合节段Cobb角及R值、R'值,差异有统计学意义,其中B组与A、C组比较,差异有统计学意义(P0.05),而A、C组之间比较无明显差异(P0.05);末次随访B组融合节段Cobb角较术后1周下降角度小于A、C两组(P0.05);末次随访B组邻近节段骨质增生及AS发生率亦明显低于A、C组(P0.05)。结论ACDF治疗颈椎病近期疗效良好,椎间撑开过度或撑开不足可能是引起术后早期邻近节段退变的因素之一,椎间撑开高度在2~4 mm之间较为理想。     

Histochemical and contractile properties of striated muscles of urethra and levator ani of dogs and sheep

AIMS: To understand their possible importance in long- and short-term control of continence, some properties of the striated muscles of the urethra and pelvic floor (levator ani) of dogs and sheep were investigated, especially fiber types and contractile characteristics. MATERIALS AND METHODS: Striated muscles of urethra and levator ani of 29 male and 6 female dogs and 11 male and 6 female sheep were removed and cut into strips. Some strips were frozen and stained for ATPase at pH 9.4 and 4.3 for fiber typing; others were set up in an organ bath to study contractile responses to nerve stimulation. RESULTS: All muscles contained both type I (slow) and type II fibers, ranging from 97% type II in female greyhound urethra to 60% in female sheep levator ani. For each muscle, there were fewer type II muscles in sheep than in dog. The diameters of the urethral fibers were about 60% of the levator ani in dogs and 34% in sheep. Contraction of the urethral muscle was faster than for levator ani and declined to about 80% of the peak, 500 msec after the beginning of stimulation at 20 Hz. The levator ani contraction rose to a steady level as long as stimulation continued. CONCLUSIONS: Both the levator ani and urethral striated muscles contain slow and fast fiber types. The levator ani muscles are capable of sustained contraction with rapid onset which will produce long-term closure of the urethra. The circular urethral muscle contraction was faster but less well maintained.     

Incorporation and release of85Sr and14C-proline-hydroxyproline in mineral and collagen of bone and incisor teeth of growing rats

The extent to which exchange and reutilization processes of mineral tracers affect skeletal mineral accretion and resorption measurements was evaluated by comparing the rates of appearance and disappearance of⁸⁵Sr and¹⁴C-proline-hydroxyproline in bones and teeth in growing rats for 12 days following simultaneous parenteral injection of these tracers. Expressions for the relative rates of collagen synthesis and breakdown, which unlike mineral metabolism are considered not to be complicated by exchange phenomena, were based on¹⁴C-proline conversion to¹⁴C-hydroxyproline; the specific activity of the latter was determined. Both the mineral and the collagen specific activities reflected the rates and patterns of growth of the samples assayed; rapid growth and a short interval of time between formation and resorption of tissue in themetaphyseal bone which contains the cartilagineous growth plate, slow growth and an interval of time between formation and resorption of tissue indiaphyseal bone and incisor teeth which is longer than the 12 days of the experiment. However, in metaphyseal bone the specific activity collagen/mineral ratio dropped by one half during the 4–12 day interval in contrast to diaphyseal bone and incisor teeth in which no change in this ratio was observed during this period of time. The data indicate that collagen in the metaphyseal growth zone is removed by resorption before it has become fully mineralized, and that exchange is a relatively unimportant factor in the long term kinetics of bone mineral.

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Zusammenfassung Das Ausmaß, bis zu welchem Austausch- und Wiederverwendungsprozesse der mineralen Tracer die Messungen des mineralen Skelett-Auf- und Abbaues beeinflussen können, wurde ausgewertet; zu diesem Zweck wurde die Geschwindigkeit des Auftretens und Verschwindens von⁸⁵Sr und von¹⁴C-Prolin-Hydroxyprolin in Knochen und Zähnen von wachsenden Ratten während der 12 auf die simultane parenterale Injektion dieser Tracer folgenden Tage verglichen.Der Ausdruck für die relative Geschwindigkeit des Kollagen-Auf- und Abbaues, bei welchem im Gegensatz zum Mineralmetabolismus kein Mitwirken des Austauschphänomens vermutet wird, basiert auf der Umwandlung von¹⁴C-Prolin zu¹⁴C-Hydroxyprolin; die spezifische Aktivität des letzteren wurde bestimmt.Aus der spezifischen Aktivität des Minerals sowie jener des Kollagens konnten die Geschwindigkeit und die Art des Wachstums der untersuchten Proben ersehen werden, d.h.schnelles Wachstum und ein kurzes Zeitintervall zwischen Bildung und Resorption des Gewebes imKnochen der Metaphyse, die auch die knorpelige Wachstumsplatte enthält, und andererseitslangsames Wachstum und längeres Zeitintervall (länger als die 12 Tage des Experimentes) zwischen Bildung und Resorption des Gewebes imKnochen der Diaphyse und in den Schneidezähnen. Immerhin fiel die spezifische Aktivität des Kollagen/Mineral-Anteils im Knochen der Metaphyse während dem 4–12tägigen Zeitintervall auf die Hälfte, im Gegensatz zum Knochen der Diaphyse und der Schneidezähne, bei welchen während dieser Zeitspanne kein Unterschied in diesem Verhältnis beobachtet wurde.Diese Ergebnisse zeigen, daß Kollagen in der Wachstumszone der Metaphyse durch Resorption verschwindet, bevor es ganz mineralisiert ist, und daß der Austausch ein relativ unwichtiger Faktor in der Kinetik auf lange Sicht des Knochenminerals ist.

     

Instrumented ligamentotaxis and stabilization of compression and burst fractures of dorsolumbar and mid-lumbar spines

Background:

Controversy continues regarding the best treatment for compression and burst fractures. The axial distraction reduction utilizing the technique employing the long straight rod or curved short rod without derotation to reduce fracture are practised together with short segment posterolateral fusion (PLF). Effects of the early postoperative mobilization without posterolateral fusion on reduction maintenance and fracture consolidation were not evaluated so far. The present prospective study is designed to assess the effectiveness of i) reduction and restoration of sagittal alignment, ii) no posterolateral fusion on the reduced, fractured vertebral body and injured disc, iii) fracture consolidation and iv) the fate of the unfused cephalad and caudal injured motion segments of the fractured vertebra.

Materials and Methods:

The study includes 15 Denis burst and two Denis type D compression fractures between T₁₂ and L₃. The lordotic distraction technique was used for ligamentotaxis utilizing the contoured short rods and pedicle screw fixator. Three vertebrae including the fractured one were fixed. The patients after surgery were braced for ten weeks with activity restriction for 2-4 weeks. The patients were evaluated for change in vertebral body height, sagittal curve, reduction of retropulsion, improvement in neural deficit. The unfused motion segments, residual postoperative pain and bone and metal failure were also evaluated.

Results:

The preoperative and postreduction percentile vertebral heights at, zero (immediate postoperative), at three, six and 12 months followup were 62.4, 94.8, 94.6, 94.5 and 94.5%, respectively. The percentages of the intracanal fragment retropulsion at preoperative, and postoperative at zero, 3, 6 and 12 months followup were 59.0, 36.2,, 36.0, 32.3, and 13.6% respectively.The preoperative and postreduction percentile loss of the canal dimension and at zero, three, six and 12 months were 52.1, 45.0, 44.0, 41.0 and 29% respectively suggesting that the under-reduced fragment was being resorbed gradually by a remodeling process. The mean initial kyphosis of 33° became mean 2° immediately after reduction and mean 3° at the final followup. The fractured vertebral bodies consolidated in an average period of ten weeks (range 8-14 weeks). The restored disc heights were relatively well maintained throughout the observation period. All paraparetic patients recovered neurologically. There were no postoperative complications.

Conclusion:

Instrument-aided ligamentotaxis for compression and burst fractures utilizing the short contoured rod derotation technique and the instrumented stabilization of the fractured spine are found to be effective procedures which contribute to the fractured vertebral body consolidation without recollapse and maintain the motion segment function.     

Principles and Practice of Hemofiltration and Hemodiafiltration

There is growing interest in the convective dialysis therapies, hemofiltration (HF) and hemodiafiltration (HDF). Both require dialysis membranes which are highly permeable to solutes as well as fluid, and in both cases large volumes of ultrafiltration are the condition for convective transport. In HDF the convection is combined with diffusion, and as a consequence, maximum clearance over the entire molecular weight spectrum is achieved. Optimal forms of HDF provide urea clearance 10–15% higher than the corresponding diffusive mode. The larger the solute, the greater is the impact of convection, and β₂-microglobulin (β₂m) levels may be up to 70% reduced. Traditional postdilution HF provides high clearance of medium sized and large molecules. Satisfactory clearance of small solutes requires blood flows in excess of 500 ml/min. With access to practically unlimited volumes of substitution solution through on-line ultrafiltration, predilution HF can now be used. This increases the clearance of small solutes to an acceptable range. For HDF as well as HF, large patient populations consistently treated for longer periods of time are needed to make valid outcome comparisons with other therapies.     

骨折不愈合与延迟愈合的成因与治疗

目的探讨骨折不愈合与延迟愈合的成因、报肯治疗的方法与设果。方法对1990年7月～2004年12月间收治的107例骨折不愈台、54例骨折延迟愈合2例先天性胫骨骨不连进行回顾性研究，分析原因，随访治疗结果。18例延迟愈合行保守治疗，本组其他145例行手术治疗，结果除2例先天性胫骨骨不连外，其余161例的成因中均有医源性因素。10例失去随访，153例平均随访17（6-28）个月，骨折均获骨性连接，愈合时间平均10（6-14）个月，肢体功能恢复良好，结论医源性技术缺陷是骨折不愈合与延迟愈合的主要原因，针对各种不同因素进行合理治疗可获得满意效果。     

Recognition and management of phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas (PPGL) are catecholamine-secreting neuroendocrine tumours arising from the chromaffin cells in the adrenal medulla. These tumours may be identified incidentally, as part of a work-up for multiple endocrine neoplasia or following haemodynamic surges during unrelated procedures. Advances in perioperative management and improved management of intraoperative haemodynamic instability have significantly reduced surgical mortality from around 40% to less than 3%. Surgery is the definitive treatment in most cases and laparoscopic resection where possible is associated with improved outcomes. Anaesthetic management of PPGL cases represents a unique haemodynamic challenge both before and after tumour resection. In this article we describe the physiology of these tumours, their diagnosis, preoperative optimization methods, intraoperative anaesthetic management and management of postoperative complications.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist and nabilone, a synthetic cannabinoid.     

Physiology and pharmacology of nausea and vomiting

Nausea and vomiting are both very unpleasant experiences. The physiology is poorly understood; however, understanding what we do know is key to tailoring a preventative or therapeutic antiemetic regime. There are two key sites in the central nervous system implicated in the organization of the vomiting reflex: the vomiting centre and the chemoreceptor trigger zone. There are five key neurotransmitters involved in afferent feedback to these areas. These are histamine (H₁ receptors), dopamine (D₂), serotonin (5-HT₃), acetyl choline (muscarinic) and neurokinin (substance P). Postoperative nausea and vomiting will occur in around one-third of elective patients who have no prophylaxis. This can result in many detrimental effects including patient dissatisfaction, unplanned admission and prolonged recovery. It is therefore essential that clinicians understand how they can prevent and treat nausea and vomiting using either a single agent or a combination of antiemetics to target relevant receptors. Commonly used drugs include antihistamines, dopamine antagonists, serotonin antagonists and steroids. More novel agents are being developed such as aprepitant, a neurokinin receptor antagonist, palonosetron, a 5HT₃ receptor antagonist, and nabilone, a synthetic cannabinoid.