Medical Complications of Pregnancy

Check this useful video podcast done by Dr Andy Neill. Andy is an Emergency Medicine doctor from Dublin.

http://vimeo.com/112509456

Check Andy"s blog for more useful information

 

Medical Complications of Pregnancy

Critical Appraisal Practice Paper 3 (Therapeutic)

Total marks: 23
Time allowed: 90 mins

You might wish to download the paper. Do it in 90 minutes and then compare with the answers provided here.

Paper: A Randomized Trial of Nebulized 3% Hypertonic Saline With Epinephrine in the Treatment of Acute Bronchiolitis in the Emergency Department

Download (PDF, 133KB)

1. Provide a summary / abstract for the paper. (Up to 5 marks)

Answer

Answer

This should include all or some of the following points:

Objective: To determine whether nebulised 3% hypertonic saline with epinephrine is more effective than nebulised 0.9% saline with epinephrine in the treatment of bronchiolitis in the emergency department.

Design: Randomised double blind controlled trial Setting: Single centre urban paediatric emergency department in Canada. Participants: Infants younger than 12 months with mild to moderate bronchiolitis.

Interventions: Patients were randomised to receive epinephrine in either hypertonic or normal saline.

Outcome measures: The primary outcome measure was the change in respiratory distress, as measured by the Respiratory Assessment Change Score (RACS) from baseline to 120 minutes. Change in oxygen saturation was also determined. Secondary outcome measures included rates of hospital admission and unbooked return to the ED following discharge.

Results: 46 patients were enrolled. The two groups had similar baseline characteristics. RACS from baseline to 120 minutes demonstrated no improvement in respiratory distress in the hypertonic saline group when compared to the normal saline group. The change in oxygen saturations in the hypertonic group was also no different to that of the normal saline group. Rates of admission and unplanned return to the ED were similar between the two groups.

Conclusion: In this study hypertonic saline with epinephrine did not improve clinical outcome in acute bronchiolitis when compared to normal saline with epinephrine.

2. Give 3 strengths and 3 weaknesses of the study design? (Up to 3 marks)

Answer

Answer

Strengths:

• Done in a paediatric ED


• Patients defined quite tightly in terms of clinical features and RDAI Score. Patients are thus likely to have bronchiolitis


• Demographic and clinical data collected by research assistants using standard data collection form.


• Excellent allocation concealment. Pharmacy made up identical looking syringes and retained the randomisation list until the end of the study.


• Blinding also good. Neither staff nor patients were aware of their treatment


• Outcomes are clearly defined and seem relevant and important.

Weaknesses:

• Limited hours of enrolment (4pm to 2 am). ? selection bias


• Only conducted if research assistant was available


• Whilst scoring system well defined it seems quite complex and open to interobserver variability (although the authors state not)


• It’s unclear who is assigning the RDAI score.

There are some things you can put into either column! These basically relate to whether you like pragmatic trials (most ED ones should be I think) or explanatory trials. Examples here include:

• Physicians being able to give any other treatment as they see fit during the study period including a further dose of the trial medication. This is very “real world” (pragmatic) and I think is a strength. You may feel that to be of any value all the patients should have had the same treatment except the trial medication (the explanatory approach) and thus see this as a weakness


• Similar argument for the use of trained and educated research assistants in collecting the data and looking after the patients. Could be seen as a weakness as it’s not very “real world” (when stressed out busy people would be trying to look after several patients at a time!). On the other hand, the data you get will be more accurate.
  

3. What is block randomisation? What are the benefits and pitfalls of this method? (Up to 3 marks)

Answer

Answer

Block randomisation is a technique used to ensure that at any particular time in a study, the number of patients in each group is roughly similar.

In this study the authors used blocks of 4. Each block will have 2 of each of the treatments (although their position within the block of 4 will be randomly allocated). The blocks themselves are then randomised. In this way one group can never have more than 2 patients more than any of the others at any time.

The biggest pitfall with this method is that it might be possible for researchers or the ED medical or nursing staff to guess what the next treatment is going to be. E.g. if the research assistant is on patient 7, and knows that the last 2 patients had got better more quickly than usual (if she had a pre conceived idea than hypertonic saline was marvellous!), she might assume that the next patient was going to get normal saline. This might affect decisions about whether to include the patient in the trial in the first place.

In this particular example this doesn’t seem to have been a problem because the treatments look the same and their effects were similar. However it can be a problem when the person initiating the trial treatment is not blinded (eg NIV versus standard facemask) or the treatments can be distinguished in other ways (e.g. a trial of iv Pabrinex versus iv “brown” saline for alcoholics when the smell might give it away!)

4. What alternative methods of treatment allocation are there? (Up to 1 mark)

Answer

Answer

Single patient randomisation

Quasi randomisation – e.g. days of the week, hour of the day etc..

5. What do you understand by the term “intention-to-treat”? What are the advantages of this? What is the opposite approach and what advantages does this have? (Up to 4 marks)

Answer

Answer

Intention to treat includes all randomised patients in the groups to which they were randomly assigned, regardless of their adherence with the entry criteria, regardless of the treatment they actually received, and regardless of subsequent withdrawal from treatment or deviation from the protocol.

Once again this is very “real world”. It’s no good if a treatment is excellent for those who actually take it but a lot of people can’t tolerate it and so withdraw from a trial. Intention to treat analysis will ensure that the real world effects of a treatment are reported by ensuring that the results from “drop outs” are included in the analysis.

The alternative approach is sometimes referred to as “per protocol” or “explanatory” and means that the analysis is done only for those patients who actually took the allocated treatments. This might result in a better understanding of the actual biological effects of the treatment but isn’t so “real world”.

6. The authors used Fishers Exact Test for analysis of some of their data. What type of data can be analysed in this way and when is this used (Up to 2 marks)

Answer

Answer

The data is categorical data and usually dichotomous. That is, there are two treatment groups and the outcome measure is binary (i.e a 2 x 2 table can be generated).

Fishers test is used when the “expected” number in any one of the 4 quadrants is low (typically less than 5). Chi squared tests should only be used when all the expected numbers are higher than this.

7. The authors state that a change in RACS Score of anything less than 3 would not be clinically important. Why is it important to decide on the minimally clinically important effect and how does this effect power and sample size. (Up to 3 marks)

Answer

Answer

There is no point in designing a study to detect a difference in effect which isn’t clinically important.

Decisions on what is considered clinically important can be made using “hunch”, previous published studies, expert opinion or patient expectations but should be justified in the paper.

Detecting a smaller difference will require a larger sample size or a reduction in the power of the study. Most studies use 80% power as the minimum acceptable.

8. The following table is taken from the paper.

What do you understand by the figure 0.74 (-1.45 to 2.93) in the top right section of the table? (Up to 3 marks)

Answer

Answer

The mean difference between the changes in RACS Score over 120 minutes is 0.74 in favour of normal saline (normal saline improving the score by 5.13 points on average compared to hypertonic saline improving the score by 4.39 on average).

However, the 95% confidence intervals for this figure cross zero with a range of -1.45 to 2.93 indicating that the range of “plausible results” lies between hypertonic saline being better and normal saline being best. i.e there is no difference between the two statistically.

9. What are your conclusions overall? Is this paper going to influence your practice? (Up to 2 Marks)

Answer

Answer

This is well constructed and described study nebulised hypertonic saline in children attending the ED with bronchiolitis.

A bigger study with across the day patient selection might be useful

It won’t change my practice regarding hypertonic saline but I may have to read about nebulised adrenaline in this condition!

 

Critical Appraisal Practice Paper 3 (Therapeutic)

Statistics in Divided Doses

Guys check out the following statistics related post from UKMi. I found some of the articles very useful.

UK Medicines Information is an NHS pharmacy based service. Its aim is to support the safe, effective and efficient use of medicines by the provision of evidence-based information and advice on their therapeutic use.

Number 1 (July 2001)

• Type and definition of data


• Precision in data measurement

Download (PDF, 132KB)

Number 2 (August 2001)

• Samples and populations


• Intersubject variations


• Standard deviations


• Use of graphs to illustrate data


• Centiles and ranges

Download (PDF, 229KB)

Number 3 (September 2001)

• Factors to consider when assessing a sample


• Confidence intervals


• Standard error of the mean


• Confidence intervals for median values


• Parametric vs. non-parametric methods

Download (PDF, 74KB)

Number 4 (May 2002)

• Random variation


• The null hypothesis


• The "P" value


• Power, sample size and errors


• Subgroup analysis


• Relevance of bias


• Randomisation

Download (PDF, 74KB)

Number 5 (November 2002)

• Standard error of the mean vs. standard deviation


• Comparing the means of large samples


• The standard error of the difference between two sample means


• The 95% confidence interval for this difference


• Testing the null hypothesis and test statistics


• The Normal probability distribution

Download (PDF, 144KB)

Number 6 (April 2003)

Dealing with small samples

The t distribution

Using the t test to compare:

• a test value to a ‘normal’ value – (a one-sample t test)


• paired samples


• unpaired samples

Download (PDF, 178KB)

Number 7 (August 2004)

• Non-parametric methods of analysis


• Wilcoxon signed rank sum test for analysing paired data


• Mann-Whitney test for analysing unpaired data

Download (PDF, 320KB)

Number 8 (July 2005)

• Some revision of confidence intervals


• Applying confidence intervals


• Factors affecting the size of the confidence interval


• Confidence intervals and P values


• Interpretation of confidence intervals

Download (PDF, 261KB)

Source: UKMi

 

Statistics in Divided Doses

Critical Appraisal Practice Paper 2

Total marks: 23
Time allowed: 90mins

Paper: High-sensitivity versus conventional troponin in the emergency department for the diagnosis of acute myocardial infarction 

Download (PDF, 446KB)

1.      Provide a summary / abstract for the paper. (Up to 5 marks)

Answer

Answer

This should include all or some of the following points:

Background: Recently, newer assays for cardiac troponin (cTn) have been developed which are able to detect changes in concentration of the biomarker at or below the 99th percentile for a normal population.

Objective: The objective of this study was to compare the diagnostic performance of a new high-sensitivity troponin T (HsTnT) assay to that of conventional cTnI for the diagnosis of acute myocardial infarction (AMI) according to pretest probability (PTP).

Design: A prospective observational study of consecutive patients who presented to emergency departments in France with chest pain suggestive of AMI.

Setting: Three French Emergency Departments.

Participants: Adult patients presenting with chest pain suggestive of acute myocardial infarction with onset within the previous 6 hours.

Outcome measures: Levels of HsTnT were measured at presentation, blinded to the emergency physicians, who were asked to estimate the empirical pretest probability (PTP) of AMI.

The discharge diagnosis (of AMI or not) was adjudicated by two independent experts (both ED physicians) on the basis of all available data up to 30 days post presentation.

Results: A total of 317 patients were included, comprising 149 (47%) who were considered to have low PTP, 109 (34%) who were considered to have moderate PTP and 59 (19%) who were considered to have high PTP.

AMI was confirmed in 45 patients (14%), 22 (9%) of whom were considered to have low to moderate PTP and 23 (39%) of whom were considered to have high PTP (P < 0.001).

In the low to moderate PTP group, HsTnT levels ≥ 0.014 μg/L identified AMI with a higher sensitivity than cTnI (91%, (95% CI 79 to 100), vs. 77% (95%

CI 60 to 95); P = 0.001), but the negative predictive value was not different (99% (95% CI 98 to 100) vs. 98% (95% CI 96 to 100)).

There was no difference in area under the receiver operating characteristic (ROC) curve between HsTnT and cTnI (0.93 (95% CI 0.90 to 0.98) vs. 0.94 (95% CI 0.88 to 0.97), respectively).

Conclusion: In patients with low to moderate PTP of AMI, HsTnT is slightly more useful than cTnI. Our results confirm that the use of HsTnT has a higher sensitivity than conventional cTnI.

2.      Give three strengths and three weaknesses of the study design (up to 3 marks)

Answer

Answer

Strengths:   

• Prospective study; consecutive patients


•  Done in a European ED setting


• Pragmatic approach to other aspects of patient care (very real world)


• Outcome measures clearly defined (AMI, unstable angina, other)^*. At least two independent people decided upon the outcome.


• Treating and enrolling physicians blind to the results of HsTnT assay.


• Biologists assessing the level of HsTnT blind to patient data.

Weaknesses:         

• Small numbers of patients


• Different analysers measured the HsTnT levels


• *ED physicians (not cardiologists) diagnosed AMI and other outcomes.


• Not all patients were admitted – its unclear if positive attempts were made to contact discharged patients to find out what happened to them at 30 days or if the authors simply used what information they had to decide upon outcome. I suspect the later.


• Different timings for the HsTnT level based only on when the patient arrived.


• Gestalt used to risk stratify patients (rather than a standardised scoring system)

3.      Explain why this study may have been subject to “incorporation” or “work up” bias. Suggest two ways in which this could have been avoided in this study (up to 4 marks)

Answer

Answer

It appears to me that the result of the conventional troponin test (cTnI) was used in some cases to determine the need for admission (or not). Since all patients had a conventional troponin test, those with a low pre-test probability of AMI and a negative cTnI were probably discharged. This seems to amount to 39% of the patients (61% were admitted).

Thus the cTnI result helps to determine whether or not further investigations are carried out. It is not too great a leap to assume that the results of cTnI and those of HsTnT are highly correlated.

Ideally the diagnosis of the reference standard (which in this case is based on a review of notes and subsequent investigations in hospital) should be made entirely independently of the interpretation of the diagnostic test under evaluation.

The test under evaluation is the troponin. However, some of the investigations in hospital were only arranged if the troponin was positive. Other patients were discharged. Hence some of the patients may have been “deprived” of the opportunity to be diagnosed with AMI

Incorporation bias thus results in an over estimation of the diagnostic accuracy of a test.

Further explanation of incorporation bias / work-up bias can be found here: http://www.cjem-online.ca/v10/n2/p174

Ways to reduce the influence of incorporation bias in this study include:

Changing the primary outcome measure to, for example, death by 30 days and obtaining the answer for all patients (but probably fewer deaths and hence a bigger study would be needed)

Admitting all patients and performing a standardised set of investigations regardless of the troponin result.

4.    The following is an excerpt from the methods section:

“We followed most of the recommendations concerning the reporting of diagnostic studies set forth by the Standards for Reporting of Diagnostic Accuracy initiative”

Give 4 elements of the STARD guidelines which should be reported in a diagnostic study such as this.  (Up to 4 marks)

Answer

Answer

STARD checklist for reporting of studies of diagnostic accuracy (version January 2003)

Section and Topic	Item#		On page #
TITLE/ABSTRACT/KEYWORDS	1	Identify the article as a study of diagnostic accuracy (recommend MeSH heading "sensitivity and specificity").
INTRODUCTION	2	State the research questions or study aims, such as estimating diagnostic accuracy or comparing accuracy between tests or across participant groups.
METHODS
Participants	3	The study population: The inclusion and exclusion criteria, setting and locations where data were collected.
	4	Participant recruitment: Was recruitment based on presenting symptoms, results from previous tests, or the fact that the participants had received the index tests or the reference standard?
	5	Participant sampling: Was the study population a consecutive series of participants defined by the selection criteria in item 3 and 4? If not, specify how participants were further selected.
	6	Data collection: Was data collection planned before the index test and reference standard were performed (prospective study) or after (retrospective study)?
Test methods	7	The reference standard and its rationale.
	8	Technical specifications of material and methods involved including how and when measurements were taken, and/or cite references for index tests and reference standard.
	9	Definition of and rationale for the units, cut-offs and/or categories of the results of the index tests and the reference standard.
	10	The number, training and expertise of the persons executing and reading the index tests and the reference standard.
	11	Whether or not the readers of the index tests and reference standard were blind (masked) to the results of the other test and describe any other clinical information available to the readers.
Statistical methods	12	Methods for calculating or comparing measures of diagnostic accuracy, and the statistical methods used to quantify uncertainty (e.g. 95% confidence intervals).
	13	Methods for calculating test reproducibility, if done.
RESULTS
Participants	14	When study was performed, including beginning and end dates of recruitment.
	15	Clinical and demographic characteristics of the study population (at least information on age, gender, spectrum of presenting symptoms).
	16	The number of participants satisfying the criteria for inclusion who did or did not undergo the index tests and/or the reference standard; describe why participants failed to undergo either test (a flow diagram is strongly recommended).
Test results	17	Time-interval between the index tests and the reference standard, and any treatment administered in between.
	18	Distribution of severity of disease (define criteria) in those with the target condition; other diagnoses in participants without the target condition.
	19	A cross tabulation of the results of the index tests (including indeterminate and missing results) by the results of the reference standard; for continuous results, the distribution of the test results by the results of the reference standard.
	20	Any adverse events from performing the index tests or the reference standard.
Estimates	21	Estimates of diagnostic accuracy and measures of statistical uncertainty (e.g. 95% confidence intervals).
	22	How indeterminate results, missing data and outliers of the index tests were handled.
	23	Estimates of variability of diagnostic accuracy between subgroups of participants, readers or centers, if done.
	24	Estimates of test reproducibility, if done.
DISCUSSION	25	Discuss the clinical applicability of the study findings.

5. The following figure is taken form the results section of the paper:

 Briefly describe how the ROC curve is generated. Broadly what does the “area under the curve” (AUC) tell you about the test? What value for AUC would be given for a perfect test and for a completely useless test? (Up to 3 marks)

Answer

Answer

ROC curves can be generated by using different cut off values to represent “positive” and “negative” for tests with continuous data points (e.g. quantitative D-Dimer, troponin I). Several points are chosen and then the sensitivity and specificity of the test for each cut off point is calculated. The ROC curve is simply a plot of the results with 1 – specificity on the x-axis and sensitivity of the y-axis (as above).

The ROC curve gives an assessment of the overall performance of the test at different cut off points for positive and negative. The larger the area under the curve then the better the test. Good tests will have curves which tend towards the top left of the graph.

A perfect test will have an AUC of 1.0 and a useless test will have an AUC of 0.5 (a straight diagonal line at 45 degrees to the origin, representing a 50:50 chance or a test no better than tossing a coin).

You will note that the 95% confidence interval for the AUC of HsTnT ranges from 0.881 to 0.971. i.e. the test appears to have good utility in the diagnosis of AMI.

6.      The following is a portion of one of the results tables:

a       Write one sentence explaining the results in each of the 4 columns pertaining to all patients with a positive cTnI. (4 marks)

Answer

Answer

71% of patients who are diagnosed with AMI will have a positive cTnI at presentation in the ED. Thus a negative test is not very good at ruling out likely development of AMI (SnOUT). It is not a very sensitive test when taken this early.

97% of patients who are not diagnosed with AMI will have a negative cTnI at presentation in the ED. cTnI is quite a specific test i.e. a positive test tends to rule AMI in (SpIN).

Only 78% of patients with a positive cTnI at presentation will be diagnosed with AMI (the PPV).

95% of patients with a negative test will not be diagnosed with AMI (the NPV).

The 95% confidence intervals around these levels indicate the range of plausible results (i.e. the range within which we are 95% certain that the real result lies).

b       Briefly explain how the prevalence of the target condition in the population influences the sensitivity of a test and its negative predictive value (2 marks)

Answer

Answer

The sensitivity of a test is unaffected by the prevalence of the disease as it only relates to patients who actually have the condition. Similarly the specificity of a test is unrelated to the prevalence of the disease as it only relates to those without the condition.

The negative predictive and positive predictive value, however, are both influenced by the prevalence of the disease in the population. If the prevalence of a condition in a population is small then the reported NPV will be higher than when using the same test in populations with a greater prevalence of the disease. This is one reason why it is important to ensure that the study patients are similar to your own before implementing the results of a study into your practice.

Put another way, if there are hardly any patients with the condition in any case then useless tests such as e.g. tossing a coin, might have quite a good NPV (because there aren’t that many cases to miss anyway). If however, half the patients had the disease tossing a tail wouldn’t always be associated with those without the disease and the NPV will fall.

Conversely, PPV for the same test is higher in populations with a high prevalence of disease and lower if the disease is uncommon.

7.      The following is another section from the same results table:

Write down the formulae for calculating the positive and negative likelihood ratios.

What do the positive and negative likelihood ratio results given in the top row mean? (Up to 3 marks)

Answer

Answer

Positive likelihood ratio:        LR+= sensitivity/1-specificity

Negative likelihood ratio:       LR-=1-sensitivity/specificity

LR + = 0.71 / 0.03    Approximately           21.5

LR- = 0.29 / 0.97      Approximately           0.32

LR+ above 10 means that a positive test will significantly increase the pre test probability enough to make the test worth doing. Figures like 21.5 mean that a positive test (cTnI) significantly increases the chance of predicting AMI (and are thus helpful in decision making).

LR – less than 0.1 means that a negative test will significantly decrease the pre test probability enough to make the test worth doing. Thus, the figure of 0.32 means that a negative test (cTnI) is not at all helpful in excluding subsequent AMI. (Mainly because it is done at arrival in ED and not the usual 12 hours).

Fagans nomogram is used to convert pre test to post test probabilities based on LRs.

Fagans nomogram

8.      What are your conclusions overall? Is this paper going to influence your practice? (Up to 2 Marks)

Answer

Answer

The HsTnT does appear to have a better sensitivity (93%) than the traditional troponin when taken on arrival in ED.  This may be helpful in improving time to discharge following attendance with chest pain and may reduce admissions.

However, the 95% CIs for the sensitivity are 89 – 100, and the possible sensitivities are thus too low to allow it to be confidently used to rule out MI based on this study.

Further studies are required.

Note: The answers are not done by me, they were given to me when I prepared my exam. If anyone have any questions, just drop a line below and we all can discuss.

 

Critical Appraisal Practice Paper 2

OSCE - Arterial Blood Gas (Teaching)

Introduction

Introduce to the junior doctor, medical student, etc.

Find out the level of knowledge of ABG sampling.

Then explain the procedure as you go along.

Then introduce yourself to the patient and take consent that you are going to teach a junior doctor.

Check patient details:

Ensure the patient is not on any anticoagulants

Check platelets are not low & confirm coagulation blood results are normal

Take note of whether the patient is requiring oxygen & record how much (e.g. 15L)

Ensure they’re no contraindications to ABG sampling:
Absolute – Poor collateral circulation / PVD in the limb / Cellulitis surrounding site / AV fistula
Relative – Impaired coagulation (anticoagulation therapy / liver disease / low platelets <50 )

Explain procedure to patient:

“I need to take a sample of blood from an artery in the wrist to assess the oxygen levels in your circulation. It will be a little painful, but will only take a short time”

Gain consent

Allen’s Test:

This test involves the assessment of the arterial supply to the hand

Ask the patient to raise their hand & make a fist for 30 seconds

Apply pressure over both the radial & ulnar artery at the wrist, occluding them

Then ask the patient to open their hand, which should appear blanched

Remove the pressure from the ulnar artery, whilst maintaining pressure over the radial

If there is adequate blood supply from the ulnar artery, colour should return within 7 seconds

It should be noted that there is no evidence performing this test reduces the rate of ischaemic complications of arterial sampling.

Gather equipment

Arterial blood gas needle – heparinised

Alcohol swabs

Gauze

Tape

Lidocaine (1%) – with small needle/syringe for administration

Preparation

Wash hands

Position patients arm – ideally the wrist should be extended to make the artery more superficial

Palpate radial artery – most pulsatile on the lateral anterior aspect of the wrist

Put on gloves

Clean the site with an alcohol wipe

Infiltrate 0.1-0.2mls of 1% lidocaine subcutaneously over the planned puncture site (unless its an emergency)

Ensure to aspirate prior to injection of local anaesthetic

Allow 60 seconds for the local anesthetic to work

Attach needle to the syringe & expel the heparin

Taking the sample

1. Use one hand to palpate the radial artery – ensure you assess the course of the artery

2. Insert the needle using your other hand at an angle of 30 degrees

3. Aim towards the pulsation you are palpating with your non-dominant hand

4. As you puncture the artery, you should observe bright red blood flashback into the needle

5. The needle should begin to self-fill, in a pulsatile manner

6. Once the required amount of blood has been collected, quickly remove the needle

7. You should immediately press down firmly with some gauze over the site

8. You need to press down firmly for at least 5 minutes, to prevent haematoma formation

9. Some ABG needle sets come with a rubber block, to insert the used needle tip into and some needle have a security cap.

10. Remove the needle from the syringe & discard into a sharps bin

11. Place a cap on the syringe

To complete the procedure

Dress the puncture site

Thank patient

Remove gloves and wash hands

Take blood gas sample to an analyser as soon as possible to ensure accurate results

Closing statements

Answer any questions the junior doctor may have during the whole process.

Ask the junior doctor to read about the indictions of doing an ABG and to discuss in 1-2 weeks time.

To perform the procedure under supervision and complete a DOPS.

Thank the junior doctor

Input from Geeky Medics

OSCE - Arterial Blood Gas (Teaching)

OSCE - Knee Examination

The following videos I found very useful for the practice of knee examination.

The first video by Geeky Medics is very good. But the missed out the McMurray test for maniscus injury in their special test. In the second video the McMurray test is shown at 4:35

Introduction

Wash hands
Introduce yourself
Check patient details – name / DOB
Explain examination
Gain consent
Expose patients legs
Position – standing
Ask if patient has any pain anywhere before you begin and offer analgesics accordingly!

Look

Inspect around bed for aids & adaptations - walking stick /wheelchair /knee brace/ etc

Gait

Is the patient demonstrating a normal heel strike / toe off gait?
Is each step of normal height? – increased stepping height is noted in foot drop
Is the gait smooth & symmetrical?
Any obvious abnormalities? – antalgia /waddling /broad based /high stepping?

Inspection from front

Scars – previous surgery / trauma
Swellings - effusions / inflammatory arthropathy / septic arthritis / gout
Asymmetry / leg length differences 
Valgus or varus deformity
Quadriceps wasting – suggests chronic inflammation / reduced mobility

Inspection from the back

Popliteal swellings – Baker’s cyst / Popliteal aneurysm

.Feel

Ask patient to lay on bed
Assess temperature – ↑ temperature may suggest inflammation / infection
Palpate joint lines – irregularities / tenderness (ask patient to flex knee slightly)
Palpate collateral ligaments – either side of joint
Palpate patello-femoral joint
Measure quadriceps circumference & compare – 2.5cm above tibial tubercle

Sweep Test- (small effusion)

1. Empty the media joint recess using a wiping motion
2. This milks any fluid into the lateral joint recess
3. Now do a similar wiping motion to the lateral recess
4. Watch the medial recess
5. If fluid is present a bulge will appear on medial recess

Patella tap- (large effusion)

1. Use your palm to milk fluid from the anterior thigh towards the patella
2. Keep tight hold of the thigh just above the patella
3. With the other hand, press on the patella with two fingers
4. If fluid is present you will feel a distinct tap against the femur

Popliteal swellings- (bakers cyst)

1. Palpate the popliteal fossa with your finger tips
2. Feel for any obvious collection of fluid

Move

Perform flexion / extension both actively & passively (feeling for creptius)

Knee flexion – ask patient to move heel towards bottom – normal ROM 0-140º
Knee extension – ask patient to straighten leg out fully 
Hyperextension –  lift both legs by the feet - note any hyperextension (<10º is normal)

Special Tests

Anterior/Posterior Drawer Test

1. Flex patients knee to 90º
2. Rest your forearm down the patients lower leg to hold their lower leg still
3. Wrap your fingers around back of the knee using both hands
4. Position thumbs over the tibial tuberosity
5. Pull the tibia anteriorly  -  significant movement suggests anterior cruciate laxity /rupture
6. Push the tibia posteriorly  -  significant movement suggests posterior cruciate laxity /rupture
With healthy cruciate ligaments there should be little or no movement noted 

Collateral Ligaments

1. Extend the patients knee fully
2. Hold just above the patients knee with one hand
3. Hold the patients lower portion of the leg with the other hand
4. Attempt to bend the lower leg medially (lateral collateral ligament)
5. Attempt to bend the lower leg laterally (medial collateral ligament)..
With healthy collateral ligaments there should be no abduction or adduction possible

If abduction/adduction is possible, it suggests laxity / rupture of the corresponding collateral ligament

McMurray Test for Maniscus

Patient lies supine

Knee flexed to 45 degrees

Hip flexed to 45 degrees

Examiner braces lower leg

One hand holds ankle

Other hand holds knee

Medial meniscus assessment

Assess for pain on palpation

Palpate medial joint line with knee flexed

Assess for “click” suggesting meniscus relocation

Apply valgus stress to flexed knee

Externally rotate leg (toes point outward)

Slowly extend the knee while still in valgus

Lateral meniscus

Repeat above with varus stress and internal rotation

Positive Test suggests Meniscal Injury

“Click” heard or palpated on above manoeuvres

Joint line tenderness on palpation

To complete the examination

Thank the patient
Wash your hands
Summarise your findings

.Say you would…

Perform a full neurovascular examination of both limbs
Examine the joint above and below - ankle/ hip
Request an X-ray of the knee joint if pathology was suspected

Input from Geeky Medics

OSCE - Knee Examination

What are Never Events?

The term ‘never event’ was first introduced in 2001 by Ken Kizer, former chief executive of the National Quality Forum in the United States, in reference to particularly shocking medical errors that should never occur.

Over time, the term has been expanded to signify adverse events that are unambiguous (clearly identifiable and measurable), serious (resulting in death or significant disability), and usually preventable if the available measures have been implemented by healthcare providers.

The information from the United States indicates that the use of the term and its associated focus has improved safety.

In the UK the term was introduced in April 2009, following Lord Darzi’s proposal in High Quality Care for All. The original list consisted of the following:

1. Wrong site surgery 


2. Retained instrument post-operation (includes swabs and throat packs)


3. Wrong route administration of chemotherapy


4. Misplaced naso or orogastric tube not detected prior to use


5. In-hospital maternal death from post-partum haemorrhage after caesarean section


6. Inpatient suicide using non-collapsible rails


7. Escape from within the secure perimeter of medium or high secure mental health services by patients who are transferred prisoners


8. Intravenous administration of mis-selected concentrated potassium chloride.

To be a never event, an incident must fulfil the following criteria:

• It has clear potential for, or has caused severe harm or death.


• There is evidence that it has occurred in the past (ie, it is a known source of risk).


• There is existing national guidance or safety recommendations on how it can be prevented and there is support for implementing these.


• It can be easily defined, identified and continually measured.

Serious events (including never events) are assessed and categorised as grade 1 or 2, depending on the seriousness of the event. They should all be reported to the primary care trust (or clinical commissioning group), as well as the National Reporting and Learning Service (NRLS – at Imperial College), with never events being specified in the free text field. Since the summer, reports should also be made to the Strategic Executive Information System.

Although such events are reported to CQC and Monitor through the NRLS, it is much better if they are reported directly to CQC (and Monitor for foundation trusts and the NHS Trust Development Authority for non-foundation trusts). Serious events are investigated and shared with the PCT and an action plan shared widely to improve the service.

CQC may use information on never events to inform our regulatory processes, alongside other indicators, and we may take enforcement action.

In the first year of reporting, there were 111 never events. Of these, 57 were due to wrong site surgery, and 41 due to misplaced nasogastric tubes. There were no events due to wrong route administration of chemotherapy, in-hospital maternal death from post-partum haemorrhage after elective caesarean section, and inpatient suicide using non-collapsible rails. The remainder were under 10 events.

We would all agree that the national reporting system is in dire need of revision to ensure that it becomes a true national learning experience.

There has been a recent review of never events and the list extended to the following:

1. Wrong site surgery


2. Wrong implant/prosthesis


3. Retained foreign object post-operation


4. Wrongly prepared high-risk injectable medication


5. Maladministration of potassium-containing solutions


6. Wrong route administration of chemotherapy


7. Wrong route administration of oral/enteral treatment


8. Intravenous administration of epidural medication


9. Maladministration of insulin


10. Overdose of midazolam during conscious sedation


11. Opioid overdose of an opioid-naïve patient


12. Inappropriate administration of daily oral methotrexate


13. Suicide using non-collapsible rails


14. Escape of a transferred prisoner


15. Falls from unrestricted windows


16. Entrapment in bedrails


17. Transfusion of ABO-incompatible blood components


18. Transplantation of ABO-incompatible organs as a result of error


19. Misplaced naso- or oro-gastric tubes


20. Wrong gas administered


21. Failure to monitor and respond to oxygen saturation


22. Air embolism


23. Misidentification of patients


24. Severe scalding of patients


25. Maternal death due to post partum haemorrhage after elective Caesarean section.

The bolded ones would be more appropriate for the Emergency Department.

Input from CQC

What are Never Events?