Functional status and survival after ICU discharge

Historically, the college examiners have been interested mainly in the influence of age on the outcome of ICU stay. For instance, a detailed all-systems look at age-related changes in the response to critical illness can be found in Question 8 from the second paper of 2007:"What are the age related factors which adversely affect outcome in the elderly (>65 years) critically ill patient?" . Other similar questions include Question 9 from the first paper of 2012 (outcome from traumatic brain injury in the elderly), Question 30 from the first paper of 2009 (tools of functional assessment) and the identical  Question 17 from the first paper of 2006. The best most recent example of these was probably Question 25 from the second paper of 2023, which asked about "post intensive care syndrome".

Post Intensive Care Syndrome (PICS)

Though most people would intuitively agree that patients emerging from prolonged critical illness are extensively affected by their ordeal, most would not realise that There Is An Acronym For That. PICS is not new, but the concept of defining it as a syndrome is a relatively recent undertaking by the Society of Critical Care Medicine, who arrived at this after two days of probing the opinions and attitudes of thirty one representatives from "key professional organizations and groups, predominantly from North America, which are involved in the care of intensive care survivors". The result was a definition, which follows: 

Definition of Post Intensive Care Syndrome

by the SCCM,

"new or worsening impairments in physical, cognitive, or mental health status arising after
critical illness and persisting beyond acute care hospitalization"

Rawal et al (2017) define it as:

"new or worsening impairment in physical (ICU-acquired neuromuscular weakness), cognitive (thinking and judgment), or mental health status arising after critical illness and persisting beyond discharge from the acute care setting"

From Inoue et al (2019):

"physical, cognition, and mental impairments that occur during ICU stay, after ICU discharge or hospital discharge, as well as the long-term prognosis of ICU patients"

So fairly robust in retelling, the definition must consist of three domains, incorporating some element of physical function, cognitive function, and mental health (eg. PTDS). 
The rest of this topic area is organised around the headings suggested by Question 25 from the second paper of 2023, and by the very similar subheadings of the excellent paper by Rawal et al (2017) which almost directly address the points asked by the college:

Clinical manifestations of Post Intensive Care Syndrome

  • Physical:
    • Weakness, disuse atrophy
    • Fatigue, reduced exercise tolerance
    • Impairment in activities of daily living
    • Impaired respiratory function, reduced lung volumes and diffusion capacity
  • Cognitive:
    • Impairments in memory, attention, executive function, mental processing speed, visuo-spatial ability
  • Mental:
    • Depression, PTSD, anxiety, sleep disturbance, sexual dysfunction

Risk factors for Post Intensive Care Syndrome

  • Risk factors for post-ICU physical impairment:
    • Prolonged mechanical ventilation (> 7 days)
    • Sepsis
    • Multisystem organ failure
    • Hyperglycaemia
    • Systemic corticosteroids
    • Age
    • Pre-existing functional impairment
  • Risk factors for post-ICU cognitive impairment:
    • Sedation
    • Hypoxia
    • ICU delirium
    • Pre-exisitng cognitive impairment
  • Risk factors for post-ICU mental illness:
    • Sedation
    • Delirium and agitation
    • Use of physical restraints

Prevention of Post Intensive Care Syndrome

  • Elimination or correction of causative factors
    • Early extubation
    • Early mobilisation
  • Monitoring for delirium and use of nonpharmacological strategies for its management
    • Using light or minimal sedation
    • Avoidance of physical restraints
  • Reduction or elimination of sources of environmental stress, including
    • Minimising alarms
    • Minimising interruptions to sleep
  • Frequent patient and family communication.

Consequences of prolonged intensive care stay

Question 30 from the first paper of 2009 asked about the "important problems encountered by the patient  following hospital discharge after a prolonged period of stay in the Intensive Care Unit." This question is heavily based on Oh's Manual Chapter 8 (Common  problems  after  ICU). If one were answering this question in the 2020s, one might be using the PICS definition above. Otherwise, a systematic list of problems would resemble the following:

  • Tracheostomy:
    • Tracheal stenosis
    • Tethering of skin
  • Mobility:
    • Muscle wasting, neuromyopathy
    • Slow recovery of normal function (up to 1 year)
  • Skin
    • Hair loss
    • Nail ridging
    • MRSA colonisation
    • Facial scraring due to pressure areas from NGT and ETT
  • Sexual dysfunction
    • a 39% incidence
  • Psychological problems
    • PTSD, in about 15% (27.5% for ARDS survivors)

Tools to assess the functional outcome of intensive care survivors

Question 30 from the first paper of 2009  also asked the candidates to list two such tools. This was also derived from the abovementioned chapter of Oh's Manual , specifically Box 8.1 on page 62 of the new edition ("Quality of life tool examples").

The contents of this box:

  • QALY(Quality Adjusted Life Years - the only objective tool)
  • HAD (Hospital Anxiety and Depression)
  • PQOL (Percieved Quality of Life)
  • EuroQol
  • SF 36 (36 item short-form survey)

Predictors of poor outcome in elderly survivors of traumatic brain injury

Determinants of poor prognosis in the head-injured elderly can be summarised thus:

  • Age over 60
  • GCS 3-5 on presentation
  • Low GCS motor score
  • Traumatic subarachnoid (worse outcome, as compared to other pathologies)
  • Pupillary abnormalities

 Everyone seems to agree that age is a predictor of poor outcome. Steyerberg et al found that age was associated with poor neurological outcomes and decreased survival. Amacher et al also found that it doesn't matter how good your GCS is on admission, your old age will still play a role. In general, it seems being over 60 is a poor prognostic indicator. Think of that when you climb on the roof next time, grandpa.

I am struggling to figure out why the college in their answer to Question 9 from the first paper of 2012 thought a subdural is an indicator of poor prognosis.Steyerberg et al found that a traumatic subarachnoid (rather than subdural) was a determinant of poor prognosis. However, it is known that mortality in elderly patients with subdural haematoma is very high if they present with a GCS 3-5, losing points on motor scores. In fact, some authors felt that for these people craniotomy is not justified, because of the extremely poor outcomes overall, and a tendency to deteriorate in spite of satisfactory post-op CT scans.

Mortality in ICU

What is normal? How many of your patients should you be losing? A medical ICU surviving at the edges of a poor community with a busy emergency department will obviously differ from a surgical ICU of a private hospital that deals exclusively with carefully selected elective patients. Additionally it should be intuitive that the diagnosis with which you present to hospital should have some bearing on your mortality, as should the severity of your illness. But how much does each illness impact? Borrowing the multipliers from the "arrAP3" variable array in the back end of this ANZICS mortality risk calculator, it is possible to create a list of mortality multipliers which are used to calculate the APACHE III risk of death (for some reason they are not available in any easier form). These are not absolute risks per se, these are merely the multipliers applied to the rest of the score that are then used to arrive at the final risk of death, and represent numerically the contribution of each diagnosis to the final mortality prediction.

Yes, you can sort the table by clicking on the column header, we're not animals. 

APACHE III code Diagnosis APACHE III coefficient APACHE II code APACHE II coefficient
402 Subarachnoid Haemorrhage 1.574573 121 0.72299
401 Intracerebral Haemorrhage 1.520735 121 0.72299
210 Parasitic Pneumonia 1.240371 106 0
202 Resp Neoplasm inc larynx/trachea 1.114274 107 0.89099
1501 Intracerebral Haemorrhage 1.064711 217 -0.78799
1209 Dissecting Aortic Aneurysm 0.965189 202 -1.315
208 Mechanical Airway Obstruction 0.916672 303 -0.88999
403 Stroke 0.879518 301 -0.759
1502 Subdural/epidural Haematoma 0.835429 217 -0.78799
1207 Coronary Artery Bypass Grafts ANZICS addition - age over 85 0.765707 1308 1.494985
204 Pulmonary Oedema non cardiac. 0.741514 103 -0.25099
404 Neurologic Infection 0.692197 301 -0.759
1410 GI Vascular ischemia resection surgery 0.679961 1304 -0.61299
409 Epidural haematoma 0.639308 121 0.72299
213 Viral Pneumonia 0.524507 106 0
1401 GI Perforation/Rupture - Not Peritonitis 0.488538 214 0.05999
206 COPD 0.437855 102 -0.367
2101 Haematological disease 0.407784 1306 0
2201 Metabolic disease 0.407784 1307 -0.19599
601 Head Trauma +/- multi trauma 0.369166 119 -0.517
205 Bacterial/viral Pneumonia 0.356565 106 0
212 Bacterial Pneumonia 0.356565 106 0
501 Sepsis other than urinary 0.353941 113 0.11299
503 Sepsis with shock other than urinary tract ANZICS addition 0.353941 113 0.11299
1506 Other Neurologic Disease 0.335437 1301 -1.15
1503 Subarachnoid Haemorrhage 0.312849 217 -0.78799
203 Respiratory Arrest 0.300772 108 -0.16799
1304 Other Respiratory Diseases 0.257491 1303 -0.61
1201 Dissecting/ruptured Aorta 0.24349 202 -1.315
1210 Ruptured Aortic Aneurysm 0.24349 202 -1.315
211 Other Respiratory Diseases 0.219583 303 -0.88999
207 Pulmonary Embolism 0.214629 105 -0.128
1601 Head Trauma +/- multi trauma 0.182766 208 -0.95499
405 Neurologic Neoplasm 0.170705 301 -0.759
1102 Cellulitis/soft tissue infection 0.13398 308 0
1904 Cellulitis/soft tissue infection 0.13398 1308 0
408 Other Neurologic Disease 0.133291 301 -0.759
201 Aspiration Pneumonia 0.123363 104 -0.142
1505 Craniotomy for Neoplasm 0.051966 218 -1.245
1404 GI Obstruction -0.013338 214 0.05999
1202 Periph. Vasc Dis-No Graft -0.062337 202 -1.315
1302 Respiratory Neoplasm - Lung -0.113698 209 -0.80199
1101 Musculoskeletal/Skin disease -0.130586 308 0
1001 Other medical disorders -0.130586 308 0
1802 Pregnancy related disorder -0.130586 1305 -0.19599
1803 Other Gynaecological disease -0.130586 1305 -0.19599
1902 Orthopedic surgery -0.130586 1308 0
1903 Skin surgery -0.130586 1308 0
1705 Genitourinary surgery/procedure -0.130586 1305 -0.19599
902 Pre-eclampsia -0.130588 305 -0.88499
1405 GI Neoplasm -0.149182 213 -0.24799
1504 Laminectomy/spinal cord surg. -0.150739 219 -0.699
1303 Respiratory Neoplasm - Mouth /larynx /sinus /trach -0.226492 1303 -0.61
901 Renal disorders -0.226863 305 -0.88499
406 Neuromuscular Disease -0.228204 301 -0.759
1301 Respiratory Infection -0.232717 1303 -0.61
1408 Other GI Diseases -0.236372 1304 -0.61299
704 Other metabolic disorder -0.248306 307 -0.88499
1409 Fistula/Abscess surgery -0.254507 1304 -0.61299
1208 Other Cardiovascular Diseases -0.258392 1302 -0.79699
1402 GI Inflammatory Disease - Not Absess/Fistula Peritonitis -0.287223 1304 -0.61299
1411 Pancreatitis -0.287223 1304 -0.61299
1412 Peritonitis -0.287223 1304 -0.61299
1413 Other GI inflammatory disease -0.287223 1304 -0.61299
903 Haemorrhage, postpartum (female only) -0.291881 302 0.46999
1403 GI Bleeding -0.297464 212 -0.61699
410 Coma -0.396898 307 -0.88499
1801 Hysterectomy -0.466038 1305 -0.19599
502 Sepsis of Urinary Tract Origin -0.485673 113 0.11299
504 Sepsis of Urinary tract origin with shock ANZICS addition -0.485673 113 0.11299
1206 Valvular Heart Surgery -0.501745 203 -1.261
1901 Hip or Extremity Fracture -0.508191 207 -1.684
1602 Multiple Trauma excluding head -0.508191 207 -1.684
1603 Burns ANZICS addition -0.508191 207 -1.684
1604 Multitrauma with spinal injury ANZICS addition -0.508191 207 -1.684
1605 Isolated cervical spinal injury ANZICS addition -0.508191 207 -1.684
407 Seizure -0.513583 120 -0.58399
1212 CABG with valve repair/replacement -0.537793 203 -1.261
602 Multiple trauma excluding head -0.619483 118 -1.228
603 Burns ANZICS addition -0.619483 118 -1.228
604 Multi trauma with spinal injury ANZICS addition -0.619483 118 -1.228
605 Isolated cervical spine injury ANZICS addition -0.619483 118 -1.228
1701 Renal Neoplasm -0.631767 215 -1.204
1211 Aorto-femoral bypass graft -0.637542 202 -1.315
209 Asthma -0.738478 101 -2.108
1406 Cholecystitis/cholangitis -0.755966 1304 -0.61299
1203 Peripheral Artery Bypass Graft e.g. Fempop -0.768555 202 -1.315
1204 Elective AA -0.828717 202 -1.315
1213 Endoluminal Aortic Repair -0.828717 202 -1.315
1205 Carotid Endarterectomy -1.019287 202 -1.315
1407 Liver Transplant -1.282196 1304 -0.61299
1703 Other Renal Diseases -1.422721 1305 -0.19599
1704 Kidney Transplant -1.422721 216 -1.042
703 Drug overdose -1.528488 122 -3.353

References

Langlois, Jean A., Wesley Rutland-Brown, and Marlena M. Wald. "The epidemiology and impact of traumatic brain injury: a brief overview." The Journal of head trauma rehabilitation 21.5 (2006): 375-378.

Steyerberg, Ewout W., et al. "Predicting outcome after traumatic brain injury: development and international validation of prognostic scores based on admission characteristics." PLoS medicine 5.8 (2008): e165.

Stocchetti, Nino, et al. "Traumatic brain injury in an aging population." Journal of neurotrauma 29.6 (2012): 1119-1125.

Amacher, Loren A., and David E. Bybee. "Toleration of head injury by the elderly." Neurosurgery 20.6 (1987): 954-958.

Jamjoom, Abdulhakim, et al. "Outcome following surgical evacuation of traumatic intracranial haematomas in the elderly." British journal of neurosurgery 6.1 (1992): 27-32.

Oh's Intensive Care manual: Chapter 8 (pp.61)  Common  problems  after  ICU   by Carl  S  Waldmann  and  Evelyn  Corner

Needham, Dale M., et al. "Improving long-term outcomes after discharge from intensive care unit: report from a stakeholders' conference.Critical care medicine 40.2 (2012): 502-509.

Inoue, Shigeaki, et al. "Post‐intensive care syndrome: its pathophysiology, prevention, and future directions." Acute medicine & surgery 6.3 (2019): 233-246.

Rawal, Gautam, Sankalp Yadav, and Raj Kumar. "Post-intensive care syndrome: an overview." Journal of translational internal medicine 5.2 (2017): 90-92.

Kim, Seung-Jun, Kyungsook Park, and Kisook Kim. "Post–intensive care syndrome and health-related quality of life in long-term survivors of intensive care unit." Australian Critical Care 36.4 (2023): 477-484.