Laminar Air-flow to Control Operating Room Infection


Surgical web site infections (SSIs) are outlined as infections occurring inside 30 days after surgical procedure or inside one 12 months if an implant is left in place and affecting both the incision or deep tissue on the operation web site (Owens and Stoessel 2008). SSIs are reported as the key reason behind excessive morbidity and mortality amongst put up -operative sufferers (Weigelt 2010). Based on UK Nationwide Joint Registry Report, throughout 2003 -2006 interval an infection was answerable for about 19 % failure of joint surgical procedure leading to revision procedures (Sandiford and skinner 2009).

Micro-organisms within the air particles decide on the wound, dressings and surgical devices and trigger infections (Chow and Yang 2005). Whyte (1982) recognized that contamination from affected person’s pores and skin as the reason for an infection in 2% circumstances and from theatre personnel in 98% circumstances. Additionally they discovered that in 30% circumstances, contaminants attain the wound from theatre personnel by way of air and in 70% circumstances it's by way of palms.

Usually air high quality within the working room is maintained air flow system. Further enhancements might be achieved by laminar air-flow system or UV lights. Laminar air-flow system is dear and require continues upkeep. Its set up will increase constructing value and the operational value (, 2004: Hansen, 2005). Research carried out to guage the effectiveness of laminar stream produced combined outcomes and there's no consensus on its position in an infection management (Sandiford 2007). On this setting, this paper evaluations the latest research to look at the effectiveness of laminar air-flow in decreasing SSIs.

Research for this evaluation had been discovered by looking out on databases similar to CINAHL, PubMed, Science Direct, Ovidsp, Science Quotation Index (ISI) and Google scholar. Key phrases used for this search are “laminar air stream”, “surgical web site an infection”, “working room air high quality”, “airborne infections + working theatre”, “LMA + an infection management”. As laminar air-flow is used primarily in orthopaedic theatres, majority of the research are on joint surgical procedure.


Indoor air in an working theatre incorporates mud which consists of drugs launched from disinfectant and sterilizers, respiratory droplets, insect components smoke launched from cautry. Mud particles act as a provider for transporting microorganisms laden particles and may decide on surgical wound and there by trigger an infection (Neil 2005). Air particles are discovered to be answerable for about 80% – 90% of microbial contamination (CDC 2005).

Trendy working theatres are typically geared up with standard air flow system by which filters can take away airborne particles of dimension >5mm about 80-95% (Dharan 2002). The efficacy of working room air flow is measured by the colony forming models (CFU) of organisms current per cubic meter. The standard air flow (Plenum) with 20 air exchanges is taken into account environment friendly if it achieves the colony rely of 35cfu/m3 or much less (Bannister 2002).

Air flow system with laminar air-flow directs the air-flow in a single path and sweeps the air particle over the wound web site to the exits (CDC 2003). Laminar air-flow with HEPA (Excessive Effectivity Particulate Arrestment) filters system has the capability to take away air particles of dimension zero.Three µm as much as 99.9 % and may produce 300 air exchanges per hour in ultraclean orthopaedic theatres. (Sandiford and skinner 2009).

Laminar air-flow models are typically two sorts; ceiling-mounted (vertical stream) or wall-mounted (horizontal stream). There are inconveniences related to each sorts. Usually the key drawback related to laminar air-flow is stream disruption. With vertical laminar stream, it's the warmth generated by surgical lamps creates air turbulence whereas with horizontal laminar stream it's the surgical crew that disrupt the air-flow (Dharan 2002).


Laminar air-flow system is especially utilized in implant surgical procedures the place even a small variety of microorganisms could cause an infection. In joint alternative surgical procedures, one of many primary causes of early (inside Three months) and delayed (inside 18 months to 2 years) deep prosthetic infections was discovered colonisation throughout surgical procedure (Knobben 2006). Laminar air stream is meant to reduce contamination by mobilizing uniform and enormous quantity of unpolluted air to the surgical space and Contaminants are flushed out immediately (Chow and Yang, 2004). Some research discovered that this technique is efficient in decreasing an infection however some others produced contradicting outcomes (give some reference)

A latest research carried out by Kakwani (2007) discovered that laminar air-flow system is efficient in decreasing the reoperation fee in Austin-Moore hemiarthroplasty. Their research in contrast the reoperation fee between theatres with laminar air-flow and theatres with out laminar air-flow system. A cohort of 435 sufferers who had Austin-Moore hemiarthroplasties at Good Hope Hospital in Birmingham between August 2000 and July 2004 had been chosen for this research. Of these 435 sufferers, 212 had operation in laminar air-flow theatres and 223 had operation in non-laminar air-flow theatres. Knowledge had been collected by reviewing case notes and radiographs. For all circumstances antibiotics had been administrated and water impervious surgical robes and drapes had been used. Within the non-laminar air-flow group it was discovered that the re-operation fee for all indication within the first 12 months after hemiarthroplasties was 5.eight % (13/223), whereas within the laminar air-flow group it was 1.four% (Three/212). Evaluation discovered that there have been no statistically important relation between re-operation fee and water impervious robe and drapes (p=zero.15), whereas use of laminar air-flow discovered a statistically important drop (p=zero.0285) in re-operation fee inside the first 12 months after hemiarthroplasties. They discovered that re-operation fee in no-laminar air-flow theatres had been 4 occasions better than that in laminar airflow theatres.

Though the goal of the research was clearly described there was no evaluation of present research to determine the hole within the analysis. Examine strategies and particulars of statistical evaluation got elaborately. The pattern dimension appears enough. Outcomes had been summarized and offered utilizing graphs and charts. Dialogue of outcomes was quick and appears not satisfactory to handle the aims of the research. There was no try to clarify the informal relationship. For instance researches had been making statements similar to “…the introduction of water-impervious drapes and robes didn't appear to make a statistically important enchancment within the result….” (p.823). Researchers didn't acknowledge any limitations of the research. Knowledge for this research was collected by reviewing sufferers’ information. Sufferers information are considers as confidential and researchers didn’t point out whether or not they obtained consent from the sufferers or moral approval kind establishment to conduct the research. This may be thought-about as an moral flaw of this research.

There are research which discovered that laminar air-flow system just isn't efficient in decreasing an infection fee. Of their research Brandt C (2008) discovered that an infection fee was considerably excessive in theatres with laminar air-flow system. This was a retrospective cohort-study based mostly on routine surveillance knowledge from German nationwide nosocomial infections surveillance system (KISS). Hospitals which had carried out not less than 100 operations between the years 2000 and 2004 had been chosen for this research. Kind of air flow know-how put in in operation rooms of chosen hospitals had been collected individually by way of questionnaire from an infection management groups within the taking part hospitals. Surgical departments had been grouped into classes based on the kind of air flow system put in. Departments utilizing synthetic working room (OR) air flow with both turbulent or laminar airflow was included on this research.

Whole 63 surgical departments from 55 hospitals had been included on this research. Evaluation was carried out to the info set created by merging the questionnaire knowledge on OR air flow and surveillance knowledge from the KISS knowledge base. The info set analysed contained 99230 operations with 1901 SSIs. Age and gender of the affected person was discovered a major danger issue of SSI in most procedures. Univariate evaluation carried out discovered that fee of SSIs was excessive in departments with laminar air stream air flow. Multivariate evaluation additionally confirmed this discovering. Authors argue that it could be as a result of improper positioning theatre personnel in horizontal laminar stream room.

Researches offered a well-researched literature evaluation which clearly recognized hole in present analysis. Aims and design of the research was correctly defined. Examine was based mostly on a big pattern dimension. Outcomes had been mentioned intimately and informal relations had been effectively defined. Sufficient tables had been used to current outcomes. Limitations had been correctly mentioned.

Knobben (2006) carried out an experimental research to guage how systemic adjustments along with behavioural adjustments can decreases intra-operative contamination. This research was carried out within the college Medical Centre Groningen, The Netherlands. A random pattern of 207 surgical procedures which concerned complete knee or hip prosthesis from July 2001 to January 2004 was chosen for this research. Two sequential sequence of behavioural and systemic adjustments had been launched to establish their position in decreasing intra-operative contamination. The management group consisted 70 circumstances. Behavioural adjustments (right use of plenum) had been launched to the primary intervention group of 67 operations. Intense behavioural and systemic adjustments had been launched to second intervention group of 70 operations. The systemic adjustments launched was the set up of recent laminar stream with improved airflow from 2700m3/h to 8100m3/h. Two samples every had been taken from used devices, unused devices and eliminated bones. Management swabs had been additionally collected to guarantee that contamination was not occurred throughout transport and culturing. Early and late intra-operative contamination was additionally checked. All sufferers had been monitored for any wound discharge whereas in hospital and followed-up for 18 months to verify whether or not intra-operative contamination impacts post-operative an infection.

Among the many management group contamination was discovered 32.9% whereas in intervention group 1 it was 34.Three% and in intervention group 2 it was eight.6%. Besides in Group 1 (p=zero.022) late section contamination was not considerably larger than early section contamination. Throughout the management interval wound discharge was present in 22.9% sufferers and 11.four% of them had wound an infection later. Deep periprosthetic an infection had been present in 7.1% of them within the follow-up interval. Deep periprosthetic an infection was present in four.5% circumstances of first intervention group and in 1.four% of circumstances in second intervention group within the follow-up interval. However none of those decreases had been discovered statistically important. Contamination, extended wound discharge and superficial surgical web site an infection had been discovered decreased after each first and second intervention. However a statistically important discount was discovered solely in second intervention (contamination p=zero.001, wound discharge p=zero.002 and superficial SSI p=zero.zero04). This research concluded that behaviour modifications along with improved air stream system can scale back intra-operative contamination considerably.

Function of the research was clearly outlined and a superb evaluation of the present literature has given. Hole in present analysis was clearly offered and justification for the research had given. Pattern dimension appears enough. It's reported that “….bacterial cultures had been taken throughout 207 random operations…” (p. 176), however no particulars of the sampling technique used had been offered. Particulars of interventions got elaborately and outcomes had been mentioned intimately. However just one desk and two charts used to current it. The readers would have been extra benefited if extra tables had been used to current the outcomes. Discussions of the outcomes had been concise and findings had been particular and satisfying the target. No info on whether or not they obtained knowledgeable consent from the sufferers and approval kind the moral committee of the establishment was lacking. This come up a critical query in regards to the ethics of this research.

It's discovered that laminar airflow is more practical when use along with occlusive clothes (Charnley, 1969 cited in Sandiford and Skinner 2009). Whereas of their latest research Miner (2007) in contrast the effectiveness of laminar airflow system and physique exhaust fits discovered that physique exhaust fits are more practical than laminar stream system in decreasing an infection.

For his or her research Miner (2007) chosen 411 hospitals which have submitted the declare for complete knee surgical procedure (TKR) for the 12 months 2000 from 4 US States had been surveyed to gather the main points of use of laminar air stream system and physique exhaust fits. These hospitals which had been fulfilled three standards had been included on this research. The inclusion standards had been 1) returned the survey instrument, 2) utilizing laminar air stream system or physique exhaust fits for an infection management and three) was proof of not less than one Medicare declare for TKR for the research interval. Whole 8288 TKRs carried out in 256 hospitals between 1st January and 30th August 2000 had been chosen. Knowledge on affected person outcomes after complete knee alternative (TKR) had been collected from Medicare claims. The sufferers who underwent bilateral TKR weren't included on this research and for many who underwent a second TKR throughout a separate hospitalisation throughout the research interval, solely the primary process was included. Worldwide Classification of Illnesses, Ninth Revision (ICDS-9) codes was used to determine post-operative deep an infection that wanted extra operation. Hospitals had been grouped as customers or non-users for each laminar airflow and physique exhaust fits. “Customers” had been outlined as those that use any of those strategies in additional than 75% procedures and “non-users” had been these use any strategies lower than 75%. The over-all 90-day incidence of deep an infection, subsequent operation was discovered required solely in 28 circumstances (that's zero.34%). Evaluation discovered that the danger ratio for laminar airflow system was larger (1.57, 95% confidence interval zero.75-Three.31) than physique exhaust fits (zero.75, 95% confidence interval zero.34-1.62). Examine discovered that there have been no important variations in an infection between hospitals that use particular both protecting measure.

Apart from mentioning few research researchers failed to offer any background of the analysis drawback. Strategies used for this research had been defined concisely. Though the pattern dimension was giant, restricted variety of occasions (28) had been there to be noticed. Evaluation was based mostly on this small variety of occasions; this will have affected the consequence. Not many variables had been included on this research, and researchers didn’t point out how they managed some doable confounders. Researchers had been profitable in figuring out the benefits and limitations of the research. Outcomes had been correctly offered in tables.

As an alternative of high-priced laminar air-flow system, set up of well-designed air flow system is discovered useful. Scaltriti (2007) carried out a research in Italy to look at effectiveness of well-designed air flow system on air high quality in operation theatre. They chose operation theatres of a newly constructed 300 beds group hospital which have air flow system designed to attain 15 full out of doors air adjustments per hour and are geared up with zero.Three µm, 99.97% HEPA filters. All these fulfill the situation for a clear room as per ISO 7 customary. Passive samples of microbiological air counts had been collected utilizing Tripticase Soy Agar 90 mm plates left open thorough out the length of the process. Lively samples had been additionally collected utilizing a single state slit-type impactor. Whole 82 microbiological samples had been collected of which 69 had been passive plates and 13 had been lively. Air mud was counted with a light-scattering particle analyser. Particulars of the surgical procedure, variety of folks within the room, door opening fee and estimated complete use of the electrocautery unit had been additionally collected.

It was discovered that there have been constructive correlations between particle contamination, surgical method (larger danger from basic standard surgical procedure), electrocauterization and operation size. Door opening fee was discovered negatively related. Researchers recommend that this will as a result of when theatre door open a turbulent air stream blows out of the working room which can consequence lower within the mud particles. No affiliation was discovered between particle contamination and variety of folks current on the time of incision. Researchers recommend that human motion fairly than human presence is the issue that determines airborne microbial contamination. It was discovered that common particle focus within the theatres didn't exceed the European ISO 14 644 customary limits for ISO 7 clear room, and so concluded that well-designed air flow system is efficient in limiting particulate contamination.

Uncultivable or unidentifiable organisms may also be a purpose for surgical web site infections. It could be tough to determine such organisms by way of customary tradition methods (Tunney 1998). Clarke (2004) carried out a quantitative research to look at the effectiveness of ultra-clean (vertical laminar stream) theatres in stopping infections by unidentifiable organisms. They used the molecular method, Polymerase Chain Response (PCR), to detect micro organism presence. Their research in contrast the wound contamination throughout main complete hip alternative (THR) carried out in customary and extremely clear operation theatres. 20 sufferers underwent main THR from 1999 to 2001 had been recruited for this research. Sufferers with earlier incidents of joint surgical procedure or an infection had been excluded. The usual operation theatres had 20 air adjustments per hour and CFU rely was 50 CFU/m3, whereas ultra-modern theatres had 530 air adjustments per hour and CFU rely was Three CFU/m3.

For all surgical procedures similar an infection management precautions had been used. Two specimens every of pericapsular tissues had been collected from posterior joint capsule each firstly and on the finish of the surgical procedure (complete 80 samples). Sufferers got antibiotic prophylaxis after taking the primary specimen. All these samples had been underwent Gram stain and tradition to detect bacterial colonies and Polymerase Chain Response (PCR) to detect bacterial DNA.

Among the many 20 specimens taken kind the usual operation theatres firstly of the surgical procedure solely Three had been discovered constructive with PCR, whereas from the ultra-clean theatres solely 2 had been discovered constructive. None from each theatres discovered constructive with tradition. Samples from the usual theatres taken on the finish of the surgical procedure, 2 discovered constructive by tradition and 9 discovered constructive by PCR. The contamination fee in the usual theatre on the finish of the surgical procedure discovered considerably better than the start (p=zero.04). Samples taken from the ultra-clean theatres, none was constructive by tradition whereas solely 6 had been constructive by PCR. Statistical evaluation discovered that contamination fee on the finish of the surgical procedure just isn't statistically completely different than the beginning (p=zero.1). It was discovered that there have been no statistically important distinction in general contamination fee (p=zero.Three) between customary and extremely clear theatres. (I'll add critique of this research right here)


Understanding the supply of contamination in working theatre and understanding the connection between bacterial virulence, affected person immune standing and wound atmosphere will assist in bettering the an infection charges (Byrne et al 2007).

Nurses are accountable to take a proactive position in guaranteeing security of their sufferers. To enhance affected person final result, it's crucial for the nurses to take lead position in environmental management and figuring out hazards by way of environmental surveillance (Neil 2005). Non-adherence to the precept of asepsis by surgical crew is recognized as a major danger issue of infections. Hectic motion of surgical crew members within the working room and presence of a number of guests had been additionally discovered as main causes of SSI (Beldi G 2009). Nurses and managers ought to emphasise on controlling elements just like the visitors in theatre, limiting the variety of employees and reinforcement of strict aseptic method (Allen 2010). Creedon (2005) argues that infections can scale back as much as one third if staffs observe greatest apply rules. For higher final result staffs wants extra schooling and constructive reinforcement.

Nurses have an important position within the growth, reviewing and approving of affected person care insurance policies relating to an infection management. Nurses should not solely answerable for training the aseptic methods but in addition answerable for monitoring different employees for his or her adherence to insurance policies. They're answerable for growing coaching programmes for members of employees. Educating the environmental companies personnel like technicians, cleaners won't solely enhance their information in affected person care but in addition present a way of dedication in affected person outcomes (Neil 2005).

Perioperative nurses can contribute in analysis relating to theatre air flow system by way of organised knowledge assortment and documenting evidences. Nurses can contribute in giving optimum and protected supply of care in areas the place environmental points can put the affected person in danger. Information is altering quick, so it will be significant that employees should maintain themselves updated. Continues high quality enchancment is required and it ought to be based mostly on proof based mostly analysis and on-going evaluation of knowledge (Hughes 2009).


Critiques of present analysis exhibits that also there's a lack consensus on the effectiveness of laminar airflow in an infection management. Research embody on this evaluation has used both medical outcomes (an infection or reoperation fee) or intermediate outcomes (particle rely or bacterial rely) to guage the effectiveness of laminar stream. Kakwani (2007) discovered that re-operation fee was decrease in laminar airflow theatres however Brandt (2008) discovered SSI fee was excessive in hospitals with laminar stream. Clarke (2004) discovered that contamination was not considerably completely different in extremely clear theatres in comparison with customary theatres geared up enhanced air flow system. Supporting this discovering Scaltriti (2007) discovered effectively designed air flow system is efficient in decreasing contamination.

Examine by Knobben (2006) discovered that mixture of systemic and behavioural adjustments are required to stop intra-operative contamination. Miner (2007) discovered that there have been no important variations in an infection between hospitals that use laminar airflow and physique exhaust fits.

From these research it may be concluded that use of laminar airflow alone can assure an infection prevention. Behavioural and different systemic adjustments are crucial to reinforce the advantages of laminar airflow. Proof exhibits that standard theatres geared up with enhanced air flow system can stop an infection successfully, this may be take into account instead for costly as laminar stream system.