850 Surgical Versus Non-Surgical Treatment of Unstable Lateral Compression Injuries of the Pelvis with Complete Sacral Fractures (LC1) in Non-Fragility Fracture Patients: A Systematic Review

Background

Lateral compression type 1 (LC1) injuries comprise two-thirds of pelvic fractures. Approximately one third of LC1 fractures are unstable and may benefit from surgical fixation to improve stability but it is not clear if this leads to better clinical or cost-effectiveness outcomes.

Method

We performed a systematic review to determine whether surgical or non-surgical treatment yielded better clinical and cost-effectiveness for the treatment of unstable LC1 pelvic injuries with complete sacral fracture, excluding fragility fractures. We searched Medline, Embase and Cochrane databases from inception to June 2021, as well as clinical trials registries.

Results

Five observational studies met the inclusion criteria. 183 patients were treated surgically, and 314 patients treated non-surgically. Patients treated surgically had lower pain levels (Visual Analogue Scale) and fewer days to mobilisation. Quality of life (EQ-5D and SF-36 questionnaires) was better in the surgical group, but not statistically significant. No statistical differences in length of hospital stay or complication rates were found. Formal meta-analysis was not possible due to available study designs and heterogeneity.

Conclusions

This review highlights the low quantity and quality of existing data on patients with unstable LC1 pelvic fractures and the need for a definitive randomised controlled trial to determine whether surgical or non-surgical care should be the preferred treatment in terms of clinical and cost-effective care.

1301 Early MRI in the Diagnosis of Suspected Scaphoid Fractures – An Audit of a Redesigned Diagnostic Pathway

Introduction

MRI is the gold standard for investigation of suspected scaphoid fractures, which can be missed on initial x-rays. This full cycle audit reports the impact of our new patient pathway, which changes repeat x-rays at 2 weeks to urgent limited sequence scaphoid MRI for those with normal initial x-rays, but clinical suspicion of fracture at initial clinic visit.

Method

A second cycle audited MRI requests for suspected scaphoid fractures at Southmead hospital following implementation of the new pathway in October 2020. We collected wait times from request to scan, and radiologist reports. Results were compared to our first cycle, 6-month time period.

Results

he results for 24 limited sequence MRIs via our new pathway were compared to 134 full wrist MRIs of the first cycle. Two scans (9.1%) were positive for scaphoid fracture versus 12% in the first cycle. 19 scans (86%) identified alternate pathology including sprain (6), bone bruise (5), non-scaphoid fractures (4) and degenerative change (3). 1 scan (4.5%) was reported as normal. 73% of MRIs were performed within 14 days, compared to 63% in previous cohort.

Conclusions

Our new pathway using limited sequence MRI identified similar rates of scaphoid fractures. Reduced time to MRI was observed compared to the previous cohort due to shorter scan durations and resulted in earlier diagnosis and fewer outpatient follow-up appointments. Our new pathway has benefits to patient experience and also reduces footfall in hospital, during a time of global Covid-19 pandemic, with no increase in costs.

1484 Tranexamic Acid Use to Decrease Blood Loss in Primary Shoulder and Elbow Replacement: A Systematic Review and Meta-Analysis

Tranexamic acid (TXA) is an inexpensive, commonly used antifibrinolytic agent that has been shown to significantly reduce perioperative blood loss and transfusion requirements after total hip and knee replacement. We conducted a systematic review and meta-analysis to synthesise the latest evidence regarding the effects of TXA on blood loss in total shoulder replacement (TSR) and total elbow replacement (TER).

We systematically searched MEDLINE, EMBASE and CENTRAL from inception to 03 September 2020 for randomised controlled trial (RCTs) and observational studies. Our primary outcome was blood loss, and secondary outcomes included the need for blood transfusion and venous thromboembolic (VTE) complications.

Four RCTs and five retrospective cohort studies (RCS) met eligibility criteria for TSRs, but none for TERs. RCT data determined that TXA administration significantly decreased estimated total blood loss, postoperative blood loss, change in haemoglobin (Hb) and total Hb loss when compared to placebo. RCS data demonstrated significant association between TXA administration and decreased in postoperative blood loss, change in Hb, change in Hct and length of stay.

This meta-analysis demonstrates that TXA administration in primary TSR significantly decreases blood loss compared with placebo and is associated with lower blood loss and shorter length of stay compared with no treatment with no increase in VTE complications. TXA administration should be part of a wider blood management strategy to minimise perioperative blood loss and blood transfusion requirements in patients undergoing TSR. Further research is needed to demonstrate if a similar treatment benefit exists in patients undergoing TER.

197 Acute Management of Traumatic Anterior Shoulder Dislocations During COVID-19: Are We Meeting Published National Standards for Treatment During the Pandemic?

Background

BESS/BOA Patient Care Pathways provide national guidelines for acute management of traumatic anterior shoulder dislocations with respect to emergency reduction and clinic follow-up. COVID-19 posed challenges in terms of analgesia choice for reductions and altered follow-up arrangements. This study aimed to assess variance from the care pathway.

Method

We performed a retrospective case note analysis of all emergency presentations with acute traumatic anterior shoulder dislocations at the MTC in Bristol from 01/04/2019-31/05/2019 to the same period in 2020 to analyse the effects of COVID-19 on management of these injuries.

Results

We identified 32 patients in 2019, and 24 in 2020. Entonox usage fell, in favour of Penthrox. Use of conscious sedation (requiring full PPE) remained around 20%. Pre- and post-reduction imaging was near 100% throughout. Referral to follow-up was 88% in 2019 but 38% in 2020. Those assessed in clinic during COVID-19, fewer were mobilised early or referred to outpatient physiotherapy compared to 2019.

Conclusions

Acute management of anterior shoulder dislocations during COVID-19 was challenged by choice of suitable analgesia that limits AGPs, and limiting access to ’face-to-face’ follow-up. A key concern was a significant decrease in patient follow-up, thus limiting the access to optimal aftercare such as physiotherapy and further imaging.

198 Orthopaedic Trauma Services During A National Lockdown and Pandemic: Workload and Outcomes from A UK Major Trauma Centre. The Need for Continuing the Provision of Services

Aim

To review the trauma operating workload, theatre time and outcomes at a time of national lockdown and the beginning of the COVID-19 pandemic, comparing it with 2019.

Method

A retrospective analysis at a single UK MTC. We included all patients undergoing emergency/urgent T&O surgery. Data collected included anatomical injury site, mechanism of injury, operative procedure, anaesthesia, theatre time, complications, and 30-day mortality.

Results

159 operations were performed on 142 patients in April 2019, and 110 operations on 106 patients in April 2020 (national lockdown). This led to a decrease of 30% due to reduced numbers from RTAs and sport-related injuries. Volumes of hip fractures and injuries from low-energy falls remained the same. Operative total theatre time increased by a mean of 14 minutes, and complications and mortality were not significantly changed. The incidence of COVID-19 in the patients tested was 8.5%, which matched the population incidence at the time.

Conclusion

Orthopaedic trauma services must be maintained during a national lockdown. There is no decrease in the volume of patients sustaining falls, including hip fractures. Mean operating time only increases by 14 minutes with the wearing of PPE. This should be part of future planning of any pandemics or national lockdowns.

Effects of nutrient content claims, sports celebrity endorsements and premium offers on pre-adolescent children's food preferences: experimental research

OBJECTIVES

To assess pre-adolescent children's responses to common child-oriented front-of-pack food promotions.

METHODS

Between-subjects, web-based experiment with four front-of-pack promotion conditions on energy-dense and nutrient-poor (EDNP) foods: no promotion [control]; nutrient content claims; sports celebrity endorsements (male athletes) and premium offers. Participants were 1302 grade 5 and 6 children (mean age 11 years) from Melbourne, Australia. Participants chose their preferred product from a randomly assigned EDNP food pack and comparable healthier food pack then completed detailed product ratings. Child-oriented pack designs with colourful, cartooned graphics, fonts and promotions were used.

RESULTS

Compared to the control condition, children were more likely to choose EDNP products featuring nutrient content claims (both genders) and sports celebrity endorsements (boys only). Perceptions of nutritional content were enhanced by nutrient content claims. Effects of promotions on some product ratings (but not choice) were negated when children referred to the nutrition information panel. Premium offers did not enhance children's product ratings or choice.

CONCLUSIONS

Nutrient content claims and sports celebrity endorsements influence pre-adolescent children's preferences towards EDNP food products displaying them. Policy interventions to reduce the impact of unhealthy food marketing to children should limit the use of these promotions.

Renal power Doppler ultrasound does not predict renal scarring after urinary tract infection

OBJECTIVE

Young children may develop renal scarring following a urinary tract infection (UTI) especially after pyelonephritis which is difficult to diagnose. Permanent renal scars are diagnosed by dimercapto-succinic acid (DMSA) scan several months later. To decrease unnecessary exposure to radiation, we investigate the role of renal power Doppler (RPD) in predicting those who may not require a late DMSA scan.

METHODS

Children under four years of age with a first UTI underwent an RPD study soon after diagnosis, and a DMSA scintigraphy six months later. The predictive values of the early RPD to detect DMSA renal scarring were calculated.

RESULTS

Twenty three children (median age 30 months) were enrolled: 13 had a febrile presentation, two with bacteraemia. Permanent scarring occurred in three children (13%). In the 46 kidney units studied, initial RPD was abnormal in two and late DMSA abnormal in three units. Overall concordance between RPD and DMSA was 93.5%. The sensitivity of RPD for renal scar as per DMSA was 33.3%, specificity 97.7%; positive predictive value 50% and a negative predictive value of 95.4%.

CONCLUSIONS

RPD offered no advantage over ultrasound to predict renal scarring and cannot be recommended to predict renal scarring following UTI.

Airborne concentrations of volatile organic compounds in neonatal incubators

OBJECTIVE

To identify and quantify airborne volatile organic compounds (VOCs) inside neonatal incubators during various modes of operation within the neonatal intensive care unit (NICU) environment.

STUDY DESIGN

Air samples were taken from 10 unoccupied incubators in four operational settings along with ambient air samples using air sampling canisters. The samples were analyzed following EPA TO-15 using a Tekmar AutoCan interfaced to Agilent 6890 Gas Chromatograph with a 5973 Mass Spectrometer calibrated for 60 EPA TO-15 method target compounds. Non-target compounds were tentatively identified using mass spectral interpretation and with a mass spectral library created by National Institute for Standards and Technology.

RESULT

Two non-target compounds, 2-heptanone and n-butyl acetate, were found at elevated concentrations inside the incubators compared with ambient room air samples. Increase in temperature and addition of humidity produced further increased concentrations of these compounds. Their identities were verified by mass spectra and relative retention times using authentic standards. They were quantified using vinyl acetate and 2-hexanone as surrogate standards.

CONCLUSION

The emission pattern of these two compounds and background measurements indicate that they originate inside the incubator. There is evidence that exposure to some VOCs may adversely impact the fetal and developing infants' health. Currently, as there is no definitive information available on the effects of acute or chronic low-level exposure to these compounds in neonates, future studies evaluating the health effects of neonatal exposure to these VOCs are needed.

Estimating the reduction of urban PM10 concentrations by trees within an environmental information system for planners

Trees have been widely quoted as effective scavengers of both gaseous and particulate pollutants from the atmosphere. Recent work on the deposition of urban aerosols onto woodland allows the effect of tree planting strategies on airborne aerosol concentrations to be quantified and considered within the planning process. By identifying the potential planting locations in the local authority area, and applying them within a dispersion and deposition model, the potential magnitude of reduction in the ambient concentration of PM(10), achievable through urban tree planting, has been quantified for two UK cities. As part of the Environmental Information Systems for Planners (EISP), flow diagrams, based on planning decisions, have incorporated output from the model to make decisions on land use planning ranging from development plans and strategic planning, to development control. In this way, for any new developments that contribute to the local PM(10) level, the mitigation by planting trees can be assessed, and in some cases, reductions can be sufficient to meet air quality objectives for PM(10).

Recall and response of smokers and recent quitters to the Australian National Tobacco Campaign

OBJECTIVE

To track national population indices of recall and response among smokers and recent quitters to an ongoing national televised anti-smoking campaign in Australia.

METHOD

National cross sectional population telephone surveys of adults.

MAIN OUTCOME MEASURES

Unprompted recall of advertising; recognition of advertising; campaign attributed encouragement to quit or stay quit; unprompted awareness of smoking related health effects; new learning about smoking and health; and agreement with campaign related attitudes.

RESULTS

Campaign advertising continued to be highly memorable over the period of study, with 88% having confirmed recognition in 2000. Campaign advertising was consistently thought by half of smokers who had seen it to make them more likely to quit (49% in 2000). Specific changes between surveys in unprompted awareness of smoking related health effects, new learning about smoking and health, and agreement with campaign related attitudes were observed in relation to the main messages of the advertisements, which were time sensitive according to the year of launch of the advert. The "artery" advertisement was associated with the largest and most consistent positive change in all of these parameters. The proportion of respondents who disagreed that the dangers of smoking had been exaggerated increased significantly from 59% in May 1997 to 68% in November 2000.

CONCLUSION

A national campaign using graphic advertising to emphasise the health risks of smoking can make significant population wide contributions to improving new learning about smoking damage and positively influence attitudes about smoking risks.

Family member ride-alongs during interfacility transport

INTRODUCTION

A significant portion of the Air Med Team (AMT) flight missions involves interfacility transport of the ill or injured to receiving facilities with comprehensive resources available for their care. In an effort to help meet the psychologic needs of our patients and their families, AMT developed a Family Member Ride-Along program that allows family members or significant others to accompany patients during interfacility transport. The purpose of this study was to evaluate the ride-along program from the perspective of the family member passenger (FMP) who has accompanied a patient during transport.

METHODS

Thirty-one family member ride-alongs responded to a 10-item questionnaire using a scaled response. Questions were designed to evaluate the benefit of the ride-along program to patients and family members from the FMP perspective.

RESULTS

All FMPs surveyed thought the program was beneficial to either themselves or the patients. Several benefits described by FMPs included the ability to offer emotional support to the patient, provide patient information to receiving physicians, and sign releases for medical treatment. During interfacility transports, FMPs did not hinder either patient care or transport safety.

CONCLUSION

Our study shows that allowing FMPs to accompany patients during transport benefits both patients and family members.

Serum lactate is not predicted by anion gap or base excess after trauma resuscitation

OBJECTIVE

The inability to normalize lactate predicts death after trauma, but lactate may not be immediately available in every center. We postulated that, in a normal acid-base environment, lactate would correlate with the anion gap and the base excess of an arterial blood gas.

METHODS

We studied 52 consecutive, invasively monitored patients with trauma admitted directly to the intensive care unit (ICU) from the emergency department or operating room in our level I center to determine whether base excess and anion gap could predict lactate. Lactate, base excess, and anion gap were recorded upon admission to the ICU and 8, 16, 24, 36, and 48 hours after admission. Correlation coefficients (r2) were calculated for the total patients, the 43 survivors, and the nine non-survivors.

RESULTS

Serum lactate was significantly higher in nonsurvivors at 16 hours after post ICU admission (4.0 +/- 1.69 vs. 2.84 +/- 1.49, p < 0.05), and this trend persisted; the greatest difference was seen at 48 hours after admission (2.92 +/- 1.47 vs. 1.76 +/- 0.57, p < 0.001). There were no differences in base excess or anion gap between survivors and nonsurvivors. We found no consistent correlation between lactate versus anion gap, lactate versus base excess, or anion gap versus base excess.

CONCLUSIONS

There is no correlation between lactate, base excess, and anion gap after initial resuscitation. Neither anion gap nor base excess was capable of predicting lactate; therefore, lactate must be directly measured. The lack of correlation of anion gap with base excess or lactate suggests the presence of unmeasured anions, an impairment in acid-base regulation after injury and resuscitation, or both.

Improving the lives of home care workers: a partnership of social work and labor

A school of social work with an occupational program specialization entered into an agreement with one of the largest trade unions in New York City to do a social and health services needs assessment for the union's newest members: home care workers. The vast majority of these home attendants are low-income African American and Latina women who care for frail aged and disabled Medicaid recipients to prevent nursing home placement. Structured interviews with a sample of 400 union members indicated a need for better health care coverage, especially for stress-related illnesses, along with personal social services to assist with housing, debt, child care, and family issues. The union used this independent university data in its subsequent collective bargaining and won expanded benefits for its members based on demonstrated need. The school then established a union-funded member assistance program to institutionalize ongoing support for these members. In the end, action research helped to create both social services and social change; low-income women of color have gained tangible new benefits; and social work's important ties to organized labor have been strengthened.

Amrinone as an inotrope in managing hypermetabolic surgical stress

Dobutamine is the standard inotrope used as cardiac support for hyperdynamic hypermetabolic patients following acute surgical stress. Amrinone has been utilized in medical patients with heart failure, but its use in hyperdynamic patients to our knowledge has never been reported. We now report the results of a trial of amrinone versus dobutamine in this setting. Over a 3-month period, we compared 28 trials of dobutamine and 27 trials of amrinone in 47 patients. Attempts were made to achieve non-flow-dependent oxygen consumption. Values are expressed as pre/post inotrope. Student's two-tailed t test was used for evaluation. [table: see text] Patients treated initially with dobutamine were slightly younger (mean, 46 vs. 57 years). They required slightly higher doses of dobutamine (mean, 12.9 vs. 12.2 micrograms/kg/min) and a slightly longer treatment period (mean, 11.3 vs. 9.8 hours) to achieve the desired effect. Of the 47 trials with dobutamine, six (13%) failed to achieve non-flow-dependent oxygen consumption. All then responded somewhat to amrinone. The failure rate for amrinone was 10%. No patient developed hypotension when treated with either drug. Amrinone is an effective inotrope useful in the cardiovascular support of hyperdynamic patients following surgical stress. Hypotension is not a problem with adequate intravascular volume loading. It should become part of the standard drug regimen in the surgical ICU.

Vaccine protection of rhesus macaques against simian immunodeficiency virus infection

Rhesus macaques (Macaca mulatta) immunized with an inactivated whole SIVmac vaccine and muramyl dipeptide (MDP), incomplete Freund's adjuvant (IFA), or aqueous suspension were challenged intravenously with 0.1 TCID50 of cell-free SIVmac. Whereas virus was readily recovered from the peripheral blood lymphocytes of 10 of 10 nonvaccinated controls following this challenge dose, virus was not recovered from the three animals that received the vaccine with MDP nor from one of two animals that received the vaccine with IFA and one of three animals that received the aqueous vaccine. The animals that were protected against challenge were those that had detectable SIV antibody response to the envelop, both the outer glycoprotein (gp120) and the truncated transmembrane glycoprotein (gp31). Protected monkeys tended to have higher titers of syncytial inhibition antibody prior to challenge. An anamnestic response after challenge was observed only in the vaccinated monkeys that became infected. Vaccinated animals that became challenge-infected tended to live longer than infected controls. These results confirm those at two other primate centers and indicate that killed whole SIV vaccines can protect against low challenge doses of SIV and prevent early death in those monkeys that do become infected. The mechanism of this protection remains undetermined. This finding adds optimism to the possibility of an eventual AIDS vaccine.

Polymorphonuclear leucocyte motility in patients with severe burns

Chemotaxis, chemokinesis and cellular orientation were measured for unstimulated and 10(-7) n-formyl methionyl leucyl phenylalanine (F-met-leu-phe) stimulated polymorphonuclear leucocytes (PMNS) of nine patients with recent 10-80 per cent burns using a computer-assisted image analysis technique. The technique records PMN movement, as viewed with a phase-contrast microscope on videotapes, and then uses computer programs to calculate the speed and direction of up to 50 PMNS over a 5-min period. Orientation was determined visually. Cellular adherence was also measured by attachment methods. PMNS from burn patients were slower (av. speed 16.8 microns/min), responded less well to F-met-leu-phe (av. speed 20.9 microns/min, av. McCutcheon index 0.32), were less often oriented towards the chemoattractant (av. 39 per cent) and were more adherent (av. 50 per cent) than control cells (av. speed 21.8 microns/min; av. speed F-met-leu-phe 32.2 microns/min; McCutcheon index 0.61; oriented 59 per cent adherent; 16 per cent). Thus PMNS from burn patients orient less well, are significantly slower and have less directionality in response to a chemoattractant, and are more adherent suggesting activation.

Obliteration of the middle ear cleft

All patients who have undergone obliteration of the middle ear cleft at Plymouth are reviewed. All had chronically discharging mastoid cavities and middle ears resistant to medical treatment, and all had at least one major operation to eradicate disease. All had an average hearing loss on the affected side of more than 80 decibels prior to operation. All ears have remained dry since obliteration, with a blind pit in the meatus. There have been no complications apart from a collection of fluid under one muscle flap.

Work stress and job satisfaction: a study of home care workers in New York City

New York has pioneered the development of publicly-financed home care, establishing a 60,000 member home care workforce that is by far the largest in the nation. This paper describes the Medicaid-funded home care program in New York City and presents findings from a recent survey of the workforce. Data are presented on working conditions in the industry suggesting that structural reform is urgently needed in the employment system for home care workers in New York City. The findings have national implications for the future planning of home care services.

Cellular telephone transmission of 12-lead electrocardiograms from ambulance to hospital

Currently, only single-lead, serial telemetry rhythm strips can be transmitted from ambulances. Triage of patients with chest pain and administration of thrombolytic therapy in ambulances is limited by the lack of specific electrocardiographic (ECG) diagnosis. A new technique is described using cellular telephone transmission of simultaneous 12-lead ECGs from ambulance to hospital to overcome this limitation. A portable 12-lead ECG installed in an ambulance was connected via modern link to a cellular telephone and digitized ECG information was transmitted to an ECG device in the hospital emergency room. Paramedics in the field placed adhesive patch electrodes and attached ECG wires. Field ECGs from 23 patients were compared with corresponding transmitted ECGs. There were no differences in heart rate, PR interval, QRS duration, QT interval or R- and T-wave axes. Baseline and transmitted ECGs had identical morphologic characteristics. Differences in R-wave amplitude in 5 transmitted tracings compared with hospital-recorded ECGs resulted in computer diagnosis of left ventricular hypertrophy by voltage, possibly due to differences in patient position. Twelve-lead ECGs can be easily transmitted from a moving ambulance using cellular telephones. This allows diagnosis before hospital arrival, improves prehospital triage of patients and may facilitate prehospital therapy with lidocaine or streptokinase. In addition, the cellular telephone link can convey both verbal and digitized information and thus improve on current telemetry systems.

Effect of 0.64 ppm ozone on rats with chronic pulmonary bacterial infection

Rats were chronically infected with Pseudomonas aeruginosa by entrapping viable bacteria in agar beads and intratracheally inoculating the beads into the left lung. The infection was allowed to stabilize over a 10-d period and the animals were then placed in environmental chambers and exposed to either filtered air or 0.64 ppm ozone (23 h/d) for 14 or 28 d. Rats exposed to ozone had reduced body weight and increased lung sizes and lung weights when compared with animals breathing filtered air. Rats inoculated with beads containing live P. aeruginosa had increased lung weights when compared with rats inoculated with beads containing heat-killed P. aeruginosa or controls. Quantitation of total viable bacteria in rats exposed to ozone or to filtered air revealed no significant differences in bacterial numbers. Thus, in this model, chronic exposure to ozone produces increases in lung volume and weight but does not enhance a smoldering Pseudomonas infection.

Immunological studies in children undergoing tonsillectomy

Serum IgA concentrations in children undergoing tonsillectomy for recurrent sore throats were lower than those of a control population. Haemophilus influenzae was usually grown from children with lower IgA concentrations, near to and below 2 SD below the control mean. Their values were significantly lower than those from patients from whom β haemolytic streptococci were grown. Some of the children with low IgA had low antistreptolysin titres and little or no lymphocyte response to PHA. There was no relationship between the immunological findings and the pre-operative severity of symptoms, but there was with the incidence of infection in the post-operative year. These findings will necessitate reappraisal of surgery and prophylactic antibiotics in the two groups separately.

These findings suggest that tonsils from children presenting with indistinguishable syndromes are infected with different bacteria, depending on the immunological function of the child. Since tonsillectomy is common, there appears to be clinical relevance for the range of immunological function near to or within the `normal limits'.

COMPARISON OF METHOXYMERCURIALS DERIVED FROM CYCLOPENTENE AND CYCLOHEXENE

The α- and β-2-methoxycyclopentylmercuric chlorides, bromides, and iodides have been prepared. The X-ray powder patterns, dipole moments, and thermal analyses among each series have been compared with the homologous methoxycyclohexyl derivatives. In both of the series the dipole moments of the β-diastereomers are greater than those of the corresponding α -isomers. In both series the α- and β-diastereomers seem to comprise isostructural series among the three halides. This isostructural relationship seems to be reflected in the melting point composition diagrams.

THE SORPTION OF ACIDS BY WOOL

The amount of acid sorbed by wool from solutions of sulphuric acid of four different strengths (namely, 0.0505, 0.0339, 0.0182, and 0.0101 molar) and containing sodium sulphate in amounts varying up to 0.16 molar has been determined. It has been found that the presence of the salt has little effect on the quantity of acid sorbed within those limits. The results are analyzed in the light of the theory of Gilbert and Rideal but this theory fails to give a satisfactory explanation of the results obtained. It is possible, however, to explain the results of the authors' experiments on the basis of the recent application of the Donnan equilibrium by Peters and Speakman. The Langmuir adsorption isotherm equation has been applied to data on the absorption of hydrochloric acid and of sulphuric acid by wool. The data appear to fit the Langmuir equation and give, for the maximum combining capacity, values that agree well with those estimated in other ways.