Month: March 2019

Accidental Intra-arterial Injection

Severe digit or limb injury including amputation has occurred from accidental intra-arterial injection of medications as well as illicit drugs. Common sites include the brachial artery at the elbow or dorsum of the hand in the radial artery, as well as inadvertent injection into arterial lines in-situ.

The most severe limb injury has occurred after Pentothal, Diazepam, Penicillin, and Clindamycin. The most commonly injected illicit medications were crushed benzodiazepines (most commonly flunitrazepam). The potential for damage depends on the drug injected, and also its formulation – benzyl alcohol appears more harmful; commonly used agents like Propofol, Succinylcholine, Rocuronium, Fentanyl, amd Ketamine have not resulted in severe injury generally, although Propofol may cause severe pain.

Incidence is difficult to determine and has been estimated between 1:3,440 and 1:56,000 with old data. Mechanisms of injury can variously or in combination include direct endothelial injury, vasospasm, drug crystallization, and thrombosis.

Many empirical treatments have been reported with a less than strong evidence base, including steroids, vasodilators and nerve blocks. The most common regimes now recommended usually include anticoagulation with Heparin, Prostacyclin, and intra-arterial thrombolytics like TPA.

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Transfontanelle Ultrasound to Predict Fluid Responsiveness in Infants

Studies have found a relationship between fluid responsiveness and respiratory variation in the arterial blood flow peak velocity in the ascending aorta.

This was a prospective observational study of 30 infants undergoing cardiac surgery. Before and after the administration of 10ml · kg–1 crystalloid, established measures – respiratory variation of the aorta blood flow peak velocity, pulse pressure variation, and central venous pressure were obtained. The respiratory variation of the internal carotid artery blood flow peak velocity was measured using transfontanelle ultrasound.

In this study the respiratory variation of the internal carotid artery blood flow peak velocity as measured using transfontanelle ultrasound predicts an increase in stroke volume in response to an intravenous fluid bolus.

Cutoffs for respiratory variation were different than aortic velocity and further larger studies are needed in diverse populations before this potentially useful non-invasive fluid responsiveness assessment modality can be more widely recommended in infants.

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Volatile Anesthetics vs. Total Intravenous Anesthesia for Cardiac Surgery

The ‘cardioprotective’ effects of volatile anesthesia gases have been seen as useful during coronary artery bypass surgery (CABG). This controlled study in elective CABG compared volatile anesthesia with total intravenous anesthesia (TIVA) and found no difference in 30 day or 1 year mortality.

The findings are important as anesthetic gases have been even recommended as useful in American and European guidelines, based on known cellular protective effects and effects on cardiac biomarkers, and suggested by previous observational and meta-analysis studies.

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Transfusion-Associated Circulatory Overload in ICUs

Transfusion-associated circulatory overload is frequent in ICU patients, about 5.5% in this review. It was associated with increased ICU and hospital length of stay.

Risk factors included positive fluid balance, the number and type of products transfused, rate of transfusion, and cardiovascular and renal comorbidities. 

In pediatric ICUs, the authors note “The lack of a pediatric-adjusted definition of transfusion-associated circulatory overload may lead to a risk of underdiagnosis of this condition in PICUs”.

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Programmed Intermittent Epidural Bolus

Programmed intermittent epidural bolus (PIEB) has been touted as more effective than continuous or patient controlled epidural analgesia in labor. Studies are limited in this new area, often due to lack of pumps capable of delivering PIEB.

Under the conditions of this study, improved outcomes with programmed intermittent epidural boluses compared to continuous epidural infusion were not found, except for less motor block with programmed intermittent epidural boluses.

“Future studies should assess whether smaller but clinically important differences exist and evaluate different parameters of programmed intermittent epidural boluses to optimize analgesia and outcomes with this mode of analgesia”.

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Intra-Abdominal Hypertension in Critically Ill Patients

In a mixed ICU patient cohort, intra-abdominal hypertension (IAH) occurred in almost half of all patients and was twice as prevalent in mechanically ventilated patients. Its presence and severity significantly and independently increased 28- and 90-day mortality.

Body mass index, APACHE II score of 18 or greater, presence of abdominal distension, absence of bowel sounds, and positive end-expiratory pressure greater than or equal to 7 cm H2O were independently associated with its development.

Positive fluid balance (as often occurs after massive resuscitation) appeared more relevant later in ICU stay. BMI was the only identified risk factor that was not directly related to increased mortality and different cutoffs for IAH may apply in obese patients.

IAH was defined as a value > 12 mmHg. The authors note: “presence and severity of IAH during the first 2 weeks of the ICU stay significantly and independently increased 28- and 90-day mortality, whereas the presence of IAH on the day of ICU admission was insufficient to predict these adverse outcomes”.

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In addition to the above full text link, the Abdominal Compartment Society has useful links at its site as well as guidelines for managing IAH and abdominal compartment syndrome.

Cesarean Maternal & Neonatal Mortality in Africa

Maternal mortality after cesarean delivery in Africa is 50 times higher than that of high-income countries and is driven by peripartum haemorrhage and anaesthesia complications. Neonatal mortality is double the global average.

These shocking figures from a prospective observational study across Africa may be due to such factors as poor access to caesarean delivery, peripartum hemorrhage, and provision of anesthesia by non-physicians.

Suggested areas to improve include risk identification (eg, ASA status, risk of bleeding), care bundles and checklists and a higher level of monitoring, use of antifibrinolytic drugs (tranexamic acid), improved access to blood and blood products with long shelf lives, such as freeze-dried plasma and fibrinogen; and novel methods of training of non-physician anaesthetists, including online support and mobile-based applications.

Intraoperative Goal-directed Balanced Crystalloid versus Colloid

Another piece for the perpetual puzzle as to the harms and/or benefits of colloids vs. crystalloids.

The potential serious kidney injury and mortality using Hydroxyethyl Starch reported in critical illness are not always replicated in the intraoperative setting.

In this study in abdominal surgery, the primary outcome was a composite of serious postoperative cardiac, pulmonary, infectious, gastrointestinal, renal, and coagulation complications. Creatinine at 6 months was assessed.

Lactated Ringers or Hydroxyethyl Starch were given in a goal directed manner using esophageal Doppler based on stroke volume and corrected aortic flow time.

“Doppler-guided intraoperative hydroxyethyl starch administration did not reduce composites of serious complications. Nor did hydroxyethyl starch reduce the duration of hospitalization, but there was also no indication of renal or other toxicity”.

No clear reason to use Hydroxyethyl Starch is apparent, in view of the greater cost.

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Medical and Health News Weekly

A moderate level of muscular strength is associated with a lower risk of type 2 diabetes link

Smoking during pregnancy doubles the risk of sudden unexpected infant death link

Canada won’t be funding homeopathy aid for Honduras any more link

Johnson & Johnson (them again!) accused of being an opioid “kingpin” link

And $29 Million asbestos talc mesothelioma award against – you guessed it – Johnson & Johnson link

Protecting children from anti-vaccination ignorance – No vaccine, no school in Italy link

Amazon joins the battle against autism cure quackery and vaccination misinformation link

Long before tobacco companies diversified into vaping, they used their industry to promote sugary drinks (Hawaiian Punch, Kool-Aid, Capri Sun, Tang) link

A wishy-washy half hearted FDA draft for controlling flavoured e-cigarettes linkh

Butterball recalls 39 tons of ground turkey after Salmonella cases link

Eggs are bad again for cardiovascular disease and mortality. Looks like they’ll have to be an occasional indulgence. Observational study, self reported data… link

Intravenous Dexmedetomidine and Dexamethasone for Postop Analgesia

Many agents have been added to peripheral nerve blocks to prolong analgesia. In some cases intravenous administration has been as successful without potential nerve toxicity concerns.

This small randomized study evaluated the difference in time to first rescue analgesic request between patients receiving co-administered intravenous dexamethasone and dexmedetomidine and patients receiving intravenous dexamethasone alone after single-shot interscslene brachial plexus block for arthroscopic shoulder surgery. Saline controls were used.

Co-administration of intravenous dexamethasone (0.11 mg kg−1) with dexmedetomidine (1.0 μg kg−1) significantly prolonged the time to first rescue analgesic request more than Dexamethasone alone, and both more so than saline controls. Also both groups had reduced postoperative opioid consumption, less sleep disruption and improved patient satisfaction compared with the control group.

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