Ashwin Kumar Mani, Nagarajan Ramakrishnan,

and Sheila Nainan Myatra

A 48-year-old male patient was admitted to the ICU with acute respiratory distress syndrome secondary to H1N1 inßuenza. He was noted to be markedly hypoxemic requiring high FiO2. He was intubated and put on a ventilator. He was tachypneic, tachycardic, and restless and was breathing at the rate of 40 per min and struggling with the ventilator.

Critically ill patients on mechanical ventilation are frequently managed with sedative and analgesics. Pain is a very common experience in the ICU. Failure to recognize pain leads to agitation and increase use of sedatives. Majority of patients Þnd even routine ICU procedures uncomfortable and painful. Inability to communicate about pain due to presence of an endotracheal tube may lead to high levels of anxiety and may precipitate development of posttraumatic stress disorder. Now it is recommended to aggressively manage pain.

Step 1: Identify the need for sedation and analgesia (Table 33.1)

¥Appropriate analgesia might obviate the need for sedation or decrease the sedation needs.

¥In certain groups of patients, sedation is very important to prevent them from selfharm (removing lines) or to decrease the work of breathing and oxygen demand.

¥Common indications of analgesia and sedation (Table 33.1).

A.K. Mani, A.B.(I.M.), A.B.( Pulm. & C.C.M.) (*)

Critical Care Medicine, Apollo First Med Hospital, Chennai, India e-mail: ashwin@icuconsultants.com

N. Ramakrishnan, A.B.(I.M.), F.A.C.P.

Department of Critical Care Services, Apollo Hospitals, Chennai, India

S.N. Myatra, M.D.

Department of Anaesthesia, Critical Care and Pain, Tata Memorial Hospital, Mumbai, India

Table 33.1 Indications of sedation and analgesia

Facilitation of endotracheal intubation and mechanical ventilation (for amnesia, anxiolysis, reduction of agitation, toleration of endotracheal tube (ETT) and to reduce cough, to alleviate dyspnea, to minimize pain, and to prevent self-extubation)

While performing invasive procedures

To facilitate nursing care

Postoperative/trauma pain

To tolerate ICU environmental inßuences (stressful environment, monitoring devices, noise, fear of illness, separation from family)

During severe hypoxemia (low tidal volume ventilation, high-frequency oscillation (HFO), and prone positioning)

To bear underlying or hospital-acquired medical illnesses

Step 2: Consider the use of commonly used sedatives and analgesics (Table 33.2)

Step 3: Choose an appropriate agent

¥There is no ideal agent for ICU sedation.

¥An ideal sedative and analgesic regimen should provide adequate sedation and pain control, rapid onset of action, and allow rapid recovery after discontinuation, minimal adverse effects, minimal systemic accumulation, and minimal delirium without increasing overall health-care costs.

¥In different clinical scenarios, some agents have been shown to be better than others. Consider the following before choosing an agent:

ÐAll patients need analgesia with or without sedation. Recent studies have shown that minimal use of continuous sedation is feasible without apparent adverse effects.

ÐHave a patient-focused approach. Select analgesic and sedative drugs based on patientsÕ needs.

¥Remember that the degree of sedation/anxiolysis and analgesia required varies between patients and in the same patient over time (physiotherapy, weaning).

¥Identify predisposing and precipitating factorsÑunderlying medical conditions such as chronic pain or arthritis, history of alcohol, or substance abuse. Psychiatric illness can inßuence medication. For example, patients who appear delirious or severely agitated in the ICU may become overmedicated with sedative drugs because their medications have been omitted.

¥Adequate analgesia should be ensured prior to sedating the patient.

¥In a nonintubated patient agitated due to pain, when opioid analgesics such as morphine or fentanyl are used, remember that they can cause respiratory depression. In patients with obstructive sleep apnea, even small doses should be used with caution.

¥For postoperative pain/trauma, epidural analgesia, if available, is a suitable option.

¥Gamma-aminobutyric acid agonists (benzodiazepines, propofol) are prone to cause acute cognitive dysfunction.

Fig. 33.1 Wong-Baker FACES pain rating scale

Step 4: Assessment of pain, sedation, and delirium

¥Use of sedation and pain scales is recommended to titrate the appropriate level of analgesia and sedation.

¥There are many scores, but one score should be followed for uniformity in the ICU.

¥The following scales/scores may be used: A. Pain

¥A critical care pain observation tool (Table 33.3)

¥Self-reporting of pain

¥Wong-Baker FACES pain rating scale (Fig. 33.1)

¥0Ð10 numeric pain scales

1Anxious and agitated

2Cooperative, oriented, tranquil

3Responds only to verbal commands

4Asleep with brisk response to light stimulation

5Asleep with sluggish response to stimulation

6Asleep without response to stimulation

B.Sedation

¥Richmond agitation-sedation scale (RASS) (Table 33.4)

¥Riker sedation-agitation scale (SAS) (Table 33.5)

¥Ramsay sedation score (Table 33.6)

C.Delirium

¥Confusion assessment method for the ICU

¥The intensive care delirium screening checklist

Step 5: Titrate sedation and analgesia

The titration of the sedative/analgesic dose to a deÞned endpoint is recommended.