Basic mechanical ventilation

Basic Mechanical Ventilation
Jairo I. Santanilla, MD Clinical Assistant Professor of Medicine Section of Emergency Medicine Section of Pulmonary/Critical Care Medicine LSUHSC New Orleans & Section of Critical Care Medicine Ochsner Medical Center

Outline
Outline
Basic Science
Lingo
Initial Settings
Common Intern Mistakes

How do we breath?
Brainstem control
Chemoreceptors
Diaphragm contraction and Chest wall expansion  increased intrathoracic volume
Leads to negative intrathoracic pressure
Air flows from high to low pressure
Negative pressure ventilation

Why do we breath?
Duh
Oxygenation
Ventilation – the exchange of CO2

Important Principles
Ventilation/Perfusion Matching
Ventilation without Perfusion
Dead space ventilation
Perfusion without ventilation
Shunt
Ideal Body Weight (kg)
Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet.
Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.

Why do people need ventilators?
Loss of airway anatomy
Edema, direct/indirect trauma, burns, infection
Loss of protective airway mechanisms
Intoxicants, brain injury, strokes
Inability to oxygenate appropriately
Shunt, alveoli filled with stuff
Inability to ventilate appropriately
Expected clinical course

Basic Ventilator Lingo
Control breath
Vent initiates the breath
Assist breath
the patient initiates the breath

What can I set?
Ventilator Target
Ventilator Mode
Respiratory Rate
PEEP
FiO2
Flow Rate
Other stuff… more later

Step 1: What is the target?
You pick what the ventilator is trying to attain
If the vent is trying to reach a Volume goal, its called Volume-Targeted
AKA volume-cycled, volume-assist, volume- control, volume-limited.
If the vent is trying to reach a Pressure goal, its called Pressure-Targeted
AKA pressure-cycled, pressure-assist, pressure- control, pressure-limited
Most adult ICUs use Volume-Targeted and most PICUs use Pressure-Targeted

Associations of the Emergency Severity Index triage categories with patients’ vital signs at triage: a prospective observational study

Associations of the Emergency Severity Index triage categories with patients’ vital signs at triage:
a prospective observational study

Ineke van der Wulp, Hebe A A Rullmann, Luke P H Leenen, Henk F van Stel

ABSTRACT
Study objective Previous studies on the construct validity of the Emergency Severity Index (ESI) were focused on outcome measures which could not be obtained directly at triage. A study was conducted to the construct validity of the ESI by measuring the association between the ESI triage categories and patients’ vital signs at triage.
Methods A prospective observational study was conducted at an emergency department (ED) in the Netherlands. All patients who entered the ED between 20 July 2009 and 21 August 2009 were eligible for inclusion in the study. Patients’ vital signs, triage category, age, gender, referrer and main complaint were registered. Vital signs were scored according to the Worthing Physiological Scoring System (WPSS) and the numerical pain rating scale. The data were analysed using ordinal logistic regression analyses.
Results An association was found between ESI triage categories and patients’ vital signs at triage. Patients in WPSS categories ‘urgent’ and ‘alert’ were more likely triaged into the urgent triage categories (ESI triage categories 1 and 2) than patients with normal WPSS scores. However, no associations were found between pain scores and ESI triage categories.
Conclusion This study supports the validity of the ESI as it showed that patients’ vital signs are associated with the ESI triage categories. However, a revision of the ESI guidelines concerning pain assessments is necessary.
INTRODUCTION
To sort the increasing number of patients presenting to emergency departments (EDs) on the urgency of their complaints, several triage systems have been developed and implemented.1e8 Frequently mentioned triage systems in the literature are: the Australasian Triage Scale, the Manchester Triage System, the Canadian Triage and Acuity Scale and the Emergency Severity Index (ESI).7910 Compared to other triage systems, the ESI is different in that, as well as the level of urgency, it estimates the number of resources that patients need. ESI resources are defined as laboratory tests, radiology, intravenous fluids, specialty consultation, a simple or complex procedure and intravenous, intramuscular or nebulised medications. Patients can be allocated into five urgency categories. ESI categories 1 and 2 represent patients who need immediate life saving interventions (eg, defibrillation), or patients at an increased risk for deterioration (eg, patients with severe pain). When ESI
categories 1 or 2 criteria are not met, the triage nurse estimates the number of ESI resources that patients need. In case more than one resource is needed, or when vital signs are in a predefined danger zone, patients are triaged into ESI category 3. Moreover, the triage nurse can decide to triage a patient in ESI category 2 on the basis of disturbed vital signs, even though initially the criteria for ESI category 2 were not met. Patients are triaged in ESI categories 4 and 5 when one or no resources are required respectively.11
For reasons of patient safety, it is important that ED triage systems are reliable and valid. Previous studies of the reliability of the ESI reported
k scores12 representing moderate to almost perfect reliability.3481013e16 The reliability places an upper limit on the validity of triage systems, that is, a triage system which produces different urgency scores when used in the same patient cannot be valid.17 The validity of the ESI has mainly been studied by means of construct validity because a gold standard to measure criterion validity is absent. The construct validity has been studied by measuring associations between the ESI triage categories and factors related to urgency. Previous studies have reported such associations of the ESI with actual ED resource usage, ED and hospital length of stay, hospital admission, mortality, survival after an ED visit and physiological measurements.124e81014e16 18 19 However, a limitation of these studies is the focus on outcomes of care because of the time lag between the moment of triage and the reported outcomes. As a result, other factors could have influenced the associations since the patient’s condition could have been changed between arrival in, and departure from the ED. To reduce this bias in triage validity studies, one could focus on measures that can be obtained directly at triage. Furthermore, because of the focus on construct validity in the validation of ED triage systems, it is important to keep studying different constructs, as construct validity is a process of making and testing inferences.17 Although vital signs play an important role in the ESI, no studies have assessed if vital signs are associated with urgency categories. Therefore, a study was conducted to the construct validity of the ESI by measuring the associations between the ESI triage categories and patients’ vital signs at triage. We hypothesised that patients triaged in the urgent triage categories of the ESI were more likely to have disturbed vital signs, and therefore at increased risk for dying in the ED, than patients triaged in less urgent triage categories.
METHODS
Study design
The study was conducted in a prospective observational design. The protocol was reviewed and approved by the medical ethics committee of the University Medical Center Utrecht. Informed consent was obtained from patients before inclusion in the study.
Study setting and population
The study was conducted at the ED of the University Medical Center Utrecht, which is a designated level one trauma centre in the Netherlands. Severely injured patients in the designated trauma region are transported to this ED. The ED is staffed 24 h a day by six full time attending physicians and has an annual census of 21000 patients. The ESI was implemented in 2008 and nurses received a 1-day training course on how to triage with the ESI before implementation. All patients over 16 years of age who entered the ED of the University Medical Center Utrecht on weekdays between 20 July 2009 and 21 August 2009 were included in the study.
Data collection
The data were prospectively collected by one researcher (HR) from Monday to Friday, 09:00 to 17:00 (4 days a week) and from 12:00 to 20:00 (1 day a week). A sample size calculation for regression analysis20 estimated a minimum required sample size of 445 patients. A drop out rate of 10% due to unforeseen circumstances was taken into account in this calculation. Each patient was triaged by the triage nurse on duty and assigned a triage category using standard procedures. Immediately after the triage nurse finished the triage assessment and reported the ESI triage category, the researcher registered patients’ gender, referrer, main complaint, age and measured vital signs that were not measured by the triage nurse. The following vital signs were registered: blood pressure, pulse rate, respiratory rate, oxygen saturation, temperature, the Alert, Voice, Pain and Unconsciousness score, and pain. They were measured using an automated vital signs monitor, a tympanic thermometer and the numerical pain rating scale. The numerical pain rating scale was scored by asking patients to allocate a score between 0 and 10, with 0 indicating no pain and 10 the worst pain imaginable. The researcher was trained in the use of these instruments by a triage nurse during a 1 day training in the ED prior to data collection. In case a patient needed to be seen by a doctor immediately, the patient’s data were collected by the triage nurse. All the data were registered on a form.
Interpretation of vital signs
The ESI guidelines state that the interpretation of vital signs for allocating a patient to ESI categories 2 or 3 is up to the triage nurse, for example, a patient with disturbed vital signs does not automatically meet ESI level 2 criteria.11 For example, a patient who has a history of COPD and presents with an oxygen saturation of 89% might not meet ESI level 2 criteria. However, another patient with the same complaints but no such history does require ESI level 2 criteria when presenting with such an oxygen saturation level. Interpreting vital signs separately is not useful in this study as disturbed vital signs are not necessarily related to higher urgency or life threatening situations. Therefore, a prognostic scoring system in which vital signs were interpreted in relation to short term mortality was applied in this study. The Worthing Physiological Scoring System (WPSS) is such a prognostic scoring system (table 1). The WPSS is based upon identifying physiological markers for mortality at an early stage to undertake timely action. The system has been derived

from and prospectively validated in ED patients and is therefore suitable for use in this study.21 Except for pain, the system consists of the vital signs used in the ESI as well as systolic blood pressure.
Data analysis
The data were analysed by means of ordinal logistic regression analyses.22 Ordinal logistic regression analysis is an extension of binary logistic regression analysis and used in case the dependent variable is ordinal. The effects of the independent variables are interpreted by assuming that they are constant over the categories of the dependent variable, that is the assumption of parallel lines. This is an important assumption and was checked in the analysis. Because of this assumption the analyses were performed using the complementary log-log link function. This link function is used when the higher categories of the dependent variable (eg, the lower urgency categories) are more common. As a result, the associations should be interpreted as rate ratios instead of ORs.23
In these analyses, the ESI category was the dependent variable. ESI categories 4 and 5 were merged because of the small number of patients triaged in ESI category 5 and used as a reference category (n¼237). Besides WPSS and pain scores, other independent variables were gender, referrer, main complaint and age. The latter four variables were used in the analyses because in a previous study these appeared to be related to the ESI triage categories.24 The variable referrer consisted of patients referred by ambulance, a specialist, a general practitioner or patients who referred themselves to the ED. The variable main complaint was coded in accordance with the chapters of the International Classification of Diseases 10th edition (ICD 10), immediately after triage.25 It was decided to code main complaints this way to decrease the variability in ICD 10 codes, which was needed for the analyses. Univariate ordinal logistic regression analyses were performed and all variables which significantly (p#0.05) predicted urgency were selected for multivariate analysis. All analyses were performed using SPSS for Mac V.17.0.
RESULTS
In total, 929 patients presented at the ED during the study hours. Of these, 584 patients (62.9%) consented for participation and were included in the study. Of these, 40 patients had missing data (WPSS score (6.0%), pain score (1.0%) or age (0.3%)) and were excluded from the study, leaving 544 patients for further analyses. No significant differences (p¼0.53) were found between included and excluded patients, based on age and

The APACHE II

The APACHE II model was originally published in 1985 based on data from the US (Knaus et al,1985). It has been recalibrated twice for use in the UK, first following the Intensive Care Society’s APACHE II study in Britain and Ireland (Rowan, 1992; Rowan et al, 1993) and subsequently using data from the Case Mix Programme Database (Harrison et al, 2006). We regularly recalibrate the model using Case Mix Programme data to ensure that each critical care unit is being compared with current data. Coefficients from the most recent recalibration are used in the eDAR.

Risk predictions in APACHE II are based on:


 The APACHE II score – a score from 0 to 71 consisting of weights for age at admission to your unit (0 to 6 points) and severe conditions in the past medical history (0 to 5 points) plus an Acute Physiology Score (0 to 60 points) based on weightings for deviations from normal in the following twelve physiological parameters during the first 24 hours in the unit

o  temperature
o mean arterial pressure o heart rate
o  respiratory rate
o  A-aDO2 (if FiO2 ≥ 0.5) or PaO2 (if FiO2 < 0.5)
o arterial pH (or serum bicarbonate if no arterial blood gas recorded) o serum sodium

o  serum potassium
o serum creatinine (with double weighting for acute renal failure) o haematocrit (estimated from haemoglobin)
o  white blood cell count
o Glasgow Coma Score (assumed to be normal for patients sedated or paralysed and sedated for the whole of the first 24 hours in the unit, or for the entire stay if less than 24 hours)
 Admission directly from theatre following emergency surgery
 Diagnostic category (weightings for 58 non-surgical diagnoses and 50 surgical diagnoses, plus seven body systems, and a weighting for CPR within 24 hours prior to admission that overrides any other diagnostic category)

Exclusions


Admissions are excluded from the calculation of the APACHE II score if:
a. age at admission to your unit is less than 16 years; or
b. length of stay in your unit is less than 8 hours.

Additionally, admissions are excluded from the calculation of an APACHE II risk prediction if:
c. the admission is for primary burns;
d. the admission is following coronary artery bypass graft (CABG) surgery;
e. the admission is transferred in from another ICU; or
f. all twelve physiological variables are missing.

Readmissions of the same patient within the same hospital stay and admissions missing ultimate hospital outcome are excluded from comparisons of observed and expected mortality.

Guideline on The Management Of Acute Respiratory Distress Syndrome (ARDS) in Adult ICU

Aim and Scope
1)To ensure that all patients in ICU with ARDS are correctly identified and receive   the best evidence based treatment.
Definition
Onset of ARDS (diagnosis) must be acute, within 7 days of some defined event,  which may be sepsis, pneumonia, or simply a patient’s recognition of worsening  respiratory symptoms. (Most cases of ARDS occur within 72 hours of recognition of  the presumed trigger.)
Bilateral opacities consistent with pulmonary edema must be present but may be
detected on CT or chest X-ray. Ultrasound may also be used to define lung  pathology and the presence of non cardiogenic extra vascular lung water
Respiratory failure can be “not fully explained by cardiac failure or fluid overload,”
in the physician’s best estimation using available information.
ARDS Severity  PaO2/FiO2*  Mortality
()kpa
Mild 200 – 300 27%
(27 – 40)
Moderate 100 – 200 32%
(13-27)
Severe < 100 45%
(<13)
*on PEEP 5+ 
General Measures
1 All patients should have 100% compliance with the Ventilator Care  bundle
2 No chest physiotherapy unless as a trial to improve lobar collapse
3 Minimal suctioning via ETT
4 Normal feed as per protocol
5 Fluids. All patients will have a liberal fluid strategy during the initial resuscitation  phase (usually 0-48hours). If patients are then still vasopressor dependent, we will  aim to maintain a neutral fluid balance. Once inotropes are discontinued or are  being used in low doses to compensate for sedation, then we will aim to remove  the excess fluid that has been given. This will initially be performed using diuretics  but may require CVVHF if the fluid balance remains positive. Vasopressor may be  required to support the BP and  allow diuresis
6.     Ventilation
Mode: 1)VC SIMV  ( Volume control, synchronized mandatory ventilation)
           2) Volume assured PC SIMV (Pressure control, volume assured,  synchronized mandatory ventilation) This is not available on all ventilators
Settings: Peep 5-10cmH2O
               TV 6ml/kg ideal body weight.
               Plateau pressure < 30cmH20
               Rate: titrated to control PaCO2
Ideal body weight is calculated as follows:
Males        Length (in cm) – 100
Females   Length (in cm) – 105
The tidal volume required must be written every day at the top on the ICU  observation chart in red. It is the responsibility of the ICU consultant 1 to ensure that  this is done
7   All patients will have subglottic suction
The following patient group will be managed with an
extended ARDS care bundle
Diagnosis of ARDS as per above criteria
Ventilated for <36hours
A PaO2/FiO2 ratio<20kpa(150mmHg) for 12-24 hours on an FiO2 >0.6. 
NDMR
All patients who meet the above criteria  will be given a cisatracurium infusion. This  will be titrated to a train of four (TOF of 2 twitches). Paralyses will continue for as  long as they meet prone ventilation criteria.
Prone ventilation
All patients who do not have specific contraindications to prone ventilation will be  prone ventilated. They will be placed prone as per unit guidelines. They will remain  prone ventilated for at least 16 hours.

Prone ventilation will be stopped when any of the following criteria are met:
1) Improvement in oxygenation. This is defined as a Pao2:Fio2 ratio of ≥20, with a  PEEP of ≤10 cm of water and an Fio2 of ≤0.6. These criteria have to be sustained in  the supine position at least 4 hours after the end of the last prone session
2) A patient deteriorates compared to their PaO2:FiO2 ratio when supine
3) > 96 hours since first episode of prone ventilation
Management of a raised PaCO2
1) pH> 7.2 secondary to a respiratory acidosis will be tolerated
     The respiratory rate and not the tidal volume should be adjusted to help maintain  a    pH >7.2
2) If the pH remains less than 7.2  for >24 hours then consideration should be given  to using extra corporeal CO2 clearance
3) If the pH is < 7.1 for 4 hours or more with no other therapy (nebulisers etc)  available to reduce it, then extra corporeal CO2 clearance should be considered.
4) All patients being considered for extra corporeal CO2 clearance should initially  be discussed with our regional ECMO centre.
Management of a persistently low PaO2 (<8kpa)
1) Increase FiO2
2) Add nebulised prostacycline as per guideline
3) Maintain TV and peep
4) Discuss with regional ECMO centre
Recruitment maneuvers
1) All patients will have ‘inspiratory hold’ recruitment. This will be performed by  using the inspiratory hold function on the ventilators.
2) This will be 30cm H2O for 30 seconds
3) It should be performed after each disconnection or suctioning episode
4) It should be repeated as required when clinically it is felt that recruitment is  required.
5) It may be used as a trial to improve the PaO2

Steroids
All patients will be given methylprednisolone 0,5mg/kg/day (or equivalent) for 14  days unless contraindicated for standard reasons.
Documentation Control
Development of Policy: Consultation with: Approved by: Signature:
Print name and position: Date of Approval: Review Date:
References
            Dr James Low
Dr. Craig Morris, Dr. Nick Reynolds
ICU  Clinical Group
Nov 2013
Nov 2016
1) JAMA, June 2012 – Vol 307, No. 23
2) NEJM  June 2013 – Vol 368, No 23
3) NEJM  August 2001- Vol 345, No. 8
4) Crit Care Med. 2009 37(9):2680.

Manajemen cidera otak

Manajemen akut Trauma Cedera Otak

Manajemen cedera otak traumatis berfokus pada stabilisasi pasien dan pencegahan cedera saraf sekunder untuk menghindari kerugian lebih lanjut dari neuron. Penuh neuromonitoring termasuk tekanan intrakranial pengukuran jarang tersedia sebelum kedatangan pasien di unit perawatan intensif. Kerusakan saraf yang signifikan dapat terjadi antara saat cedera dan CT scan, pengukuran yang akurat dari ICP dan parameter lainnya. Manajemen akut pasien ini karena diarahkan dengan asumsi ada patologi intrakranial signifikan dan melembagakan langkah-langkah untuk melindungi jaringan otak hidup.

Penilaian

Penilaian cedera otak bergantung pada evaluasi Skor Glasgow Coma (GCS) dan pemeriksaan murid. Tradisional GCS di bawah 9 dianggap mencerminkan cedera otak parah. Namun dengan perbaikan dalam perawatan pra-rumah sakit dan pengetahuan yang lebih besar dari cedera otak, pasien tiba di departemen darurat sebelumnya dan cedera otak mereka masih dapat berkembang. Oleh karena itu langkah-langkah berikut harus dipertimbangkan dan porbably dilembagakan pada semua pasien dengan skor koma dari 12 atau di bawah.

Hipotensi akan mempengaruhi perfusi otak dan karena itu menurunkan Skor Koma Glasgow. Namun otak cedera manajemen harus dilembagakan atas dasar pemeriksaan awal dan tidak boleh ada penundaan untuk menilai apakah GCS membaik dengan resusitasi volume. Hal ini penting untuk mengidentifikasi tanda-tanda herniasi transtentorial yang akan datang karena ini akan mempengaruhi jalannya manajemen segera pasien ini. Hal ini diidentifikasi oleh sikap yang abnormal unilateral dan / atau adanya dilatasi pupil unilateral.

Serial penilaian adalah penting. Pasien mungkin tiba dengan GCS agak terganggu dan cepat memburuk akibat perluasan hematoma atau meningkatkan pembengkakan otak. Murid mungkin awalnya normal dan kemudian melebarkan sebagai kenaikan tekanan intrakranial dan otak mulai mengalami herniasi.

Pengelolaan

Tujuan spesifik dalam pengelolaan akut cedera otak traumatik parah adalah:

Melindungi jalan nafas & oksigenatVentilasi untuk normocapniahipovolemia yang benar dan hipotensiCT scan saat yang tepatBedah Saraf jika diindikasikanPerawatan Intensif untuk lebih lanjut monitoring dan manajemen

Hipoksia dan hipotensi adalah ancaman terbesar bagi hasil fungsional di cedera otak. Kontrol akut awal dari tiga parameter di atas mungkin memiliki dampak yang lebih dari semua langkah-langkah lain kemudian dipekerjakan. Hilangnya neuron progresif terjadi dari waktu cedera, bukan waktu kedatangan di rumah sakit. Cepat urut intubasi harus digunakan jika tersedia untuk mengamankan jalan napas dan maksimal mengoksidasi pasien. Hipovolemia dan hipotensi harus diperbaiki lebih awal dan mengambil prioritas di atas intervensi lain untuk cedera otak. Cedera lain yang menyebabkan perdarahan harus dibenahi pertama (atau secara bersamaan) sehingga memadai tekanan perfusi serebral dipertahankan. Pasien harus disimpan dibius untuk mencegah batuk atau Valsava manuver dari pertempuran ventilator, karena kenaikan ini tekanan intrakranial .

M salah satu intervensi yang digunakan dalam pengelolaan tekanan intrakranial mungkin memiliki efek yang merugikan pada resusitasi cardiopulmonary (misalnya. Manitol ) yang pada gilirannya akan memiliki efek yang merugikan pada perfusi serebral. Selain itu beberapa langkah dapat menjadi kontraproduktif bila digunakan tanpa pengawasan yang memadai (misalnya. Hiperventilasi ). Dengan demikian intervensi lebih lanjut digunakan tanpa bimbingan dari CT scan atau pemantauan ICP hanya ketika ada bukti herniasi yang akan datang otak (sikap unilateral dan / atau unilateral dilatasi pupil).

Sebuah CT scan otak harus diperoleh saat yang tepat, seperti yang ditentukan oleh kehadiran cedera lain dan gangguan fisiologis. Ini akan menggambarkan cedera otak dan menentukan apakah operasi diindikasikan untuk menghilangkan lesi intrakranial massa (epidural / subdural hematoma), dan tingkat cedera difus dan otak hadir pembengkakan.

Selama periode ini ada berpotensi melanjutkan iskemia otak dan kematian neuronal dan ketepatan waktu adalah esensi. Seharusnya tidak ada investigasi atau prosedur yang tidak perlu dan merusak teknik pengendalian harus digunakan sebagai diperlukan. Tidak ada tulang belakang atau panjang pencitraan tulang harus dilakukan sebelum CT scan investigasi ini tidak akan mempengaruhi manajemen pasien segera. Pasien hemodinamik tidak stabil harus memiliki investigasi minimum, kontrol perdarahan dengan sederhana berarti (operasi dan disingkat jika perlu) yang sesuai dan kemudian CT scan dan pengobatan cedera otak.

Jika ada tanda-tanda herniasi yang akan datang transtentorial (sikap unilateral dan / atau unilateral dilatasi pupil) atau jika ada yang cepat kerusakan neurologis progresif (tanpa sebab ekstrakranial), maka ada hipertensi intrakranial signifikan dan langkah-langkah harus diambil untuk mengendalikan ICP segera. Hiperventilasi harus dilembagakan untuk mengurangi PaCO 2 untuk tidak lebih rendah dari 3.5kPa (25mmHg) dan manitol harus diberikan sebagai bolus. Oksigenasi dan perfusi serebral harus dijaga. CT scan muncul, seperti operasi jika diindikasikan.

Jika ada luka lain yang mengarah ke perdarahan dan hipotensi ini masih diprioritaskan. Namun mungkin perlu untuk mempertimbangkan pengobatan cedera otak secara bersamaan dengan pengelolaan cedera ini (laparotomy atau torakotomi), bahkan tanpa CT scan untuk memandu terapi. lubang burr buta untuk mendeteksi koleksi ekstra-aksial mungkin tepat sebagai upaya terakhir dalam kasus ini.

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Referensi

Chesnut RM, Marshall LF, Klauber MR et al. Peran cedera otak sekunder dalam menentukan hasil dari cedera kepala berat. J trauma 34: 216-222, 1993

Chesnut RM, Marshall SB, Piek J et al. Awal dan akhir hipotensi sistemik sebagai sumber sering dan fundamental iskemia serebral berikut cedera otak parah di Traumatic Coma Data Bank . Acta Neurochir Suppl (Wein) 59: 121-125, 1993

Bukit DA, Abraham KJ, West RH. Faktor-faktor yang mempengaruhi hasil dalam resusitasi pasien terluka parah. Aust NZ J Surg 63: 604-609, 1993

Jones PA, Andrews PJ, Midgley S et al. Mengukur beban penghinaan sekunder pada pasien cedera kepala selama perawatan intensif. J Neurosurg Anesthesiol 6: 4-14, 1994

Otak Trauma Foundation. Pedoman pengelolaan cedera kepala berat. 1995